$acgl 2018 Q4 10-K

Concept	2018 Q4	2018 Q3	2018 Q2
Revenue	$1.361B	$1.404B	$1.411B
YoY Change	-2.28%	-5.12%	0.23%
Cost Of Revenue		$699.4M	$726.2M
YoY Change		-33.14%	5.26%
Gross Profit		$704.4M	$684.7M
YoY Change		62.52%	-4.6%
Gross Profit Margin		50.18%	48.53%
Selling, General & Admin	$26.80M	$14.30M	$22.50M
YoY Change	91.43%	-16.37%	-9.64%
% of Gross Profit		2.03%	3.29%
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$26.20M	$201.6M	$202.8M
YoY Change	-17.87%	4.0%	6.51%
% of Gross Profit		28.62%	29.63%
Operating Expenses	$1.256B	$1.103B	$1.154B
YoY Change	13.81%	-24.41%	4.35%
Operating Profit		-$398.4M	-$469.4M
YoY Change		-61.15%	20.89%
Interest Expense	-$12.10M	$29.73M	$30.34M
YoY Change	-58.13%	0.75%	5.55%
% of Operating Profit
Other Income/Expense, Net		$161.1M	$176.2M
YoY Change		-5.31%	3.65%
Pretax Income	$91.30M	$282.1M	$280.0M
YoY Change	-64.69%	-861.92%	20.04%
Income Tax	$35.00M	$33.36M	$23.67M
% Of Pretax Income	38.34%	11.82%	8.45%
Net Earnings	$136.5M	$227.4M	$243.6M
YoY Change	-36.41%	-775.68%	31.58%
Net Earnings / Revenue	10.03%	16.2%	17.27%
Basic Earnings Per Share	$0.31	$0.54	$0.58
Diluted Earnings Per Share	$0.31	$0.53	$0.56
COMMON SHARES
Basic Shares Outstanding	404.7M shares	402.9M shares	404.8M shares
Diluted Shares Outstanding		411.7M shares	413.1M shares

Concept	2018 Q4	2018 Q3	2018 Q2
SHORT-TERM ASSETS
Cash & Short-Term Investments
YoY Change
Cash & Equivalents	$646.6M	$651.0M	$526.6M
Short-Term Investments
Other Short-Term Assets
YoY Change
Inventory
Prepaid Expenses
Receivables
Other Receivables
Total Short-Term Assets
YoY Change
LONG-TERM ASSETS
Property, Plant & Equipment
YoY Change
Goodwill	$249.6M
YoY Change	25.92%
Intangibles
YoY Change
Long-Term Investments	$1.494B	$1.524B	$1.429B
YoY Change	43.45%	58.35%	50.56%
Other Assets
YoY Change
Total Long-Term Assets
YoY Change
TOTAL ASSETS
Total Short-Term Assets
Total Long-Term Assets
Total Assets	$32.22B	$32.25B	$31.85B
YoY Change	0.52%	-1.14%	3.21%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable
YoY Change
Accrued Expenses
YoY Change
Deferred Revenue
YoY Change
Short-Term Debt	$0.00	$0.00	$0.00
YoY Change
Long-Term Debt Due
YoY Change
Total Short-Term Liabilities	$90.00M	$255.0M	$357.0M
YoY Change	-79.96%	-76.63%	-22.22%
LONG-TERM LIABILITIES
Long-Term Debt	$2.189B	$2.288B	$2.306B
YoY Change	-14.12%	-10.59%	-4.67%
Other Long-Term Liabilities	$1.422B	$1.376B	$1.247B
YoY Change	-5.2%	-17.95%	-22.79%
Total Long-Term Liabilities	$3.611B	$3.664B	$3.553B
YoY Change	-10.82%	-13.5%	-11.92%
TOTAL LIABILITIES
Total Short-Term Liabilities	$90.00M	$255.0M	$357.0M
Total Long-Term Liabilities	$3.611B	$3.664B	$3.553B
Total Liabilities	$21.78B	$21.81B	$21.62B
YoY Change	-0.11%	-3.68%	3.55%
SHAREHOLDERS EQUITY
Retained Earnings	$9.426B	$9.300B	$9.083B
YoY Change	10.08%	11.26%	7.98%
Common Stock	$1.794B	$1.776B	$1.761B
YoY Change	45.74%	46.36%	47.08%
Preferred Stock
YoY Change
Treasury Stock (at cost)	$2.382B	$2.280B	$2.267B
YoY Change	14.65%	11.03%	10.49%
Treasury Stock Shares	168.3M shares	164.5M shares	164.0M shares
Shareholders Equity	$9.440B	$9.355B	$9.164B
YoY Change
Total Liabilities & Shareholders Equity	$32.22B	$32.25B	$31.85B
YoY Change	0.52%	-1.14%	3.21%

Concept	2018 Q4	2018 Q3	2018 Q2
OPERATING ACTIVITIES
Net Income	$136.5M	$227.4M	$243.6M
YoY Change	-36.41%	-775.68%	31.58%
Depreciation, Depletion And Amortization	$26.20M	$201.6M	$202.8M
YoY Change	-17.87%	4.0%	6.51%
Cash From Operating Activities	$438.3M	$624.1M	$96.70M
YoY Change	1181.58%	18.38%	-72.36%
INVESTING ACTIVITIES
Capital Expenditures	-$10.70M	-$5.900M	-$9.000M
YoY Change	81.36%	1.72%	52.54%
Acquisitions
YoY Change
Other Investing Activities	-$153.2M	-$486.6M	$169.3M
YoY Change	-67.62%	-15.78%	-202.73%
Cash From Investing Activities	-$163.9M	-$492.5M	$160.3M
YoY Change	-65.8%	-15.6%	-193.91%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	-252.1M	-3.700M	-394.1M
YoY Change	-231.64%	-102.78%	293.71%
NET CHANGE
Cash From Operating Activities	438.3M	624.1M	96.70M
Cash From Investing Activities	-163.9M	-492.5M	160.3M
Cash From Financing Activities	-252.1M	-3.700M	-394.1M
Net Change In Cash	22.30M	127.9M	-137.1M
YoY Change	-108.79%	66.97%	-273.54%
FREE CASH FLOW
Cash From Operating Activities	$438.3M	$624.1M	$96.70M
Capital Expenditures	-$10.70M	-$5.900M	-$9.000M
Free Cash Flow	$449.0M	$630.0M	$105.7M
YoY Change	1019.7%	18.2%	-70.28%

Frame	Concept Type	Concept / XBRL Key	Value	Unit
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CY2019	acgl	Equity Method Investments Time Lag For Reporting High Endof Range EquityMethodInvestmentsTimeLagForReportingHighEndofRange	P3M
CY2019	acgl	Equity Method Investments Time Lag For Reporting Low Endof Range EquityMethodInvestmentsTimeLagForReportingLowEndofRange	P1M
CY2018Q4	acgl	Other Than Temporary Impairment Losses Investments Available For Sale Securitiess At Current Fair Value OtherThanTemporaryImpairmentLossesInvestmentsAvailableForSaleSecuritiessAtCurrentFairValue	0	USD
CY2018Q4	acgl	Securities Lending Investments Pledged Amortized Cost SecuritiesLendingInvestmentsPledgedAmortizedCost	266786000	USD
CY2019Q4	acgl	Securities Lending Investments Pledged Amortized Cost SecuritiesLendingInvestmentsPledgedAmortizedCost	378738000	USD
CY2018Q4	acgl	Securities Received As Collateral Amortized Cost SecuritiesReceivedAsCollateralAmortizedCost	274125000	USD
CY2019Q4	acgl	Securities Received As Collateral Amortized Cost SecuritiesReceivedAsCollateralAmortizedCost	388366000	USD
CY2018Q4	acgl	Short Term Investments Cost Amount ShortTermInvestmentsCostAmount	956238000	USD
CY2019Q4	acgl	Short Term Investments Cost Amount ShortTermInvestmentsCostAmount	957283000	USD
CY2019	dei	Amendment Flag AmendmentFlag	false
CY2019	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
CY2019	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	FY
CY2019	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2019
CY2019	dei	Entity Central Index Key EntityCentralIndexKey	0000947484
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CY2019Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	16598808000	USD
CY2018Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.0011
CY2019	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Award Requisite Service Period1 ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1	P3Y
CY2019	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Award Vesting Period1 ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1	P3Y
CY2019	dei	Document Type DocumentType	10-K
CY2019	dei	Document Annual Report DocumentAnnualReport	true
CY2019	dei	Document Transition Report DocumentTransitionReport	false
CY2019	dei	Document Period End Date DocumentPeriodEndDate	2019-12-31
CY2019	dei	Entity File Number EntityFileNumber	001-16209
CY2019	dei	Entity Registrant Name EntityRegistrantName	ARCH CAPITAL GROUP LTD.
CY2019	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	D0
CY2019	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	98-0374481
CY2019	dei	Entity Address Address Line1 EntityAddressAddressLine1	Waterloo House, Ground Floor
CY2019	dei	Entity Address Address Line2 EntityAddressAddressLine2	100 Pitts Bay Road,
CY2019	dei	Entity Address City Or Town EntityAddressCityOrTown	Pembroke
CY2019	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	HM 08,
CY2019	dei	Entity Address Country EntityAddressCountry	BM
CY2019	dei	City Area Code CityAreaCode	(441)
CY2019	dei	Local Phone Number LocalPhoneNumber	278-9250
CY2019	dei	Entity Well Known Seasoned Issuer EntityWellKnownSeasonedIssuer	Yes
CY2019	dei	Entity Voluntary Filers EntityVoluntaryFilers	No
CY2019	dei	Entity Interactive Data Current EntityInteractiveDataCurrent	Yes
CY2019	dei	Entity Current Reporting Status EntityCurrentReportingStatus	Yes
CY2019	dei	Entity Filer Category EntityFilerCategory	Large Accelerated Filer
CY2019	dei	Entity Small Business EntitySmallBusiness	false
CY2019	dei	Entity Emerging Growth Company EntityEmergingGrowthCompany	false
CY2019	dei	Entity Shell Company EntityShellCompany	false
CY2019Q2	dei	Entity Public Float EntityPublicFloat	14600000000	USD
CY2020Q1	dei	Entity Common Stock Shares Outstanding EntityCommonStockSharesOutstanding	406658701	shares
CY2019Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	16894526000	USD
CY2018Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	14699010000	USD
CY2019Q4	us-gaap	Other Short Term Investments OtherShortTermInvestments	956546000	USD
CY2018Q4	us-gaap	Other Short Term Investments OtherShortTermInvestments	955880000	USD
CY2019Q4	us-gaap	Securities Received As Collateral SecuritiesReceivedAsCollateral	388376000	USD
CY2018Q4	us-gaap	Securities Received As Collateral SecuritiesReceivedAsCollateral	274133000	USD
CY2019Q4	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	838925000	USD
CY2018Q4	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	338899000	USD
CY2019Q4	acgl	Investments Accounted For Using Fair Value Option InvestmentsAccountedForUsingFairValueOption	3663477000	USD
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CY2019Q4	us-gaap	Equity Method Investments EquityMethodInvestments	1660396000	USD
CY2018Q4	us-gaap	Equity Method Investments EquityMethodInvestments	1493791000	USD
CY2019Q4	us-gaap	Investments Investments	24402246000	USD
CY2018Q4	us-gaap	Investments Investments	21745284000	USD
CY2019Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	726230000	USD
CY2018Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	646556000	USD
CY2019Q4	us-gaap	Accrued Investment Income Receivable AccruedInvestmentIncomeReceivable	117937000	USD
CY2018Q4	us-gaap	Accrued Investment Income Receivable AccruedInvestmentIncomeReceivable	114641000	USD
CY2019Q4	acgl	Fixed Maturities And Short Term Investments Pledged Under Securities Lending Fair Value FixedMaturitiesAndShortTermInvestmentsPledgedUnderSecuritiesLendingFairValue	379868000	USD
CY2018Q4	acgl	Fixed Maturities And Short Term Investments Pledged Under Securities Lending Fair Value FixedMaturitiesAndShortTermInvestmentsPledgedUnderSecuritiesLendingFairValue	268395000	USD
CY2019Q4	us-gaap	Premiums Receivable At Carrying Value PremiumsReceivableAtCarryingValue	1778717000	USD
CY2018Q4	us-gaap	Premiums Receivable At Carrying Value PremiumsReceivableAtCarryingValue	1299150000	USD
CY2019Q4	us-gaap	Reinsurance Recoverables ReinsuranceRecoverables	4346816000	USD
CY2018Q4	us-gaap	Reinsurance Recoverables ReinsuranceRecoverables	2919372000	USD
CY2019Q4	acgl	Contractholder Deductibles Receivable ContractholderDeductiblesReceivable	2119460000	USD
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CY2019Q4	us-gaap	Prepaid Reinsurance Premiums PrepaidReinsurancePremiums	1234683000	USD
CY2018Q4	us-gaap	Prepaid Reinsurance Premiums PrepaidReinsurancePremiums	975469000	USD
CY2019Q4	us-gaap	Deferred Policy Acquisition Costs DeferredPolicyAcquisitionCosts	633400000	USD
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CY2019Q4	us-gaap	Receivables From Brokers Dealers And Clearing Organizations ReceivablesFromBrokersDealersAndClearingOrganizations	24133000	USD
CY2018Q4	us-gaap	Receivables From Brokers Dealers And Clearing Organizations ReceivablesFromBrokersDealersAndClearingOrganizations	36246000	USD
CY2019Q4	acgl	Intangible Assets Liabilitiesand Goodwill Net IntangibleAssetsLiabilitiesandGoodwillNet	738083000	USD
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CY2019Q4	us-gaap	Other Assets OtherAssets	1383788000	USD
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CY2019Q4	us-gaap	Assets Assets	37885361000	USD
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CY2019Q4	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	13891842000	USD
CY2018Q4	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	11853297000	USD
CY2019Q4	us-gaap	Unearned Premiums UnearnedPremiums	4339549000	USD
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CY2019Q4	us-gaap	Reinsurance Payable ReinsurancePayable	667072000	USD
CY2018Q4	us-gaap	Reinsurance Payable ReinsurancePayable	393107000	USD
CY2019Q4	acgl	Contract Holder Payables ContractHolderPayables	2119460000	USD
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CY2019Q4	us-gaap	Policyholder Contract Deposits PolicyholderContractDeposits	206698000	USD
CY2018Q4	us-gaap	Policyholder Contract Deposits PolicyholderContractDeposits	236630000	USD
CY2019Q4	us-gaap	Senior Long Term Notes SeniorLongTermNotes	1871626000	USD
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CY2019Q4	us-gaap	Line Of Credit LineOfCredit	484287000	USD
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CY2019Q4	us-gaap	Obligation To Return Securities Received As Collateral ObligationToReturnSecuritiesReceivedAsCollateral	388366000	USD
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CY2019Q4	srt	Payables To Broker Dealers And Clearing Organizations PayablesToBrokerDealersAndClearingOrganizations	87579000	USD
CY2018Q4	srt	Payables To Broker Dealers And Clearing Organizations PayablesToBrokerDealersAndClearingOrganizations	90034000	USD
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CY2019Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	212091000	USD
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CY2019Q4	us-gaap	Treasury Stock Value TreasuryStockValue	2406047000	USD
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CY2019	us-gaap	Revenues Revenues	6928200000	USD
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CY2019	us-gaap	Policyholder Benefits And Claims Incurred Net PolicyholderBenefitsAndClaimsIncurredNet	3133452000	USD
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CY2017	us-gaap	Policyholder Benefits And Claims Incurred Net PolicyholderBenefitsAndClaimsIncurredNet	2967446000	USD
CY2019	us-gaap	Deferred Policy Acquisition Cost Amortization Expense DeferredPolicyAcquisitionCostAmortizationExpense	840945000	USD
CY2018	us-gaap	Deferred Policy Acquisition Cost Amortization Expense DeferredPolicyAcquisitionCostAmortizationExpense	805135000	USD
CY2017	us-gaap	Deferred Policy Acquisition Cost Amortization Expense DeferredPolicyAcquisitionCostAmortizationExpense	775458000	USD
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CY2019	us-gaap	Interest Expense InterestExpense	120872000	USD
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CY2017	us-gaap	Interest Expense InterestExpense	117431000	USD
CY2019	us-gaap	Foreign Currency Transaction Gain Loss Before Tax ForeignCurrencyTransactionGainLossBeforeTax	-20609000	USD
CY2018	us-gaap	Foreign Currency Transaction Gain Loss Before Tax ForeignCurrencyTransactionGainLossBeforeTax	69402000	USD
CY2017	us-gaap	Foreign Currency Transaction Gain Loss Before Tax ForeignCurrencyTransactionGainLossBeforeTax	-115782000	USD
CY2019	us-gaap	Benefits Losses And Expenses BenefitsLossesAndExpenses	5079090000	USD
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CY2017	us-gaap	Benefits Losses And Expenses BenefitsLossesAndExpenses	4870098000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	1849110000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	841772000	USD
CY2017	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	757277000	USD
CY2019	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	144361000	USD
CY2018	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	85863000	USD
CY2017	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	-45736000	USD
CY2019	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	11449000	USD
CY2018	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	28088000	USD
CY2017	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	173304000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	155810000	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	113951000	USD
CY2017	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	127568000	USD
CY2019	us-gaap	Profit Loss ProfitLoss	1693300000	USD
CY2017	us-gaap	Other Comprehensive Income Foreign Currency Transaction And Translation Gain Loss Arising During Period Net Of Tax OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossArisingDuringPeriodNetOfTax	47014000	USD
CY2018	us-gaap	Profit Loss ProfitLoss	727821000	USD
CY2017	us-gaap	Profit Loss ProfitLoss	629709000	USD
CY2019	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	56981000	USD
CY2018	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	-30150000	USD
CY2017	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	10431000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	1636319000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	757971000	USD
CY2017	us-gaap	Net Income Loss NetIncomeLoss	619278000	USD
CY2019	us-gaap	Preferred Stock Dividends Income Statement Impact PreferredStockDividendsIncomeStatementImpact	41612000	USD
CY2018	us-gaap	Preferred Stock Dividends Income Statement Impact PreferredStockDividendsIncomeStatementImpact	41645000	USD
CY2017	us-gaap	Preferred Stock Dividends Income Statement Impact PreferredStockDividendsIncomeStatementImpact	46041000	USD
CY2019	us-gaap	Preferred Stock Redemption Premium PreferredStockRedemptionPremium	0	USD
CY2018	us-gaap	Preferred Stock Redemption Premium PreferredStockRedemptionPremium	2710000	USD
CY2017	us-gaap	Preferred Stock Redemption Premium PreferredStockRedemptionPremium	6735000	USD
CY2019	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	1594707000	USD
CY2018	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	713616000	USD
CY2017	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	566502000	USD
CY2019	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.97
CY2018	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.76
CY2017	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.40
CY2019	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.87
CY2018	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.73
CY2017	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.36
CY2019	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	401802815	shares
CY2018	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	404347621	shares
CY2017	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	404138364	shares
CY2019	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	411609478	shares
CY2018	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	412906478	shares
CY2017	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	417785025	shares
CY2019	us-gaap	Profit Loss ProfitLoss	1693300000	USD
CY2018	us-gaap	Profit Loss ProfitLoss	727821000	USD
CY2017	us-gaap	Profit Loss ProfitLoss	629709000	USD
CY2019	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	500771000	USD
CY2018	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-270057000	USD
CY2017	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	252904000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	118941000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	-144573000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	67863000	USD
CY2019	us-gaap	Other Comprehensive Income Foreign Currency Transaction And Translation Gain Loss Arising During Period Net Of Tax OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossArisingDuringPeriodNetOfTax	18110000	USD
CY2018	us-gaap	Other Comprehensive Income Foreign Currency Transaction And Translation Gain Loss Arising During Period Net Of Tax OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossArisingDuringPeriodNetOfTax	-24830000	USD
CY2019	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	2093240000	USD
CY2018	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	577507000	USD
CY2017	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	861764000	USD
CY2019	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	56981000	USD
CY2018	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	-30150000	USD
CY2017	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	10431000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Noncontrolling Interest OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToNoncontrollingInterest	9130000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Noncontrolling Interest OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToNoncontrollingInterest	-3346000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Noncontrolling Interest OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToNoncontrollingInterest	-530000	USD
CY2019	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	2027129000	USD
CY2018	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	611003000	USD
CY2017	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	851863000	USD
CY2019Q4	us-gaap	Stockholders Equity StockholdersEquity	11497371000	USD
CY2018Q4	us-gaap	Stockholders Equity StockholdersEquity	9439827000	USD
CY2017Q4	us-gaap	Stockholders Equity StockholdersEquity	9196602000	USD
CY2019Q4	us-gaap	Minority Interest MinorityInterest	762777000	USD
CY2018Q4	us-gaap	Minority Interest MinorityInterest	791560000	USD
CY2017Q4	us-gaap	Minority Interest MinorityInterest	843411000	USD
CY2019Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	12260148000	USD
CY2018Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	10231387000	USD
CY2017Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	10040013000	USD
CY2019	us-gaap	Profit Loss ProfitLoss	1693300000	USD
CY2018	us-gaap	Profit Loss ProfitLoss	727821000	USD
CY2017	us-gaap	Profit Loss ProfitLoss	629709000	USD
CY2019	acgl	Net Realized Gains Losses NetRealizedGainsLosses	381132000	USD
CY2018	acgl	Net Realized Gains Losses NetRealizedGainsLosses	-387550000	USD
CY2017	acgl	Net Realized Gains Losses NetRealizedGainsLosses	174517000	USD
CY2019	us-gaap	Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNet	3165000	USD
CY2018	us-gaap	Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNet	2829000	USD
CY2017	us-gaap	Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNet	7138000	USD
CY2019	acgl	Equity In Net Income Loss Of Investment Funds Accounted For Using Equity Method And Other Income Loss EquityInNetIncomeLossOfInvestmentFundsAccountedForUsingEquityMethodAndOtherIncomeLoss	14013000	USD
CY2018	acgl	Equity In Net Income Loss Of Investment Funds Accounted For Using Equity Method And Other Income Loss EquityInNetIncomeLossOfInvestmentFundsAccountedForUsingEquityMethodAndOtherIncomeLoss	-36694000	USD
CY2017	acgl	Equity In Net Income Loss Of Investment Funds Accounted For Using Equity Method And Other Income Loss EquityInNetIncomeLossOfInvestmentFundsAccountedForUsingEquityMethodAndOtherIncomeLoss	79540000	USD
CY2019	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	82104000	USD
CY2018	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	105670000	USD
CY2017	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	125778000	USD
CY2019	us-gaap	Share Based Compensation ShareBasedCompensation	66417000	USD
CY2018	us-gaap	Share Based Compensation ShareBasedCompensation	55776000	USD
CY2017	us-gaap	Share Based Compensation ShareBasedCompensation	67798000	USD
CY2019	acgl	Increase Decrease In Loss And Loss Adjustment Expenses Net Of Recoverables IncreaseDecreaseInLossAndLossAdjustmentExpensesNetOfRecoverables	489981000	USD
CY2019	acgl	Increase Decrease In Unearned Premiums Net Of Prepaid Reinsurance Premiums IncreaseDecreaseInUnearnedPremiumsNetOfPrepaidReinsurancePremiums	252569000	USD
CY2017	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	907417000	USD
CY2018	acgl	Increase Decrease In Loss And Loss Adjustment Expenses Net Of Recoverables IncreaseDecreaseInLossAndLossAdjustmentExpensesNetOfRecoverables	243734000	USD
CY2017	acgl	Increase Decrease In Loss And Loss Adjustment Expenses Net Of Recoverables IncreaseDecreaseInLossAndLossAdjustmentExpensesNetOfRecoverables	614534000	USD
CY2018	acgl	Increase Decrease In Unearned Premiums Net Of Prepaid Reinsurance Premiums IncreaseDecreaseInUnearnedPremiumsNetOfPrepaidReinsurancePremiums	114772000	USD
CY2017	acgl	Increase Decrease In Unearned Premiums Net Of Prepaid Reinsurance Premiums IncreaseDecreaseInUnearnedPremiumsNetOfPrepaidReinsurancePremiums	116841000	USD
CY2019	us-gaap	Increase Decrease In Premiums Receivable IncreaseDecreaseInPremiumsReceivable	237752000	USD
CY2018	us-gaap	Increase Decrease In Premiums Receivable IncreaseDecreaseInPremiumsReceivable	211296000	USD
CY2017	us-gaap	Increase Decrease In Premiums Receivable IncreaseDecreaseInPremiumsReceivable	31405000	USD
CY2019	us-gaap	Increase Decrease In Deferred Policy Acquisition Costs IncreaseDecreaseInDeferredPolicyAcquisitionCosts	47260000	USD
CY2018	us-gaap	Increase Decrease In Deferred Policy Acquisition Costs IncreaseDecreaseInDeferredPolicyAcquisitionCosts	37847000	USD
CY2017	us-gaap	Increase Decrease In Deferred Policy Acquisition Costs IncreaseDecreaseInDeferredPolicyAcquisitionCosts	78378000	USD
CY2019	us-gaap	Increase Decrease In Reinsurance Payables IncreaseDecreaseInReinsurancePayables	182132000	USD
CY2018	us-gaap	Increase Decrease In Reinsurance Payables IncreaseDecreaseInReinsurancePayables	73438000	USD
CY2017	us-gaap	Increase Decrease In Reinsurance Payables IncreaseDecreaseInReinsurancePayables	8529000	USD
CY2019	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	41052000	USD
CY2018	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	-60181000	USD
CY2017	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	111609000	USD
CY2019	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	2048459000	USD
CY2018	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	1559322000	USD
CY2017	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	1094878000	USD
CY2019	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	30053777000	USD
CY2018	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	33327660000	USD
CY2017	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	36806913000	USD
CY2019	us-gaap	Payments To Acquire Trading Securities Heldforinvestment PaymentsToAcquireTradingSecuritiesHeldforinvestment	811967000	USD
CY2018	us-gaap	Payments To Acquire Trading Securities Heldforinvestment PaymentsToAcquireTradingSecuritiesHeldforinvestment	1001149000	USD
CY2017	us-gaap	Payments To Acquire Trading Securities Heldforinvestment PaymentsToAcquireTradingSecuritiesHeldforinvestment	1021016000	USD
CY2019	us-gaap	Payments To Acquire Other Investments PaymentsToAcquireOtherInvestments	1470545000	USD
CY2018	us-gaap	Payments To Acquire Other Investments PaymentsToAcquireOtherInvestments	2014622000	USD
CY2017	us-gaap	Payments To Acquire Other Investments PaymentsToAcquireOtherInvestments	2020624000	USD
CY2019	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	28595865000	USD
CY2018	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	31513271000	USD
CY2017	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	35686779000	USD
CY2019	us-gaap	Proceeds From Sale Of Trading Securities Heldforinvestment ProceedsFromSaleOfTradingSecuritiesHeldforinvestment	429818000	USD
CY2018	us-gaap	Proceeds From Sale Of Trading Securities Heldforinvestment ProceedsFromSaleOfTradingSecuritiesHeldforinvestment	1118445000	USD
CY2017	us-gaap	Proceeds From Sale Of Trading Securities Heldforinvestment ProceedsFromSaleOfTradingSecuritiesHeldforinvestment	1056401000	USD
CY2019	us-gaap	Proceeds From Sale Of Other Investments ProceedsFromSaleOfOtherInvestments	1209559000	USD
CY2018	us-gaap	Proceeds From Sale Of Other Investments ProceedsFromSaleOfOtherInvestments	1561958000	USD
CY2017	us-gaap	Proceeds From Sale Of Other Investments ProceedsFromSaleOfOtherInvestments	1528617000	USD
CY2019	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	643265000	USD
CY2018	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	892755000	USD
CY2019	us-gaap	Payments For Proceeds From Derivative Instrument Investing Activities PaymentsForProceedsFromDerivativeInstrumentInvestingActivities	-59982000	USD
CY2018	us-gaap	Payments For Proceeds From Derivative Instrument Investing Activities PaymentsForProceedsFromDerivativeInstrumentInvestingActivities	-44699000	USD
CY2017	us-gaap	Payments For Proceeds From Derivative Instrument Investing Activities PaymentsForProceedsFromDerivativeInstrumentInvestingActivities	28563000	USD
CY2019	us-gaap	Payments For Proceeds From Short Term Investments PaymentsForProceedsFromShortTermInvestments	-39833000	USD
CY2018	us-gaap	Payments For Proceeds From Short Term Investments PaymentsForProceedsFromShortTermInvestments	-485473000	USD
CY2017	us-gaap	Payments For Proceeds From Short Term Investments PaymentsForProceedsFromShortTermInvestments	734554000	USD
CY2019	us-gaap	Increase Decrease In Cash Collateral For Borrowed Securities IncreaseDecreaseInCashCollateralForBorrowedSecurities	62193000	USD
CY2018	us-gaap	Increase Decrease In Cash Collateral For Borrowed Securities IncreaseDecreaseInCashCollateralForBorrowedSecurities	-180883000	USD
CY2017	us-gaap	Increase Decrease In Cash Collateral For Borrowed Securities IncreaseDecreaseInCashCollateralForBorrowedSecurities	-12540000	USD
CY2019	us-gaap	Payments To Acquire Productive Assets PaymentsToAcquireProductiveAssets	37837000	USD
CY2018	us-gaap	Payments To Acquire Productive Assets PaymentsToAcquireProductiveAssets	29809000	USD
CY2017	us-gaap	Payments To Acquire Productive Assets PaymentsToAcquireProductiveAssets	22841000	USD
CY2019	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	348486000	USD
CY2018	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	-21736000	USD
CY2017	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	-90875000	USD
CY2019	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-1806483000	USD
CY2018	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-554020000	USD
CY2017	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-1351882000	USD
CY2019	us-gaap	Proceeds From Issuance Of Preferred Stock And Preference Stock ProceedsFromIssuanceOfPreferredStockAndPreferenceStock	0	USD
CY2018	us-gaap	Proceeds From Issuance Of Preferred Stock And Preference Stock ProceedsFromIssuanceOfPreferredStockAndPreferenceStock	0	USD
CY2017	us-gaap	Proceeds From Issuance Of Preferred Stock And Preference Stock ProceedsFromIssuanceOfPreferredStockAndPreferenceStock	319694000	USD
CY2019	us-gaap	Payments For Repurchase Of Preferred Stock And Preference Stock PaymentsForRepurchaseOfPreferredStockAndPreferenceStock	0	USD
CY2018	us-gaap	Payments For Repurchase Of Preferred Stock And Preference Stock PaymentsForRepurchaseOfPreferredStockAndPreferenceStock	92555000	USD
CY2017	us-gaap	Payments For Repurchase Of Preferred Stock And Preference Stock PaymentsForRepurchaseOfPreferredStockAndPreferenceStock	230000000	USD
CY2019	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	2871000	USD
CY2018	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	282762000	USD
CY2017	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	0	USD
CY2019	us-gaap	Proceeds From Repurchase Of Equity ProceedsFromRepurchaseOfEquity	6203000	USD
CY2018	us-gaap	Proceeds From Repurchase Of Equity ProceedsFromRepurchaseOfEquity	-7608000	USD
CY2017	us-gaap	Proceeds From Repurchase Of Equity ProceedsFromRepurchaseOfEquity	-21048000	USD
CY2019	us-gaap	Proceeds From Other Debt ProceedsFromOtherDebt	200083000	USD
CY2018	us-gaap	Proceeds From Other Debt ProceedsFromOtherDebt	218259000	USD
CY2017	us-gaap	Proceeds From Other Debt ProceedsFromOtherDebt	253415000	USD
CY2019	us-gaap	Repayments Of Other Debt RepaymentsOfOtherDebt	49182000	USD
CY2018	us-gaap	Repayments Of Other Debt RepaymentsOfOtherDebt	576401000	USD
CY2017	us-gaap	Repayments Of Other Debt RepaymentsOfOtherDebt	197000000	USD
CY2019	us-gaap	Increase Decrease In Cash Collateral For Loaned Securities IncreaseDecreaseInCashCollateralForLoanedSecurities	62193000	USD
CY2018	us-gaap	Increase Decrease In Cash Collateral For Loaned Securities IncreaseDecreaseInCashCollateralForLoanedSecurities	-180883000	USD
CY2017	us-gaap	Increase Decrease In Cash Collateral For Loaned Securities IncreaseDecreaseInCashCollateralForLoanedSecurities	-12540000	USD
CY2019	us-gaap	Proceeds From Payments To Minority Shareholders ProceedsFromPaymentsToMinorityShareholders	-75056000	USD
CY2018	us-gaap	Proceeds From Payments To Minority Shareholders ProceedsFromPaymentsToMinorityShareholders	0	USD
CY2017	us-gaap	Proceeds From Payments To Minority Shareholders ProceedsFromPaymentsToMinorityShareholders	0	USD
CY2019	us-gaap	Proceeds From Repurchase Of Redeemable Preferred Stock ProceedsFromRepurchaseOfRedeemablePreferredStock	-161882000	USD
CY2018	us-gaap	Proceeds From Repurchase Of Redeemable Preferred Stock ProceedsFromRepurchaseOfRedeemablePreferredStock	0	USD
CY2017	us-gaap	Proceeds From Repurchase Of Redeemable Preferred Stock ProceedsFromRepurchaseOfRedeemablePreferredStock	0	USD
CY2019	us-gaap	Payments Of Dividends Minority Interest PaymentsOfDividendsMinorityInterest	12515000	USD
CY2018	us-gaap	Payments Of Dividends Minority Interest PaymentsOfDividendsMinorityInterest	17989000	USD
CY2017	us-gaap	Payments Of Dividends Minority Interest PaymentsOfDividendsMinorityInterest	17989000	USD
CY2019	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	-6023000	USD
CY2018	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	-7226000	USD
CY2017	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	-51896000	USD
CY2019	us-gaap	Payments Of Dividends Preferred Stock And Preference Stock PaymentsOfDividendsPreferredStockAndPreferenceStock	41612000	USD
CY2018	us-gaap	Payments Of Dividends Preferred Stock And Preference Stock PaymentsOfDividendsPreferredStockAndPreferenceStock	41645000	USD
CY2017	us-gaap	Payments Of Dividends Preferred Stock And Preference Stock PaymentsOfDividendsPreferredStockAndPreferenceStock	46041000	USD
CY2019	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-80662000	USD
CY2018	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-988810000	USD
CY2017	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-3405000	USD
CY2019	us-gaap	Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	17741000	USD
CY2018	us-gaap	Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	-19133000	USD
CY2017	us-gaap	Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	18124000	USD
CY2019	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	179055000	USD
CY2018	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-2641000	USD
CY2017	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-242285000	USD
CY2018Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	724643000	USD
CY2017Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	727284000	USD
CY2016Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	969569000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	903698000	USD
CY2018Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	724643000	USD
CY2017Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	727284000	USD
CY2019	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	109463000	USD
CY2018	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	-980000	USD
CY2017	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	51781000	USD
CY2019	us-gaap	Interest Paid Net InterestPaidNet	126945000	USD
CY2018	us-gaap	Interest Paid Net InterestPaidNet	119775000	USD
CY2017	us-gaap	Interest Paid Net InterestPaidNet	117374000	USD
CY2019	us-gaap	Use Of Estimates UseOfEstimates	<div style="line-height:120%;padding-bottom:13px;text-align:justify;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ materially from those estimates and assumptions. The Company’s principal estimates include:</span></div><table cellpadding="0" cellspacing="0" style="padding-bottom:4px;font-family:Times New Roman; font-size:10pt;"><tr><td style="width:24px;"/><td/></tr><tr><td style="vertical-align:top"><div style="line-height:120%;font-size:10pt;padding-left:0px;"><span style="font-family:inherit;font-size:10pt;">•</span></div></td><td style="vertical-align:top;"><div style="line-height:120%;text-align:justify;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">The reserve for losses and loss adjustment expenses;</span></div></td></tr></table><table cellpadding="0" cellspacing="0" style="padding-bottom:4px;font-family:Times New Roman; font-size:10pt;"><tr><td style="width:24px;"/><td/></tr><tr><td style="vertical-align:top"><div style="line-height:120%;font-size:10pt;padding-left:0px;"><span style="font-family:inherit;font-size:10pt;">•</span></div></td><td style="vertical-align:top;"><div style="line-height:120%;text-align:justify;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">Reinsurance recoverable on unpaid and paid losses and loss adjustment expenses, including the provision for uncollectible amounts;</span></div></td></tr></table><table cellpadding="0" cellspacing="0" style="padding-bottom:4px;font-family:Times New Roman; font-size:10pt;"><tr><td style="width:24px;"/><td/></tr><tr><td style="vertical-align:top"><div style="line-height:120%;font-size:10pt;padding-left:0px;"><span style="font-family:inherit;font-size:10pt;">•</span></div></td><td style="vertical-align:top;"><div style="line-height:120%;text-align:justify;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">Estimates of written and earned premiums;</span></div></td></tr></table><table cellpadding="0" cellspacing="0" style="padding-bottom:4px;font-family:Times New Roman; font-size:10pt;"><tr><td style="width:24px;"/><td/></tr><tr><td style="vertical-align:top"><div style="line-height:120%;font-size:10pt;padding-left:0px;"><span style="font-family:inherit;font-size:10pt;">•</span></div></td><td style="vertical-align:top;"><div style="line-height:120%;text-align:justify;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">The valuation of the investment portfolio and assessment of other-than-temporary impairments (“OTTI”);</span></div></td></tr></table><table cellpadding="0" cellspacing="0" style="padding-bottom:4px;font-family:Times New Roman; font-size:10pt;"><tr><td style="width:24px;"/><td/></tr><tr><td style="vertical-align:top"><div style="line-height:120%;font-size:10pt;padding-left:0px;"><span style="font-family:inherit;font-size:10pt;">•</span></div></td><td style="vertical-align:top;"><div style="line-height:120%;text-align:justify;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">The valuation of purchased intangible assets;</span></div></td></tr></table><table cellpadding="0" cellspacing="0" style="padding-bottom:4px;font-family:Times New Roman; font-size:10pt;"><tr><td style="width:24px;"/><td/></tr><tr><td style="vertical-align:top"><div style="line-height:120%;font-size:10pt;padding-left:0px;"><span style="font-family:inherit;font-size:10pt;">•</span></div></td><td style="vertical-align:top;"><div style="line-height:120%;text-align:justify;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">The assessment of goodwill and intangible assets for impairment; and</span></div></td></tr></table><div style="line-height:120%;font-size:10pt;padding-left:0px;"><span style="font-family:inherit;font-size:10pt;">•</span></div><div style="line-height:120%;text-align:justify;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">the valuation of deferred tax assets.</span></div>
CY2018	us-gaap	Stockholders Equity Note Stock Split Conversion Ratio1 StockholdersEquityNoteStockSplitConversionRatio1	3
CY2019	acgl	Premium Revenue Recognition Period PremiumRevenueRecognitionPeriod	P12M
CY2019	acgl	Securities Lending Rate Of Collateral Required SecuritiesLendingRateOfCollateralRequired	1.02
CY2019	us-gaap	Derivatives Methods Of Accounting Nonhedging Derivatives DerivativesMethodsOfAccountingNonhedgingDerivatives	<div style="line-height:120%;padding-bottom:13px;text-align:justify;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">The Company recognizes all derivative instruments, including embedded derivative instruments, at fair value in its consolidated balance sheets. The Company employs the use of derivative instruments within its operations to mitigate risks arising from assets and liabilities held in foreign currencies as well as part of its overall investment strategy. For such instruments, changes in assets and liabilities measured at fair value are recorded as “Net realized gains” in the consolidated statements of income. In addition, the Company’s derivative instruments include amounts related to underwriting activities where an insurance or reinsurance contract meets the accounting definition of a derivative instrument. For such contracts, changes in fair value are reflected in “Other underwriting income” in the consolidated statements of income as the underlying contract originates from the Company’s underwriting operations. For the periods ended </span><span style="font-family:inherit;font-size:10pt;">2019</span><span style="font-family:inherit;font-size:10pt;">, </span><span style="font-family:inherit;font-size:10pt;">2018</span><span style="font-family:inherit;font-size:10pt;">, and </span><span style="font-family:inherit;font-size:10pt;">2017</span><span style="font-family:inherit;font-size:10pt;">, the Company did not designate any derivative instruments as hedges under the relevant accounting guidance. See </span><a href="#s9FF8819A3C77571DA77AADD75CEF9C0F" style="font-family:inherit;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">note 10, “Derivative Instruments”</span></a><span style="font-family:inherit;font-size:10pt;"> for additional information.</span></div>
CY2019	us-gaap	Premiums Written Gross PremiumsWrittenGross	8138960000	USD
CY2019	us-gaap	Ceded Premiums Written CededPremiumsWritten	2099893000	USD
CY2019	us-gaap	Premiums Written Net PremiumsWrittenNet	6039067000	USD
CY2019	us-gaap	Increase Decrease In Unearned Premiums Net IncreaseDecreaseInUnearnedPremiumsNet	-252569000	USD
CY2019	us-gaap	Premiums Earned Net PremiumsEarnedNet	5786498000	USD
CY2019	us-gaap	Insurance Commissions And Fees InsuranceCommissionsAndFees	24861000	USD
CY2019	us-gaap	Policyholder Benefits And Claims Incurred Net PolicyholderBenefitsAndClaimsIncurredNet	3133452000	USD
CY2019	us-gaap	Deferred Policy Acquisition Cost Amortization Expense DeferredPolicyAcquisitionCostAmortizationExpense	840945000	USD
CY2019	us-gaap	Other Expenses OtherExpenses	800997000	USD
CY2019	acgl	Underwriting Income Loss Segment UnderwritingIncomeLossSegment	1035965000	USD
CY2019	us-gaap	Investment Income Net InvestmentIncomeNet	627738000	USD
CY2019	us-gaap	Marketable Securities Gain Loss Excluding Other Than Temporary Impairments MarketableSecuritiesGainLossExcludingOtherThanTemporaryImpairments	366363000	USD
CY2019	us-gaap	Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNet	3165000	USD
CY2019	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	123672000	USD
CY2019	us-gaap	Other Operating Income Expense Net OtherOperatingIncomeExpenseNet	2233000	USD
CY2019	acgl	Segment Other Cost And Expense Operating SegmentOtherCostAndExpenseOperating	65667000	USD
CY2019	us-gaap	Business Combination Acquisition Related Costs BusinessCombinationAcquisitionRelatedCosts	14444000	USD
CY2019	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	82104000	USD
CY2019	us-gaap	Interest Expense InterestExpense	120872000	USD
CY2019	us-gaap	Foreign Currency Transaction Gain Loss Before Tax ForeignCurrencyTransactionGainLossBeforeTax	-20609000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	1849110000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	155810000	USD
CY2019	us-gaap	Profit Loss ProfitLoss	1693300000	USD
CY2019	us-gaap	Net Income Loss Attributable To Redeemable Noncontrolling Interest NetIncomeLossAttributableToRedeemableNoncontrollingInterest	16909000	USD
CY2019	us-gaap	Net Income Loss Attributable To Nonredeemable Noncontrolling Interest NetIncomeLossAttributableToNonredeemableNoncontrollingInterest	40072000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	1636319000	USD
CY2019	us-gaap	Preferred Stock Dividends Income Statement Impact PreferredStockDividendsIncomeStatementImpact	41612000	USD
CY2019	us-gaap	Preferred Stock Redemption Premium PreferredStockRedemptionPremium	0	USD
CY2019	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	1594707000	USD
CY2019	us-gaap	Loss Ratio LossRatio	0.542
CY2019	acgl	Acquisition Expense Ratio Percentage AcquisitionExpenseRatioPercentage	0.145
CY2019	acgl	Other Operating Expense Ratio Percentage OtherOperatingExpenseRatioPercentage	0.138
CY2019	acgl	Combined Ratio Percentage CombinedRatioPercentage	0.825
CY2019Q4	us-gaap	Intangible Assets Net Including Goodwill IntangibleAssetsNetIncludingGoodwill	738083000	USD
CY2019Q4	acgl	Investable Assets InvestableAssets	24990265000	USD
CY2019Q4	us-gaap	Assets Assets	37885361000	USD
CY2019Q4	us-gaap	Liabilities Liabilities	25569809000	USD
CY2018	us-gaap	Premiums Written Gross PremiumsWrittenGross	6961004000	USD
CY2018	us-gaap	Ceded Premiums Written CededPremiumsWritten	1614257000	USD
CY2018	us-gaap	Premiums Written Net PremiumsWrittenNet	5346747000	USD
CY2018	us-gaap	Increase Decrease In Unearned Premiums Net IncreaseDecreaseInUnearnedPremiumsNet	-114772000	USD
CY2018	us-gaap	Premiums Earned Net PremiumsEarnedNet	5231975000	USD
CY2018	us-gaap	Insurance Commissions And Fees InsuranceCommissionsAndFees	15073000	USD
CY2018	us-gaap	Policyholder Benefits And Claims Incurred Net PolicyholderBenefitsAndClaimsIncurredNet	2890106000	USD
CY2018	us-gaap	Deferred Policy Acquisition Cost Amortization Expense DeferredPolicyAcquisitionCostAmortizationExpense	805135000	USD
CY2018	us-gaap	Other Expenses OtherExpenses	677809000	USD
CY2018	acgl	Underwriting Income Loss Segment UnderwritingIncomeLossSegment	873998000	USD
CY2018	us-gaap	Investment Income Net InvestmentIncomeNet	563633000	USD
CY2018	us-gaap	Marketable Securities Gain Loss Excluding Other Than Temporary Impairments MarketableSecuritiesGainLossExcludingOtherThanTemporaryImpairments	-405344000	USD
CY2018	us-gaap	Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNet	2829000	USD
CY2018	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	45641000	USD
CY2018	us-gaap	Other Operating Income Expense Net OtherOperatingIncomeExpenseNet	2419000	USD
CY2018	acgl	Segment Other Cost And Expense Operating SegmentOtherCostAndExpenseOperating	58608000	USD
CY2018	us-gaap	Business Combination Acquisition Related Costs BusinessCombinationAcquisitionRelatedCosts	20386000	USD
CY2018	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	105670000	USD
CY2018	us-gaap	Interest Expense InterestExpense	120484000	USD
CY2018	us-gaap	Foreign Currency Transaction Gain Loss Before Tax ForeignCurrencyTransactionGainLossBeforeTax	69402000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	841772000	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	113951000	USD
CY2018	us-gaap	Profit Loss ProfitLoss	727821000	USD
CY2018	us-gaap	Net Income Loss Attributable To Redeemable Noncontrolling Interest NetIncomeLossAttributableToRedeemableNoncontrollingInterest	18357000	USD
CY2018	us-gaap	Net Income Loss Attributable To Nonredeemable Noncontrolling Interest NetIncomeLossAttributableToNonredeemableNoncontrollingInterest	-48507000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	757971000	USD
CY2018	us-gaap	Preferred Stock Dividends Income Statement Impact PreferredStockDividendsIncomeStatementImpact	41645000	USD
CY2018	us-gaap	Preferred Stock Redemption Premium PreferredStockRedemptionPremium	2710000	USD
CY2018	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	713616000	USD
CY2018	us-gaap	Loss Ratio LossRatio	0.552
CY2018	acgl	Acquisition Expense Ratio Percentage AcquisitionExpenseRatioPercentage	0.154
CY2018	acgl	Other Operating Expense Ratio Percentage OtherOperatingExpenseRatioPercentage	0.130
CY2018	acgl	Combined Ratio Percentage CombinedRatioPercentage	0.836
CY2018Q4	us-gaap	Intangible Assets Net Including Goodwill IntangibleAssetsNetIncludingGoodwill	634920000	USD
CY2018Q4	acgl	Investable Assets InvestableAssets	22324524000	USD
CY2018Q4	us-gaap	Assets Assets	32218329000	USD
CY2018Q4	us-gaap	Liabilities Liabilities	21780650000	USD
CY2017	us-gaap	Premiums Written Gross PremiumsWrittenGross	6368425000	USD
CY2017	us-gaap	Ceded Premiums Written CededPremiumsWritten	1407052000	USD
CY2017	us-gaap	Premiums Written Net PremiumsWrittenNet	4961373000	USD
CY2017	us-gaap	Increase Decrease In Unearned Premiums Net IncreaseDecreaseInUnearnedPremiumsNet	-116841000	USD
CY2017	us-gaap	Premiums Earned Net PremiumsEarnedNet	4844532000	USD
CY2017	us-gaap	Insurance Commissions And Fees InsuranceCommissionsAndFees	30253000	USD
CY2017	us-gaap	Policyholder Benefits And Claims Incurred Net PolicyholderBenefitsAndClaimsIncurredNet	2967446000	USD
CY2017	us-gaap	Deferred Policy Acquisition Cost Amortization Expense DeferredPolicyAcquisitionCostAmortizationExpense	775458000	USD
CY2017	us-gaap	Other Expenses OtherExpenses	684451000	USD
CY2017	acgl	Underwriting Income Loss Segment UnderwritingIncomeLossSegment	447430000	USD
CY2017	us-gaap	Investment Income Net InvestmentIncomeNet	470872000	USD
CY2017	us-gaap	Marketable Securities Gain Loss Excluding Other Than Temporary Impairments MarketableSecuritiesGainLossExcludingOtherThanTemporaryImpairments	149141000	USD
CY2017	us-gaap	Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNet	7138000	USD
CY2017	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	142286000	USD
CY2017	us-gaap	Other Operating Income Expense Net OtherOperatingIncomeExpenseNet	-2571000	USD
CY2017	acgl	Segment Other Cost And Expense Operating SegmentOtherCostAndExpenseOperating	61602000	USD
CY2017	us-gaap	Business Combination Acquisition Related Costs BusinessCombinationAcquisitionRelatedCosts	22150000	USD
CY2017	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	125778000	USD
CY2017	us-gaap	Interest Expense InterestExpense	117431000	USD
CY2017	us-gaap	Foreign Currency Transaction Gain Loss Before Tax ForeignCurrencyTransactionGainLossBeforeTax	-115782000	USD
CY2017	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	757277000	USD
CY2017	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	127568000	USD
CY2017	us-gaap	Profit Loss ProfitLoss	629709000	USD
CY2017	us-gaap	Net Income Loss Attributable To Redeemable Noncontrolling Interest NetIncomeLossAttributableToRedeemableNoncontrollingInterest	18344000	USD
CY2017	us-gaap	Net Income Loss Attributable To Nonredeemable Noncontrolling Interest NetIncomeLossAttributableToNonredeemableNoncontrollingInterest	-7913000	USD
CY2017	us-gaap	Net Income Loss NetIncomeLoss	619278000	USD
CY2017	us-gaap	Preferred Stock Dividends Income Statement Impact PreferredStockDividendsIncomeStatementImpact	46041000	USD
CY2017	us-gaap	Preferred Stock Redemption Premium PreferredStockRedemptionPremium	6735000	USD

CY2019

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Amortization Period Excessof Loss Portfolio

AmortizationPeriodExcessofLossPortfolio

P10Y

CY2019

acgl

Equity Method Investments Time Lag For Reporting High Endof Range

EquityMethodInvestmentsTimeLagForReportingHighEndofRange

P3M

CY2019

acgl

Equity Method Investments Time Lag For Reporting Low Endof Range

EquityMethodInvestmentsTimeLagForReportingLowEndofRange

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CY2018Q4

acgl

Other Than Temporary Impairment Losses Investments Available For Sale Securitiess At Current Fair Value

OtherThanTemporaryImpairmentLossesInvestmentsAvailableForSaleSecuritiessAtCurrentFairValue

0

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CY2018Q4

acgl

Securities Lending Investments Pledged Amortized Cost

SecuritiesLendingInvestmentsPledgedAmortizedCost

266786000

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CY2019Q4

acgl

Securities Lending Investments Pledged Amortized Cost

SecuritiesLendingInvestmentsPledgedAmortizedCost

378738000

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CY2018Q4

acgl

Securities Received As Collateral Amortized Cost

SecuritiesReceivedAsCollateralAmortizedCost

274125000

USD

CY2019Q4

acgl

Securities Received As Collateral Amortized Cost

SecuritiesReceivedAsCollateralAmortizedCost

388366000

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CY2018Q4

acgl

Short Term Investments Cost Amount

ShortTermInvestmentsCostAmount

956238000

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CY2019Q4

acgl

Short Term Investments Cost Amount

ShortTermInvestmentsCostAmount

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Current Fiscal Year End Date

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FY

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Document Fiscal Year Focus

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2019

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Entity Central Index Key

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CY2018Q4

us-gaap

Available For Sale Debt Securities Amortized Cost Basis

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14829902000

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CY2019Q4

us-gaap

Available For Sale Debt Securities Amortized Cost Basis

AvailableForSaleDebtSecuritiesAmortizedCostBasis

16598808000

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CY2018Q4

us-gaap

Common Stock Par Or Stated Value Per Share

CommonStockParOrStatedValuePerShare

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CY2019

us-gaap

Share Based Compensation Arrangement By Share Based Payment Award Award Requisite Service Period1

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Share Based Compensation Arrangement By Share Based Payment Award Award Vesting Period1

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Document Annual Report

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Document Period End Date

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2019-12-31

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Entity File Number

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001-16209

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Entity Registrant Name

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ARCH CAPITAL GROUP LTD.

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Entity Incorporation State Country Code

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D0

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Entity Tax Identification Number

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98-0374481

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Entity Address Address Line1

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Waterloo House, Ground Floor

CY2019

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Entity Address Address Line2

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100 Pitts Bay Road,

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Entity Address City Or Town

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Pembroke

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Entity Address Postal Zip Code

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HM 08,

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Entity Address Country

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BM

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City Area Code

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(441)

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Local Phone Number

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278-9250

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Entity Well Known Seasoned Issuer

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Yes

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Entity Voluntary Filers

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Entity Interactive Data Current

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Yes

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Entity Current Reporting Status

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Entity Filer Category

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Entity Small Business

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Entity Emerging Growth Company

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Entity Shell Company

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Available For Sale Securities Debt Securities

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16894526000

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Available For Sale Securities Debt Securities

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14699010000

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CY2019Q4

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Other Short Term Investments

OtherShortTermInvestments

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Other Short Term Investments

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Securities Received As Collateral

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Securities Received As Collateral

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Equity Securities Fv Ni

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Equity Securities Fv Ni

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Investments Accounted For Using Fair Value Option

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Investments Accounted For Using Fair Value Option

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Equity Method Investments

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Equity Method Investments

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Investments

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Investments

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CY2019Q4

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Cash And Cash Equivalents At Carrying Value

CashAndCashEquivalentsAtCarryingValue

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Cash And Cash Equivalents At Carrying Value

CashAndCashEquivalentsAtCarryingValue

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CY2019Q4

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Accrued Investment Income Receivable

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Accrued Investment Income Receivable

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acgl

Fixed Maturities And Short Term Investments Pledged Under Securities Lending Fair Value

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Fixed Maturities And Short Term Investments Pledged Under Securities Lending Fair Value

FixedMaturitiesAndShortTermInvestmentsPledgedUnderSecuritiesLendingFairValue

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CY2019Q4

us-gaap

Premiums Receivable At Carrying Value

PremiumsReceivableAtCarryingValue

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CY2018Q4

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Premiums Receivable At Carrying Value

PremiumsReceivableAtCarryingValue

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CY2019Q4

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Reinsurance Recoverables

ReinsuranceRecoverables

4346816000

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CY2018Q4

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Reinsurance Recoverables

ReinsuranceRecoverables

2919372000

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Contractholder Deductibles Receivable

ContractholderDeductiblesReceivable

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Contractholder Deductibles Receivable

ContractholderDeductiblesReceivable

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Prepaid Reinsurance Premiums

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Prepaid Reinsurance Premiums

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CY2019Q4

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Deferred Policy Acquisition Costs

DeferredPolicyAcquisitionCosts

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CY2018Q4

us-gaap

Deferred Policy Acquisition Costs

DeferredPolicyAcquisitionCosts

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CY2019Q4

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Receivables From Brokers Dealers And Clearing Organizations

ReceivablesFromBrokersDealersAndClearingOrganizations

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CY2018Q4

us-gaap

Receivables From Brokers Dealers And Clearing Organizations

ReceivablesFromBrokersDealersAndClearingOrganizations

36246000

USD

CY2019Q4

acgl

Intangible Assets Liabilitiesand Goodwill Net

IntangibleAssetsLiabilitiesandGoodwillNet

738083000

USD

CY2018Q4

acgl

Intangible Assets Liabilitiesand Goodwill Net

IntangibleAssetsLiabilitiesandGoodwillNet

634920000

USD

CY2019Q4

us-gaap

Other Assets

OtherAssets

1383788000

USD

CY2018Q4

us-gaap

Other Assets

OtherAssets

929611000

USD

CY2019Q4

us-gaap

Assets

37885361000

USD

CY2018Q4

us-gaap

Assets

32218329000

USD

CY2019Q4

us-gaap

Liability For Claims And Claims Adjustment Expense

LiabilityForClaimsAndClaimsAdjustmentExpense

13891842000

USD

CY2018Q4

us-gaap

Liability For Claims And Claims Adjustment Expense

LiabilityForClaimsAndClaimsAdjustmentExpense

11853297000

USD

CY2019Q4

us-gaap

Unearned Premiums

UnearnedPremiums

4339549000

USD

CY2018Q4

us-gaap

Unearned Premiums

UnearnedPremiums

3753636000

USD

CY2019Q4

us-gaap

Reinsurance Payable

ReinsurancePayable

667072000

USD

CY2018Q4

us-gaap

Reinsurance Payable

ReinsurancePayable

393107000

USD

CY2019Q4

acgl

Contract Holder Payables

ContractHolderPayables

2119460000

USD

CY2018Q4

acgl

Contract Holder Payables

ContractHolderPayables

2079111000

USD

CY2019Q4

us-gaap

Policyholder Contract Deposits

PolicyholderContractDeposits

206698000

USD

CY2018Q4

us-gaap

Policyholder Contract Deposits

PolicyholderContractDeposits

236630000

USD

CY2019Q4

us-gaap

Senior Long Term Notes

SeniorLongTermNotes

1871626000

USD

CY2018Q4

us-gaap

Senior Long Term Notes

SeniorLongTermNotes

1733528000

USD

CY2019Q4

us-gaap

Line Of Credit

LineOfCredit

484287000

USD

CY2018Q4

us-gaap

Line Of Credit

LineOfCredit

455682000

USD

CY2019Q4

us-gaap

Obligation To Return Securities Received As Collateral

ObligationToReturnSecuritiesReceivedAsCollateral

388366000

USD

CY2018Q4

us-gaap

Obligation To Return Securities Received As Collateral

ObligationToReturnSecuritiesReceivedAsCollateral

274125000

USD

CY2019Q4

srt

Payables To Broker Dealers And Clearing Organizations

PayablesToBrokerDealersAndClearingOrganizations

87579000

USD

CY2018Q4

srt

Payables To Broker Dealers And Clearing Organizations

PayablesToBrokerDealersAndClearingOrganizations

90034000

USD

CY2019Q4

us-gaap

Other Liabilities

OtherLiabilities

1513330000

USD

CY2018Q4

us-gaap

Other Liabilities

OtherLiabilities

911500000

USD

CY2019Q4

us-gaap

Liabilities

25569809000

USD

CY2018Q4

us-gaap

Liabilities

21780650000

USD

CY2019Q4

us-gaap

Commitments And Contingencies

CommitmentsAndContingencies

USD

CY2018Q4

us-gaap

Commitments And Contingencies

CommitmentsAndContingencies

USD

CY2019Q4

us-gaap

Redeemable Noncontrolling Interest Equity Fair Value

RedeemableNoncontrollingInterestEquityFairValue

55404000

USD

CY2018Q4

us-gaap

Redeemable Noncontrolling Interest Equity Fair Value

RedeemableNoncontrollingInterestEquityFairValue

206292000

USD

CY2019Q4

us-gaap

Preferred Stock Value

PreferredStockValue

780000000

USD

CY2018Q4

us-gaap

Preferred Stock Value

PreferredStockValue

780000000

USD

CY2019Q4

us-gaap

Common Stock Value

CommonStockValue

638000

USD

CY2018Q4

us-gaap

Common Stock Value

CommonStockValue

634000

USD

CY2019Q4

us-gaap

Additional Paid In Capital Common Stock

AdditionalPaidInCapitalCommonStock

1889683000

USD

CY2018Q4

us-gaap

Additional Paid In Capital Common Stock

AdditionalPaidInCapitalCommonStock

1793781000

USD

CY2019Q4

us-gaap

Retained Earnings Accumulated Deficit

RetainedEarningsAccumulatedDeficit

11021006000

USD

CY2018Q4

us-gaap

Retained Earnings Accumulated Deficit

RetainedEarningsAccumulatedDeficit

9426299000

USD

CY2019Q4

us-gaap

Accumulated Other Comprehensive Income Loss Net Of Tax

AccumulatedOtherComprehensiveIncomeLossNetOfTax

212091000

USD

CY2018Q4

us-gaap

Accumulated Other Comprehensive Income Loss Net Of Tax

AccumulatedOtherComprehensiveIncomeLossNetOfTax

-178720000

USD

CY2019Q4

us-gaap

Treasury Stock Value

TreasuryStockValue

2406047000

USD

CY2018Q4

us-gaap

Treasury Stock Value

TreasuryStockValue

2382167000

USD

CY2019Q4

us-gaap

Stockholders Equity

StockholdersEquity

11497371000

USD

CY2018Q4

us-gaap

Stockholders Equity

StockholdersEquity

9439827000

USD

CY2019Q4

us-gaap

Minority Interest

MinorityInterest

762777000

USD

CY2018Q4

us-gaap

Minority Interest

MinorityInterest

791560000

USD

CY2019Q4

us-gaap

Stockholders Equity Including Portion Attributable To Noncontrolling Interest

StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest

12260148000

USD

CY2018Q4

us-gaap

Stockholders Equity Including Portion Attributable To Noncontrolling Interest

StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest

10231387000

USD

CY2019Q4

us-gaap

Liabilities And Stockholders Equity

LiabilitiesAndStockholdersEquity

37885361000

USD

CY2018Q4

us-gaap

Liabilities And Stockholders Equity

LiabilitiesAndStockholdersEquity

32218329000

USD

CY2019

us-gaap

Premiums Written Net

PremiumsWrittenNet

6039067000

USD

CY2018

us-gaap

Premiums Written Net

PremiumsWrittenNet

5346747000

USD

CY2017

us-gaap

Premiums Written Net

PremiumsWrittenNet

4961373000

USD

CY2019

us-gaap

Increase Decrease In Unearned Premiums Net

IncreaseDecreaseInUnearnedPremiumsNet

-252569000

USD

CY2018

us-gaap

Increase Decrease In Unearned Premiums Net

IncreaseDecreaseInUnearnedPremiumsNet

-114772000

USD

CY2017

us-gaap

Increase Decrease In Unearned Premiums Net

IncreaseDecreaseInUnearnedPremiumsNet

-116841000

USD

CY2019

us-gaap

Premiums Earned Net

PremiumsEarnedNet

5786498000

USD

CY2018

us-gaap

Premiums Earned Net

PremiumsEarnedNet

5231975000

USD

CY2017

us-gaap

Premiums Earned Net

PremiumsEarnedNet

4844532000

USD

CY2019

us-gaap

Investment Income Net

InvestmentIncomeNet

627738000

USD

CY2018

us-gaap

Investment Income Net

InvestmentIncomeNet

563633000

USD

CY2017

us-gaap

Investment Income Net

InvestmentIncomeNet

470872000

USD

CY2019

us-gaap

Marketable Securities Gain Loss Excluding Other Than Temporary Impairments

MarketableSecuritiesGainLossExcludingOtherThanTemporaryImpairments

366363000

USD

CY2018

us-gaap

Marketable Securities Gain Loss Excluding Other Than Temporary Impairments

MarketableSecuritiesGainLossExcludingOtherThanTemporaryImpairments

-405344000

USD

CY2017

us-gaap

Marketable Securities Gain Loss Excluding Other Than Temporary Impairments

MarketableSecuritiesGainLossExcludingOtherThanTemporaryImpairments

149141000

USD

CY2019

us-gaap

Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net

OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNet

3165000

USD

CY2018

us-gaap

Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net

OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNet

2829000

USD

CY2017

us-gaap

Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net

OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNet

7138000

USD

CY2019

us-gaap

Insurance Commissions And Fees

InsuranceCommissionsAndFees

24861000

USD

CY2018

us-gaap

Insurance Commissions And Fees

InsuranceCommissionsAndFees

15073000

USD

CY2017

us-gaap

Insurance Commissions And Fees

InsuranceCommissionsAndFees

30253000

USD

CY2019

us-gaap

Income Loss From Equity Method Investments

IncomeLossFromEquityMethodInvestments

123672000

USD

CY2018

us-gaap

Income Loss From Equity Method Investments

IncomeLossFromEquityMethodInvestments

45641000

USD

CY2017

us-gaap

Income Loss From Equity Method Investments

IncomeLossFromEquityMethodInvestments

142286000

USD

CY2019

us-gaap

Other Operating Income Expense Net

OtherOperatingIncomeExpenseNet

2233000

USD

CY2018

us-gaap

Other Operating Income Expense Net

OtherOperatingIncomeExpenseNet

2419000

USD

CY2017

us-gaap

Other Operating Income Expense Net

OtherOperatingIncomeExpenseNet

-2571000

USD

CY2019

us-gaap

Revenues

6928200000

USD

CY2018

us-gaap

Revenues

5450568000

USD

CY2017

us-gaap

Revenues

5627375000

USD

CY2019

us-gaap

Policyholder Benefits And Claims Incurred Net

PolicyholderBenefitsAndClaimsIncurredNet

3133452000

USD

CY2018

us-gaap

Policyholder Benefits And Claims Incurred Net

PolicyholderBenefitsAndClaimsIncurredNet

2890106000

USD

CY2017

us-gaap

Policyholder Benefits And Claims Incurred Net

PolicyholderBenefitsAndClaimsIncurredNet

2967446000

USD

CY2019

us-gaap

Deferred Policy Acquisition Cost Amortization Expense

DeferredPolicyAcquisitionCostAmortizationExpense

840945000

USD

CY2018

us-gaap

Deferred Policy Acquisition Cost Amortization Expense

DeferredPolicyAcquisitionCostAmortizationExpense

805135000

USD

CY2017

us-gaap

Deferred Policy Acquisition Cost Amortization Expense

DeferredPolicyAcquisitionCostAmortizationExpense

775458000

USD

CY2019

us-gaap

Other Cost And Expense Operating

OtherCostAndExpenseOperating

800997000

USD

CY2018

us-gaap

Other Cost And Expense Operating

OtherCostAndExpenseOperating

677809000

USD

CY2017

us-gaap

Other Cost And Expense Operating

OtherCostAndExpenseOperating

684451000

USD

CY2019

us-gaap

General And Administrative Expense

GeneralAndAdministrativeExpense

80111000

USD

CY2018

us-gaap

General And Administrative Expense

GeneralAndAdministrativeExpense

78994000

USD

CY2017

us-gaap

General And Administrative Expense

GeneralAndAdministrativeExpense

83752000

USD

CY2019

us-gaap

Amortization Of Intangible Assets

AmortizationOfIntangibleAssets

82104000

USD

CY2018

us-gaap

Amortization Of Intangible Assets

AmortizationOfIntangibleAssets

105670000

USD

CY2017

us-gaap

Amortization Of Intangible Assets

AmortizationOfIntangibleAssets

125778000

USD

CY2019

us-gaap

Interest Expense

InterestExpense

120872000

USD

CY2018

us-gaap

Interest Expense

InterestExpense

120484000

USD

CY2017

us-gaap

Interest Expense

InterestExpense

117431000

USD

CY2019

us-gaap

Foreign Currency Transaction Gain Loss Before Tax

ForeignCurrencyTransactionGainLossBeforeTax

-20609000

USD

CY2018

us-gaap

Foreign Currency Transaction Gain Loss Before Tax

ForeignCurrencyTransactionGainLossBeforeTax

69402000

USD

CY2017

us-gaap

Foreign Currency Transaction Gain Loss Before Tax

ForeignCurrencyTransactionGainLossBeforeTax

-115782000

USD

CY2019

us-gaap

Benefits Losses And Expenses

BenefitsLossesAndExpenses

5079090000

USD

CY2018

us-gaap

Benefits Losses And Expenses

BenefitsLossesAndExpenses

4608796000

USD

CY2017

us-gaap

Benefits Losses And Expenses

BenefitsLossesAndExpenses

4870098000

USD

CY2019

us-gaap

Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest

IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest

1849110000

USD

CY2018

us-gaap

Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest

IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest

841772000

USD

CY2017

us-gaap

Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest

IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest

757277000

USD

CY2019

us-gaap

Current Income Tax Expense Benefit

CurrentIncomeTaxExpenseBenefit

144361000

USD

CY2018

us-gaap

Current Income Tax Expense Benefit

CurrentIncomeTaxExpenseBenefit

85863000

USD

CY2017

us-gaap

Current Income Tax Expense Benefit

CurrentIncomeTaxExpenseBenefit

-45736000

USD

CY2019

us-gaap

Deferred Income Tax Expense Benefit

DeferredIncomeTaxExpenseBenefit

11449000

USD

CY2018

us-gaap

Deferred Income Tax Expense Benefit

DeferredIncomeTaxExpenseBenefit

28088000

USD

CY2017

us-gaap

Deferred Income Tax Expense Benefit

DeferredIncomeTaxExpenseBenefit

173304000

USD

CY2019

us-gaap

Income Tax Expense Benefit

IncomeTaxExpenseBenefit

155810000

USD

CY2018

us-gaap

Income Tax Expense Benefit

IncomeTaxExpenseBenefit

113951000

USD

CY2017

us-gaap

Income Tax Expense Benefit

IncomeTaxExpenseBenefit

127568000

USD

CY2019

us-gaap

Profit Loss

ProfitLoss

1693300000

USD

CY2017

us-gaap

Other Comprehensive Income Foreign Currency Transaction And Translation Gain Loss Arising During Period Net Of Tax

OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossArisingDuringPeriodNetOfTax

47014000

USD

CY2018

us-gaap

Profit Loss

ProfitLoss

727821000

USD

CY2017

us-gaap

Profit Loss

ProfitLoss

629709000

USD

CY2019

us-gaap

Net Income Loss Attributable To Noncontrolling Interest

NetIncomeLossAttributableToNoncontrollingInterest

56981000

USD

CY2018

us-gaap

Net Income Loss Attributable To Noncontrolling Interest

NetIncomeLossAttributableToNoncontrollingInterest

-30150000

USD

CY2017

us-gaap

Net Income Loss Attributable To Noncontrolling Interest

NetIncomeLossAttributableToNoncontrollingInterest

10431000

USD

CY2019

us-gaap

Net Income Loss

NetIncomeLoss

1636319000

USD

CY2018

us-gaap

Net Income Loss

NetIncomeLoss

757971000

USD

CY2017

us-gaap

Net Income Loss

NetIncomeLoss

619278000

USD

CY2019

us-gaap

Preferred Stock Dividends Income Statement Impact

PreferredStockDividendsIncomeStatementImpact

41612000

USD

CY2018

us-gaap

Preferred Stock Dividends Income Statement Impact

PreferredStockDividendsIncomeStatementImpact

41645000

USD

CY2017

us-gaap

Preferred Stock Dividends Income Statement Impact

PreferredStockDividendsIncomeStatementImpact

46041000

USD

CY2019

us-gaap

Preferred Stock Redemption Premium

PreferredStockRedemptionPremium

0

USD

CY2018

us-gaap

Preferred Stock Redemption Premium

PreferredStockRedemptionPremium

2710000

USD

CY2017

us-gaap

Preferred Stock Redemption Premium

PreferredStockRedemptionPremium

6735000

USD

CY2019

us-gaap

Net Income Loss Available To Common Stockholders Basic

NetIncomeLossAvailableToCommonStockholdersBasic

1594707000

USD

CY2018

us-gaap

Net Income Loss Available To Common Stockholders Basic

NetIncomeLossAvailableToCommonStockholdersBasic

713616000

USD

CY2017

us-gaap

Net Income Loss Available To Common Stockholders Basic

NetIncomeLossAvailableToCommonStockholdersBasic

566502000

USD

CY2019

us-gaap

Earnings Per Share Basic

EarningsPerShareBasic

3.97

CY2018

us-gaap

Earnings Per Share Basic

EarningsPerShareBasic

1.76

CY2017

us-gaap

Earnings Per Share Basic

EarningsPerShareBasic

1.40

CY2019

us-gaap

Earnings Per Share Diluted

EarningsPerShareDiluted

3.87

CY2018

us-gaap

Earnings Per Share Diluted

EarningsPerShareDiluted

1.73

CY2017

us-gaap

Earnings Per Share Diluted

EarningsPerShareDiluted

1.36

CY2019

us-gaap

Weighted Average Number Of Shares Outstanding Basic

WeightedAverageNumberOfSharesOutstandingBasic

401802815

shares

CY2018

us-gaap

Weighted Average Number Of Shares Outstanding Basic

WeightedAverageNumberOfSharesOutstandingBasic

404347621

shares

CY2017

us-gaap

Weighted Average Number Of Shares Outstanding Basic

WeightedAverageNumberOfSharesOutstandingBasic

404138364

shares

CY2019

us-gaap

Weighted Average Number Of Diluted Shares Outstanding

WeightedAverageNumberOfDilutedSharesOutstanding

411609478

shares

CY2018

us-gaap

Weighted Average Number Of Diluted Shares Outstanding

WeightedAverageNumberOfDilutedSharesOutstanding

412906478

shares

CY2017

us-gaap

Weighted Average Number Of Diluted Shares Outstanding

WeightedAverageNumberOfDilutedSharesOutstanding

417785025

shares

CY2019

us-gaap

Profit Loss

ProfitLoss

1693300000

USD

CY2018

us-gaap

Profit Loss

ProfitLoss

727821000

USD

CY2017

us-gaap

Profit Loss

ProfitLoss

629709000

USD

CY2019

us-gaap

Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax

OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax

500771000

USD

CY2018

us-gaap

Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax

OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax

-270057000

USD

CY2017

us-gaap

Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax

OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax

252904000

USD

CY2019

us-gaap

Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax

OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax

118941000

USD

CY2018

us-gaap

Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax

OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax

-144573000

USD

CY2017

us-gaap

Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax

OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax

67863000

USD

CY2019

us-gaap

Other Comprehensive Income Foreign Currency Transaction And Translation Gain Loss Arising During Period Net Of Tax

OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossArisingDuringPeriodNetOfTax

18110000

USD

CY2018

us-gaap

Other Comprehensive Income Foreign Currency Transaction And Translation Gain Loss Arising During Period Net Of Tax

OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossArisingDuringPeriodNetOfTax

-24830000

USD

CY2019

us-gaap

Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest

ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest

2093240000

USD

CY2018

us-gaap

Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest

ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest

577507000

USD

CY2017

us-gaap

Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest

ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest

861764000

USD

CY2019

us-gaap

Net Income Loss Attributable To Noncontrolling Interest

NetIncomeLossAttributableToNoncontrollingInterest

56981000

USD

CY2018

us-gaap

Net Income Loss Attributable To Noncontrolling Interest

NetIncomeLossAttributableToNoncontrollingInterest

-30150000

USD

CY2017

us-gaap

Net Income Loss Attributable To Noncontrolling Interest

NetIncomeLossAttributableToNoncontrollingInterest

10431000

USD

CY2019

us-gaap

Other Comprehensive Income Loss Net Of Tax Portion Attributable To Noncontrolling Interest

OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToNoncontrollingInterest

9130000

USD

CY2018

us-gaap

Other Comprehensive Income Loss Net Of Tax Portion Attributable To Noncontrolling Interest

OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToNoncontrollingInterest

-3346000

USD

CY2017

us-gaap

Other Comprehensive Income Loss Net Of Tax Portion Attributable To Noncontrolling Interest

OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToNoncontrollingInterest

-530000

USD

CY2019

us-gaap

Comprehensive Income Net Of Tax

ComprehensiveIncomeNetOfTax

2027129000

USD

CY2018

us-gaap

Comprehensive Income Net Of Tax

ComprehensiveIncomeNetOfTax

611003000

USD

CY2017

us-gaap

Comprehensive Income Net Of Tax

ComprehensiveIncomeNetOfTax

851863000

USD

CY2019Q4

us-gaap

Stockholders Equity

StockholdersEquity

11497371000

USD

CY2018Q4

us-gaap

Stockholders Equity

StockholdersEquity

9439827000

USD

CY2017Q4

us-gaap

Stockholders Equity

StockholdersEquity

9196602000

USD

CY2019Q4

us-gaap

Minority Interest

MinorityInterest

762777000

USD

CY2018Q4

us-gaap

Minority Interest

MinorityInterest

791560000

USD

CY2017Q4

us-gaap

Minority Interest

MinorityInterest

843411000

USD

CY2019Q4

us-gaap

Stockholders Equity Including Portion Attributable To Noncontrolling Interest

StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest

12260148000

USD

CY2018Q4

us-gaap

Stockholders Equity Including Portion Attributable To Noncontrolling Interest

StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest

10231387000

USD

CY2017Q4

us-gaap

Stockholders Equity Including Portion Attributable To Noncontrolling Interest

StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest

10040013000

USD

CY2019

us-gaap

Profit Loss

ProfitLoss

1693300000

USD

CY2018

us-gaap

Profit Loss

ProfitLoss

727821000

USD

CY2017

us-gaap

Profit Loss

ProfitLoss

629709000

USD

CY2019

acgl

Net Realized Gains Losses

NetRealizedGainsLosses

381132000

USD

CY2018

acgl

Net Realized Gains Losses

NetRealizedGainsLosses

-387550000

USD

CY2017

acgl

Net Realized Gains Losses

NetRealizedGainsLosses

174517000

USD

CY2019

us-gaap

Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net

OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNet

3165000

USD

CY2018

us-gaap

Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net

OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNet

2829000

USD

CY2017

us-gaap

Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net

OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNet

7138000

USD

CY2019

acgl

Equity In Net Income Loss Of Investment Funds Accounted For Using Equity Method And Other Income Loss

EquityInNetIncomeLossOfInvestmentFundsAccountedForUsingEquityMethodAndOtherIncomeLoss

14013000

USD

CY2018

acgl

Equity In Net Income Loss Of Investment Funds Accounted For Using Equity Method And Other Income Loss

EquityInNetIncomeLossOfInvestmentFundsAccountedForUsingEquityMethodAndOtherIncomeLoss

-36694000

USD

CY2017

acgl

Equity In Net Income Loss Of Investment Funds Accounted For Using Equity Method And Other Income Loss

EquityInNetIncomeLossOfInvestmentFundsAccountedForUsingEquityMethodAndOtherIncomeLoss

79540000

USD

CY2019

us-gaap

Amortization Of Intangible Assets

AmortizationOfIntangibleAssets

82104000

USD

CY2018

us-gaap

Amortization Of Intangible Assets

AmortizationOfIntangibleAssets

105670000

USD

CY2017

us-gaap

Amortization Of Intangible Assets

AmortizationOfIntangibleAssets

125778000

USD

CY2019

us-gaap

Share Based Compensation

ShareBasedCompensation

66417000

USD

CY2018

us-gaap

Share Based Compensation

ShareBasedCompensation

55776000

USD

CY2017

us-gaap

Share Based Compensation

ShareBasedCompensation

67798000

USD

CY2019

acgl

Increase Decrease In Loss And Loss Adjustment Expenses Net Of Recoverables

IncreaseDecreaseInLossAndLossAdjustmentExpensesNetOfRecoverables

489981000

USD

CY2019

acgl

Increase Decrease In Unearned Premiums Net Of Prepaid Reinsurance Premiums

IncreaseDecreaseInUnearnedPremiumsNetOfPrepaidReinsurancePremiums

252569000

USD

CY2017

us-gaap

Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities

ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities

907417000

USD

CY2018

acgl

Increase Decrease In Loss And Loss Adjustment Expenses Net Of Recoverables

IncreaseDecreaseInLossAndLossAdjustmentExpensesNetOfRecoverables

243734000

USD

CY2017

acgl

Increase Decrease In Loss And Loss Adjustment Expenses Net Of Recoverables

IncreaseDecreaseInLossAndLossAdjustmentExpensesNetOfRecoverables

614534000

USD

CY2018

acgl

Increase Decrease In Unearned Premiums Net Of Prepaid Reinsurance Premiums

IncreaseDecreaseInUnearnedPremiumsNetOfPrepaidReinsurancePremiums

114772000

USD

CY2017

acgl

Increase Decrease In Unearned Premiums Net Of Prepaid Reinsurance Premiums

IncreaseDecreaseInUnearnedPremiumsNetOfPrepaidReinsurancePremiums

116841000

USD

CY2019

us-gaap

Increase Decrease In Premiums Receivable

IncreaseDecreaseInPremiumsReceivable

237752000

USD

CY2018

us-gaap

Increase Decrease In Premiums Receivable

IncreaseDecreaseInPremiumsReceivable

211296000

USD

CY2017

us-gaap

Increase Decrease In Premiums Receivable

IncreaseDecreaseInPremiumsReceivable

31405000

USD

CY2019

us-gaap

Increase Decrease In Deferred Policy Acquisition Costs

IncreaseDecreaseInDeferredPolicyAcquisitionCosts

47260000

USD

CY2018

us-gaap

Increase Decrease In Deferred Policy Acquisition Costs

IncreaseDecreaseInDeferredPolicyAcquisitionCosts

37847000

USD

CY2017

us-gaap

Increase Decrease In Deferred Policy Acquisition Costs

IncreaseDecreaseInDeferredPolicyAcquisitionCosts

78378000

USD

CY2019

us-gaap

Increase Decrease In Reinsurance Payables

IncreaseDecreaseInReinsurancePayables

182132000

USD

CY2018

us-gaap

Increase Decrease In Reinsurance Payables

IncreaseDecreaseInReinsurancePayables

73438000

USD

CY2017

us-gaap

Increase Decrease In Reinsurance Payables

IncreaseDecreaseInReinsurancePayables

8529000

USD

CY2019

us-gaap

Increase Decrease In Other Operating Capital Net

IncreaseDecreaseInOtherOperatingCapitalNet

41052000

USD

CY2018

us-gaap

Increase Decrease In Other Operating Capital Net

IncreaseDecreaseInOtherOperatingCapitalNet

-60181000

USD

CY2017

us-gaap

Increase Decrease In Other Operating Capital Net

IncreaseDecreaseInOtherOperatingCapitalNet

111609000

USD

CY2019

us-gaap

Net Cash Provided By Used In Operating Activities

NetCashProvidedByUsedInOperatingActivities

2048459000

USD

CY2018

us-gaap

Net Cash Provided By Used In Operating Activities

NetCashProvidedByUsedInOperatingActivities

1559322000

USD

CY2017

us-gaap

Net Cash Provided By Used In Operating Activities

NetCashProvidedByUsedInOperatingActivities

1094878000

USD

CY2019

us-gaap

Payments To Acquire Available For Sale Securities Debt

PaymentsToAcquireAvailableForSaleSecuritiesDebt

30053777000

USD

CY2018

us-gaap

Payments To Acquire Available For Sale Securities Debt

PaymentsToAcquireAvailableForSaleSecuritiesDebt

33327660000

USD

CY2017

us-gaap

Payments To Acquire Available For Sale Securities Debt

PaymentsToAcquireAvailableForSaleSecuritiesDebt

36806913000

USD

CY2019

us-gaap

Payments To Acquire Trading Securities Heldforinvestment

PaymentsToAcquireTradingSecuritiesHeldforinvestment

811967000

USD

CY2018

us-gaap

Payments To Acquire Trading Securities Heldforinvestment

PaymentsToAcquireTradingSecuritiesHeldforinvestment

1001149000

USD

CY2017

us-gaap

Payments To Acquire Trading Securities Heldforinvestment

PaymentsToAcquireTradingSecuritiesHeldforinvestment

1021016000

USD

CY2019

us-gaap

Payments To Acquire Other Investments

PaymentsToAcquireOtherInvestments

1470545000

USD

CY2018

us-gaap

Payments To Acquire Other Investments

PaymentsToAcquireOtherInvestments

2014622000

USD

CY2017

us-gaap

Payments To Acquire Other Investments

PaymentsToAcquireOtherInvestments

2020624000

USD

CY2019

us-gaap

Proceeds From Sale Of Available For Sale Securities Debt

ProceedsFromSaleOfAvailableForSaleSecuritiesDebt

28595865000

USD

CY2018

us-gaap

Proceeds From Sale Of Available For Sale Securities Debt

ProceedsFromSaleOfAvailableForSaleSecuritiesDebt

31513271000

USD

CY2017

us-gaap

Proceeds From Sale Of Available For Sale Securities Debt

ProceedsFromSaleOfAvailableForSaleSecuritiesDebt

35686779000

USD

CY2019

us-gaap

Proceeds From Sale Of Trading Securities Heldforinvestment

ProceedsFromSaleOfTradingSecuritiesHeldforinvestment

429818000

USD

CY2018

us-gaap

Proceeds From Sale Of Trading Securities Heldforinvestment

ProceedsFromSaleOfTradingSecuritiesHeldforinvestment

1118445000

USD

CY2017

us-gaap

Proceeds From Sale Of Trading Securities Heldforinvestment

ProceedsFromSaleOfTradingSecuritiesHeldforinvestment

1056401000

USD

CY2019

us-gaap

Proceeds From Sale Of Other Investments

ProceedsFromSaleOfOtherInvestments

1209559000

USD

CY2018

us-gaap

Proceeds From Sale Of Other Investments

ProceedsFromSaleOfOtherInvestments

1561958000

USD

CY2017

us-gaap

Proceeds From Sale Of Other Investments

ProceedsFromSaleOfOtherInvestments

1528617000

USD

CY2019

us-gaap

Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities

ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities

643265000

USD

CY2018

us-gaap

Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities

ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities

892755000

USD

CY2019

us-gaap

Payments For Proceeds From Derivative Instrument Investing Activities

PaymentsForProceedsFromDerivativeInstrumentInvestingActivities

-59982000

USD

CY2018

us-gaap

Payments For Proceeds From Derivative Instrument Investing Activities

PaymentsForProceedsFromDerivativeInstrumentInvestingActivities

-44699000

USD

CY2017

us-gaap

Payments For Proceeds From Derivative Instrument Investing Activities

PaymentsForProceedsFromDerivativeInstrumentInvestingActivities

28563000

USD

CY2019

us-gaap

Payments For Proceeds From Short Term Investments

PaymentsForProceedsFromShortTermInvestments

-39833000

USD

CY2018

us-gaap

Payments For Proceeds From Short Term Investments

PaymentsForProceedsFromShortTermInvestments

-485473000

USD

CY2017

us-gaap

Payments For Proceeds From Short Term Investments

PaymentsForProceedsFromShortTermInvestments

734554000

USD

CY2019

us-gaap

Increase Decrease In Cash Collateral For Borrowed Securities

IncreaseDecreaseInCashCollateralForBorrowedSecurities

62193000

USD

CY2018

us-gaap

Increase Decrease In Cash Collateral For Borrowed Securities

IncreaseDecreaseInCashCollateralForBorrowedSecurities

-180883000

USD

CY2017

us-gaap

Increase Decrease In Cash Collateral For Borrowed Securities

IncreaseDecreaseInCashCollateralForBorrowedSecurities

-12540000

USD

CY2019

us-gaap

Payments To Acquire Productive Assets

PaymentsToAcquireProductiveAssets

37837000

USD

CY2018

us-gaap

Payments To Acquire Productive Assets

PaymentsToAcquireProductiveAssets

29809000

USD

CY2017

us-gaap

Payments To Acquire Productive Assets

PaymentsToAcquireProductiveAssets

22841000

USD

CY2019

us-gaap

Payments For Proceeds From Other Investing Activities

PaymentsForProceedsFromOtherInvestingActivities

348486000

USD

CY2018

us-gaap

Payments For Proceeds From Other Investing Activities

PaymentsForProceedsFromOtherInvestingActivities

-21736000

USD

CY2017

us-gaap

Payments For Proceeds From Other Investing Activities

PaymentsForProceedsFromOtherInvestingActivities

-90875000

USD

CY2019

us-gaap

Net Cash Provided By Used In Investing Activities

NetCashProvidedByUsedInInvestingActivities

-1806483000

USD

CY2018

us-gaap

Net Cash Provided By Used In Investing Activities

NetCashProvidedByUsedInInvestingActivities

-554020000

USD

CY2017

us-gaap

Net Cash Provided By Used In Investing Activities

NetCashProvidedByUsedInInvestingActivities

-1351882000

USD

CY2019

us-gaap

Proceeds From Issuance Of Preferred Stock And Preference Stock

ProceedsFromIssuanceOfPreferredStockAndPreferenceStock

0

USD

CY2018

us-gaap

Proceeds From Issuance Of Preferred Stock And Preference Stock

ProceedsFromIssuanceOfPreferredStockAndPreferenceStock

0

USD

CY2017

us-gaap

Proceeds From Issuance Of Preferred Stock And Preference Stock

ProceedsFromIssuanceOfPreferredStockAndPreferenceStock

319694000

USD

CY2019

us-gaap

Payments For Repurchase Of Preferred Stock And Preference Stock

PaymentsForRepurchaseOfPreferredStockAndPreferenceStock

0

USD

CY2018

us-gaap

Payments For Repurchase Of Preferred Stock And Preference Stock

PaymentsForRepurchaseOfPreferredStockAndPreferenceStock

92555000

USD

CY2017

us-gaap

Payments For Repurchase Of Preferred Stock And Preference Stock

PaymentsForRepurchaseOfPreferredStockAndPreferenceStock

230000000

USD

CY2019

us-gaap

Payments For Repurchase Of Common Stock

PaymentsForRepurchaseOfCommonStock

2871000

USD

CY2018

us-gaap

Payments For Repurchase Of Common Stock

PaymentsForRepurchaseOfCommonStock

282762000

USD

CY2017

us-gaap

Payments For Repurchase Of Common Stock

PaymentsForRepurchaseOfCommonStock

0

USD

CY2019

us-gaap

Proceeds From Repurchase Of Equity

ProceedsFromRepurchaseOfEquity

6203000

USD

CY2018

us-gaap

Proceeds From Repurchase Of Equity

ProceedsFromRepurchaseOfEquity

-7608000

USD

CY2017

us-gaap

Proceeds From Repurchase Of Equity

ProceedsFromRepurchaseOfEquity

-21048000

USD

CY2019

us-gaap

Proceeds From Other Debt

ProceedsFromOtherDebt

200083000

USD

CY2018

us-gaap

Proceeds From Other Debt

ProceedsFromOtherDebt

218259000

USD

CY2017

us-gaap

Proceeds From Other Debt

ProceedsFromOtherDebt

253415000

USD

CY2019

us-gaap

Repayments Of Other Debt

RepaymentsOfOtherDebt

49182000

USD

CY2018

us-gaap

Repayments Of Other Debt

RepaymentsOfOtherDebt

576401000

USD

CY2017

us-gaap

Repayments Of Other Debt

RepaymentsOfOtherDebt

197000000

USD

CY2019

us-gaap

Increase Decrease In Cash Collateral For Loaned Securities

IncreaseDecreaseInCashCollateralForLoanedSecurities

62193000

USD

CY2018

us-gaap

Increase Decrease In Cash Collateral For Loaned Securities

IncreaseDecreaseInCashCollateralForLoanedSecurities

-180883000

USD

CY2017

us-gaap

Increase Decrease In Cash Collateral For Loaned Securities

IncreaseDecreaseInCashCollateralForLoanedSecurities

-12540000

USD

CY2019

us-gaap

Proceeds From Payments To Minority Shareholders

ProceedsFromPaymentsToMinorityShareholders

-75056000

USD

CY2018

us-gaap

Proceeds From Payments To Minority Shareholders

ProceedsFromPaymentsToMinorityShareholders

0

USD

CY2017

us-gaap

Proceeds From Payments To Minority Shareholders

ProceedsFromPaymentsToMinorityShareholders

0

USD

CY2019

us-gaap

Proceeds From Repurchase Of Redeemable Preferred Stock

ProceedsFromRepurchaseOfRedeemablePreferredStock

-161882000

USD

CY2018

us-gaap

Proceeds From Repurchase Of Redeemable Preferred Stock

ProceedsFromRepurchaseOfRedeemablePreferredStock

0

USD

CY2017

us-gaap

Proceeds From Repurchase Of Redeemable Preferred Stock

ProceedsFromRepurchaseOfRedeemablePreferredStock

0

USD

CY2019

us-gaap

Payments Of Dividends Minority Interest

PaymentsOfDividendsMinorityInterest

12515000

USD

CY2018

us-gaap

Payments Of Dividends Minority Interest

PaymentsOfDividendsMinorityInterest

17989000

USD

CY2017

us-gaap

Payments Of Dividends Minority Interest

PaymentsOfDividendsMinorityInterest

17989000

USD

CY2019

us-gaap

Proceeds From Payments For Other Financing Activities

ProceedsFromPaymentsForOtherFinancingActivities

-6023000

USD

CY2018

us-gaap

Proceeds From Payments For Other Financing Activities

ProceedsFromPaymentsForOtherFinancingActivities

-7226000

USD

CY2017

us-gaap

Proceeds From Payments For Other Financing Activities

ProceedsFromPaymentsForOtherFinancingActivities

-51896000

USD

CY2019

us-gaap

Payments Of Dividends Preferred Stock And Preference Stock

PaymentsOfDividendsPreferredStockAndPreferenceStock

41612000

USD

CY2018

us-gaap

Payments Of Dividends Preferred Stock And Preference Stock

PaymentsOfDividendsPreferredStockAndPreferenceStock

41645000

USD

CY2017

us-gaap

Payments Of Dividends Preferred Stock And Preference Stock

PaymentsOfDividendsPreferredStockAndPreferenceStock

46041000

USD

CY2019

us-gaap

Net Cash Provided By Used In Financing Activities

NetCashProvidedByUsedInFinancingActivities

-80662000

USD

CY2018

us-gaap

Net Cash Provided By Used In Financing Activities

NetCashProvidedByUsedInFinancingActivities

-988810000

USD

CY2017

us-gaap

Net Cash Provided By Used In Financing Activities

NetCashProvidedByUsedInFinancingActivities

-3405000

USD

CY2019

us-gaap

Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents

EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

17741000

USD

CY2018

us-gaap

Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents

EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

-19133000

USD

CY2017

us-gaap

Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents

EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

18124000

USD

CY2019

us-gaap

Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect

CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect

179055000

USD

CY2018

us-gaap

Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect

CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect

-2641000

USD

CY2017

us-gaap

Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect

CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect

-242285000

USD

CY2018Q4

us-gaap

Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents

CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

724643000

USD

CY2017Q4

us-gaap

Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents

CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

727284000

USD

CY2016Q4

us-gaap

Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents

CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

969569000

USD

CY2019Q4

us-gaap

Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents

CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

903698000

USD

CY2018Q4

us-gaap

Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents

CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

724643000

USD

CY2017Q4

us-gaap

Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents

CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

727284000

USD

CY2019

us-gaap

Income Taxes Paid Net

IncomeTaxesPaidNet

109463000

USD

CY2018

us-gaap

Income Taxes Paid Net

IncomeTaxesPaidNet

-980000

USD

CY2017

us-gaap

Income Taxes Paid Net

IncomeTaxesPaidNet

51781000

USD

CY2019

us-gaap

Interest Paid Net

InterestPaidNet

126945000

USD

CY2018

us-gaap

Interest Paid Net

InterestPaidNet

119775000

USD

CY2017

us-gaap

Interest Paid Net

InterestPaidNet

117374000

USD

CY2019

us-gaap

Use Of Estimates

UseOfEstimates

<div style="line-height:120%;padding-bottom:13px;text-align:justify;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ materially from those estimates and assumptions. The Company’s principal estimates include:</span></div><table cellpadding="0" cellspacing="0" style="padding-bottom:4px;font-family:Times New Roman; font-size:10pt;"><tr><td style="width:24px;"/><td/></tr><tr><td style="vertical-align:top"><div style="line-height:120%;font-size:10pt;padding-left:0px;"><span style="font-family:inherit;font-size:10pt;">•</span></div></td><td style="vertical-align:top;"><div style="line-height:120%;text-align:justify;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">The reserve for losses and loss adjustment expenses;</span></div></td></tr></table><table cellpadding="0" cellspacing="0" style="padding-bottom:4px;font-family:Times New Roman; font-size:10pt;"><tr><td style="width:24px;"/><td/></tr><tr><td style="vertical-align:top"><div style="line-height:120%;font-size:10pt;padding-left:0px;"><span style="font-family:inherit;font-size:10pt;">•</span></div></td><td style="vertical-align:top;"><div style="line-height:120%;text-align:justify;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">Reinsurance recoverable on unpaid and paid losses and loss adjustment expenses, including the provision for uncollectible amounts;</span></div></td></tr></table><table cellpadding="0" cellspacing="0" style="padding-bottom:4px;font-family:Times New Roman; font-size:10pt;"><tr><td style="width:24px;"/><td/></tr><tr><td style="vertical-align:top"><div style="line-height:120%;font-size:10pt;padding-left:0px;"><span style="font-family:inherit;font-size:10pt;">•</span></div></td><td style="vertical-align:top;"><div style="line-height:120%;text-align:justify;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">Estimates of written and earned premiums;</span></div></td></tr></table><table cellpadding="0" cellspacing="0" style="padding-bottom:4px;font-family:Times New Roman; font-size:10pt;"><tr><td style="width:24px;"/><td/></tr><tr><td style="vertical-align:top"><div style="line-height:120%;font-size:10pt;padding-left:0px;"><span style="font-family:inherit;font-size:10pt;">•</span></div></td><td style="vertical-align:top;"><div style="line-height:120%;text-align:justify;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">The valuation of the investment portfolio and assessment of other-than-temporary impairments (“OTTI”);</span></div></td></tr></table><table cellpadding="0" cellspacing="0" style="padding-bottom:4px;font-family:Times New Roman; font-size:10pt;"><tr><td style="width:24px;"/><td/></tr><tr><td style="vertical-align:top"><div style="line-height:120%;font-size:10pt;padding-left:0px;"><span style="font-family:inherit;font-size:10pt;">•</span></div></td><td style="vertical-align:top;"><div style="line-height:120%;text-align:justify;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">The valuation of purchased intangible assets;</span></div></td></tr></table><table cellpadding="0" cellspacing="0" style="padding-bottom:4px;font-family:Times New Roman; font-size:10pt;"><tr><td style="width:24px;"/><td/></tr><tr><td style="vertical-align:top"><div style="line-height:120%;font-size:10pt;padding-left:0px;"><span style="font-family:inherit;font-size:10pt;">•</span></div></td><td style="vertical-align:top;"><div style="line-height:120%;text-align:justify;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">The assessment of goodwill and intangible assets for impairment; and</span></div></td></tr></table><div style="line-height:120%;font-size:10pt;padding-left:0px;"><span style="font-family:inherit;font-size:10pt;">•</span></div><div style="line-height:120%;text-align:justify;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">the valuation of deferred tax assets.</span></div>

CY2018

us-gaap

Stockholders Equity Note Stock Split Conversion Ratio1

StockholdersEquityNoteStockSplitConversionRatio1

3

CY2019

acgl

Premium Revenue Recognition Period

PremiumRevenueRecognitionPeriod

P12M

CY2019

acgl

Securities Lending Rate Of Collateral Required

SecuritiesLendingRateOfCollateralRequired

1.02

CY2019

us-gaap

Derivatives Methods Of Accounting Nonhedging Derivatives

DerivativesMethodsOfAccountingNonhedgingDerivatives

<div style="line-height:120%;padding-bottom:13px;text-align:justify;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">The Company recognizes all derivative instruments, including embedded derivative instruments, at fair value in its consolidated balance sheets. The Company employs the use of derivative instruments within its operations to mitigate risks arising from assets and liabilities held in foreign currencies as well as part of its overall investment strategy. For such instruments, changes in assets and liabilities measured at fair value are recorded as “Net realized gains” in the consolidated statements of income. In addition, the Company’s derivative instruments include amounts related to underwriting activities where an insurance or reinsurance contract meets the accounting definition of a derivative instrument. For such contracts, changes in fair value are reflected in “Other underwriting income” in the consolidated statements of income as the underlying contract originates from the Company’s underwriting operations. For the periods ended </span><span style="font-family:inherit;font-size:10pt;">2019</span><span style="font-family:inherit;font-size:10pt;">, </span><span style="font-family:inherit;font-size:10pt;">2018</span><span style="font-family:inherit;font-size:10pt;">, and </span><span style="font-family:inherit;font-size:10pt;">2017</span><span style="font-family:inherit;font-size:10pt;">, the Company did not designate any derivative instruments as hedges under the relevant accounting guidance. See </span><a href="#s9FF8819A3C77571DA77AADD75CEF9C0F" style="font-family:inherit;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">note 10, “Derivative Instruments”</span></a><span style="font-family:inherit;font-size:10pt;"> for additional information.</span></div>

CY2019

us-gaap

Premiums Written Gross

PremiumsWrittenGross

8138960000

USD

CY2019

us-gaap

Ceded Premiums Written

CededPremiumsWritten

2099893000

USD

CY2019

us-gaap

Premiums Written Net

PremiumsWrittenNet

6039067000

USD

CY2019

us-gaap

Increase Decrease In Unearned Premiums Net

IncreaseDecreaseInUnearnedPremiumsNet

-252569000

USD

CY2019

us-gaap

Premiums Earned Net

PremiumsEarnedNet

5786498000

USD

CY2019

us-gaap

Insurance Commissions And Fees

InsuranceCommissionsAndFees

24861000

USD

CY2019

us-gaap

Policyholder Benefits And Claims Incurred Net

PolicyholderBenefitsAndClaimsIncurredNet

3133452000

USD

CY2019

us-gaap

Deferred Policy Acquisition Cost Amortization Expense

DeferredPolicyAcquisitionCostAmortizationExpense

840945000

USD

CY2019

us-gaap

Other Expenses

OtherExpenses

800997000

USD

CY2019

acgl

Underwriting Income Loss Segment

UnderwritingIncomeLossSegment

1035965000

USD

CY2019

us-gaap

Investment Income Net

InvestmentIncomeNet

627738000

USD

CY2019

us-gaap

Marketable Securities Gain Loss Excluding Other Than Temporary Impairments

MarketableSecuritiesGainLossExcludingOtherThanTemporaryImpairments

366363000

USD

CY2019

us-gaap

Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net

OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNet

3165000

USD

CY2019

us-gaap

Income Loss From Equity Method Investments

IncomeLossFromEquityMethodInvestments

123672000

USD

CY2019

us-gaap

Other Operating Income Expense Net

OtherOperatingIncomeExpenseNet

2233000

USD

CY2019

acgl

Segment Other Cost And Expense Operating

SegmentOtherCostAndExpenseOperating

65667000

USD

CY2019

us-gaap

Business Combination Acquisition Related Costs

BusinessCombinationAcquisitionRelatedCosts

14444000

USD

CY2019

us-gaap

Amortization Of Intangible Assets

AmortizationOfIntangibleAssets

82104000

USD

CY2019

us-gaap

Interest Expense

InterestExpense

120872000

USD

CY2019

us-gaap

Foreign Currency Transaction Gain Loss Before Tax

ForeignCurrencyTransactionGainLossBeforeTax

-20609000

USD

CY2019

us-gaap

Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest

IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest

1849110000

USD

CY2019

us-gaap

Income Tax Expense Benefit

IncomeTaxExpenseBenefit

155810000

USD

CY2019

us-gaap

Profit Loss

ProfitLoss

1693300000

USD

CY2019

us-gaap

Net Income Loss Attributable To Redeemable Noncontrolling Interest

NetIncomeLossAttributableToRedeemableNoncontrollingInterest

16909000

USD

CY2019

us-gaap

Net Income Loss Attributable To Nonredeemable Noncontrolling Interest

NetIncomeLossAttributableToNonredeemableNoncontrollingInterest

40072000

USD

CY2019

us-gaap

Net Income Loss

NetIncomeLoss

1636319000

USD

CY2019

us-gaap

Preferred Stock Dividends Income Statement Impact

PreferredStockDividendsIncomeStatementImpact

41612000

USD

CY2019

us-gaap

Preferred Stock Redemption Premium

PreferredStockRedemptionPremium

0

USD

CY2019

us-gaap

Net Income Loss Available To Common Stockholders Basic

NetIncomeLossAvailableToCommonStockholdersBasic

1594707000

USD

CY2019

us-gaap

Loss Ratio

LossRatio

0.542

CY2019

acgl

Acquisition Expense Ratio Percentage

AcquisitionExpenseRatioPercentage

0.145

CY2019

acgl

Other Operating Expense Ratio Percentage

OtherOperatingExpenseRatioPercentage

0.138

CY2019

acgl

Combined Ratio Percentage

CombinedRatioPercentage

0.825

CY2019Q4

us-gaap

Intangible Assets Net Including Goodwill

IntangibleAssetsNetIncludingGoodwill

738083000

USD

CY2019Q4

acgl

Investable Assets

InvestableAssets

24990265000

USD

CY2019Q4

us-gaap

Assets

37885361000

USD

CY2019Q4

us-gaap

Liabilities

25569809000

USD

CY2018

us-gaap

Premiums Written Gross

PremiumsWrittenGross

6961004000

USD

CY2018

us-gaap

Ceded Premiums Written

CededPremiumsWritten

1614257000

USD

CY2018

us-gaap

Premiums Written Net

PremiumsWrittenNet

5346747000

USD

CY2018

us-gaap

Increase Decrease In Unearned Premiums Net

IncreaseDecreaseInUnearnedPremiumsNet

-114772000

USD

CY2018

us-gaap

Premiums Earned Net

PremiumsEarnedNet

5231975000

USD

CY2018

us-gaap

Insurance Commissions And Fees

InsuranceCommissionsAndFees

15073000

USD

CY2018

us-gaap

Policyholder Benefits And Claims Incurred Net

PolicyholderBenefitsAndClaimsIncurredNet

2890106000

USD

CY2018

us-gaap

Deferred Policy Acquisition Cost Amortization Expense

DeferredPolicyAcquisitionCostAmortizationExpense

805135000

USD

CY2018

us-gaap

Other Expenses

OtherExpenses

677809000

USD

CY2018

acgl

Underwriting Income Loss Segment

UnderwritingIncomeLossSegment

873998000

USD

CY2018

us-gaap

Investment Income Net

InvestmentIncomeNet

563633000

USD

CY2018

us-gaap

Marketable Securities Gain Loss Excluding Other Than Temporary Impairments

MarketableSecuritiesGainLossExcludingOtherThanTemporaryImpairments

-405344000

USD

CY2018

us-gaap

Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net

OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNet

2829000

USD

CY2018

us-gaap

Income Loss From Equity Method Investments

IncomeLossFromEquityMethodInvestments

45641000

USD

CY2018

us-gaap

Other Operating Income Expense Net

OtherOperatingIncomeExpenseNet

2419000

USD

CY2018

acgl

Segment Other Cost And Expense Operating

SegmentOtherCostAndExpenseOperating

58608000

USD

CY2018

us-gaap

Business Combination Acquisition Related Costs

BusinessCombinationAcquisitionRelatedCosts

20386000

USD

CY2018

us-gaap

Amortization Of Intangible Assets

AmortizationOfIntangibleAssets

105670000

USD

CY2018

us-gaap

Interest Expense

InterestExpense

120484000

USD

CY2018

us-gaap

Foreign Currency Transaction Gain Loss Before Tax

ForeignCurrencyTransactionGainLossBeforeTax

69402000

USD

CY2018

us-gaap

Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest

IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest

841772000

USD

CY2018

us-gaap

Income Tax Expense Benefit

IncomeTaxExpenseBenefit

113951000

USD

CY2018

us-gaap

Profit Loss

ProfitLoss

727821000

USD

CY2018

us-gaap

Net Income Loss Attributable To Redeemable Noncontrolling Interest

NetIncomeLossAttributableToRedeemableNoncontrollingInterest

18357000

USD

CY2018

us-gaap

Net Income Loss Attributable To Nonredeemable Noncontrolling Interest

NetIncomeLossAttributableToNonredeemableNoncontrollingInterest

-48507000

USD

CY2018

us-gaap

Net Income Loss

NetIncomeLoss

757971000

USD

CY2018

us-gaap

Preferred Stock Dividends Income Statement Impact

PreferredStockDividendsIncomeStatementImpact

41645000

USD

CY2018

us-gaap

Preferred Stock Redemption Premium

PreferredStockRedemptionPremium

2710000

USD

CY2018

us-gaap

Net Income Loss Available To Common Stockholders Basic

NetIncomeLossAvailableToCommonStockholdersBasic

713616000

USD

CY2018

us-gaap

Loss Ratio

LossRatio

0.552

CY2018

acgl

Acquisition Expense Ratio Percentage

AcquisitionExpenseRatioPercentage

0.154

CY2018

acgl

Other Operating Expense Ratio Percentage

OtherOperatingExpenseRatioPercentage

0.130

CY2018

acgl

Combined Ratio Percentage

CombinedRatioPercentage

0.836

CY2018Q4

us-gaap

Intangible Assets Net Including Goodwill

IntangibleAssetsNetIncludingGoodwill

634920000

USD

CY2018Q4

acgl

Investable Assets

InvestableAssets

22324524000

USD

CY2018Q4

us-gaap

Assets

32218329000

USD

CY2018Q4

us-gaap

Liabilities

21780650000

USD

CY2017

us-gaap

Premiums Written Gross

PremiumsWrittenGross

6368425000

USD

CY2017

us-gaap

Ceded Premiums Written

CededPremiumsWritten

1407052000

USD

CY2017

us-gaap

Premiums Written Net

PremiumsWrittenNet

4961373000

USD

CY2017

us-gaap

Increase Decrease In Unearned Premiums Net

IncreaseDecreaseInUnearnedPremiumsNet

-116841000

USD

CY2017

us-gaap

Premiums Earned Net

PremiumsEarnedNet

4844532000

USD

CY2017

us-gaap

Insurance Commissions And Fees

InsuranceCommissionsAndFees

30253000

USD

CY2017

us-gaap

Policyholder Benefits And Claims Incurred Net

PolicyholderBenefitsAndClaimsIncurredNet

2967446000

USD

CY2017

us-gaap

Deferred Policy Acquisition Cost Amortization Expense

DeferredPolicyAcquisitionCostAmortizationExpense

775458000

USD

CY2017

us-gaap

Other Expenses

OtherExpenses

684451000

USD

CY2017

acgl

Underwriting Income Loss Segment

UnderwritingIncomeLossSegment

447430000

USD

CY2017

us-gaap

Investment Income Net

InvestmentIncomeNet

470872000

USD

CY2017

us-gaap

Marketable Securities Gain Loss Excluding Other Than Temporary Impairments

MarketableSecuritiesGainLossExcludingOtherThanTemporaryImpairments

149141000

USD

CY2017

us-gaap

Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net

OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNet

7138000

USD

CY2017

us-gaap

Income Loss From Equity Method Investments

IncomeLossFromEquityMethodInvestments

142286000

USD

CY2017

us-gaap

Other Operating Income Expense Net

OtherOperatingIncomeExpenseNet

-2571000

USD

CY2017

acgl

Segment Other Cost And Expense Operating

SegmentOtherCostAndExpenseOperating

61602000

USD

CY2017

us-gaap

Business Combination Acquisition Related Costs

BusinessCombinationAcquisitionRelatedCosts

22150000

USD

CY2017

us-gaap

Amortization Of Intangible Assets

AmortizationOfIntangibleAssets

125778000

USD

CY2017

us-gaap

Interest Expense

InterestExpense

117431000

USD

CY2017

us-gaap

Foreign Currency Transaction Gain Loss Before Tax

ForeignCurrencyTransactionGainLossBeforeTax

-115782000

USD

CY2017

us-gaap

Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest

IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest

757277000

USD

CY2017

us-gaap

Income Tax Expense Benefit

IncomeTaxExpenseBenefit

127568000

USD

CY2017

us-gaap

Profit Loss

ProfitLoss

629709000

USD

CY2017

us-gaap

Net Income Loss Attributable To Redeemable Noncontrolling Interest

NetIncomeLossAttributableToRedeemableNoncontrollingInterest

18344000

USD

CY2017

us-gaap

Net Income Loss Attributable To Nonredeemable Noncontrolling Interest

NetIncomeLossAttributableToNonredeemableNoncontrollingInterest

-7913000

USD

CY2017

us-gaap

Net Income Loss

NetIncomeLoss

619278000

USD

CY2017

us-gaap

Preferred Stock Dividends Income Statement Impact

PreferredStockDividendsIncomeStatementImpact

46041000

USD

CY2017

us-gaap

Preferred Stock Redemption Premium

PreferredStockRedemptionPremium

6735000

USD

CY2017

us-gaap

Net Income Loss Available To Common Stockholders Basic

NetIncomeLossAvailableToCommonStockholdersBasic

566502000

USD

CY2017

us-gaap

Loss Ratio

LossRatio

0.613

CY2017

acgl

Acquisition Expense Ratio Percentage

AcquisitionExpenseRatioPercentage

0.160

CY2017

acgl

Other Operating Expense Ratio Percentage

OtherOperatingExpenseRatioPercentage

0.141

CY2017

acgl

Combined Ratio Percentage

CombinedRatioPercentage

0.914

CY2017Q4

us-gaap

Intangible Assets Net Including Goodwill

IntangibleAssetsNetIncludingGoodwill

652611000

USD

CY2017Q4

acgl

Investable Assets

InvestableAssets

22156488000

USD

CY2017Q4

us-gaap

Assets

32051658000

USD

CY2017Q4

us-gaap

Liabilities

21805723000

USD

CY2019

us-gaap

Schedule Of Liability For Unpaid Claims And Claims Adjustment Expense

ScheduleOfLiabilityForUnpaidClaimsAndClaimsAdjustmentExpense

<div style="line-height:120%;"><hr/></div><div style="line-height:120%;font-size:11pt;"><span style="font-family:inherit;font-size:11pt;"><br/></span></div><div style="line-height:120%;padding-bottom:13px;text-align:justify;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">The following table represents an analysis of losses and loss adjustment expenses and a reconciliation of the beginning and ending reserve for losses and loss adjustment expenses:</span></div><div style="line-height:120%;padding-bottom:13px;text-align:justify;text-indent:0px;font-size:10pt;"><div style="padding-left:0px;text-indent:0px;line-height:normal;padding-top:10px;"><table cellpadding="0" cellspacing="0" style="font-family:Times New Roman;font-size:10pt;width:100%;border-collapse:collapse;text-align:left;"><tr><td colspan="12"/></tr><tr><td style="width:62%;"/><td style="width:1%;"/><td style="width:10%;"/><td style="width:1%;"/><td style="width:1%;"/><td style="width:1%;"/><td style="width:10%;"/><td style="width:1%;"/><td style="width:1%;"/><td style="width:1%;"/><td style="width:10%;"/><td style="width:1%;"/></tr><tr><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="11" style="vertical-align:bottom;border-bottom:1px solid #000000;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:center;padding-left:5px;font-size:7.5pt;"><span style="font-family:inherit;font-size:7.5pt;font-weight:bold;">Year Ended December 31,</span></div></td></tr><tr><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="3" style="vertical-align:bottom;border-bottom:1px solid #000000;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:5px;border-top:1px solid #000000;"><div style="text-align:center;padding-left:5px;font-size:7.5pt;"><span style="font-family:inherit;font-size:7.5pt;font-weight:bold;">2019</span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;border-top:1px solid #000000;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="3" style="vertical-align:bottom;border-bottom:1px solid #000000;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:5px;border-top:1px solid #000000;"><div style="text-align:center;padding-left:5px;font-size:7.5pt;"><span style="font-family:inherit;font-size:7.5pt;font-weight:bold;">2018</span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;border-top:1px solid #000000;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="3" style="vertical-align:bottom;border-bottom:1px solid #000000;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:5px;border-top:1px solid #000000;"><div style="text-align:center;padding-left:5px;font-size:7.5pt;"><span style="font-family:inherit;font-size:7.5pt;font-weight:bold;">2017</span></div></td></tr><tr><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="text-align:left;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;">Reserve for losses and loss adjustment expenses at beginning of year</span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;background-color:#cceeff;border-top:1px solid #000000;"><div style="text-align:left;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;">$</span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-top:2px;padding-bottom:2px;border-top:1px solid #000000;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>11,853,297</span></span></div></td><td style="vertical-align:bottom;background-color:#cceeff;border-top:1px solid #000000;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;background-color:#cceeff;border-top:1px solid #000000;"><div style="text-align:left;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;">$</span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-top:2px;padding-bottom:2px;border-top:1px solid #000000;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>11,383,792</span></span></div></td><td style="vertical-align:bottom;background-color:#cceeff;border-top:1px solid #000000;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;background-color:#cceeff;"><div style="text-align:left;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;">$</span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>10,200,960</span></span></div></td><td style="vertical-align:bottom;background-color:#cceeff;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td></tr><tr><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="text-align:left;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;">Unpaid losses and loss adjustment expenses recoverable</span></div></td><td colspan="2" style="vertical-align:bottom;border-bottom:1px solid #000000;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>2,814,291</span></span></div></td><td style="vertical-align:bottom;border-bottom:1px solid #000000;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;border-bottom:1px solid #000000;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>2,464,910</span></span></div></td><td style="vertical-align:bottom;border-bottom:1px solid #000000;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;border-bottom:1px solid #000000;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>2,083,575</span></span></div></td><td style="vertical-align:bottom;border-bottom:1px solid #000000;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td></tr><tr><td style="vertical-align:bottom;background-color:#cceeff;padding-left:12px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="text-align:left;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;">Net reserve for losses and loss adjustment expenses at beginning of year</span></div></td><td colspan="2" style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>9,039,006</span></span></div></td><td style="vertical-align:bottom;background-color:#cceeff;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>8,918,882</span></span></div></td><td style="vertical-align:bottom;background-color:#cceeff;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>8,117,385</span></span></div></td><td style="vertical-align:bottom;background-color:#cceeff;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td></tr><tr><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;height:14px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="3" style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;height:14px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;height:14px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="3" style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;height:14px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;height:14px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="3" style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;height:14px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td></tr><tr><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="text-align:left;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;">Net incurred losses and loss adjustment expenses relating to losses occurring in:</span></div></td><td colspan="3" style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="3" style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="3" style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td></tr><tr><td style="vertical-align:bottom;padding-left:12px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="text-align:left;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;">Current year</span></div></td><td colspan="2" style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>3,297,037</span></span></div></td><td style="vertical-align:bottom;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>3,162,818</span></span></div></td><td style="vertical-align:bottom;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>3,205,428</span></span></div></td><td style="vertical-align:bottom;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td></tr><tr><td style="vertical-align:bottom;background-color:#cceeff;padding-left:12px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="text-align:left;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;">Prior years</span></div></td><td colspan="2" style="vertical-align:bottom;border-bottom:1px solid #000000;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>(163,585</span></span></div></td><td style="vertical-align:bottom;border-bottom:1px solid #000000;background-color:#cceeff;padding-right:5px;padding-top:2px;padding-bottom:2px;"><div style="text-align:left;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;">)</span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;border-bottom:1px solid #000000;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>(272,712</span></span></div></td><td style="vertical-align:bottom;border-bottom:1px solid #000000;background-color:#cceeff;padding-right:5px;padding-top:2px;padding-bottom:2px;"><div style="text-align:left;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;">)</span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;border-bottom:1px solid #000000;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>(237,982</span></span></div></td><td style="vertical-align:bottom;border-bottom:1px solid #000000;background-color:#cceeff;padding-right:5px;padding-top:2px;padding-bottom:2px;"><div style="text-align:left;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;">)</span></div></td></tr><tr><td style="vertical-align:bottom;padding-left:20px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="text-align:left;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;">Total net incurred losses and loss adjustment expenses</span></div></td><td colspan="2" style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>3,133,452</span></span></div></td><td style="vertical-align:bottom;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>2,890,106</span></span></div></td><td style="vertical-align:bottom;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>2,967,446</span></span></div></td><td style="vertical-align:bottom;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td></tr><tr><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;height:14px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="3" style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;height:14px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;height:14px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="3" style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;height:14px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;height:14px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="3" style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;height:14px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td></tr><tr><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="text-align:left;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;">Net losses and loss adjustment expense reserves of acquired business (1)</span></div></td><td colspan="2" style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>209,486</span></span></div></td><td style="vertical-align:bottom;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>—</span></span></div></td><td style="vertical-align:bottom;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>—</span></span></div></td><td style="vertical-align:bottom;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td></tr><tr><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;height:14px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="3" style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;height:14px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;height:14px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="3" style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;height:14px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;height:14px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="3" style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;height:14px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td></tr><tr><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="text-align:left;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;">Retroactive reinsurance transactions (2)</span></div></td><td colspan="2" style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>(225,500</span></span></div></td><td style="vertical-align:bottom;padding-right:5px;padding-top:2px;padding-bottom:2px;"><div style="text-align:left;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;">)</span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>(420,404</span></span></div></td><td style="vertical-align:bottom;padding-right:5px;padding-top:2px;padding-bottom:2px;"><div style="text-align:left;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;">)</span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>—</span></span></div></td><td style="vertical-align:bottom;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td></tr><tr><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;height:14px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="3" style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;height:14px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;height:14px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="3" style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;height:14px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;height:14px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="3" style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;height:14px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td></tr><tr><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="text-align:left;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;">Foreign exchange (gains) losses</span></div></td><td colspan="2" style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>36,003</span></span></div></td><td style="vertical-align:bottom;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>(143,414</span></span></div></td><td style="vertical-align:bottom;padding-right:5px;padding-top:2px;padding-bottom:2px;"><div style="text-align:left;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;">)</span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>186,963</span></span></div></td><td style="vertical-align:bottom;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td></tr><tr><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;height:14px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="3" style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;height:14px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;height:14px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="3" style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;height:14px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;height:14px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="3" style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;height:14px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td></tr><tr><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="text-align:left;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;">Net paid losses and loss adjustment expenses relating to losses occurring in:</span></div></td><td colspan="3" style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="3" style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="3" style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td></tr><tr><td style="vertical-align:bottom;background-color:#cceeff;padding-left:12px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="text-align:left;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;">Current year</span></div></td><td colspan="2" style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>(621,202</span></span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-right:5px;padding-top:2px;padding-bottom:2px;"><div style="text-align:left;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;">)</span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>(524,048</span></span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-right:5px;padding-top:2px;padding-bottom:2px;"><div style="text-align:left;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;">)</span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>(505,424</span></span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-right:5px;padding-top:2px;padding-bottom:2px;"><div style="text-align:left;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;">)</span></div></td></tr><tr><td style="vertical-align:bottom;padding-left:12px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="text-align:left;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;">Prior years</span></div></td><td colspan="2" style="vertical-align:bottom;border-bottom:1px solid #000000;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>(1,762,053</span></span></div></td><td style="vertical-align:bottom;border-bottom:1px solid #000000;padding-right:5px;padding-top:2px;padding-bottom:2px;"><div style="text-align:left;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;">)</span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;border-bottom:1px solid #000000;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>(1,682,116</span></span></div></td><td style="vertical-align:bottom;border-bottom:1px solid #000000;padding-right:5px;padding-top:2px;padding-bottom:2px;"><div style="text-align:left;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;">)</span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;border-bottom:1px solid #000000;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>(1,847,488</span></span></div></td><td style="vertical-align:bottom;border-bottom:1px solid #000000;padding-right:5px;padding-top:2px;padding-bottom:2px;"><div style="text-align:left;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;">)</span></div></td></tr><tr><td style="vertical-align:bottom;background-color:#cceeff;padding-left:20px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="text-align:left;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;">Total net paid losses and loss adjustment expenses</span></div></td><td colspan="2" style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>(2,383,255</span></span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-right:5px;padding-top:2px;padding-bottom:2px;"><div style="text-align:left;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;">)</span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>(2,206,164</span></span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-right:5px;padding-top:2px;padding-bottom:2px;"><div style="text-align:left;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;">)</span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>(2,352,912</span></span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-right:5px;padding-top:2px;padding-bottom:2px;"><div style="text-align:left;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;">)</span></div></td></tr><tr><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;height:14px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="3" style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;height:14px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;height:14px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="3" style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;height:14px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;height:14px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="3" style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;height:14px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td></tr><tr><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="text-align:left;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;">Net reserve for losses and loss adjustment expenses at end of year</span></div></td><td colspan="2" style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>9,809,192</span></span></div></td><td style="vertical-align:bottom;background-color:#cceeff;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>9,039,006</span></span></div></td><td style="vertical-align:bottom;background-color:#cceeff;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>8,918,882</span></span></div></td><td style="vertical-align:bottom;background-color:#cceeff;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td></tr><tr><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="text-align:left;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;">Unpaid losses and loss adjustment expenses recoverable</span></div></td><td colspan="2" style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>4,082,650</span></span></div></td><td style="vertical-align:bottom;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>2,814,291</span></span></div></td><td style="vertical-align:bottom;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>2,464,910</span></span></div></td><td style="vertical-align:bottom;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td></tr><tr><td style="vertical-align:bottom;background-color:#cceeff;padding-left:12px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="text-align:left;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;">Reserve for losses and loss adjustment expenses at end of year</span></div></td><td style="vertical-align:bottom;border-bottom:2px solid #000000;padding-left:2px;padding-top:2px;padding-bottom:2px;background-color:#cceeff;border-top:1px solid #000000;"><div style="text-align:left;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;">$</span></div></td><td style="vertical-align:bottom;border-bottom:2px solid #000000;background-color:#cceeff;padding-top:2px;padding-bottom:2px;border-top:1px solid #000000;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>13,891,842</span></span></div></td><td style="vertical-align:bottom;border-bottom:2px solid #000000;background-color:#cceeff;border-top:1px solid #000000;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td style="vertical-align:bottom;border-bottom:2px solid #000000;padding-left:2px;padding-top:2px;padding-bottom:2px;background-color:#cceeff;border-top:1px solid #000000;"><div style="text-align:left;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;">$</span></div></td><td style="vertical-align:bottom;border-bottom:2px solid #000000;background-color:#cceeff;padding-top:2px;padding-bottom:2px;border-top:1px solid #000000;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>11,853,297</span></span></div></td><td style="vertical-align:bottom;border-bottom:2px solid #000000;background-color:#cceeff;border-top:1px solid #000000;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td style="vertical-align:bottom;border-bottom:2px solid #000000;padding-left:2px;padding-top:2px;padding-bottom:2px;background-color:#cceeff;border-top:1px solid #000000;"><div style="text-align:left;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;">$</span></div></td><td style="vertical-align:bottom;border-bottom:2px solid #000000;background-color:#cceeff;padding-top:2px;padding-bottom:2px;border-top:1px solid #000000;"><div style="text-align:right;text-indent:2px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;"><span>11,383,792</span></span></div></td><td style="vertical-align:bottom;border-bottom:2px solid #000000;background-color:#cceeff;border-top:1px solid #000000;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td></tr></table></div><span style="font-family:inherit;font-size:10pt;"><br/></span></div><table cellpadding="0" cellspacing="0" style="font-family:Times New Roman; font-size:10pt;"><tr><td style="width:0px;"/><td/></tr><tr><td style="vertical-align:top"><div style="line-height:120%;font-size:9pt;padding-left:0px;"><span style="font-family:inherit;font-size:9pt;">(1)</span></div></td><td style="vertical-align:top;padding-left:30px;"><div style="line-height:120%;text-align:left;font-size:9pt;text-indent:-30px;"><span style="font-family:inherit;font-size:9pt;">The 2019 amount primarily related to the acquisition of Barbican.</span></div></td></tr></table><table cellpadding="0" cellspacing="0" style="font-family:Times New Roman; font-size:10pt;"><tr><td style="width:0px;"/><td/></tr><tr><td style="vertical-align:top"><div style="line-height:120%;font-size:9pt;padding-left:0px;"><span style="font-family:inherit;font-size:9pt;">(2)</span></div></td><td style="vertical-align:top;padding-left:30px;"><div style="line-height:120%;text-align:left;font-size:9pt;text-indent:-30px;"><span style="font-family:inherit;font-size:9pt;">During the 2019 first quarter and 2018 second quarter, a subsidiary of the Company entered into two separate retroactive reinsurance transactions with third party reinsurers to reinsure run-off liabilities associated with certain U.S. insurance exposures.</span></div></td></tr></table><div style="line-height:120%;text-align:center;padding-left:24px;text-indent:-24px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div>

CY2018Q4

us-gaap

Liability For Claims And Claims Adjustment Expense

LiabilityForClaimsAndClaimsAdjustmentExpense

11853297000

USD

CY2017Q4

us-gaap

Liability For Claims And Claims Adjustment Expense

LiabilityForClaimsAndClaimsAdjustmentExpense

11383792000

USD

CY2016Q4

us-gaap

Liability For Claims And Claims Adjustment Expense

LiabilityForClaimsAndClaimsAdjustmentExpense

10200960000

USD

CY2018Q4

us-gaap

Reinsurance Recoverable For Unpaid Claims And Claims Adjustments

ReinsuranceRecoverableForUnpaidClaimsAndClaimsAdjustments

2814291000

USD

CY2017Q4

us-gaap

Reinsurance Recoverable For Unpaid Claims And Claims Adjustments

ReinsuranceRecoverableForUnpaidClaimsAndClaimsAdjustments

2464910000

USD

CY2016Q4

us-gaap

Reinsurance Recoverable For Unpaid Claims And Claims Adjustments

ReinsuranceRecoverableForUnpaidClaimsAndClaimsAdjustments

2083575000

USD

CY2018Q4

us-gaap

Liability For Unpaid Claims And Claims Adjustment Expense Net

LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet

9039006000

USD

CY2017Q4

us-gaap

Liability For Unpaid Claims And Claims Adjustment Expense Net

LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet

8918882000

USD

CY2016Q4

us-gaap

Liability For Unpaid Claims And Claims Adjustment Expense Net

LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet

8117385000

USD

CY2019

us-gaap

Supplemental Information For Property Casualty Insurance Underwriters Current Year Claims And Claims Adjustment Expense

SupplementalInformationForPropertyCasualtyInsuranceUnderwritersCurrentYearClaimsAndClaimsAdjustmentExpense

3297037000

USD

CY2018

us-gaap

Supplemental Information For Property Casualty Insurance Underwriters Current Year Claims And Claims Adjustment Expense

SupplementalInformationForPropertyCasualtyInsuranceUnderwritersCurrentYearClaimsAndClaimsAdjustmentExpense

3162818000

USD

CY2017

us-gaap

Supplemental Information For Property Casualty Insurance Underwriters Current Year Claims And Claims Adjustment Expense

SupplementalInformationForPropertyCasualtyInsuranceUnderwritersCurrentYearClaimsAndClaimsAdjustmentExpense

3205428000

USD

CY2019

us-gaap

Supplemental Information For Property Casualty Insurance Underwriters Prior Year Claims And Claims Adjustment Expense

SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense

-163585000

USD

CY2018

us-gaap

Supplemental Information For Property Casualty Insurance Underwriters Prior Year Claims And Claims Adjustment Expense

SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense

-272712000

USD

CY2017

us-gaap

Supplemental Information For Property Casualty Insurance Underwriters Prior Year Claims And Claims Adjustment Expense

SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense

-237982000

USD

CY2019

us-gaap

Liability For Unpaid Claims And Claims Adjustment Expense Incurred Claims1

LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaims1

3133452000

USD

CY2018

us-gaap

Liability For Unpaid Claims And Claims Adjustment Expense Incurred Claims1

LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaims1

2890106000

USD

CY2017

us-gaap

Liability For Unpaid Claims And Claims Adjustment Expense Incurred Claims1

LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaims1

2967446000

USD

CY2019

us-gaap

Liability For Unpaid Claims And Claims Adjustment Expense Business Acquisitions

LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseBusinessAcquisitions

209486000

USD

CY2018

us-gaap

Liability For Unpaid Claims And Claims Adjustment Expense Business Acquisitions

LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseBusinessAcquisitions

0

USD

CY2017

us-gaap

Liability For Unpaid Claims And Claims Adjustment Expense Business Acquisitions

LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseBusinessAcquisitions

0

USD

CY2019

acgl

Liability For Unpaid Claims And Claims Adjustment Expense Incurred Claims Retroactive Reinsurance

LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaimsRetroactiveReinsurance

225500000

USD

CY2018

acgl

Liability For Unpaid Claims And Claims Adjustment Expense Incurred Claims Retroactive Reinsurance

LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaimsRetroactiveReinsurance

420404000

USD

CY2017

acgl

Liability For Unpaid Claims And Claims Adjustment Expense Incurred Claims Retroactive Reinsurance

LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaimsRetroactiveReinsurance

0

USD

CY2019

us-gaap

Liability For Unpaid Claims And Claims Adjustment Expense Foreign Currency Translation Gain Loss

LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseForeignCurrencyTranslationGainLoss

-36003000

USD

CY2018

us-gaap

Liability For Unpaid Claims And Claims Adjustment Expense Foreign Currency Translation Gain Loss

LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseForeignCurrencyTranslationGainLoss

143414000

USD

CY2017

us-gaap

Liability For Unpaid Claims And Claims Adjustment Expense Foreign Currency Translation Gain Loss

LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseForeignCurrencyTranslationGainLoss

-186963000

USD

CY2019

us-gaap

Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Current Year1

LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidCurrentYear1

621202000

USD

CY2018

us-gaap

Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Current Year1

LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidCurrentYear1

524048000

USD

CY2017

us-gaap

Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Current Year1

LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidCurrentYear1

505424000

USD

CY2019

us-gaap

Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Prior Years1

LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidPriorYears1

1762053000

USD

CY2018

us-gaap

Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Prior Years1

LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidPriorYears1

1682116000

USD

CY2017

us-gaap

Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Prior Years1

LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidPriorYears1

1847488000

USD

CY2019

us-gaap

Payments For Losses And Loss Adjustment Expense

PaymentsForLossesAndLossAdjustmentExpense

2383255000

USD

CY2018

us-gaap

Payments For Losses And Loss Adjustment Expense

PaymentsForLossesAndLossAdjustmentExpense

2206164000

USD

CY2017

us-gaap

Payments For Losses And Loss Adjustment Expense

PaymentsForLossesAndLossAdjustmentExpense

2352912000

USD

CY2019Q4

us-gaap

Liability For Unpaid Claims And Claims Adjustment Expense Net

LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet

9809192000

USD

CY2018Q4

us-gaap

Liability For Unpaid Claims And Claims Adjustment Expense Net

LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet

9039006000

USD

CY2017Q4

us-gaap

Liability For Unpaid Claims And Claims Adjustment Expense Net

LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet

8918882000

USD

CY2019Q4

us-gaap

Reinsurance Recoverable For Unpaid Claims And Claims Adjustments

ReinsuranceRecoverableForUnpaidClaimsAndClaimsAdjustments

4082650000

USD

CY2018Q4

us-gaap

Reinsurance Recoverable For Unpaid Claims And Claims Adjustments

ReinsuranceRecoverableForUnpaidClaimsAndClaimsAdjustments

2814291000

USD

CY2017Q4

us-gaap

Reinsurance Recoverable For Unpaid Claims And Claims Adjustments

ReinsuranceRecoverableForUnpaidClaimsAndClaimsAdjustments

2464910000

USD

CY2019Q4

us-gaap

Liability For Claims And Claims Adjustment Expense

LiabilityForClaimsAndClaimsAdjustmentExpense

13891842000

USD

CY2018Q4

us-gaap

Liability For Claims And Claims Adjustment Expense

LiabilityForClaimsAndClaimsAdjustmentExpense

11853297000

USD

CY2017Q4

us-gaap

Liability For Claims And Claims Adjustment Expense

LiabilityForClaimsAndClaimsAdjustmentExpense

11383792000

USD

CY2019

us-gaap

Supplemental Information For Property Casualty Insurance Underwriters Prior Year Claims And Claims Adjustment Expense

SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense

-163600000

USD

CY2018

us-gaap

Supplemental Information For Property Casualty Insurance Underwriters Prior Year Claims And Claims Adjustment Expense

SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense

-272700000

USD

CY2017

us-gaap

Supplemental Information For Property Casualty Insurance Underwriters Prior Year Claims And Claims Adjustment Expense

SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense

-238000000.0

USD

CY2019Q4

us-gaap

Shortduration Insurance Contracts Liability For Unpaid Claims And Allocated Claim Adjustment Expense Net

ShortdurationInsuranceContractsLiabilityForUnpaidClaimsAndAllocatedClaimAdjustmentExpenseNet

9536526000

USD

CY2019Q4

us-gaap

Shortduration Insurance Contracts Liability For Unpaid Claims And Claim Adjustment Expense Other Reconciling Item

ShortdurationInsuranceContractsLiabilityForUnpaidClaimsAndClaimAdjustmentExpenseOtherReconcilingItem

55989000

USD

CY2019Q4

us-gaap

Shortduration Insurance Contracts Discounted Liabilities Aggregate Discount

ShortdurationInsuranceContractsDiscountedLiabilitiesAggregateDiscount

22012000

USD

CY2019Q4

us-gaap

Shortduration Insurance Contracts Liability For Unpaid Claims And Claims Adjustment Expense Accumulated Unallocated Claim Adjustment Expense

ShortdurationInsuranceContractsLiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseAccumulatedUnallocatedClaimAdjustmentExpense

188055000

USD

CY2019Q4

us-gaap

Shortduration Insurance Contracts Liability For Unpaid Claims And Claim Adjustment Expense Aggregate Reconciling Items

ShortdurationInsuranceContractsLiabilityForUnpaidClaimsAndClaimAdjustmentExpenseAggregateReconcilingItems

222032000

USD

CY2019Q4

us-gaap

Liability For Claims And Claims Adjustment Expense

LiabilityForClaimsAndClaimsAdjustmentExpense

13891842000

USD

CY2019

us-gaap

Direct Premiums Written

DirectPremiumsWritten

5681523000

USD

CY2018

us-gaap

Direct Premiums Written

DirectPremiumsWritten

4838902000

USD

CY2017

us-gaap

Direct Premiums Written

DirectPremiumsWritten

4447457000

USD

CY2019

us-gaap

Assumed Premiums Written

AssumedPremiumsWritten

2457437000

USD

CY2018

us-gaap

Assumed Premiums Written

AssumedPremiumsWritten

2122102000

USD

CY2017

us-gaap

Assumed Premiums Written

AssumedPremiumsWritten

1920968000

USD

CY2019

us-gaap

Ceded Premiums Written

CededPremiumsWritten

2099893000

USD

CY2018

us-gaap

Ceded Premiums Written

CededPremiumsWritten

1614257000

USD

CY2017

us-gaap

Ceded Premiums Written

CededPremiumsWritten

1407052000

USD

CY2019

us-gaap

Premiums Written Net

PremiumsWrittenNet

6039067000

USD

CY2018

us-gaap

Premiums Written Net

PremiumsWrittenNet

5346747000

USD

CY2017

us-gaap

Premiums Written Net

PremiumsWrittenNet

4961373000

USD

CY2019

us-gaap

Direct Premiums Earned

DirectPremiumsEarned

5447829000

USD

CY2018

us-gaap

Direct Premiums Earned

DirectPremiumsEarned

4799842000

USD

CY2017

us-gaap

Direct Premiums Earned

DirectPremiumsEarned

4379131000

USD

CY2019

us-gaap

Assumed Premiums Earned

AssumedPremiumsEarned

2337950000

USD

CY2018

us-gaap

Assumed Premiums Earned

AssumedPremiumsEarned

1988038000

USD

CY2017

us-gaap

Assumed Premiums Earned

AssumedPremiumsEarned

1856573000

USD

CY2019

us-gaap

Ceded Premiums Earned

CededPremiumsEarned

1999281000

USD

CY2018

us-gaap

Ceded Premiums Earned

CededPremiumsEarned

1555905000

USD

CY2017

us-gaap

Ceded Premiums Earned

CededPremiumsEarned

1391172000

USD

CY2019

us-gaap

Premiums Earned Net

PremiumsEarnedNet

5786498000

USD

CY2018

us-gaap

Premiums Earned Net

PremiumsEarnedNet

5231975000

USD

CY2017

us-gaap

Premiums Earned Net

PremiumsEarnedNet

4844532000

USD

CY2019

us-gaap

Policyholder Benefits And Claims Incurred Gross

PolicyholderBenefitsAndClaimsIncurredGross

2953072000

USD

CY2018

us-gaap

Policyholder Benefits And Claims Incurred Gross

PolicyholderBenefitsAndClaimsIncurredGross

2472133000

USD

CY2017

us-gaap

Policyholder Benefits And Claims Incurred Gross

PolicyholderBenefitsAndClaimsIncurredGross

2568327000

USD

CY2019

us-gaap

Reinsurance Effect On Claims And Benefits Incurred Amount Assumed

ReinsuranceEffectOnClaimsAndBenefitsIncurredAmountAssumed

1602528000

USD

CY2018

us-gaap

Reinsurance Effect On Claims And Benefits Incurred Amount Assumed

ReinsuranceEffectOnClaimsAndBenefitsIncurredAmountAssumed

1307317000

USD

CY2017

us-gaap

Reinsurance Effect On Claims And Benefits Incurred Amount Assumed

ReinsuranceEffectOnClaimsAndBenefitsIncurredAmountAssumed

1442077000

USD

CY2019

us-gaap

Reinsurance Effect On Claims And Benefits Incurred Amount Ceded

ReinsuranceEffectOnClaimsAndBenefitsIncurredAmountCeded

1422148000

USD

CY2018

us-gaap

Reinsurance Effect On Claims And Benefits Incurred Amount Ceded

ReinsuranceEffectOnClaimsAndBenefitsIncurredAmountCeded

889344000

USD

CY2017

us-gaap

Reinsurance Effect On Claims And Benefits Incurred Amount Ceded

ReinsuranceEffectOnClaimsAndBenefitsIncurredAmountCeded

1042958000

USD

CY2019

us-gaap

Policyholder Benefits And Claims Incurred Net

PolicyholderBenefitsAndClaimsIncurredNet

3133452000

USD

CY2018

us-gaap

Policyholder Benefits And Claims Incurred Net

PolicyholderBenefitsAndClaimsIncurredNet

2890106000

USD

CY2017

us-gaap

Policyholder Benefits And Claims Incurred Net

PolicyholderBenefitsAndClaimsIncurredNet

2967446000

USD

CY2019Q4

us-gaap

Reinsurance Recoverables

ReinsuranceRecoverables

4346816000

USD

CY2018Q4

us-gaap

Reinsurance Recoverables

ReinsuranceRecoverables

2919372000

USD

CY2019Q4

acgl

Investable Assets

InvestableAssets

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USD

CY2019Q4

us-gaap

Available For Sale Securities

AvailableForSaleSecurities

18219582000

USD

CY2019Q4

us-gaap

Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax

AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax

351114000

USD

CY2019Q4

us-gaap

Available For Sale Securities Accumulated Gross Unrealized Loss Before Tax

AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax

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USD

CY2019Q4

us-gaap

Available For Sale Securities Amortized Cost

AvailableForSaleSecuritiesAmortizedCost

17923471000

USD

CY2019

us-gaap

Other Than Temporary Impairment Losses Investments Availableforsale Securities

OtherThanTemporaryImpairmentLossesInvestmentsAvailableforsaleSecurities

6000

USD

CY2018Q4

us-gaap

Available For Sale Securities

AvailableForSaleSecurities

15908390000

USD

CY2018Q4

us-gaap

Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax

AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax

76259000

USD

CY2018Q4

us-gaap

Available For Sale Securities Accumulated Gross Unrealized Loss Before Tax

AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax

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USD

CY2018Q4

us-gaap

Available For Sale Securities Amortized Cost

AvailableForSaleSecuritiesAmortizedCost

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USD

CY2018

us-gaap

Other Than Temporary Impairment Losses Investments Availableforsale Securities

OtherThanTemporaryImpairmentLossesInvestmentsAvailableforsaleSecurities

75000

USD

CY2019Q4

acgl

Other Than Temporary Impairment Losses Investments Available For Sale Securitiess At Current Fair Value

OtherThanTemporaryImpairmentLossesInvestmentsAvailableForSaleSecuritiessAtCurrentFairValue

0

USD

CY2019Q4

us-gaap

Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value

AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue

4280273000

USD

CY2019Q4

us-gaap

Available For Sale Securities Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss

AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss

52926000

USD

CY2019Q4

us-gaap

Available For Sale Securities Continuous Unrealized Loss Position Twelve Months Or Longer Fair Value

AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue

158538000

USD

CY2019Q4

us-gaap

Available For Sale Securities Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss

AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss

2077000

USD

CY2019Q4

us-gaap

Available For Sale Securities Continuous Unrealized Loss Position Fair Value

AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue

4438811000

USD

CY2019Q4

us-gaap

Available For Sale Securities Continuous Unrealized Loss Position Accumulated Loss

AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLoss

55003000

USD

CY2018Q4

us-gaap

Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value

AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue

5843772000

USD

CY2018Q4

us-gaap

Available For Sale Securities Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss

AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss

120614000

USD

CY2018Q4

us-gaap

Available For Sale Securities Continuous Unrealized Loss Position Twelve Months Or Longer Fair Value

AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue

3094853000

USD

CY2018Q4

us-gaap

Available For Sale Securities Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss

AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss

85286000

USD

CY2018Q4

us-gaap

Available For Sale Securities Continuous Unrealized Loss Position Fair Value

AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue

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USD

CY2018Q4

us-gaap

Available For Sale Securities Continuous Unrealized Loss Position Accumulated Loss

AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLoss

205900000

USD

CY2019Q4

us-gaap

Availableforsale Securities In Unrealized Loss Positions Qualitative Disclosure Number Of Positions1

AvailableforsaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions1

2230

lots

CY2019Q4

acgl

Available For Sale Securities Qualitative Disclosure Number Of Positions

AvailableForSaleSecuritiesQualitativeDisclosureNumberOfPositions

9590

lots

CY2019Q4

acgl

Available For Sale Securities Qualitative Disclosure Largest Single Loss

AvailableForSaleSecuritiesQualitativeDisclosureLargestSingleLoss

900000

USD

CY2018Q4

us-gaap

Availableforsale Securities In Unrealized Loss Positions Qualitative Disclosure Number Of Positions1

AvailableforsaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions1

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CY2018Q4

acgl

Available For Sale Securities Qualitative Disclosure Number Of Positions

AvailableForSaleSecuritiesQualitativeDisclosureNumberOfPositions

8450

lots

CY2018Q4

acgl

Available For Sale Securities Qualitative Disclosure Largest Single Loss

AvailableForSaleSecuritiesQualitativeDisclosureLargestSingleLoss

2600000

USD

CY2019Q4

us-gaap

Obligation To Return Securities Received As Collateral

ObligationToReturnSecuritiesReceivedAsCollateral

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USD

CY2019Q4

us-gaap

Secured Borrowings Gross Difference Amount

SecuredBorrowingsGrossDifferenceAmount

0

USD

CY2019Q4

us-gaap

Secured Borrowings Gross Including Not Subject To Master Netting Arrangement

SecuredBorrowingsGrossIncludingNotSubjectToMasterNettingArrangement

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USD

CY2018Q4

us-gaap

Obligation To Return Securities Received As Collateral

ObligationToReturnSecuritiesReceivedAsCollateral

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USD

CY2018Q4

us-gaap

Secured Borrowings Gross Difference Amount

SecuredBorrowingsGrossDifferenceAmount

0

USD

CY2018Q4

us-gaap

Secured Borrowings Gross Including Not Subject To Master Netting Arrangement

SecuredBorrowingsGrossIncludingNotSubjectToMasterNettingArrangement

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USD

CY2019Q4

us-gaap

Equity Securities Fv Ni

EquitySecuritiesFvNi

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CY2018Q4

us-gaap

Equity Securities Fv Ni

EquitySecuritiesFvNi

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CY2019Q4

acgl

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OtherInvestmentsAndOtherFairValueOptionInvestments

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USD

CY2018Q4

acgl

Other Investments And Other Fair Value Option Investments

OtherInvestmentsAndOtherFairValueOptionInvestments

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CY2019Q4

us-gaap

Equity Method Investments

EquityMethodInvestments

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USD

CY2018Q4

us-gaap

Equity Method Investments

EquityMethodInvestments

1493791000

USD

CY2019Q4

acgl

Equity Method Investment Summarized Financial Information Invested Assets

EquityMethodInvestmentSummarizedFinancialInformationInvestedAssets

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CY2018Q4

acgl

Equity Method Investment Summarized Financial Information Invested Assets

EquityMethodInvestmentSummarizedFinancialInformationInvestedAssets

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CY2019Q4

us-gaap

Equity Method Investment Summarized Financial Information Assets

EquityMethodInvestmentSummarizedFinancialInformationAssets

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USD

CY2018Q4

us-gaap

Equity Method Investment Summarized Financial Information Assets

EquityMethodInvestmentSummarizedFinancialInformationAssets

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USD

CY2019Q4

us-gaap

Equity Method Investment Summarized Financial Information Liabilities

EquityMethodInvestmentSummarizedFinancialInformationLiabilities

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USD

CY2018Q4

us-gaap

Equity Method Investment Summarized Financial Information Liabilities

EquityMethodInvestmentSummarizedFinancialInformationLiabilities

3406612000

USD

CY2019Q4

us-gaap

Equity Method Investment Summarized Financial Information Equity

EquityMethodInvestmentSummarizedFinancialInformationEquity

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USD

CY2018Q4

us-gaap

Equity Method Investment Summarized Financial Information Equity

EquityMethodInvestmentSummarizedFinancialInformationEquity

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USD

CY2019

us-gaap

Equity Method Investment Summarized Financial Information Revenue

EquityMethodInvestmentSummarizedFinancialInformationRevenue

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USD

CY2018

us-gaap

Equity Method Investment Summarized Financial Information Revenue

EquityMethodInvestmentSummarizedFinancialInformationRevenue

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USD

CY2017

us-gaap

Equity Method Investment Summarized Financial Information Revenue

EquityMethodInvestmentSummarizedFinancialInformationRevenue

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USD

CY2019

acgl

Equity Method Investment Summarized Financial Information Total Expenses

EquityMethodInvestmentSummarizedFinancialInformationTotalExpenses

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USD

CY2018

acgl

Equity Method Investment Summarized Financial Information Total Expenses

EquityMethodInvestmentSummarizedFinancialInformationTotalExpenses

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USD

CY2017

acgl

Equity Method Investment Summarized Financial Information Total Expenses

EquityMethodInvestmentSummarizedFinancialInformationTotalExpenses

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USD

CY2019

us-gaap

Equity Method Investment Summarized Financial Information Net Income Loss

EquityMethodInvestmentSummarizedFinancialInformationNetIncomeLoss

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USD

CY2018

us-gaap

Equity Method Investment Summarized Financial Information Net Income Loss

EquityMethodInvestmentSummarizedFinancialInformationNetIncomeLoss

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USD

CY2017

us-gaap

Equity Method Investment Summarized Financial Information Net Income Loss

EquityMethodInvestmentSummarizedFinancialInformationNetIncomeLoss

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USD

CY2019Q4

acgl

Investments Accounted For Using Fair Value Option

InvestmentsAccountedForUsingFairValueOption

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USD

CY2018Q4

acgl

Investments Accounted For Using Fair Value Option

InvestmentsAccountedForUsingFairValueOption

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CY2019Q4

us-gaap

Variable Interest Entity Entity Maximum Loss Exposure Amount

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CY2018Q4

us-gaap

Variable Interest Entity Entity Maximum Loss Exposure Amount

VariableInterestEntityEntityMaximumLossExposureAmount

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USD

CY2019

us-gaap

Investment Income Interest And Dividend

InvestmentIncomeInterestAndDividend

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USD

CY2018

us-gaap

Investment Income Interest And Dividend

InvestmentIncomeInterestAndDividend

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USD

CY2017

us-gaap

Investment Income Interest And Dividend

InvestmentIncomeInterestAndDividend

562901000

USD

CY2019

us-gaap

Investment Income Investment Expense

InvestmentIncomeInvestmentExpense

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USD

CY2018

us-gaap

Investment Income Investment Expense

InvestmentIncomeInvestmentExpense

92094000

USD

CY2017

us-gaap

Investment Income Investment Expense

InvestmentIncomeInvestmentExpense

92029000

USD

CY2019

us-gaap

Investment Income Net

InvestmentIncomeNet

627738000

USD

CY2018

us-gaap

Investment Income Net

InvestmentIncomeNet

563633000

USD

CY2017

us-gaap

Investment Income Net

InvestmentIncomeNet

470872000

USD

CY2019

us-gaap

Available For Sale Securities Gross Realized Gains

AvailableForSaleSecuritiesGrossRealizedGains

235655000

USD

CY2018

us-gaap

Available For Sale Securities Gross Realized Gains

AvailableForSaleSecuritiesGrossRealizedGains

69299000

USD

CY2017

us-gaap

Available For Sale Securities Gross Realized Gains

AvailableForSaleSecuritiesGrossRealizedGains

286415000

USD

CY2019

us-gaap

Availableforsale Securities Gross Realized Losses Excluding Other Than Temporary Impairments

AvailableforsaleSecuritiesGrossRealizedLossesExcludingOtherThanTemporaryImpairments

104612000

USD

CY2018

us-gaap

Availableforsale Securities Gross Realized Losses Excluding Other Than Temporary Impairments

AvailableforsaleSecuritiesGrossRealizedLossesExcludingOtherThanTemporaryImpairments

223123000

USD

CY2017

us-gaap

Availableforsale Securities Gross Realized Losses Excluding Other Than Temporary Impairments

AvailableforsaleSecuritiesGrossRealizedLossesExcludingOtherThanTemporaryImpairments

203873000

USD

CY2019

us-gaap

Equity Securities Fv Ni Realized Gain Loss

EquitySecuritiesFvNiRealizedGainLoss

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USD

CY2018

us-gaap

Equity Securities Fv Ni Realized Gain Loss

EquitySecuritiesFvNiRealizedGainLoss

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CY2017

us-gaap

Equity Securities Fv Ni Realized Gain Loss

EquitySecuritiesFvNiRealizedGainLoss

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USD

CY2019

us-gaap

Equity Securities Fv Ni Unrealized Gain Loss

EquitySecuritiesFvNiUnrealizedGainLoss

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CY2018

us-gaap

Equity Securities Fv Ni Unrealized Gain Loss

EquitySecuritiesFvNiUnrealizedGainLoss

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CY2017

us-gaap

Equity Securities Fv Ni Unrealized Gain Loss

EquitySecuritiesFvNiUnrealizedGainLoss

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USD

CY2019

us-gaap

Derivative Gain Loss On Derivative Net

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CY2018

us-gaap

Derivative Gain Loss On Derivative Net

DerivativeGainLossOnDerivativeNet

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CY2017

us-gaap

Derivative Gain Loss On Derivative Net

DerivativeGainLossOnDerivativeNet

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CY2019

us-gaap

Gain Loss On Sale Of Other Investments

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CY2018

us-gaap

Gain Loss On Sale Of Other Investments

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CY2017

us-gaap

Gain Loss On Sale Of Other Investments

GainLossOnSaleOfOtherInvestments

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CY2019

us-gaap

Marketable Securities Gain Loss Excluding Other Than Temporary Impairments

MarketableSecuritiesGainLossExcludingOtherThanTemporaryImpairments

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CY2018

us-gaap

Marketable Securities Gain Loss Excluding Other Than Temporary Impairments

MarketableSecuritiesGainLossExcludingOtherThanTemporaryImpairments

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USD

CY2017

us-gaap

Marketable Securities Gain Loss Excluding Other Than Temporary Impairments

MarketableSecuritiesGainLossExcludingOtherThanTemporaryImpairments

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CY2019

us-gaap

Income Loss From Equity Method Investments

IncomeLossFromEquityMethodInvestments

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CY2018

us-gaap

Income Loss From Equity Method Investments

IncomeLossFromEquityMethodInvestments

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CY2017

us-gaap

Income Loss From Equity Method Investments

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CY2019

us-gaap

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CY2018

us-gaap

Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net

OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNet

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CY2017

us-gaap

Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net

OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNet

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CY2018Q4

us-gaap

Other Than Temporary Impairment Credit Losses Recognized In Earnings Credit Losses On Debt Securities Held

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CY2017Q4

us-gaap

Other Than Temporary Impairment Credit Losses Recognized In Earnings Credit Losses On Debt Securities Held

OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsCreditLossesOnDebtSecuritiesHeld

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CY2016Q4

us-gaap

Other Than Temporary Impairment Credit Losses Recognized In Earnings Credit Losses On Debt Securities Held

OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsCreditLossesOnDebtSecuritiesHeld

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CY2019

us-gaap

Other Than Temporary Impairment Credit Losses Recognized In Earnings Additions No Previous Impairment

OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsAdditionsNoPreviousImpairment

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CY2018

us-gaap

Other Than Temporary Impairment Credit Losses Recognized In Earnings Additions No Previous Impairment

OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsAdditionsNoPreviousImpairment

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USD

CY2017

us-gaap

Other Than Temporary Impairment Credit Losses Recognized In Earnings Additions No Previous Impairment

OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsAdditionsNoPreviousImpairment

31000

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CY2019

us-gaap

Other Than Temporary Impairment Credit Losses Recognized In Earnings Additions Additional Credit Losses

OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsAdditionsAdditionalCreditLosses

0

USD

CY2018

us-gaap

Other Than Temporary Impairment Credit Losses Recognized In Earnings Additions Additional Credit Losses

OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsAdditionsAdditionalCreditLosses

0

USD

CY2017

us-gaap

Other Than Temporary Impairment Credit Losses Recognized In Earnings Additions Additional Credit Losses

OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsAdditionsAdditionalCreditLosses

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USD

CY2019

us-gaap

Other Than Temporary Impairment Credit Losses Recognized In Earnings Reductions Cash Flows

OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsReductionsCashFlows

0

USD

CY2018

us-gaap

Other Than Temporary Impairment Credit Losses Recognized In Earnings Reductions Cash Flows

OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsReductionsCashFlows

0

USD

CY2017

us-gaap

Other Than Temporary Impairment Credit Losses Recognized In Earnings Reductions Cash Flows

OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsReductionsCashFlows

0

USD

CY2019

us-gaap

Other Than Temporary Impairment Credit Losses Recognized In Earnings Reductions Securities Sold

OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsReductionsSecuritiesSold

291000

USD

CY2018

us-gaap

Other Than Temporary Impairment Credit Losses Recognized In Earnings Reductions Securities Sold

OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsReductionsSecuritiesSold

130000

USD

CY2017

us-gaap

Other Than Temporary Impairment Credit Losses Recognized In Earnings Reductions Securities Sold

OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsReductionsSecuritiesSold

12612000

USD

CY2019Q4

us-gaap

Other Than Temporary Impairment Credit Losses Recognized In Earnings Credit Losses On Debt Securities Held

OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsCreditLossesOnDebtSecuritiesHeld

346000

USD

CY2018Q4

us-gaap

Other Than Temporary Impairment Credit Losses Recognized In Earnings Credit Losses On Debt Securities Held

OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsCreditLossesOnDebtSecuritiesHeld

637000

USD

CY2017Q4

us-gaap

Other Than Temporary Impairment Credit Losses Recognized In Earnings Credit Losses On Debt Securities Held

OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsCreditLossesOnDebtSecuritiesHeld

767000

USD

CY2019Q4

acgl

Restricted Assets

RestrictedAssets

7721618000

USD

CY2018Q4

acgl

Restricted Assets

RestrictedAssets

7553903000

USD

CY2019Q4

us-gaap

Cash And Cash Equivalents At Carrying Value

CashAndCashEquivalentsAtCarryingValue

726230000

USD

CY2018Q4

us-gaap

Cash And Cash Equivalents At Carrying Value

CashAndCashEquivalentsAtCarryingValue

646556000

USD

CY2017Q4

us-gaap

Cash And Cash Equivalents At Carrying Value

CashAndCashEquivalentsAtCarryingValue

606199000

USD

CY2019Q4

us-gaap

Restricted Cash And Cash Equivalents

RestrictedCashAndCashEquivalents

177468000

USD

CY2018Q4

us-gaap

Restricted Cash And Cash Equivalents

RestrictedCashAndCashEquivalents

78087000

USD

CY2017Q4

us-gaap

Restricted Cash And Cash Equivalents

RestrictedCashAndCashEquivalents

121085000

USD

CY2019Q4

us-gaap

Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents

CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

903698000

USD

CY2018Q4

us-gaap

Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents

CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

724643000

USD

CY2017Q4

us-gaap

Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents

CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

727284000

USD

CY2019Q4

acgl

Total Assets And Liabilities Measured At Fair Value

TotalAssetsAndLiabilitiesMeasuredAtFairValue

22900000000

USD

CY2019Q4

acgl

Total Assets And Liabilities Measured At Fair Value Priced Using Non Binding Broker Quotes

TotalAssetsAndLiabilitiesMeasuredAtFairValuePricedUsingNonBindingBrokerQuotes

179600000

USD

CY2019Q4

acgl

Percentage Of Total Assets And Liabilities Measured At Fair Value Priced Using Non Binding Broker Quotes

PercentageOfTotalAssetsAndLiabilitiesMeasuredAtFairValuePricedUsingNonBindingBrokerQuotes

0.008

CY2018Q4

acgl

Total Assets And Liabilities Measured At Fair Value

TotalAssetsAndLiabilitiesMeasuredAtFairValue

20400000000

USD

CY2018Q4

acgl

Total Assets And Liabilities Measured At Fair Value Priced Using Non Binding Broker Quotes

TotalAssetsAndLiabilitiesMeasuredAtFairValuePricedUsingNonBindingBrokerQuotes

217900000

USD

CY2018Q4

acgl

Percentage Of Total Assets And Liabilities Measured At Fair Value Priced Using Non Binding Broker Quotes

PercentageOfTotalAssetsAndLiabilitiesMeasuredAtFairValuePricedUsingNonBindingBrokerQuotes

0.011

CY2019Q4

us-gaap

Derivative Fair Value Of Derivative Asset Amount Not Offset Against Collateral

DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral

97800000

USD

CY2017

acgl

Redeemable Noncontrolling Interest Increasefrom Subsidiary Equity Issuance

RedeemableNoncontrollingInterestIncreasefromSubsidiaryEquityIssuance

0

USD

CY2019

acgl

Redeemable Noncontrolling Interest Accretionof Issuance Costs

RedeemableNoncontrollingInterestAccretionofIssuanceCosts

244000

USD

CY2018

acgl

Redeemable Noncontrolling Interest Accretionof Issuance Costs

RedeemableNoncontrollingInterestAccretionofIssuanceCosts

370000

USD

CY2019Q4

us-gaap

Derivative Fair Value Of Derivative Liability Amount Not Offset Against Collateral

DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral

37800000

USD

CY2018Q4

us-gaap

Derivative Fair Value Of Derivative Asset Amount Not Offset Against Collateral

DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral

80400000

USD

CY2018Q4

us-gaap

Derivative Fair Value Of Derivative Liability Amount Not Offset Against Collateral

DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral

18900000

USD

CY2018Q4

us-gaap

Redeemable Noncontrolling Interest Equity Fair Value

RedeemableNoncontrollingInterestEquityFairValue

206292000

USD

CY2017Q4

us-gaap

Redeemable Noncontrolling Interest Equity Fair Value

RedeemableNoncontrollingInterestEquityFairValue

205922000

USD

CY2016Q4

us-gaap

Redeemable Noncontrolling Interest Equity Fair Value

RedeemableNoncontrollingInterestEquityFairValue

205553000

USD

CY2019

acgl

Redeemable Noncontrolling Interest Increasefrom Subsidiary Equity Issuance

RedeemableNoncontrollingInterestIncreasefromSubsidiaryEquityIssuance

-157709000

USD

CY2018

acgl

Redeemable Noncontrolling Interest Increasefrom Subsidiary Equity Issuance

RedeemableNoncontrollingInterestIncreasefromSubsidiaryEquityIssuance

0

USD

CY2017

acgl

Redeemable Noncontrolling Interest Accretionof Issuance Costs

RedeemableNoncontrollingInterestAccretionofIssuanceCosts

369000

USD

CY2019

acgl

Noncontrolling Interest Period Increase Decrease Other

NoncontrollingInterestPeriodIncreaseDecreaseOther

6577000

USD

CY2018

acgl

Noncontrolling Interest Period Increase Decrease Other

NoncontrollingInterestPeriodIncreaseDecreaseOther

0

USD

CY2017

acgl

Noncontrolling Interest Period Increase Decrease Other

NoncontrollingInterestPeriodIncreaseDecreaseOther

0

USD

CY2019Q4

us-gaap

Redeemable Noncontrolling Interest Equity Fair Value

RedeemableNoncontrollingInterestEquityFairValue

55404000

USD

CY2018Q4

us-gaap

Redeemable Noncontrolling Interest Equity Fair Value

RedeemableNoncontrollingInterestEquityFairValue

206292000

USD

CY2017Q4

us-gaap

Redeemable Noncontrolling Interest Equity Fair Value

RedeemableNoncontrollingInterestEquityFairValue

205922000

USD

CY2018Q4

us-gaap

Accumulated Other Comprehensive Income Loss Net Of Tax

AccumulatedOtherComprehensiveIncomeLossNetOfTax

-178720000

USD

CY2019

us-gaap

Oci Before Reclassifications Net Of Tax Attributable To Parent

OciBeforeReclassificationsNetOfTaxAttributableToParent

509752000

USD

CY2019

us-gaap

Reclassification From Aoci Current Period Net Of Tax Attributable To Parent

ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent

118941000

USD

CY2019

us-gaap

Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent

OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent

390811000

USD

CY2019Q4

us-gaap

Accumulated Other Comprehensive Income Loss Net Of Tax

AccumulatedOtherComprehensiveIncomeLossNetOfTax

212091000

USD

CY2017Q4

us-gaap

Accumulated Other Comprehensive Income Loss Net Of Tax

AccumulatedOtherComprehensiveIncomeLossNetOfTax

118044000

USD

CY2017Q4

us-gaap

Cumulative Effect Of New Accounting Principle In Period Of Adoption

CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption

-149794000

USD

CY2018

us-gaap

Oci Before Reclassifications Net Of Tax Attributable To Parent

OciBeforeReclassificationsNetOfTaxAttributableToParent

-291543000

USD

CY2018

us-gaap

Reclassification From Aoci Current Period Net Of Tax Attributable To Parent

ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent

-144573000

USD

CY2018

us-gaap

Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent

OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent

-146970000

USD

CY2018Q4

us-gaap

Accumulated Other Comprehensive Income Loss Net Of Tax

AccumulatedOtherComprehensiveIncomeLossNetOfTax

-178720000

USD

CY2016Q4

us-gaap

Accumulated Other Comprehensive Income Loss Net Of Tax

AccumulatedOtherComprehensiveIncomeLossNetOfTax

-114541000

USD

CY2017

us-gaap

Oci Before Reclassifications Net Of Tax Attributable To Parent

OciBeforeReclassificationsNetOfTaxAttributableToParent

300448000

USD

CY2017

us-gaap

Reclassification From Aoci Current Period Net Of Tax Attributable To Parent

ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent

67863000

USD

CY2017

us-gaap

Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent

OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent

232585000

USD

CY2017Q4

us-gaap

Accumulated Other Comprehensive Income Loss Net Of Tax

AccumulatedOtherComprehensiveIncomeLossNetOfTax

118044000

USD

CY2019

us-gaap

Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax

OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax

562576000

USD

CY2019

us-gaap

Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax

OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax

61805000

USD

CY2019

us-gaap

Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax

OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax

500771000

USD

CY2019

us-gaap

Reclassification From Accumulated Other Comprehensive Income Current Period Before Tax

ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodBeforeTax

127878000

USD

CY2019

us-gaap

Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax

OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax

8937000

USD

CY2019

us-gaap

Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax

ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax

118941000

USD

CY2019

us-gaap

Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Before Tax

OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax

18463000

USD

CY2019

us-gaap

Other Comprehensive Income Loss Foreign Currency Translation Adjustment Tax

OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax

353000

USD

CY2019

us-gaap

Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax

OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax

18110000

USD

CY2019

us-gaap

Other Comprehensive Income Loss Before Tax

OtherComprehensiveIncomeLossBeforeTax

453161000

USD

CY2019

us-gaap

Other Comprehensive Income Loss Tax

OtherComprehensiveIncomeLossTax

53221000

USD

CY2019

us-gaap

Other Comprehensive Income Loss Net Of Tax

OtherComprehensiveIncomeLossNetOfTax

399940000

USD

CY2018

us-gaap

Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax

OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax

-294267000

USD

CY2018

us-gaap

Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax

OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax

-24210000

USD

CY2018

us-gaap

Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax

OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax

-270057000

USD

CY2018

us-gaap

Reclassification From Accumulated Other Comprehensive Income Current Period Before Tax

ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodBeforeTax

-156651000

USD

CY2018

us-gaap

Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax

OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax

-12078000

USD

CY2018

us-gaap

Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax

ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax

-144573000

USD

CY2018

us-gaap

Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Before Tax

OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax

-25006000

USD

CY2018

us-gaap

Other Comprehensive Income Loss Foreign Currency Translation Adjustment Tax

OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax

-176000

USD

CY2018

us-gaap

Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax

OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax

-24830000

USD

CY2018

us-gaap

Other Comprehensive Income Loss Before Tax

OtherComprehensiveIncomeLossBeforeTax

-162622000

USD

CY2018

us-gaap

Other Comprehensive Income Loss Tax

OtherComprehensiveIncomeLossTax

-12308000

USD

CY2018

us-gaap

Other Comprehensive Income Loss Net Of Tax

OtherComprehensiveIncomeLossNetOfTax

-150314000

USD

CY2017

us-gaap

Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax

OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax

266559000

USD

CY2017

us-gaap

Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax

OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax

13655000

USD

CY2017

us-gaap

Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax

OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax

252904000

USD

CY2017

us-gaap

Reclassification From Accumulated Other Comprehensive Income Current Period Before Tax

ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodBeforeTax

75404000

USD

CY2017

us-gaap

Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax

OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax

7541000

USD

CY2017

us-gaap

Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax

ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax

67863000

USD

CY2017

us-gaap

Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Before Tax

OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax

47549000

USD

CY2017

us-gaap

Other Comprehensive Income Loss Foreign Currency Translation Adjustment Tax

OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax

535000

USD

CY2017

us-gaap

Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax

OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax

47014000

USD

CY2017

us-gaap

Other Comprehensive Income Loss Before Tax

OtherComprehensiveIncomeLossBeforeTax

238704000

USD

CY2017

us-gaap

Other Comprehensive Income Loss Tax

OtherComprehensiveIncomeLossTax

6649000

USD

CY2017

us-gaap

Other Comprehensive Income Loss Net Of Tax

OtherComprehensiveIncomeLossNetOfTax

232055000

USD

CY2019

us-gaap

Profit Loss

ProfitLoss

1693300000

USD

CY2018

us-gaap

Profit Loss

ProfitLoss

727821000

USD

CY2017

us-gaap

Profit Loss

ProfitLoss

629709000

USD

CY2019

us-gaap

Net Income Loss Attributable To Noncontrolling Interest

NetIncomeLossAttributableToNoncontrollingInterest

56981000

USD

CY2018

us-gaap

Net Income Loss Attributable To Noncontrolling Interest

NetIncomeLossAttributableToNoncontrollingInterest

-30150000

USD

CY2017

us-gaap

Net Income Loss Attributable To Noncontrolling Interest

NetIncomeLossAttributableToNoncontrollingInterest

10431000

USD

CY2019

us-gaap

Net Income Loss

NetIncomeLoss

1636319000

USD

CY2018

us-gaap

Net Income Loss

NetIncomeLoss

757971000

USD

CY2017

us-gaap

Net Income Loss

NetIncomeLoss

619278000

USD

CY2019

us-gaap

Preferred Stock Dividends Income Statement Impact

PreferredStockDividendsIncomeStatementImpact

41612000

USD

CY2018

us-gaap

Preferred Stock Dividends Income Statement Impact

PreferredStockDividendsIncomeStatementImpact

41645000

USD

CY2017

us-gaap

Preferred Stock Dividends Income Statement Impact

PreferredStockDividendsIncomeStatementImpact

46041000

USD

CY2019

us-gaap

Preferred Stock Redemption Premium

PreferredStockRedemptionPremium

0

USD

CY2018

us-gaap

Preferred Stock Redemption Premium

PreferredStockRedemptionPremium

2710000

USD

CY2017

us-gaap

Preferred Stock Redemption Premium

PreferredStockRedemptionPremium

6735000

USD

CY2019

us-gaap

Net Income Loss Available To Common Stockholders Basic

NetIncomeLossAvailableToCommonStockholdersBasic

1594707000

USD

CY2018

us-gaap

Net Income Loss Available To Common Stockholders Basic

NetIncomeLossAvailableToCommonStockholdersBasic

713616000

USD

CY2017

us-gaap

Net Income Loss Available To Common Stockholders Basic

NetIncomeLossAvailableToCommonStockholdersBasic

566502000

USD

CY2019

us-gaap

Weighted Average Number Of Shares Issued Basic

WeightedAverageNumberOfSharesIssuedBasic

401802815

shares

CY2018

us-gaap

Weighted Average Number Of Shares Issued Basic

WeightedAverageNumberOfSharesIssuedBasic

401036376

shares

CY2017

us-gaap

Weighted Average Number Of Shares Issued Basic

WeightedAverageNumberOfSharesIssuedBasic

377531628

shares

CY2019

us-gaap

Weighted Average Number Of Shares Contingently Issuable

WeightedAverageNumberOfSharesContingentlyIssuable

0

shares

CY2018

us-gaap

Weighted Average Number Of Shares Contingently Issuable

WeightedAverageNumberOfSharesContingentlyIssuable

3311245

shares

CY2017

us-gaap

Weighted Average Number Of Shares Contingently Issuable

WeightedAverageNumberOfSharesContingentlyIssuable

26606736

shares

CY2019

us-gaap

Weighted Average Number Of Shares Outstanding Basic

WeightedAverageNumberOfSharesOutstandingBasic

401802815

shares

CY2018

us-gaap

Weighted Average Number Of Shares Outstanding Basic

WeightedAverageNumberOfSharesOutstandingBasic

404347621

shares

CY2017

us-gaap

Weighted Average Number Of Shares Outstanding Basic

WeightedAverageNumberOfSharesOutstandingBasic

404138364

shares

CY2019

us-gaap

Incremental Common Shares Attributable To Nonvested Shares With Forfeitable Dividends

IncrementalCommonSharesAttributableToNonvestedSharesWithForfeitableDividends

1673770

shares

CY2018

us-gaap

Incremental Common Shares Attributable To Nonvested Shares With Forfeitable Dividends

IncrementalCommonSharesAttributableToNonvestedSharesWithForfeitableDividends

1474207

shares

CY2017

us-gaap

Incremental Common Shares Attributable To Nonvested Shares With Forfeitable Dividends

IncrementalCommonSharesAttributableToNonvestedSharesWithForfeitableDividends

3936594

shares

CY2019

us-gaap

Incremental Common Shares Attributable To Call Options And Warrants

IncrementalCommonSharesAttributableToCallOptionsAndWarrants

8132893

shares

CY2018

us-gaap

Incremental Common Shares Attributable To Call Options And Warrants

IncrementalCommonSharesAttributableToCallOptionsAndWarrants

7084650

shares

CY2018

us-gaap

Deferred Federal State And Local Tax Expense Benefit

DeferredFederalStateAndLocalTaxExpenseBenefit

19544000

USD

CY2017

us-gaap

Deferred Federal State And Local Tax Expense Benefit

DeferredFederalStateAndLocalTaxExpenseBenefit

169093000

USD

CY2019

us-gaap

Deferred Foreign Income Tax Expense Benefit

DeferredForeignIncomeTaxExpenseBenefit

-400000

USD

CY2018

us-gaap

Deferred Foreign Income Tax Expense Benefit

DeferredForeignIncomeTaxExpenseBenefit

8544000

USD

CY2017

us-gaap

Deferred Foreign Income Tax Expense Benefit

DeferredForeignIncomeTaxExpenseBenefit

4211000

USD

CY2019

us-gaap

Deferred Income Tax Expense Benefit

DeferredIncomeTaxExpenseBenefit

11449000

USD

CY2018

us-gaap

Deferred Income Tax Expense Benefit

DeferredIncomeTaxExpenseBenefit

28088000

USD

CY2017

us-gaap

Incremental Common Shares Attributable To Call Options And Warrants

IncrementalCommonSharesAttributableToCallOptionsAndWarrants

9710067

shares

CY2019

us-gaap

Weighted Average Number Of Diluted Shares Outstanding

WeightedAverageNumberOfDilutedSharesOutstanding

411609478

shares

CY2018

us-gaap

Weighted Average Number Of Diluted Shares Outstanding

WeightedAverageNumberOfDilutedSharesOutstanding

412906478

shares

CY2017

us-gaap

Weighted Average Number Of Diluted Shares Outstanding

WeightedAverageNumberOfDilutedSharesOutstanding

417785025

shares

CY2019

us-gaap

Earnings Per Share Basic

EarningsPerShareBasic

3.97

CY2018

us-gaap

Earnings Per Share Basic

EarningsPerShareBasic

1.76

CY2017

us-gaap

Earnings Per Share Basic

EarningsPerShareBasic

1.40

CY2019

us-gaap

Earnings Per Share Diluted

EarningsPerShareDiluted

3.87

CY2018

us-gaap

Earnings Per Share Diluted

EarningsPerShareDiluted

1.73

CY2017

us-gaap

Earnings Per Share Diluted

EarningsPerShareDiluted

1.36

CY2019

us-gaap

Current Federal State And Local Tax Expense Benefit

CurrentFederalStateAndLocalTaxExpenseBenefit

139407000

USD

CY2018

us-gaap

Current Federal State And Local Tax Expense Benefit

CurrentFederalStateAndLocalTaxExpenseBenefit

73078000

USD

CY2017

us-gaap

Current Federal State And Local Tax Expense Benefit

CurrentFederalStateAndLocalTaxExpenseBenefit

-51705000

USD

CY2019

us-gaap

Current Foreign Tax Expense Benefit

CurrentForeignTaxExpenseBenefit

4954000

USD

CY2018

us-gaap

Current Foreign Tax Expense Benefit

CurrentForeignTaxExpenseBenefit

12785000

USD

CY2017

us-gaap

Current Foreign Tax Expense Benefit

CurrentForeignTaxExpenseBenefit

5969000

USD

CY2019

us-gaap

Current Income Tax Expense Benefit

CurrentIncomeTaxExpenseBenefit

144361000

USD

CY2018

us-gaap

Current Income Tax Expense Benefit

CurrentIncomeTaxExpenseBenefit

85863000

USD

CY2017

us-gaap

Current Income Tax Expense Benefit

CurrentIncomeTaxExpenseBenefit

-45736000

USD

CY2019

us-gaap

Deferred Federal State And Local Tax Expense Benefit

DeferredFederalStateAndLocalTaxExpenseBenefit

11849000

USD

CY2017

us-gaap

Deferred Income Tax Expense Benefit

DeferredIncomeTaxExpenseBenefit

173304000

USD

CY2019

us-gaap

Income Tax Expense Benefit

IncomeTaxExpenseBenefit

155810000

USD

CY2018

us-gaap

Income Tax Expense Benefit

IncomeTaxExpenseBenefit

113951000

USD

CY2017

us-gaap

Income Tax Expense Benefit

IncomeTaxExpenseBenefit

127568000

USD

CY2019

us-gaap

Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest

IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest

1849110000

USD

CY2018

us-gaap

Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest

IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest

841772000

USD

CY2017

us-gaap

Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest

IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest

757277000

USD

CY2019

us-gaap

Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate

IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate

149799000

USD

CY2018

us-gaap

Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate

IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate

91529000

USD

CY2017

us-gaap

Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate

IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate

126262000

USD

CY2019

us-gaap

Income Tax Reconciliation Tax Exempt Income

IncomeTaxReconciliationTaxExemptIncome

3091000

USD

CY2018

us-gaap

Income Tax Reconciliation Tax Exempt Income

IncomeTaxReconciliationTaxExemptIncome

4790000

USD

CY2017

us-gaap

Income Tax Reconciliation Tax Exempt Income

IncomeTaxReconciliationTaxExemptIncome

13330000

USD

CY2019

us-gaap

Income Tax Reconciliation Nondeductible Expense Meals And Entertainment

IncomeTaxReconciliationNondeductibleExpenseMealsAndEntertainment

1134000

USD

CY2018

us-gaap

Income Tax Reconciliation Nondeductible Expense Meals And Entertainment

IncomeTaxReconciliationNondeductibleExpenseMealsAndEntertainment

1060000

USD

CY2017

us-gaap

Income Tax Reconciliation Nondeductible Expense Meals And Entertainment

IncomeTaxReconciliationNondeductibleExpenseMealsAndEntertainment

1063000

USD

CY2019

us-gaap

Income Tax Reconciliation State And Local Income Taxes

IncomeTaxReconciliationStateAndLocalIncomeTaxes

3314000

USD

CY2018

us-gaap

Income Tax Reconciliation State And Local Income Taxes

IncomeTaxReconciliationStateAndLocalIncomeTaxes

2086000

USD

CY2017

us-gaap

Income Tax Reconciliation State And Local Income Taxes

IncomeTaxReconciliationStateAndLocalIncomeTaxes

732000

USD

CY2019

us-gaap

Income Tax Reconciliation Foreign Income Tax Rate Differential

IncomeTaxReconciliationForeignIncomeTaxRateDifferential

1231000

USD

CY2018

us-gaap

Income Tax Reconciliation Foreign Income Tax Rate Differential

IncomeTaxReconciliationForeignIncomeTaxRateDifferential

5428000

USD

CY2017

us-gaap

Income Tax Reconciliation Foreign Income Tax Rate Differential

IncomeTaxReconciliationForeignIncomeTaxRateDifferential

5752000

USD

CY2019

us-gaap

Income Tax Reconciliation Prior Year Income Taxes

IncomeTaxReconciliationPriorYearIncomeTaxes

632000

USD

CY2018

us-gaap

Income Tax Reconciliation Prior Year Income Taxes

IncomeTaxReconciliationPriorYearIncomeTaxes

-2522000

USD

CY2017

us-gaap

Income Tax Reconciliation Prior Year Income Taxes

IncomeTaxReconciliationPriorYearIncomeTaxes

-559000

USD

CY2019

us-gaap

Income Tax Reconciliation Nondeductible Expense Other

IncomeTaxReconciliationNondeductibleExpenseOther

436000

USD

CY2018

us-gaap

Income Tax Reconciliation Nondeductible Expense Other

IncomeTaxReconciliationNondeductibleExpenseOther

1293000

USD

CY2017

us-gaap

Income Tax Reconciliation Nondeductible Expense Other

IncomeTaxReconciliationNondeductibleExpenseOther

-572000

USD

CY2019

us-gaap

Income Tax Reconciliation Change In Enacted Tax Rate

IncomeTaxReconciliationChangeInEnactedTaxRate

0

USD

CY2018

us-gaap

Income Tax Reconciliation Change In Enacted Tax Rate

IncomeTaxReconciliationChangeInEnactedTaxRate

-128000

USD

CY2017

us-gaap

Income Tax Reconciliation Change In Enacted Tax Rate

IncomeTaxReconciliationChangeInEnactedTaxRate

7745000

USD

CY2019

acgl

Income Tax Reconciliation Dividend Withholding Taxes

IncomeTaxReconciliationDividendWithholdingTaxes

6510000

USD

CY2018

acgl

Income Tax Reconciliation Dividend Withholding Taxes

IncomeTaxReconciliationDividendWithholdingTaxes

6594000

USD

CY2017

acgl

Income Tax Reconciliation Dividend Withholding Taxes

IncomeTaxReconciliationDividendWithholdingTaxes

232000

USD

CY2019

us-gaap

Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance

IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance

1628000

USD

CY2018

us-gaap

Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance

IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance

18396000

USD

CY2017

us-gaap

Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance

IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance

14798000

USD

CY2019

acgl

Reconciliation Of Effective Tax Rate Contingent Consideration

ReconciliationOfEffectiveTaxRateContingentConsideration

190000

USD

CY2018

acgl

Reconciliation Of Effective Tax Rate Contingent Consideration

ReconciliationOfEffectiveTaxRateContingentConsideration

740000

USD

CY2017

acgl

Reconciliation Of Effective Tax Rate Contingent Consideration

ReconciliationOfEffectiveTaxRateContingentConsideration

3785000

USD

CY2019

us-gaap

Income Tax Reconciliation Nondeductible Expense Share Based Compensation Cost

IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost

-6592000

USD

CY2018

us-gaap

Income Tax Reconciliation Nondeductible Expense Share Based Compensation Cost

IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost

-5356000

USD

CY2017

us-gaap

Income Tax Reconciliation Nondeductible Expense Share Based Compensation Cost

IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost

-18733000

USD

CY2019

us-gaap

Income Tax Reconciliation Other Adjustments

IncomeTaxReconciliationOtherAdjustments

619000

USD

CY2018

us-gaap

Income Tax Reconciliation Other Adjustments

IncomeTaxReconciliationOtherAdjustments

-379000

USD

CY2017

us-gaap

Income Tax Reconciliation Other Adjustments

IncomeTaxReconciliationOtherAdjustments

393000

USD

CY2019

us-gaap

Income Tax Expense Benefit

IncomeTaxExpenseBenefit

155810000

USD

CY2018

us-gaap

Income Tax Expense Benefit

IncomeTaxExpenseBenefit

113951000

USD

CY2017

us-gaap

Income Tax Expense Benefit

IncomeTaxExpenseBenefit

127568000

USD

CY2019Q4

us-gaap

Deferred Tax Assets Operating Loss Carryforwards

DeferredTaxAssetsOperatingLossCarryforwards

30836000

USD

CY2018Q4

us-gaap

Deferred Tax Assets Operating Loss Carryforwards

DeferredTaxAssetsOperatingLossCarryforwards

24089000

USD

CY2019Q4

acgl

Lloyds Syndicate Uncrystallized Losses Deferred Tax Asset

LloydsSyndicateUncrystallizedLossesDeferredTaxAsset

1565000

USD

CY2018Q4

acgl

Lloyds Syndicate Uncrystallized Losses Deferred Tax Asset

LloydsSyndicateUncrystallizedLossesDeferredTaxAsset

7960000

USD

CY2019Q4

us-gaap

Deferred Tax Assets Tax Credit Carryforwards Alternative Minimum Tax

DeferredTaxAssetsTaxCreditCarryforwardsAlternativeMinimumTax

1323000

USD

CY2018Q4

us-gaap

Deferred Tax Assets Tax Credit Carryforwards Alternative Minimum Tax

DeferredTaxAssetsTaxCreditCarryforwardsAlternativeMinimumTax

2652000

USD

CY2019Q4

us-gaap

Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Loss Reserves

DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsLossReserves

52582000

USD

CY2018Q4

us-gaap

Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Loss Reserves

DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsLossReserves

43130000

USD

CY2019Q4

us-gaap

Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Unearned Premiums Reserve

DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsUnearnedPremiumsReserve

64269000

USD

CY2018Q4

us-gaap

Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Unearned Premiums Reserve

DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsUnearnedPremiumsReserve

68305000

USD

CY2019Q4

us-gaap

Deferred Tax Assets Tax Deferred Expense Compensation And Benefits

DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits

21693000

USD

CY2018Q4

us-gaap

Deferred Tax Assets Tax Deferred Expense Compensation And Benefits

DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits

20492000

USD

CY2019Q4

us-gaap

Deferred Tax Assets Tax Credit Carryforwards Foreign

DeferredTaxAssetsTaxCreditCarryforwardsForeign

9521000

USD

CY2018Q4

us-gaap

Deferred Tax Assets Tax Credit Carryforwards Foreign

DeferredTaxAssetsTaxCreditCarryforwardsForeign

9116000

USD

CY2019Q4

us-gaap

Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Other

DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsOther

0

USD

CY2018Q4

us-gaap

Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Other

DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsOther

1387000

USD

CY2019Q4

us-gaap

Deferred Tax Assets Goodwill And Intangible Assets

DeferredTaxAssetsGoodwillAndIntangibleAssets

11644000

USD

CY2018Q4

us-gaap

Deferred Tax Assets Goodwill And Intangible Assets

DeferredTaxAssetsGoodwillAndIntangibleAssets

17127000

USD

CY2019Q4

us-gaap

Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Reserves

DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsReserves

5983000

USD

CY2018Q4

us-gaap

Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Reserves

DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsReserves

5626000

USD

CY2019Q4

acgl

Deferred Tax Asset Lease Liability

DeferredTaxAssetLeaseLiability

26438000

USD

CY2018Q4

acgl

Deferred Tax Asset Lease Liability

DeferredTaxAssetLeaseLiability

0

USD

CY2019Q4

us-gaap

Deferred Tax Assets Unrealized Currency Losses

DeferredTaxAssetsUnrealizedCurrencyLosses

598000

USD

CY2018Q4

us-gaap

Deferred Tax Assets Unrealized Currency Losses

DeferredTaxAssetsUnrealizedCurrencyLosses

949000

USD

CY2019Q4

us-gaap

Deferred Tax Assets Unrealized Losses On Availablefor Sale Securities Gross

DeferredTaxAssetsUnrealizedLossesOnAvailableforSaleSecuritiesGross

0

USD

CY2018Q4

us-gaap

Deferred Tax Assets Unrealized Losses On Availablefor Sale Securities Gross

DeferredTaxAssetsUnrealizedLossesOnAvailableforSaleSecuritiesGross

13453000

USD

CY2019Q4

us-gaap

Deferred Tax Assets Tax Deferred Expense Other

DeferredTaxAssetsTaxDeferredExpenseOther

206000

USD

CY2018Q4

us-gaap

Deferred Tax Assets Tax Deferred Expense Other

DeferredTaxAssetsTaxDeferredExpenseOther

3418000

USD

CY2019Q4

us-gaap

Deferred Tax Assets Gross

DeferredTaxAssetsGross

226658000

USD

CY2018Q4

us-gaap

Deferred Tax Assets Gross

DeferredTaxAssetsGross

217704000

USD

CY2019Q4

us-gaap

Deferred Tax Assets Valuation Allowance

DeferredTaxAssetsValuationAllowance

48219000

USD

CY2018Q4

us-gaap

Deferred Tax Assets Valuation Allowance

DeferredTaxAssetsValuationAllowance

44659000

USD

CY2019Q4

us-gaap

Deferred Tax Assets Net

DeferredTaxAssetsNet

178439000

USD

CY2018Q4

us-gaap

Deferred Tax Assets Net

DeferredTaxAssetsNet

173045000

USD

CY2019Q4

us-gaap

Deferred Tax Liabilities Other Finite Lived Assets

DeferredTaxLiabilitiesOtherFiniteLivedAssets

1215000

USD

CY2018Q4

us-gaap

Deferred Tax Liabilities Other Finite Lived Assets

DeferredTaxLiabilitiesOtherFiniteLivedAssets

2559000

USD

CY2019Q4

us-gaap

Deferred Tax Liabilities Tax Deferred Income

DeferredTaxLiabilitiesTaxDeferredIncome

2169000

USD

CY2018Q4

us-gaap

Deferred Tax Liabilities Tax Deferred Income

DeferredTaxLiabilitiesTaxDeferredIncome

2292000

USD

CY2019Q4

acgl

Deferred Tax Liability Contingency Reserve

DeferredTaxLiabilityContingencyReserve

132831000

USD

CY2018Q4

acgl

Deferred Tax Liability Contingency Reserve

DeferredTaxLiabilityContingencyReserve

112852000

USD

CY2019Q4

us-gaap

Deferred Tax Liabilities Deferred Expense Other Capitalized Costs

DeferredTaxLiabilitiesDeferredExpenseOtherCapitalizedCosts

29847000

USD

CY2018Q4

us-gaap

Deferred Tax Liabilities Deferred Expense Other Capitalized Costs

DeferredTaxLiabilitiesDeferredExpenseOtherCapitalizedCosts

32105000

USD

CY2019Q4

us-gaap

Deferred Tax Liabilities Investments

DeferredTaxLiabilitiesInvestments

38764000

USD

CY2018Q4

us-gaap

Deferred Tax Liabilities Investments

DeferredTaxLiabilitiesInvestments

0

USD

CY2019Q4

acgl

Deferred Tax L Iabilities Right Of Use Asset

DeferredTaxLIabilitiesRightOfUseAsset

23416000

USD

CY2018Q4

acgl

Deferred Tax L Iabilities Right Of Use Asset

DeferredTaxLIabilitiesRightOfUseAsset

0

USD

CY2019Q4

us-gaap

Deferred Tax Liabilities Other

DeferredTaxLiabilitiesOther

3680000

USD

CY2018Q4

us-gaap

Deferred Tax Liabilities Other

DeferredTaxLiabilitiesOther

735000

USD

CY2019Q4

us-gaap

Deferred Income Tax Liabilities

DeferredIncomeTaxLiabilities

231922000

USD

CY2018Q4

us-gaap

Deferred Income Tax Liabilities

DeferredIncomeTaxLiabilities

150543000

USD

CY2019Q4

us-gaap

Deferred Tax Liabilities

DeferredTaxLiabilities

53483000

USD

CY2018Q4

us-gaap

Deferred Tax Assets Liabilities Net

DeferredTaxAssetsLiabilitiesNet

22502000

USD

CY2019Q4

us-gaap

Deferred Tax Assets Valuation Allowance

DeferredTaxAssetsValuationAllowance

48200000

USD

CY2018Q4

us-gaap

Deferred Tax Assets Valuation Allowance

DeferredTaxAssetsValuationAllowance

44700000

USD

CY2019Q4

us-gaap

Unrecognized Tax Benefits

UnrecognizedTaxBenefits

2000000.0

USD

CY2018Q4

us-gaap

Unrecognized Tax Benefits

UnrecognizedTaxBenefits

2008000

USD

CY2017Q4

us-gaap

Unrecognized Tax Benefits

UnrecognizedTaxBenefits

2008000

USD

CY2019

us-gaap

Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions

UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions

0

USD

CY2018

us-gaap

Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions

UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions

0

USD

CY2019

us-gaap

Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions

UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions

0

USD

CY2018

us-gaap

Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions

UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions

0

USD

CY2019

us-gaap

Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions

UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions

0

USD

CY2018

us-gaap

Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions

UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions

0

USD

CY2019

acgl

Unrecognized Tax Benefits Change Resulting From Settlements With Taxing Authorities

UnrecognizedTaxBenefitsChangeResultingFromSettlementsWithTaxingAuthorities

0

USD

CY2018

acgl

Unrecognized Tax Benefits Change Resulting From Settlements With Taxing Authorities

UnrecognizedTaxBenefitsChangeResultingFromSettlementsWithTaxingAuthorities

0

USD

CY2019Q4

us-gaap

Unrecognized Tax Benefits

UnrecognizedTaxBenefits

2008000

USD

CY2018Q4

us-gaap

Unrecognized Tax Benefits

UnrecognizedTaxBenefits

2008000

USD

CY2019Q4

us-gaap

Accrued Income Taxes Current

AccruedIncomeTaxesCurrent

13500000

USD

CY2019

us-gaap

Operating Lease Expense

OperatingLeaseExpense

30478000

USD

CY2019

us-gaap

Operating Lease Payments

OperatingLeasePayments

27521000

USD

CY2019

us-gaap

Right Of Use Asset Obtained In Exchange For Operating Lease Liability

RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability

7445000

USD

CY2019Q4

us-gaap

Operating Lease Weighted Average Discount Rate Percent

OperatingLeaseWeightedAverageDiscountRatePercent

0.039

CY2019Q4

us-gaap

Operating Lease Weighted Average Remaining Lease Term1

OperatingLeaseWeightedAverageRemainingLeaseTerm1

P6Y4M24D

CY2019Q4

us-gaap

Lessee Operating Lease Liability Payments Due Next Twelve Months

LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths

31907000

USD

CY2019Q4

us-gaap

Lessee Operating Lease Liability Payments Due Year Two

LesseeOperatingLeaseLiabilityPaymentsDueYearTwo

30842000

USD

CY2019Q4

us-gaap

Lessee Operating Lease Liability Payments Due Year Three

LesseeOperatingLeaseLiabilityPaymentsDueYearThree

27597000

USD

CY2019Q4

us-gaap

Lessee Operating Lease Liability Payments Due Year Four

LesseeOperatingLeaseLiabilityPaymentsDueYearFour

23027000

USD

CY2019Q4

us-gaap

Lessee Operating Lease Liability Payments Due Year Five

LesseeOperatingLeaseLiabilityPaymentsDueYearFive

16913000

USD

CY2019Q4

us-gaap

Lessee Operating Lease Liability Payments Due After Year Five

LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive

40167000

USD

CY2019Q4

us-gaap

Lessee Operating Lease Liability Payments Due

LesseeOperatingLeaseLiabilityPaymentsDue

170453000

USD

CY2019Q4

us-gaap

Lessee Operating Lease Liability Undiscounted Excess Amount

LesseeOperatingLeaseLiabilityUndiscountedExcessAmount

19934000

USD

CY2019Q4

us-gaap

Operating Lease Liability

OperatingLeaseLiability

150519000

USD

CY2019Q4

us-gaap

Operating Leases Future Minimum Payments Due Current

OperatingLeasesFutureMinimumPaymentsDueCurrent

31088000

USD

CY2019Q4

us-gaap

Operating Leases Future Minimum Payments Due In Two Years

OperatingLeasesFutureMinimumPaymentsDueInTwoYears

30491000

USD

CY2019Q4

us-gaap

Operating Leases Future Minimum Payments Due In Three Years

OperatingLeasesFutureMinimumPaymentsDueInThreeYears

29351000

USD

CY2019Q4

us-gaap

Operating Leases Future Minimum Payments Due In Four Years

OperatingLeasesFutureMinimumPaymentsDueInFourYears

26068000

USD

CY2019Q4

us-gaap

Operating Leases Future Minimum Payments Due In Five Years

OperatingLeasesFutureMinimumPaymentsDueInFiveYears

21408000

USD

CY2019Q4

us-gaap

Operating Leases Future Minimum Payments Due Thereafter

OperatingLeasesFutureMinimumPaymentsDueThereafter

54745000

USD

CY2019Q4

us-gaap

Operating Leases Future Minimum Payments Due

OperatingLeasesFutureMinimumPaymentsDue

193151000

USD

CY2019

us-gaap

Operating Lease Expense

OperatingLeaseExpense

30500000

USD

CY2018

us-gaap

Operating Lease Expense

OperatingLeaseExpense

27600000

USD

CY2017

us-gaap

Operating Lease Expense

OperatingLeaseExpense

31100000

USD

CY2019Q4

us-gaap

Finance Lease Liability Payments Due Year Two

FinanceLeaseLiabilityPaymentsDueYearTwo

4800000

USD

CY2019Q4

us-gaap

Finance Lease Liability Payments Due Year Three

FinanceLeaseLiabilityPaymentsDueYearThree

2100000

USD

CY2019

us-gaap

Concentration Risk Percentage1

ConcentrationRiskPercentage1

0.10

CY2019

us-gaap

Concentration Risk Percentage1

ConcentrationRiskPercentage1

0.10

CY2019Q4

acgl

Investment Commitments

InvestmentCommitments

1690000000

USD

CY2018Q4

acgl

Investment Commitments

InvestmentCommitments

1770000000

USD

CY2019Q4

us-gaap

Purchase Commitment Remaining Minimum Amount Committed

PurchaseCommitmentRemainingMinimumAmountCommitted

55600000

USD

CY2018Q4

us-gaap

Purchase Commitment Remaining Minimum Amount Committed

PurchaseCommitmentRemainingMinimumAmountCommitted

39500000

USD

CY2019

us-gaap

Amortization Of Intangible Assets

AmortizationOfIntangibleAssets

82104000

USD

CY2019

us-gaap

Amortization Of Intangible Assets

AmortizationOfIntangibleAssets

82104000

USD

CY2019Q4

us-gaap

Security Owned And Pledged As Collateral Fair Value

SecurityOwnedAndPledgedAsCollateralFairValue

255400000

USD

CY2019Q4

us-gaap

Line Of Credit

LineOfCredit

484287000

USD

CY2018Q4

us-gaap

Line Of Credit

LineOfCredit

455682000

USD

CY2017Q4

us-gaap

Goodwill

198236000

USD

CY2017Q4

us-gaap

Indefinite Lived Intangible Assets Excluding Goodwill

IndefiniteLivedIntangibleAssetsExcludingGoodwill

68174000

USD

CY2017Q4

us-gaap

Finite Lived Intangible Assets Net

FiniteLivedIntangibleAssetsNet

386201000

USD

CY2017Q4

us-gaap

Intangible Assets Net Including Goodwill

IntangibleAssetsNetIncludingGoodwill

652611000

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CY2018

us-gaap

Goodwill Acquired During Period

GoodwillAcquiredDuringPeriod

51476000

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CY2018

us-gaap

Indefinitelived Intangible Assets Acquired

IndefinitelivedIntangibleAssetsAcquired

0

USD

CY2018

us-gaap

Finitelived Intangible Assets Acquired1

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43000000

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CY2018

acgl

Intangible Assets Including Goodwill Acquired Duringthe Period

IntangibleAssetsIncludingGoodwillAcquiredDuringthePeriod

94476000

USD

CY2018

us-gaap

Amortization Of Intangible Assets

AmortizationOfIntangibleAssets

105670000

USD

CY2018

us-gaap

Amortization Of Intangible Assets

AmortizationOfIntangibleAssets

105670000

USD

CY2018

us-gaap

Goodwill Impairment Loss

GoodwillImpairmentLoss

0

USD

CY2018

us-gaap

Impairment Of Intangible Assets Indefinitelived Excluding Goodwill

ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill

6300000

USD

CY2018

us-gaap

Impairment Of Intangible Assets Finitelived

ImpairmentOfIntangibleAssetsFinitelived

0

USD

CY2018

us-gaap

Goodwill And Intangible Asset Impairment

GoodwillAndIntangibleAssetImpairment

6300000

USD

CY2018

us-gaap

Goodwill Foreign Currency Translation Gain Loss

GoodwillForeignCurrencyTranslationGainLoss

92000

USD

CY2018

us-gaap

Indefinite Lived Intangible Assets Foreign Currency Translation Gain Loss

IndefiniteLivedIntangibleAssetsForeignCurrencyTranslationGainLoss

0

USD

CY2018

us-gaap

Finite Lived Intangible Assets Foreign Currency Translation Gain Loss

FiniteLivedIntangibleAssetsForeignCurrencyTranslationGainLoss

105000

USD

CY2018

acgl

Intangible Assets Including Goodwill Foreign Currency Translation And Other Adjustments

IntangibleAssetsIncludingGoodwillForeignCurrencyTranslationAndOtherAdjustments

197000

USD

CY2018Q4

us-gaap

Goodwill

249620000

USD

CY2018Q4

us-gaap

Indefinite Lived Intangible Assets Excluding Goodwill

IndefiniteLivedIntangibleAssetsExcludingGoodwill

61874000

USD

CY2018Q4

us-gaap

Finite Lived Intangible Assets Net

FiniteLivedIntangibleAssetsNet

323426000

USD

CY2018Q4

us-gaap

Intangible Assets Net Including Goodwill

IntangibleAssetsNetIncludingGoodwill

634920000

USD

CY2019

us-gaap

Goodwill Acquired During Period

GoodwillAcquiredDuringPeriod

74780000

USD

CY2019

us-gaap

Indefinitelived Intangible Assets Acquired

IndefinitelivedIntangibleAssetsAcquired

24431000

USD

CY2019

us-gaap

Finitelived Intangible Assets Acquired1

FinitelivedIntangibleAssetsAcquired1

82482000

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CY2019

acgl

Intangible Assets Including Goodwill Acquired Duringthe Period

IntangibleAssetsIncludingGoodwillAcquiredDuringthePeriod

181693000

USD

CY2019

us-gaap

Goodwill Impairment Loss

GoodwillImpairmentLoss

0

USD

CY2019

us-gaap

Impairment Of Intangible Assets Indefinitelived Excluding Goodwill

ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill

1000000

USD

CY2019

us-gaap

Impairment Of Intangible Assets Finitelived

ImpairmentOfIntangibleAssetsFinitelived

0

USD

CY2019

us-gaap

Goodwill And Intangible Asset Impairment

GoodwillAndIntangibleAssetImpairment

1000000

USD

CY2019

us-gaap

Impairment Of Intangible Assets Indefinitelived Excluding Goodwill

ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill

1000000.0

USD

CY2019

us-gaap

Goodwill Foreign Currency Translation Gain Loss

GoodwillForeignCurrencyTranslationGainLoss

-2151000

USD

CY2019

us-gaap

Indefinite Lived Intangible Assets Foreign Currency Translation Gain Loss

IndefiniteLivedIntangibleAssetsForeignCurrencyTranslationGainLoss

-605000

USD

CY2019

us-gaap

Finite Lived Intangible Assets Foreign Currency Translation Gain Loss

FiniteLivedIntangibleAssetsForeignCurrencyTranslationGainLoss

-1817000

USD

CY2019

acgl

Intangible Assets Including Goodwill Foreign Currency Translation And Other Adjustments

IntangibleAssetsIncludingGoodwillForeignCurrencyTranslationAndOtherAdjustments

-4574000

USD

CY2019Q4

us-gaap

Goodwill

326551000

USD

CY2019Q4

us-gaap

Indefinite Lived Intangible Assets Excluding Goodwill

IndefiniteLivedIntangibleAssetsExcludingGoodwill

85910000

USD

CY2019Q4

us-gaap

Finite Lived Intangible Assets Net

FiniteLivedIntangibleAssetsNet

325621000

USD

CY2019Q4

us-gaap

Intangible Assets Net Including Goodwill

IntangibleAssetsNetIncludingGoodwill

738083000

USD

CY2019Q4

acgl

Intangible Assets Gross Including Goodwill

IntangibleAssetsGrossIncludingGoodwill

1161336000

USD

CY2019Q4

us-gaap

Finite Lived Intangible Assets Accumulated Amortization

FiniteLivedIntangibleAssetsAccumulatedAmortization

419294000

USD

CY2019

us-gaap

Indefinite Lived Intangible Assets Foreign Currency Translation Gain Loss

IndefiniteLivedIntangibleAssetsForeignCurrencyTranslationGainLoss

-605000

USD

CY2019Q4

acgl

Intangible Assets Including Goodwill Accumulated Foreign Currency And Other Adjustments

IntangibleAssetsIncludingGoodwillAccumulatedForeignCurrencyAndOtherAdjustments

3959000

USD

CY2019Q4

us-gaap

Intangible Assets Net Including Goodwill

IntangibleAssetsNetIncludingGoodwill

738083000

USD

CY2018

us-gaap

Impairment Of Intangible Assets Indefinitelived Excluding Goodwill

ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill

6300000

USD

CY2019Q4

acgl

Intangible Assets Liabilitiesand Goodwill Gross

IntangibleAssetsLiabilitiesandGoodwillGross

1161336000

USD

CY2019Q4

us-gaap

Finite Lived Intangible Assets Accumulated Amortization

FiniteLivedIntangibleAssetsAccumulatedAmortization

419294000

USD

CY2019Q4

acgl

Intangible Assets Including Goodwill Accumulated Foreign Currency And Other Adjustments

IntangibleAssetsIncludingGoodwillAccumulatedForeignCurrencyAndOtherAdjustments

3959000

USD

CY2019Q4

acgl

Intangible Assets Liabilitiesand Goodwill Net

IntangibleAssetsLiabilitiesandGoodwillNet

738083000

USD

CY2018Q4

acgl

Intangible Assets Liabilitiesand Goodwill Gross

IntangibleAssetsLiabilitiesandGoodwillGross

980643000

USD

CY2018Q4

us-gaap

Finite Lived Intangible Assets Accumulated Amortization

FiniteLivedIntangibleAssetsAccumulatedAmortization

337190000

USD

CY2018Q4

acgl

Intangible Assets Including Goodwill Accumulated Foreign Currency And Other Adjustments

IntangibleAssetsIncludingGoodwillAccumulatedForeignCurrencyAndOtherAdjustments

8533000

USD

CY2018Q4

acgl

Intangible Assets Liabilitiesand Goodwill Net

IntangibleAssetsLiabilitiesandGoodwillNet

634920000

USD

CY2019Q4

us-gaap

Finite Lived Intangible Assets Amortization Expense Next Twelve Months

FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths

65958000

USD

CY2019Q4

us-gaap

Finite Lived Intangible Assets Amortization Expense Year Two

FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo

48063000

USD

CY2019Q4

us-gaap

Finite Lived Intangible Assets Amortization Expense Year Three

FiniteLivedIntangibleAssetsAmortizationExpenseYearThree

33972000

USD

CY2019Q4

us-gaap

Finite Lived Intangible Assets Amortization Expense Year Four

FiniteLivedIntangibleAssetsAmortizationExpenseYearFour

31731000

USD

CY2019Q4

us-gaap

Finite Lived Intangible Assets Amortization Expense Year Five

FiniteLivedIntangibleAssetsAmortizationExpenseYearFive

27566000

USD

CY2019Q4

us-gaap

Finite Lived Intangible Assets Amortization Expense After Year Five

FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive

118331000

USD

CY2019Q4

us-gaap

Finite Lived Intangible Assets Net

FiniteLivedIntangibleAssetsNet

325621000

USD

CY2019Q4

us-gaap

Common Stock Shares Authorized

CommonStockSharesAuthorized

1800000000

shares

CY2019Q4

us-gaap

Common Stock Par Or Stated Value Per Share

CommonStockParOrStatedValuePerShare

0.0011

CY2019Q4

us-gaap

Preferred Stock Shares Authorized

PreferredStockSharesAuthorized

50000000

shares

CY2019Q4

us-gaap

Preferred Stock Par Or Stated Value Per Share

PreferredStockParOrStatedValuePerShare

0.01

CY2018Q4

us-gaap

Common Stock Shares Issued

CommonStockSharesIssued

570737283

shares

CY2017Q4

us-gaap

Common Stock Shares Issued

CommonStockSharesIssued

549872226

shares

CY2016Q4

us-gaap

Common Stock Shares Issued

CommonStockSharesIssued

523932303

shares

CY2019

us-gaap

Stock Issued During Period Shares New Issues

StockIssuedDuringPeriodSharesNewIssues

2835994

shares

CY2018

us-gaap

Stock Issued During Period Shares New Issues

StockIssuedDuringPeriodSharesNewIssues

2757506

shares

CY2017

us-gaap

Stock Issued During Period Shares New Issues

StockIssuedDuringPeriodSharesNewIssues

3388344

shares

CY2019

us-gaap

Conversion Of Stock Shares Converted1

ConversionOfStockSharesConverted1

0

shares

CY2018

us-gaap

Conversion Of Stock Shares Converted1

ConversionOfStockSharesConverted1

17022600

shares

CY2017

us-gaap

Conversion Of Stock Shares Converted1

ConversionOfStockSharesConverted1

21265860

shares

CY2019

us-gaap

Stock Issued During Period Shares Restricted Stock Award Net Of Forfeitures

StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures

1043918

shares

CY2018

us-gaap

Stock Issued During Period Shares Restricted Stock Award Net Of Forfeitures

StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures

1084951

shares

CY2017

us-gaap

Stock Issued During Period Shares Restricted Stock Award Net Of Forfeitures

StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures

1285719

shares

CY2019Q4

us-gaap

Common Stock Shares Issued

CommonStockSharesIssued

574617195

shares

CY2018Q4

us-gaap

Common Stock Shares Issued

CommonStockSharesIssued

570737283

shares

CY2017Q4

us-gaap

Common Stock Shares Issued

CommonStockSharesIssued

549872226

shares

CY2019Q4

us-gaap

Treasury Stock Shares

TreasuryStockShares

168997994

shares

CY2018Q4

us-gaap

Treasury Stock Shares

TreasuryStockShares

168282449

shares

CY2017Q4

us-gaap

Treasury Stock Shares

TreasuryStockShares

156938409

shares

CY2019Q4

us-gaap

Common Stock Shares Outstanding

CommonStockSharesOutstanding

405619201

shares

CY2018Q4

us-gaap

Common Stock Shares Outstanding

CommonStockSharesOutstanding

402454834

shares

CY2017Q4

us-gaap

Common Stock Shares Outstanding

CommonStockSharesOutstanding

392933817

shares

CY2018Q2

us-gaap

Stockholders Equity Note Stock Split Conversion Ratio1

StockholdersEquityNoteStockSplitConversionRatio1

3

CY2018Q2

us-gaap

Common Stock Shares Authorized

CommonStockSharesAuthorized

1800000000

shares

CY2018Q2

us-gaap

Common Stock Shares Authorized

CommonStockSharesAuthorized

600000000

shares

CY2018Q2

us-gaap

Common Stock Par Or Stated Value Per Share

CommonStockParOrStatedValuePerShare

0.0011

CY2018Q2

us-gaap

Common Stock Par Or Stated Value Per Share

CommonStockParOrStatedValuePerShare

0.0033

CY2019Q4

us-gaap

Treasury Stock Shares

TreasuryStockShares

169000000.0

shares

CY2019Q4

us-gaap

Treasury Stock Value

TreasuryStockValue

2410000000

USD

CY2019

us-gaap

Treasury Stock Value Acquired Cost Method

TreasuryStockValueAcquiredCostMethod

2871000

USD

CY2018

us-gaap

Treasury Stock Value Acquired Cost Method

TreasuryStockValueAcquiredCostMethod

282762000

USD

CY2017

us-gaap

Treasury Stock Value Acquired Cost Method

TreasuryStockValueAcquiredCostMethod

0

USD

CY2019

us-gaap

Treasury Stock Shares Acquired

TreasuryStockSharesAcquired

110598

shares

CY2018

us-gaap

Treasury Stock Shares Acquired

TreasuryStockSharesAcquired

10559850

shares

CY2017

us-gaap

Treasury Stock Shares Acquired

TreasuryStockSharesAcquired

0

shares

CY2019

us-gaap

Treasury Stock Acquired Average Cost Per Share

TreasuryStockAcquiredAverageCostPerShare

25.96

CY2018

us-gaap

Treasury Stock Acquired Average Cost Per Share

TreasuryStockAcquiredAverageCostPerShare

26.78

CY2017

us-gaap

Treasury Stock Acquired Average Cost Per Share

TreasuryStockAcquiredAverageCostPerShare

0

CY2019

us-gaap

Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Dividend Rate

ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate

0

CY2018

us-gaap

Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Dividend Rate

ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate

0

CY2017

us-gaap

Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Dividend Rate

ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate

0

CY2019

us-gaap

Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate

ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate

0.181

CY2018

us-gaap

Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate

ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate

0.213

CY2017

us-gaap

Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate

ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate

0.213

CY2019

us-gaap

Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate

ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate

0.025

CY2018

us-gaap

Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate

ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate

0.028

CY2017

us-gaap

Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate

ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate

0.020

CY2019

us-gaap

Sharebased Compensation Arrangement By Sharebased Payment Award Fair Value Assumptions Expected Term1

SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1

P6Y

CY2018

us-gaap

Sharebased Compensation Arrangement By Sharebased Payment Award Fair Value Assumptions Expected Term1

SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1

P6Y

CY2017

us-gaap

Sharebased Compensation Arrangement By Sharebased Payment Award Fair Value Assumptions Expected Term1

SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1

P6Y

CY2019

us-gaap

Allocated Share Based Compensation Expense

AllocatedShareBasedCompensationExpense

63848000

USD

CY2018

us-gaap

Allocated Share Based Compensation Expense

AllocatedShareBasedCompensationExpense

55935000

USD

CY2017

us-gaap

Allocated Share Based Compensation Expense

AllocatedShareBasedCompensationExpense

67863000

USD

CY2019

us-gaap

Allocated Share Based Compensation Expense Net Of Tax

AllocatedShareBasedCompensationExpenseNetOfTax

55502000

USD

CY2018

us-gaap

Allocated Share Based Compensation Expense Net Of Tax

AllocatedShareBasedCompensationExpenseNetOfTax

49179000

USD

CY2017

us-gaap

Allocated Share Based Compensation Expense Net Of Tax

AllocatedShareBasedCompensationExpenseNetOfTax

56098000

USD

CY2019

us-gaap

Defined Contribution Plan Cost Recognized

DefinedContributionPlanCostRecognized

44800000

USD

CY2018

us-gaap

Defined Contribution Plan Cost Recognized

DefinedContributionPlanCostRecognized

40800000

USD

CY2017

us-gaap

Defined Contribution Plan Cost Recognized

DefinedContributionPlanCostRecognized

40700000

USD

CY2019Q4

us-gaap

Premiums Written Net

PremiumsWrittenNet

1455453000

USD

CY2019Q3

us-gaap

Premiums Written Net

PremiumsWrittenNet

1613457000

USD

CY2019Q2

us-gaap

Premiums Written Net

PremiumsWrittenNet

1444898000

USD

CY2019Q1

us-gaap

Premiums Written Net

PremiumsWrittenNet

1525259000

USD

CY2019Q4

us-gaap

Premiums Earned Net

PremiumsEarnedNet

1515882000

USD

CY2019Q3

us-gaap

Premiums Earned Net

PremiumsEarnedNet

1438023000

USD

CY2019Q2

us-gaap

Premiums Earned Net

PremiumsEarnedNet

1463727000

USD

CY2019Q1

us-gaap

Premiums Earned Net

PremiumsEarnedNet

1368866000

USD

CY2019Q4

us-gaap

Investment Income Net

InvestmentIncomeNet

154263000

USD

CY2019Q3

us-gaap

Investment Income Net

InvestmentIncomeNet

161488000

USD

CY2019Q2

us-gaap

Investment Income Net

InvestmentIncomeNet

155038000

USD

CY2019Q1

us-gaap

Investment Income Net

InvestmentIncomeNet

156949000

USD

CY2019Q4

us-gaap

Marketable Securities Gain Loss Excluding Other Than Temporary Impairments

MarketableSecuritiesGainLossExcludingOtherThanTemporaryImpairments

41474000

USD

CY2019Q3

us-gaap

Marketable Securities Gain Loss Excluding Other Than Temporary Impairments

MarketableSecuritiesGainLossExcludingOtherThanTemporaryImpairments

62518000

USD

CY2019Q2

us-gaap

Marketable Securities Gain Loss Excluding Other Than Temporary Impairments

MarketableSecuritiesGainLossExcludingOtherThanTemporaryImpairments

120806000

USD

CY2019Q1

us-gaap

Marketable Securities Gain Loss Excluding Other Than Temporary Impairments

MarketableSecuritiesGainLossExcludingOtherThanTemporaryImpairments

141565000

USD

CY2019Q4

us-gaap

Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net

OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNet

644000

USD

CY2019Q3

us-gaap

Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net

OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNet

1163000

USD

CY2019Q2

us-gaap

Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net

OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNet

49000

USD

CY2019Q1

us-gaap

Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net

OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNet

1309000

USD

CY2019Q1

us-gaap

Preferred Stock Dividends Income Statement Impact

PreferredStockDividendsIncomeStatementImpact

10403000

USD

CY2019Q4

us-gaap

Net Income Loss Available To Common Stockholders Basic

NetIncomeLossAvailableToCommonStockholdersBasic

315981000

USD

CY2019Q3

us-gaap

Net Income Loss Available To Common Stockholders Basic

NetIncomeLossAvailableToCommonStockholdersBasic

382050000

USD

CY2019Q2

us-gaap

Net Income Loss Available To Common Stockholders Basic

NetIncomeLossAvailableToCommonStockholdersBasic

458551000

USD

CY2019Q1

us-gaap

Net Income Loss Available To Common Stockholders Basic

NetIncomeLossAvailableToCommonStockholdersBasic

438125000

USD

CY2019Q4

acgl

Underwriting Income Loss Segment

UnderwritingIncomeLossSegment

251421000

USD

CY2019Q3

acgl

Underwriting Income Loss Segment

UnderwritingIncomeLossSegment

231262000

USD

CY2019Q2

acgl

Underwriting Income Loss Segment

UnderwritingIncomeLossSegment

293134000

USD

CY2019Q1

acgl

Underwriting Income Loss Segment

UnderwritingIncomeLossSegment

260148000

USD

CY2019Q4

us-gaap

Profit Loss

ProfitLoss

326384000

USD

CY2019Q3

us-gaap

Profit Loss

ProfitLoss

392453000

USD

CY2019Q2

us-gaap

Profit Loss

ProfitLoss

468954000

USD

CY2019Q1

us-gaap

Profit Loss

ProfitLoss

448528000

USD

CY2019Q4

us-gaap

Preferred Stock Dividends Income Statement Impact

PreferredStockDividendsIncomeStatementImpact

10403000

USD

CY2019Q3

us-gaap

Preferred Stock Dividends Income Statement Impact

PreferredStockDividendsIncomeStatementImpact

10403000

USD

CY2019Q2

us-gaap

Preferred Stock Dividends Income Statement Impact

PreferredStockDividendsIncomeStatementImpact

10403000

USD

CY2019Q4

us-gaap

Earnings Per Share Basic

EarningsPerShareBasic

0.78

CY2019Q3

us-gaap

Earnings Per Share Basic

EarningsPerShareBasic

0.95

CY2019Q2

us-gaap

Earnings Per Share Basic

EarningsPerShareBasic

1.14

CY2019Q1

us-gaap

Earnings Per Share Basic

EarningsPerShareBasic

1.09

CY2019Q4

us-gaap

Earnings Per Share Diluted

EarningsPerShareDiluted

0.76

CY2019Q3

us-gaap

Earnings Per Share Diluted

EarningsPerShareDiluted

0.92

CY2019Q2

us-gaap

Earnings Per Share Diluted

EarningsPerShareDiluted

1.12

CY2019Q1

us-gaap

Earnings Per Share Diluted

EarningsPerShareDiluted

1.07

CY2018Q4

us-gaap

Premiums Written Net

PremiumsWrittenNet

1301754000

USD

CY2018Q3

us-gaap

Premiums Written Net

PremiumsWrittenNet

1333553000

USD

CY2018Q2

us-gaap

Premiums Written Net

PremiumsWrittenNet

1298896000

USD

CY2018Q1

us-gaap

Premiums Written Net

PremiumsWrittenNet

1412544000

USD

CY2018Q4

us-gaap

Premiums Earned Net

PremiumsEarnedNet

1369435000

USD

CY2018Q3

us-gaap

Premiums Earned Net

PremiumsEarnedNet

1290878000

USD

CY2018Q2

us-gaap

Premiums Earned Net

PremiumsEarnedNet

1336763000

USD

CY2018Q1

us-gaap

Premiums Earned Net

PremiumsEarnedNet

1234899000

USD

CY2018Q4

us-gaap

Investment Income Net

InvestmentIncomeNet

157217000

USD

CY2018Q3

us-gaap

Investment Income Net

InvestmentIncomeNet

144024000

USD

CY2018Q2

us-gaap

Investment Income Net

InvestmentIncomeNet

135668000

USD

CY2018Q1

us-gaap

Investment Income Net

InvestmentIncomeNet

126724000

USD

CY2018Q4

us-gaap

Marketable Securities Gain Loss Excluding Other Than Temporary Impairments

MarketableSecuritiesGainLossExcludingOtherThanTemporaryImpairments

-166030000

USD

CY2018Q3

us-gaap

Marketable Securities Gain Loss Excluding Other Than Temporary Impairments

MarketableSecuritiesGainLossExcludingOtherThanTemporaryImpairments

-51705000

USD

CY2018Q2

us-gaap

Marketable Securities Gain Loss Excluding Other Than Temporary Impairments

MarketableSecuritiesGainLossExcludingOtherThanTemporaryImpairments

-76611000

USD

CY2018Q1

us-gaap

Marketable Securities Gain Loss Excluding Other Than Temporary Impairments

MarketableSecuritiesGainLossExcludingOtherThanTemporaryImpairments

-110998000

USD

CY2018Q4

us-gaap

Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net

OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNet

1705000

USD

CY2018Q3

us-gaap

Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net

OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNet

492000

USD

CY2018Q2

us-gaap

Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net

OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNet

470000

USD

CY2018Q1

us-gaap

Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net

OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNet

162000

USD

CY2018Q4

acgl

Underwriting Income Loss Segment

UnderwritingIncomeLossSegment

166955000

USD

CY2018Q3

acgl

Underwriting Income Loss Segment

UnderwritingIncomeLossSegment

234581000

USD

CY2018Q2

acgl

Underwriting Income Loss Segment

UnderwritingIncomeLossSegment

235465000

USD

CY2018Q1

acgl

Underwriting Income Loss Segment

UnderwritingIncomeLossSegment

236997000

USD

CY2018Q4

us-gaap

Profit Loss

ProfitLoss

136494000

USD

CY2018Q3

us-gaap

Profit Loss

ProfitLoss

227408000

USD

CY2018Q2

us-gaap

Profit Loss

ProfitLoss

243646000

USD

CY2018Q1

us-gaap

Profit Loss

ProfitLoss

150423000

USD

CY2018Q4

us-gaap

Preferred Stock Dividends Income Statement Impact

PreferredStockDividendsIncomeStatementImpact

10403000

USD

CY2018Q3

us-gaap

Preferred Stock Dividends Income Statement Impact

PreferredStockDividendsIncomeStatementImpact

10402000

USD

CY2018Q2

us-gaap

Preferred Stock Dividends Income Statement Impact

PreferredStockDividendsIncomeStatementImpact

10403000

USD

CY2018Q1

us-gaap

Preferred Stock Dividends Income Statement Impact

PreferredStockDividendsIncomeStatementImpact

10437000

USD

CY2018Q4

us-gaap

Net Income Loss Available To Common Stockholders Basic

NetIncomeLossAvailableToCommonStockholdersBasic

126091000

USD

CY2018Q3

us-gaap

Net Income Loss Available To Common Stockholders Basic

NetIncomeLossAvailableToCommonStockholdersBasic

217006000

USD

CY2018Q2

us-gaap

Net Income Loss Available To Common Stockholders Basic

NetIncomeLossAvailableToCommonStockholdersBasic

233243000

USD

CY2018Q1

us-gaap

Net Income Loss Available To Common Stockholders Basic

NetIncomeLossAvailableToCommonStockholdersBasic

137276000

USD

CY2018Q4

us-gaap

Earnings Per Share Basic

EarningsPerShareBasic

0.31

CY2018Q3

us-gaap

Earnings Per Share Basic

EarningsPerShareBasic

0.54

CY2018Q2

us-gaap

Earnings Per Share Basic

EarningsPerShareBasic

0.58

CY2018Q1

us-gaap

Earnings Per Share Basic

EarningsPerShareBasic

0.34

CY2018Q4

us-gaap

Earnings Per Share Diluted

EarningsPerShareDiluted

0.31

CY2018Q3

us-gaap

Earnings Per Share Diluted

EarningsPerShareDiluted

0.53

CY2018Q2

us-gaap

Earnings Per Share Diluted

EarningsPerShareDiluted

0.56

CY2018Q1

us-gaap

Earnings Per Share Diluted

EarningsPerShareDiluted

0.33

CY2019Q4

acgl

Subsidiary Investee Percentage Ownership

SubsidiaryInvesteePercentageOwnership

1

CY2019Q4

us-gaap

Investments

24402246000

USD

CY2019Q4

us-gaap

Cash And Cash Equivalents At Carrying Value

CashAndCashEquivalentsAtCarryingValue

726230000

USD

CY2019Q4

acgl

Investment In Subsidiaries

InvestmentInSubsidiaries

0

USD

CY2019Q4

us-gaap

Advances To Affiliate

AdvancesToAffiliate

0

USD

CY2019Q4

us-gaap

Premiums Receivable At Carrying Value

PremiumsReceivableAtCarryingValue

1778717000

USD

CY2019Q4

us-gaap

Reinsurance Recoverables

ReinsuranceRecoverables

4346816000

USD

CY2019Q4

acgl

Contractholder Deductibles Receivable

ContractholderDeductiblesReceivable

2119460000

USD

CY2019Q4

us-gaap

Prepaid Reinsurance Premiums

PrepaidReinsurancePremiums

1234683000

USD

CY2019Q4

us-gaap

Deferred Policy Acquisition Costs

DeferredPolicyAcquisitionCosts

633400000

USD

CY2019Q4

acgl

Intangible Assets Liabilitiesand Goodwill Net

IntangibleAssetsLiabilitiesandGoodwillNet

738083000

USD

CY2019Q4

us-gaap

Policyholder Contract Deposits

PolicyholderContractDeposits

206698000

USD

CY2019Q4

us-gaap

Senior Long Term Notes

SeniorLongTermNotes

1871626000

USD

CY2019Q4

us-gaap

Line Of Credit

LineOfCredit

484287000

USD

CY2019Q4

us-gaap

Due To Affiliate Current And Noncurrent

DueToAffiliateCurrentAndNoncurrent

0

USD

CY2019Q4

us-gaap

Accrued Liabilities And Other Liabilities

AccruedLiabilitiesAndOtherLiabilities

1989275000

USD

CY2019Q4

us-gaap

Liabilities

25569809000

USD

CY2019Q4

us-gaap

Redeemable Noncontrolling Interest Equity Fair Value

RedeemableNoncontrollingInterestEquityFairValue

55404000

USD

CY2019Q4

us-gaap

Stockholders Equity

StockholdersEquity

11497371000

USD

CY2019Q4

us-gaap

Minority Interest

MinorityInterest

762777000

USD

CY2019Q4

us-gaap

Prepaid Expense And Other Assets

PrepaidExpenseAndOtherAssets

1905726000

USD

CY2019Q4

us-gaap

Assets

37885361000

USD

CY2019Q4

us-gaap

Liability For Claims And Claims Adjustment Expense

LiabilityForClaimsAndClaimsAdjustmentExpense

13891842000

USD

CY2019Q4

us-gaap

Unearned Premiums

UnearnedPremiums

4339549000

USD

CY2019Q4

us-gaap

Reinsurance Payable

ReinsurancePayable

667072000

USD

CY2019Q4

acgl

Contract Holder Payables

ContractHolderPayables

2119460000

USD

CY2019Q4

us-gaap

Stockholders Equity Including Portion Attributable To Noncontrolling Interest

StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest

12260148000

USD

CY2019Q4

us-gaap

Liabilities And Stockholders Equity

LiabilitiesAndStockholdersEquity

37885361000

USD

CY2018Q4

us-gaap

Investments

21745284000

USD

CY2018Q4

us-gaap

Cash And Cash Equivalents At Carrying Value

CashAndCashEquivalentsAtCarryingValue

646556000

USD

CY2018Q4

acgl

Investment In Subsidiaries

InvestmentInSubsidiaries

0

USD

CY2018Q4

us-gaap

Advances To Affiliate

AdvancesToAffiliate

0

USD

CY2018Q4

us-gaap

Premiums Receivable At Carrying Value

PremiumsReceivableAtCarryingValue

1299150000

USD

CY2018Q4

us-gaap

Reinsurance Recoverables

ReinsuranceRecoverables

2919372000

USD

CY2018Q4

acgl

Contractholder Deductibles Receivable

ContractholderDeductiblesReceivable

2079111000

USD

CY2018Q4

us-gaap

Prepaid Reinsurance Premiums

PrepaidReinsurancePremiums

975469000

USD

CY2018Q4

us-gaap

Deferred Policy Acquisition Costs

DeferredPolicyAcquisitionCosts

569574000

USD

CY2018Q4

acgl

Intangible Assets Liabilitiesand Goodwill Net

IntangibleAssetsLiabilitiesandGoodwillNet

634920000

USD

CY2018Q4

us-gaap

Prepaid Expense And Other Assets

PrepaidExpenseAndOtherAssets

1348893000

USD

CY2018Q4

us-gaap

Assets

32218329000

USD

CY2018Q4

us-gaap

Liability For Claims And Claims Adjustment Expense

LiabilityForClaimsAndClaimsAdjustmentExpense

11853297000

USD

CY2018Q4

us-gaap

Unearned Premiums

UnearnedPremiums

3753636000

USD

CY2018Q4

us-gaap

Reinsurance Payable

ReinsurancePayable

393107000

USD

CY2018Q4

acgl

Contract Holder Payables

ContractHolderPayables

2079111000

USD

CY2018Q4

us-gaap

Policyholder Contract Deposits

PolicyholderContractDeposits

236630000

USD

CY2018Q4

us-gaap

Senior Long Term Notes

SeniorLongTermNotes

1733528000

USD

CY2018Q4

us-gaap

Line Of Credit

LineOfCredit

455682000

USD

CY2018Q4

us-gaap

Due To Affiliate Current And Noncurrent

DueToAffiliateCurrentAndNoncurrent

0

USD

CY2018Q4

us-gaap

Accrued Liabilities And Other Liabilities

AccruedLiabilitiesAndOtherLiabilities

1275659000

USD

CY2018Q4

us-gaap

Liabilities

21780650000

USD

CY2018Q4

us-gaap

Redeemable Noncontrolling Interest Equity Fair Value

RedeemableNoncontrollingInterestEquityFairValue

206292000

USD

CY2018Q4

us-gaap

Stockholders Equity

StockholdersEquity

9439827000

USD

CY2018Q4

us-gaap

Minority Interest

MinorityInterest

791560000

USD

CY2018Q4

us-gaap

Stockholders Equity Including Portion Attributable To Noncontrolling Interest

StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest

10231387000

USD

CY2018Q4

us-gaap

Liabilities And Stockholders Equity

LiabilitiesAndStockholdersEquity

32218329000

USD

CY2019

us-gaap

Premiums Earned Net

PremiumsEarnedNet

5786498000

USD

CY2019

us-gaap

Investment Income Net

InvestmentIncomeNet

627738000

USD

CY2019

us-gaap

Marketable Securities Gain Loss Excluding Other Than Temporary Impairments

MarketableSecuritiesGainLossExcludingOtherThanTemporaryImpairments

366363000

USD

CY2019

us-gaap

Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net

OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNet

3165000

USD

CY2019

acgl

Other Underwriting Income Loss

OtherUnderwritingIncomeLoss

24861000

USD

CY2019

us-gaap

Income Loss From Equity Method Investments

IncomeLossFromEquityMethodInvestments

123672000

USD

CY2019

us-gaap

Other Operating Income Expense Net

OtherOperatingIncomeExpenseNet

2233000

USD

CY2019

us-gaap

Revenues

6928200000

USD

CY2019

us-gaap

Policyholder Benefits And Claims Incurred Net

PolicyholderBenefitsAndClaimsIncurredNet

3133452000

USD

CY2019

us-gaap

Deferred Policy Acquisition Cost Amortization Expense

DeferredPolicyAcquisitionCostAmortizationExpense

840945000

USD

CY2019

us-gaap

Other Cost And Expense Operating

OtherCostAndExpenseOperating

800997000

USD

CY2019

us-gaap

General And Administrative Expense

GeneralAndAdministrativeExpense

80111000

USD

CY2019

us-gaap

Amortization Of Intangible Assets

AmortizationOfIntangibleAssets

82104000

USD

CY2019

us-gaap

Interest Expense

InterestExpense

120872000

USD

CY2019

us-gaap

Foreign Currency Transaction Gain Loss Before Tax

ForeignCurrencyTransactionGainLossBeforeTax

-20609000

USD

CY2019

us-gaap

Benefits Losses And Expenses

BenefitsLossesAndExpenses

5079090000

USD

CY2019

acgl

Income Loss Before Income Taxes And Equity In Net Income Of Subsidiaries

IncomeLossBeforeIncomeTaxesAndEquityInNetIncomeOfSubsidiaries

1849110000

USD

CY2019

us-gaap

Income Tax Expense Benefit

IncomeTaxExpenseBenefit

155810000

USD

CY2019

acgl

Income Loss Net Of Income Taxes And Before Equity In Net Income Of Subsidiaries

IncomeLossNetOfIncomeTaxesAndBeforeEquityInNetIncomeOfSubsidiaries

1693300000

USD

CY2019

us-gaap

Income Loss From Subsidiaries Net Of Tax

IncomeLossFromSubsidiariesNetOfTax

0

USD

CY2019

us-gaap

Profit Loss

ProfitLoss

1693300000

USD

CY2019

us-gaap

Net Income Loss Attributable To Noncontrolling Interest

NetIncomeLossAttributableToNoncontrollingInterest

56981000

USD

CY2019

us-gaap

Net Income Loss

NetIncomeLoss

1636319000

USD

CY2019

us-gaap

Preferred Stock Dividends Income Statement Impact

PreferredStockDividendsIncomeStatementImpact

41612000

USD

CY2019

us-gaap

Net Income Loss Available To Common Stockholders Basic

NetIncomeLossAvailableToCommonStockholdersBasic

1594707000

USD

CY2019

us-gaap

Comprehensive Income Net Of Tax

ComprehensiveIncomeNetOfTax

2027129000

USD

CY2018

us-gaap

Premiums Earned Net

PremiumsEarnedNet

5231975000

USD

CY2018

us-gaap

Investment Income Net

InvestmentIncomeNet

563633000

USD

CY2018

us-gaap

Marketable Securities Gain Loss Excluding Other Than Temporary Impairments

MarketableSecuritiesGainLossExcludingOtherThanTemporaryImpairments

-405344000

USD

CY2018

us-gaap

Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net

OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNet

2829000

USD

CY2018

acgl

Other Underwriting Income Loss

OtherUnderwritingIncomeLoss

15073000

USD

CY2018

us-gaap

Income Loss From Equity Method Investments

IncomeLossFromEquityMethodInvestments

45641000

USD

CY2018

us-gaap

Other Operating Income Expense Net

OtherOperatingIncomeExpenseNet

2419000

USD

CY2018

us-gaap

Revenues

5450568000

USD

CY2018

us-gaap

Policyholder Benefits And Claims Incurred Net

PolicyholderBenefitsAndClaimsIncurredNet

2890106000

USD

CY2018

us-gaap

Deferred Policy Acquisition Cost Amortization Expense

DeferredPolicyAcquisitionCostAmortizationExpense

805135000

USD

CY2018

us-gaap

Other Cost And Expense Operating

OtherCostAndExpenseOperating

677809000

USD

CY2018

us-gaap

General And Administrative Expense

GeneralAndAdministrativeExpense

78994000

USD

CY2018

us-gaap

Amortization Of Intangible Assets

AmortizationOfIntangibleAssets

105670000

USD

CY2018

us-gaap

Interest Expense

InterestExpense

120484000

USD

CY2018

us-gaap

Foreign Currency Transaction Gain Loss Before Tax

ForeignCurrencyTransactionGainLossBeforeTax

69402000

USD

CY2018

us-gaap

Benefits Losses And Expenses

BenefitsLossesAndExpenses

4608796000

USD

CY2018

acgl

Income Loss Before Income Taxes And Equity In Net Income Of Subsidiaries

IncomeLossBeforeIncomeTaxesAndEquityInNetIncomeOfSubsidiaries

841772000

USD

CY2018

us-gaap

Income Tax Expense Benefit

IncomeTaxExpenseBenefit

113951000

USD

CY2018

acgl

Income Loss Net Of Income Taxes And Before Equity In Net Income Of Subsidiaries

IncomeLossNetOfIncomeTaxesAndBeforeEquityInNetIncomeOfSubsidiaries

727821000

USD

CY2018

us-gaap

Income Loss From Subsidiaries Net Of Tax

IncomeLossFromSubsidiariesNetOfTax

0

USD

CY2018

us-gaap

Profit Loss

ProfitLoss

727821000

USD

CY2018

us-gaap

Net Income Loss Attributable To Noncontrolling Interest

NetIncomeLossAttributableToNoncontrollingInterest

-30150000

USD

CY2018

us-gaap

Net Income Loss

NetIncomeLoss

757971000

USD

CY2018

us-gaap

Preferred Stock Dividends Income Statement Impact

PreferredStockDividendsIncomeStatementImpact

41645000

USD

CY2018

us-gaap

Preferred Stock Redemption Premium

PreferredStockRedemptionPremium

2710000

USD

CY2018

us-gaap

Net Income Loss Available To Common Stockholders Basic

NetIncomeLossAvailableToCommonStockholdersBasic

713616000

USD

CY2018

us-gaap

Comprehensive Income Net Of Tax

ComprehensiveIncomeNetOfTax

611003000

USD

CY2017

us-gaap

Premiums Earned Net

PremiumsEarnedNet

4844532000

USD

CY2017

us-gaap

Investment Income Net

InvestmentIncomeNet

470872000

USD

CY2017

us-gaap

Marketable Securities Gain Loss Excluding Other Than Temporary Impairments

MarketableSecuritiesGainLossExcludingOtherThanTemporaryImpairments

149141000

USD

CY2017

us-gaap

Other Than Temporary Impairment Losses Investments Portion Recognized In Earnings Net

OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNet

7138000

USD

CY2017

acgl

Other Underwriting Income Loss

OtherUnderwritingIncomeLoss

30253000

USD

CY2017

us-gaap

Income Loss From Equity Method Investments

IncomeLossFromEquityMethodInvestments

142286000

USD

CY2017

us-gaap

Other Operating Income Expense Net

OtherOperatingIncomeExpenseNet

-2571000

USD

CY2017

us-gaap

Revenues

5627375000

USD

CY2017

us-gaap

Policyholder Benefits And Claims Incurred Net

PolicyholderBenefitsAndClaimsIncurredNet

2967446000

USD

CY2017

us-gaap

Deferred Policy Acquisition Cost Amortization Expense

DeferredPolicyAcquisitionCostAmortizationExpense

775458000

USD

CY2017

us-gaap

Other Cost And Expense Operating

OtherCostAndExpenseOperating

684451000

USD

CY2017

us-gaap

General And Administrative Expense

GeneralAndAdministrativeExpense

83752000

USD

CY2017

us-gaap

Amortization Of Intangible Assets

AmortizationOfIntangibleAssets

125778000

USD

CY2017

us-gaap

Interest Expense

InterestExpense

117431000

USD

CY2017

us-gaap

Foreign Currency Transaction Gain Loss Before Tax

ForeignCurrencyTransactionGainLossBeforeTax

-115782000

USD

CY2017

us-gaap

Benefits Losses And Expenses

BenefitsLossesAndExpenses

4870098000

USD

CY2017

acgl

Income Loss Before Income Taxes And Equity In Net Income Of Subsidiaries

IncomeLossBeforeIncomeTaxesAndEquityInNetIncomeOfSubsidiaries

757277000

USD

CY2017

us-gaap

Income Tax Expense Benefit

IncomeTaxExpenseBenefit

127568000

USD

CY2017

acgl

Income Loss Net Of Income Taxes And Before Equity In Net Income Of Subsidiaries

IncomeLossNetOfIncomeTaxesAndBeforeEquityInNetIncomeOfSubsidiaries

629709000

USD

CY2017

us-gaap

Income Loss From Subsidiaries Net Of Tax

IncomeLossFromSubsidiariesNetOfTax

0

USD

CY2017

us-gaap

Profit Loss

ProfitLoss

629709000

USD

CY2017

us-gaap

Net Income Loss Attributable To Noncontrolling Interest

NetIncomeLossAttributableToNoncontrollingInterest

10431000

USD

CY2017

us-gaap

Net Income Loss Available To Common Stockholders Basic

NetIncomeLossAvailableToCommonStockholdersBasic

566502000

USD

CY2017

us-gaap

Net Income Loss

NetIncomeLoss

619278000

USD

CY2017

us-gaap

Preferred Stock Dividends Income Statement Impact

PreferredStockDividendsIncomeStatementImpact

46041000

USD

CY2017

us-gaap

Preferred Stock Redemption Premium

PreferredStockRedemptionPremium

6735000

USD

CY2017

us-gaap

Comprehensive Income Net Of Tax

ComprehensiveIncomeNetOfTax

851863000

USD

CY2019

us-gaap

Net Cash Provided By Used In Operating Activities

NetCashProvidedByUsedInOperatingActivities

2048459000

USD

CY2019

us-gaap

Payments To Acquire Available For Sale Securities Debt

PaymentsToAcquireAvailableForSaleSecuritiesDebt

30053777000

USD

CY2019

us-gaap

Payments To Acquire Trading Securities Heldforinvestment

PaymentsToAcquireTradingSecuritiesHeldforinvestment

811967000

USD

CY2019

us-gaap

Payments To Acquire Other Investments

PaymentsToAcquireOtherInvestments

1470545000

USD

CY2019

us-gaap

Proceeds From Sale Of Available For Sale Securities Debt

ProceedsFromSaleOfAvailableForSaleSecuritiesDebt

28595865000

USD

CY2019

us-gaap

Proceeds From Sale Of Trading Securities Heldforinvestment

ProceedsFromSaleOfTradingSecuritiesHeldforinvestment

429818000

USD

CY2019

us-gaap

Proceeds From Sale Of Other Investments

ProceedsFromSaleOfOtherInvestments

1209559000

USD

CY2019

us-gaap

Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities

ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities

643265000

USD

CY2019

us-gaap

Payments For Proceeds From Derivative Instrument Investing Activities

PaymentsForProceedsFromDerivativeInstrumentInvestingActivities

-59982000

USD

CY2019

us-gaap

Payments For Proceeds From Short Term Investments

PaymentsForProceedsFromShortTermInvestments

-39833000

USD

CY2019

us-gaap

Increase Decrease In Cash Collateral For Borrowed Securities

IncreaseDecreaseInCashCollateralForBorrowedSecurities

62193000

USD

CY2019

acgl

Capital Contributions To Subsidiaries

CapitalContributionsToSubsidiaries

0

USD

CY2019

acgl

Payments For Proceeds From Intercompany Loans

PaymentsForProceedsFromIntercompanyLoans

0

USD

CY2019

us-gaap

Payments To Acquire Productive Assets

PaymentsToAcquireProductiveAssets

37837000

USD

CY2019

us-gaap

Payments For Proceeds From Other Investing Activities

PaymentsForProceedsFromOtherInvestingActivities

348486000

USD

CY2019

us-gaap

Net Cash Provided By Used In Investing Activities

NetCashProvidedByUsedInInvestingActivities

-1806483000

USD

CY2019

us-gaap

Payments For Repurchase Of Common Stock

PaymentsForRepurchaseOfCommonStock

2871000

USD

CY2019

us-gaap

Proceeds From Repurchase Of Equity

ProceedsFromRepurchaseOfEquity

6203000

USD

CY2019

acgl

Proceeds From Intercompany Loans Financing Activities

ProceedsFromIntercompanyLoansFinancingActivities

0

USD

CY2019

us-gaap

Proceeds From Other Debt

ProceedsFromOtherDebt

200083000

USD

CY2019

us-gaap

Repayments Of Other Debt

RepaymentsOfOtherDebt

49182000

USD

CY2019

us-gaap

Increase Decrease In Cash Collateral For Loaned Securities

IncreaseDecreaseInCashCollateralForLoanedSecurities

62193000

USD

CY2019

us-gaap

Proceeds From Payments To Minority Shareholders

ProceedsFromPaymentsToMinorityShareholders

-75056000

USD

CY2019

us-gaap

Proceeds From Repurchase Of Redeemable Preferred Stock

ProceedsFromRepurchaseOfRedeemablePreferredStock

-161882000

USD

CY2019

us-gaap

Payments Of Dividends Minority Interest

PaymentsOfDividendsMinorityInterest

12515000

USD

CY2019

us-gaap

Cash Dividends Paid To Parent Company By Consolidated Subsidiaries

CashDividendsPaidToParentCompanyByConsolidatedSubsidiaries

0

USD

CY2019

us-gaap

Proceeds From Payments For Other Financing Activities

ProceedsFromPaymentsForOtherFinancingActivities

-6023000

USD

CY2019

us-gaap

Payments Of Dividends Preferred Stock And Preference Stock

PaymentsOfDividendsPreferredStockAndPreferenceStock

41612000

USD

CY2019

us-gaap

Net Cash Provided By Used In Financing Activities

NetCashProvidedByUsedInFinancingActivities

-80662000

USD

CY2019

us-gaap

Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents

EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

17741000

USD

CY2019

us-gaap

Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect

CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect

179055000

USD

CY2018Q4

us-gaap

Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents

CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

724643000

USD

CY2019Q4

us-gaap

Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents

CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

903698000

USD

CY2018

us-gaap

Net Cash Provided By Used In Operating Activities

NetCashProvidedByUsedInOperatingActivities

1559322000

USD

CY2018

us-gaap

Payments To Acquire Trading Securities Heldforinvestment

PaymentsToAcquireTradingSecuritiesHeldforinvestment

1001149000

USD

CY2018

us-gaap

Payments To Acquire Other Investments

PaymentsToAcquireOtherInvestments

2014622000

USD

CY2018

us-gaap

Proceeds From Sale Of Available For Sale Securities Debt

ProceedsFromSaleOfAvailableForSaleSecuritiesDebt

31513271000

USD

CY2018

us-gaap

Payments To Acquire Available For Sale Securities Debt

PaymentsToAcquireAvailableForSaleSecuritiesDebt

33327660000

USD

CY2018

us-gaap

Proceeds From Sale Of Trading Securities Heldforinvestment

ProceedsFromSaleOfTradingSecuritiesHeldforinvestment

1118445000

USD

CY2018

us-gaap

Proceeds From Sale Of Other Investments

ProceedsFromSaleOfOtherInvestments

1561958000

USD

CY2018

us-gaap

Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities

ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities

892755000

USD

CY2018

us-gaap

Payments For Proceeds From Derivative Instrument Investing Activities

PaymentsForProceedsFromDerivativeInstrumentInvestingActivities

-44699000

USD

CY2018

us-gaap

Payments For Proceeds From Short Term Investments

PaymentsForProceedsFromShortTermInvestments

-485473000

USD

CY2018

us-gaap

Increase Decrease In Cash Collateral For Borrowed Securities

IncreaseDecreaseInCashCollateralForBorrowedSecurities

-180883000

USD

CY2018

acgl

Capital Contributions To Subsidiaries

CapitalContributionsToSubsidiaries

0

USD

CY2018

us-gaap

Payments To Acquire Productive Assets

PaymentsToAcquireProductiveAssets

29809000

USD

CY2018

us-gaap

Payments For Proceeds From Other Investing Activities

PaymentsForProceedsFromOtherInvestingActivities

-21736000

USD

CY2018

us-gaap

Net Cash Provided By Used In Investing Activities

NetCashProvidedByUsedInInvestingActivities

-554020000

USD

CY2018

us-gaap

Payments For Repurchase Of Preferred Stock And Preference Stock

PaymentsForRepurchaseOfPreferredStockAndPreferenceStock

92555000

USD

CY2018

us-gaap

Payments For Repurchase Of Common Stock

PaymentsForRepurchaseOfCommonStock

282762000

USD

CY2018

us-gaap

Proceeds From Repurchase Of Equity

ProceedsFromRepurchaseOfEquity

-7608000

USD

CY2018

us-gaap

Proceeds From Other Debt

ProceedsFromOtherDebt

218259000

USD

CY2018

us-gaap

Repayments Of Other Debt

RepaymentsOfOtherDebt

576401000

USD

CY2018

us-gaap

Increase Decrease In Cash Collateral For Loaned Securities

IncreaseDecreaseInCashCollateralForLoanedSecurities

-180883000

USD

CY2018

us-gaap

Payments Of Dividends Minority Interest

PaymentsOfDividendsMinorityInterest

17989000

USD

CY2018

us-gaap

Cash Dividends Paid To Parent Company By Consolidated Subsidiaries

CashDividendsPaidToParentCompanyByConsolidatedSubsidiaries

0

USD

CY2018

us-gaap

Proceeds From Payments For Other Financing Activities

ProceedsFromPaymentsForOtherFinancingActivities

-7226000

USD

CY2018

us-gaap

Payments Of Dividends Preferred Stock And Preference Stock

PaymentsOfDividendsPreferredStockAndPreferenceStock

41645000

USD

CY2018

us-gaap

Net Cash Provided By Used In Financing Activities

NetCashProvidedByUsedInFinancingActivities

-988810000

USD

CY2018

us-gaap

Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents

EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

-19133000

USD

CY2018

us-gaap

Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect

CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect

-2641000

USD

CY2017Q4

us-gaap

Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents

CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

727284000

USD

CY2018Q4

us-gaap

Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents

CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

724643000

USD

CY2017

us-gaap

Net Cash Provided By Used In Operating Activities

NetCashProvidedByUsedInOperatingActivities

1094878000

USD

CY2017

us-gaap

Payments To Acquire Available For Sale Securities Debt

PaymentsToAcquireAvailableForSaleSecuritiesDebt

36806913000

USD

CY2017

us-gaap

Payments To Acquire Trading Securities Heldforinvestment

PaymentsToAcquireTradingSecuritiesHeldforinvestment

1021016000

USD

CY2017

us-gaap

Payments To Acquire Other Investments

PaymentsToAcquireOtherInvestments

2020624000

USD

CY2017

us-gaap

Proceeds From Sale Of Available For Sale Securities Debt

ProceedsFromSaleOfAvailableForSaleSecuritiesDebt

35686779000

USD

CY2017

us-gaap

Proceeds From Sale Of Trading Securities Heldforinvestment

ProceedsFromSaleOfTradingSecuritiesHeldforinvestment

1056401000

USD

CY2017

us-gaap

Proceeds From Sale Of Other Investments

ProceedsFromSaleOfOtherInvestments

1528617000

USD

CY2017

us-gaap

Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities

ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities

907417000

USD

CY2017

us-gaap

Payments For Proceeds From Derivative Instrument Investing Activities

PaymentsForProceedsFromDerivativeInstrumentInvestingActivities

28563000

USD

CY2017

us-gaap

Proceeds From Equity Method Investment Dividends Or Distributions Return Of Capital

ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital

0

USD

CY2017

us-gaap

Payments For Proceeds From Short Term Investments

PaymentsForProceedsFromShortTermInvestments

734554000

USD

CY2017

us-gaap

Increase Decrease In Cash Collateral For Borrowed Securities

IncreaseDecreaseInCashCollateralForBorrowedSecurities

-12540000

USD

CY2017

acgl

Capital Contributions To Subsidiaries

CapitalContributionsToSubsidiaries

0

USD

CY2017

acgl

Payments For Proceeds From Intercompany Loans

PaymentsForProceedsFromIntercompanyLoans

0

USD

CY2017

acgl

Repayments Of Intercompany Loans Investing Activities

RepaymentsOfIntercompanyLoansInvestingActivities

0

USD

CY2017

us-gaap

Payments To Acquire Productive Assets

PaymentsToAcquireProductiveAssets

22841000

USD

CY2017

us-gaap

Payments For Proceeds From Other Investing Activities

PaymentsForProceedsFromOtherInvestingActivities

-90875000

USD

CY2017

us-gaap

Net Cash Provided By Used In Investing Activities

NetCashProvidedByUsedInInvestingActivities

-1351882000

USD

CY2017

us-gaap

Proceeds From Issuance Of Preferred Stock And Preference Stock

ProceedsFromIssuanceOfPreferredStockAndPreferenceStock

319694000

USD

CY2017

us-gaap

Payments For Repurchase Of Preferred Stock And Preference Stock

PaymentsForRepurchaseOfPreferredStockAndPreferenceStock

230000000

USD

CY2017

us-gaap

Payments For Repurchase Of Common Stock

PaymentsForRepurchaseOfCommonStock

0

USD

CY2017

us-gaap

Proceeds From Repurchase Of Equity

ProceedsFromRepurchaseOfEquity

-21048000

USD

CY2017

acgl

Proceeds From Intercompany Loans Financing Activities

ProceedsFromIntercompanyLoansFinancingActivities

0

USD

CY2017

us-gaap

Proceeds From Other Debt

ProceedsFromOtherDebt

253415000

USD

CY2017

acgl

Repaymentsof Intercompany Debt Financing Activities

RepaymentsofIntercompanyDebtFinancingActivities

0

USD

CY2017

us-gaap

Repayments Of Other Debt

RepaymentsOfOtherDebt

197000000

USD

CY2017

us-gaap

Increase Decrease In Cash Collateral For Loaned Securities

IncreaseDecreaseInCashCollateralForLoanedSecurities

-12540000

USD

CY2017

us-gaap

Payments Of Dividends Minority Interest

PaymentsOfDividendsMinorityInterest

17989000

USD

CY2017

us-gaap

Cash Dividends Paid To Parent Company By Consolidated Subsidiaries

CashDividendsPaidToParentCompanyByConsolidatedSubsidiaries

0

USD

CY2017

us-gaap

Proceeds From Payments For Other Financing Activities

ProceedsFromPaymentsForOtherFinancingActivities

-51896000

USD

CY2017

us-gaap

Payments Of Dividends Preferred Stock And Preference Stock

PaymentsOfDividendsPreferredStockAndPreferenceStock

46041000

USD

CY2017

us-gaap

Net Cash Provided By Used In Financing Activities

NetCashProvidedByUsedInFinancingActivities

-3405000

USD

CY2017

us-gaap

Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents

EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

18124000

USD

CY2017

us-gaap

Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect

CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect

-242285000

USD

CY2016Q4

us-gaap

Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents

CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

969569000

USD

CY2017Q4

us-gaap

Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents

CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

727284000

USD

CY2019Q4

us-gaap

Supplementary Insurance Information Deferred Policy Acquisition Costs

SupplementaryInsuranceInformationDeferredPolicyAcquisitionCosts

633400000

USD

CY2019Q4

us-gaap

Supplementary Insurance Information Liability For Future Policy Benefits Losses Claims And Loss Expense Reserves

SupplementaryInsuranceInformationLiabilityForFuturePolicyBenefitsLossesClaimsAndLossExpenseReserves

13891842000

USD

CY2019Q4

us-gaap

Supplementary Insurance Information Unearned Premiums

SupplementaryInsuranceInformationUnearnedPremiums

4339549000

USD

CY2019

us-gaap

Supplementary Insurance Information Premium Revenue

SupplementaryInsuranceInformationPremiumRevenue

5786498000

USD

CY2019

us-gaap

Supplementary Insurance Information Benefits Claims Losses And Settlement Expense

SupplementaryInsuranceInformationBenefitsClaimsLossesAndSettlementExpense

3133452000

USD

CY2019

us-gaap

Supplementary Insurance Information Amortization Of Deferred Policy Acquisition Costs

SupplementaryInsuranceInformationAmortizationOfDeferredPolicyAcquisitionCosts

840945000

USD

CY2019

us-gaap

Supplementary Insurance Information Other Operating Expense

SupplementaryInsuranceInformationOtherOperatingExpense

800997000

USD

CY2019

us-gaap

Supplementary Insurance Information Premiums Written

SupplementaryInsuranceInformationPremiumsWritten

6039067000

USD

CY2018Q4

us-gaap

Supplementary Insurance Information Deferred Policy Acquisition Costs

SupplementaryInsuranceInformationDeferredPolicyAcquisitionCosts

569574000

USD

CY2018Q4

us-gaap

Supplementary Insurance Information Liability For Future Policy Benefits Losses Claims And Loss Expense Reserves

SupplementaryInsuranceInformationLiabilityForFuturePolicyBenefitsLossesClaimsAndLossExpenseReserves

11853297000

USD

CY2018Q4

us-gaap

Supplementary Insurance Information Unearned Premiums

SupplementaryInsuranceInformationUnearnedPremiums

3753636000

USD

CY2018

us-gaap

Supplementary Insurance Information Premium Revenue

SupplementaryInsuranceInformationPremiumRevenue

5231975000

USD

CY2018

us-gaap

Supplementary Insurance Information Benefits Claims Losses And Settlement Expense

SupplementaryInsuranceInformationBenefitsClaimsLossesAndSettlementExpense

2890106000

USD

CY2018

us-gaap

Supplementary Insurance Information Amortization Of Deferred Policy Acquisition Costs

SupplementaryInsuranceInformationAmortizationOfDeferredPolicyAcquisitionCosts

805135000

USD

CY2018

us-gaap

Supplementary Insurance Information Other Operating Expense

SupplementaryInsuranceInformationOtherOperatingExpense

677809000

USD

CY2018

us-gaap

Supplementary Insurance Information Premiums Written

SupplementaryInsuranceInformationPremiumsWritten

5346747000

USD

CY2017Q4

us-gaap

Supplementary Insurance Information Deferred Policy Acquisition Costs

SupplementaryInsuranceInformationDeferredPolicyAcquisitionCosts

535824000

USD

CY2017Q4

us-gaap

Supplementary Insurance Information Liability For Future Policy Benefits Losses Claims And Loss Expense Reserves

SupplementaryInsuranceInformationLiabilityForFuturePolicyBenefitsLossesClaimsAndLossExpenseReserves

11383792000

USD

CY2017Q4

us-gaap

Supplementary Insurance Information Unearned Premiums

SupplementaryInsuranceInformationUnearnedPremiums

3622314000

USD

CY2017

us-gaap

Supplementary Insurance Information Premium Revenue

SupplementaryInsuranceInformationPremiumRevenue

4844532000

USD

CY2017

us-gaap

Supplementary Insurance Information Benefits Claims Losses And Settlement Expense

SupplementaryInsuranceInformationBenefitsClaimsLossesAndSettlementExpense

2967446000

USD

CY2017

us-gaap

Supplementary Insurance Information Amortization Of Deferred Policy Acquisition Costs

SupplementaryInsuranceInformationAmortizationOfDeferredPolicyAcquisitionCosts

775458000

USD

CY2017

us-gaap

Supplementary Insurance Information Other Operating Expense

SupplementaryInsuranceInformationOtherOperatingExpense

684451000

USD

CY2017

us-gaap

Supplementary Insurance Information Premiums Written

SupplementaryInsuranceInformationPremiumsWritten

4961373000

USD

CY2019

us-gaap

Direct Premiums Written

DirectPremiumsWritten

5681523000

USD

CY2019

us-gaap

Ceded Premiums Written

CededPremiumsWritten

2099893000

USD

CY2019

us-gaap

Assumed Premiums Written

AssumedPremiumsWritten

2457437000

USD

CY2019

us-gaap

Premiums Written Net

PremiumsWrittenNet

6039067000

USD

CY2019

acgl

Premiums Written Percentage Assumed To Net

PremiumsWrittenPercentageAssumedToNet

0.407

CY2018

us-gaap

Direct Premiums Written

DirectPremiumsWritten

4838902000

USD

CY2018

us-gaap

Ceded Premiums Written

CededPremiumsWritten

1614257000

USD

CY2018

us-gaap

Assumed Premiums Written

AssumedPremiumsWritten

2122102000

USD

CY2018

us-gaap

Premiums Written Net

PremiumsWrittenNet

5346747000

USD

CY2018

acgl

Premiums Written Percentage Assumed To Net

PremiumsWrittenPercentageAssumedToNet

0.397

CY2017

us-gaap

Direct Premiums Written

DirectPremiumsWritten

4447457000

USD

CY2017

us-gaap

Ceded Premiums Written

CededPremiumsWritten

1407052000

USD

CY2017

us-gaap

Assumed Premiums Written

AssumedPremiumsWritten

1920968000

USD

CY2017

us-gaap

Premiums Written Net

PremiumsWrittenNet

4961373000

USD

CY2017

acgl

Premiums Written Percentage Assumed To Net

PremiumsWrittenPercentageAssumedToNet

0.387

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$ACGL
ARCH CAPITAL GROUP LTD. Stock $acgl

2018 Q4 Form 10-K Financial Statement

#000094748420000012 Filed on February 28, 2020

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$ACGL ARCH CAPITAL GROUP LTD. Stock $acgl

2018 Q4 Form 10-K Financial Statement

#000094748420000012 Filed on February 28, 2020

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$ACGL
ARCH CAPITAL GROUP LTD. Stock $acgl