$WRB
BERKLEY W R CORP Stock $wrb

$wrb Overview Financials Valuation SEC Filings Company Website

2020 Form 10-K Financial Statement

#000001154421000013 Filed on February 18, 2021

Income Statement

Concept	2020	2019 Q4	2019
Revenue	$8.099B	$1.976B	$7.902B
YoY Change	2.49%	1.25%	2.74%
Cost Of Revenue	$4.469B		$4.131B
YoY Change	8.17%		3.94%
Gross Profit	$3.630B		$3.771B
YoY Change	-3.74%		1.46%
Gross Profit Margin	44.82%		47.72%
Selling, General & Admin	$130.0M	$34.90M	$145.4M
YoY Change	-10.59%	27.37%	22.8%
% of Gross Profit	3.58%		3.86%
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$53.00M	$71.40M	$54.00M
YoY Change	-1.85%	30.77%	0.0%
% of Gross Profit	1.46%		1.43%
Operating Expenses	$7.064B	$1.797B	$6.927B
YoY Change	1.98%	2.51%	2.63%
Operating Profit	-$3.434B		-$3.156B
YoY Change	8.81%		4.06%
Interest Expense	$150.5M	-$31.90M	$153.4M
YoY Change	-1.87%	-10.14%	-2.4%
% of Operating Profit
Other Income/Expense, Net
YoY Change
Pretax Income	$704.8M	$146.8M	$852.9M
YoY Change	-17.37%	-9.72%	5.03%
Income Tax	$171.8M	$27.00M	$168.9M
% Of Pretax Income	24.38%	18.39%	19.81%
Net Earnings	$530.7M	$119.3M	$681.9M
YoY Change	-22.18%	-9.86%	6.43%
Net Earnings / Revenue	6.55%	6.04%	8.63%
Basic Earnings Per Share	$2.84	$0.62	$3.58
Diluted Earnings Per Share	$2.81	$0.62	$3.52
COMMON SHARES
Basic Shares Outstanding	186.9K shares	183.7M shares	190.7K shares
Diluted Shares Outstanding	188.8K shares		193.5K shares

Balance Sheet

Concept	2020	2019 Q4	2019
SHORT-TERM ASSETS
Cash & Short-Term Investments
YoY Change
Cash & Equivalents	$2.372B	$1.024B	$1.024B
Short-Term Investments
Other Short-Term Assets
YoY Change
Inventory
Prepaid Expenses
Receivables
Other Receivables
Total Short-Term Assets	$525.0M	$424.0M	$424.0M
YoY Change	23.82%	22.19%	22.19%
LONG-TERM ASSETS
Property, Plant & Equipment	$406.0M	$422.1M	$615.0M
YoY Change	-33.98%	1.37%	47.84%
Goodwill		$169.7M
YoY Change		-1.96%
Intangibles
YoY Change
Long-Term Investments	$16.52B	$1.214B	$16.37B
YoY Change	0.93%	-8.95%	3.82%
Other Assets		$9.000M	$9.000M
YoY Change		-74.29%	-74.29%
Total Long-Term Assets	$28.05B	$26.24B	$26.24B
YoY Change	6.89%	6.88%	6.88%
TOTAL ASSETS
Total Short-Term Assets	$525.0M	$424.0M	$424.0M
Total Long-Term Assets	$28.05B	$26.24B	$26.24B
Total Assets	$28.57B	$26.66B	$26.66B
YoY Change	7.16%	7.09%	7.09%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable
YoY Change
Accrued Expenses		$230.0M	$230.0M
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		$240.0M	$240.0M
YoY Change
LONG-TERM LIABILITIES
Long-Term Debt	$2.725B	$2.626B	$2.626B
YoY Change	3.77%	-5.88%	-5.88%
Other Long-Term Liabilities	$1.189B	$1.051B	$1.051B
YoY Change	13.13%	0.77%	0.77%
Total Long-Term Liabilities	$3.914B	$3.677B	$3.677B
YoY Change	6.45%	-4.07%	-4.07%
TOTAL LIABILITIES
Total Short-Term Liabilities		$240.0M	$240.0M
Total Long-Term Liabilities	$3.914B	$3.677B	$3.677B
Total Liabilities	$22.26B	$20.54B	$20.59B
YoY Change	8.13%	5.81%	5.8%
SHAREHOLDERS EQUITY
Retained Earnings		$7.932B
YoY Change		4.94%
Common Stock		$1.127B
YoY Change		1.48%
Preferred Stock
YoY Change
Treasury Stock (at cost)		$2.727B
YoY Change		0.23%
Treasury Stock Shares		169.3M shares
Shareholders Equity	$6.311B	$6.075B	$6.075B
YoY Change
Total Liabilities & Shareholders Equity	$28.57B	$26.66B	$26.66B
YoY Change	7.16%	7.09%	7.09%

Cashflow Statement

Concept	2020	2019 Q4	2019
OPERATING ACTIVITIES
Net Income	$530.7M	$119.3M	$681.9M
YoY Change	-22.18%	-9.86%	6.43%
Depreciation, Depletion And Amortization	$53.00M	$71.40M	$54.00M
YoY Change	-1.85%	30.77%	0.0%
Cash From Operating Activities	$1.617B	$348.8M	$1.144B
YoY Change	41.34%	25.6%	84.42%
INVESTING ACTIVITIES
Capital Expenditures	-$38.20M	-$28.90M	$60.46M
YoY Change	-163.19%	-60.89%	21.25%
Acquisitions	$0.00		$0.00
YoY Change			-100.0%
Other Investing Activities	$157.9M	-$204.1M	-$217.7M
YoY Change	-172.53%	79.35%	44.84%
Cash From Investing Activities	$119.7M	-$232.9M	-$424.9M
YoY Change	-128.17%	24.08%	-40.51%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net	$346.4M		$18.23M
YoY Change	1800.45%		-26.36%
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	-$397.8M	86.00M	-$513.2M
YoY Change	-22.48%	-186.78%	6832.23%
NET CHANGE
Cash From Operating Activities	$1.617B	348.8M	$1.144B
Cash From Investing Activities	$119.7M	-232.9M	-$424.9M
Cash From Financing Activities	-$397.8M	86.00M	-$513.2M
Net Change In Cash	$1.349B	201.9M	$206.1M
YoY Change	554.34%	-2318.68%	-255.12%
FREE CASH FLOW
Cash From Operating Activities	$1.617B	$348.8M	$1.144B
Capital Expenditures	-$38.20M	-$28.90M	$60.46M
Free Cash Flow	$1.655B	$377.7M	$1.083B
YoY Change	52.76%	7.42%	89.95%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
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CY2020	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2020
CY2020	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	FY
CY2020	dei	Amendment Flag AmendmentFlag	false
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CY2020Q4	us-gaap	Operating Lease Liability Statement Of Financial Position Extensible List OperatingLeaseLiabilityStatementOfFinancialPositionExtensibleList	us-gaap:OtherLiabilities
CY2020	dei	Document Type DocumentType	10-K
CY2020	dei	Document Annual Report DocumentAnnualReport	true
CY2020	dei	Document Period End Date DocumentPeriodEndDate	2020-12-31
CY2020	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
CY2020	dei	Document Transition Report DocumentTransitionReport	false
CY2020	dei	Entity File Number EntityFileNumber	1-15202
CY2020	dei	Entity Registrant Name EntityRegistrantName	W. R. BERKLEY CORP
CY2020	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	DE
CY2020	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	22-1867895
CY2020	dei	Entity Address Address Line1 EntityAddressAddressLine1	475 Steamboat Road
CY2020	dei	Entity Address City Or Town EntityAddressCityOrTown	Greenwich,
CY2020	dei	Entity Address State Or Province EntityAddressStateOrProvince	CT
CY2020	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	06830
CY2020	dei	City Area Code CityAreaCode	203
CY2020	dei	Local Phone Number LocalPhoneNumber	629-3000
CY2020	dei	Security12b Title Security12bTitle	Common Stock, par value $.20 per share
CY2020	dei	Trading Symbol TradingSymbol	WRB
CY2020	dei	Security Exchange Name SecurityExchangeName	NYSE
CY2020	dei	Entity Well Known Seasoned Issuer EntityWellKnownSeasonedIssuer	Yes
CY2020	dei	Entity Voluntary Filers EntityVoluntaryFilers	No
CY2020	dei	Entity Current Reporting Status EntityCurrentReportingStatus	Yes
CY2020	dei	Entity Interactive Data Current EntityInteractiveDataCurrent	Yes
CY2020	dei	Entity Filer Category EntityFilerCategory	Large Accelerated Filer
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CY2020	dei	Entity Emerging Growth Company EntityEmergingGrowthCompany	false
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CY2020Q4	us-gaap	Taxes Payable Current TaxesPayableCurrent	41282000	USD
CY2019Q4	us-gaap	Taxes Payable Current TaxesPayableCurrent	10006000	USD
CY2020Q4	us-gaap	Deferred Income Tax Liabilities Net DeferredIncomeTaxLiabilitiesNet	42161000	USD
CY2019Q4	us-gaap	Deferred Income Tax Liabilities Net DeferredIncomeTaxLiabilitiesNet	26416000	USD
CY2020Q4	us-gaap	Other Liabilities OtherLiabilities	1178546000	USD
CY2019Q4	us-gaap	Other Liabilities OtherLiabilities	1244888000	USD
CY2020Q4	wrb	Senior Notes And Other Debt SeniorNotesAndOtherDebt	1623025000	USD
CY2019Q4	wrb	Senior Notes And Other Debt SeniorNotesAndOtherDebt	1427575000	USD
CY2020Q4	us-gaap	Junior Subordinated Notes JuniorSubordinatedNotes	1102309000	USD
CY2019Q4	us-gaap	Junior Subordinated Notes JuniorSubordinatedNotes	1198704000	USD
CY2020Q4	us-gaap	Liabilities Liabilities	22281116000	USD
CY2019Q4	us-gaap	Liabilities Liabilities	20543802000	USD
CY2020Q4	us-gaap	Preferred Stock Par Or Stated Value Per Share PreferredStockParOrStatedValuePerShare	0.10
CY2019Q4	us-gaap	Preferred Stock Par Or Stated Value Per Share PreferredStockParOrStatedValuePerShare	0.10
CY2020Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	5000000	shares
CY2019Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	5000000	shares
CY2020Q4	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	0	shares
CY2019Q4	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	0	shares
CY2019Q4	us-gaap	Preferred Stock Shares Outstanding PreferredStockSharesOutstanding	0	shares
CY2020Q4	us-gaap	Preferred Stock Shares Outstanding PreferredStockSharesOutstanding	0	shares
CY2020Q4	us-gaap	Preferred Stock Value PreferredStockValue	0	USD
CY2019Q4	us-gaap	Preferred Stock Value PreferredStockValue	0	USD
CY2019Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.20
CY2020Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.20
CY2019Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	500000000	shares
CY2020Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	500000000	shares
CY2020Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	177825150	shares
CY2020Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	177825150	shares
CY2019Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	183411907	shares
CY2019Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	183411907	shares
CY2020Q4	us-gaap	Common Stock Value CommonStockValue	70535000	USD
CY2019Q4	us-gaap	Common Stock Value CommonStockValue	70535000	USD
CY2020Q4	us-gaap	Additional Paid In Capital Common Stock AdditionalPaidInCapitalCommonStock	1012483000	USD
CY2019Q4	us-gaap	Additional Paid In Capital Common Stock AdditionalPaidInCapitalCommonStock	1056042000	USD
CY2020Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	8348381000	USD
CY2019Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	7932372000	USD
CY2020Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-62172000	USD
CY2019Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-257299000	USD
CY2020Q4	us-gaap	Treasury Stock Shares TreasuryStockShares	174851350	shares
CY2019Q4	us-gaap	Treasury Stock Shares TreasuryStockShares	169264857	shares
CY2020Q4	us-gaap	Treasury Stock Value TreasuryStockValue	3058425000	USD
CY2019Q4	us-gaap	Treasury Stock Value TreasuryStockValue	2726711000	USD
CY2020Q4	us-gaap	Stockholders Equity StockholdersEquity	6310802000	USD
CY2019Q4	us-gaap	Stockholders Equity StockholdersEquity	6074939000	USD
CY2020Q4	us-gaap	Minority Interest MinorityInterest	14995000	USD
CY2019Q4	us-gaap	Minority Interest MinorityInterest	43403000	USD
CY2020Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	6325797000	USD
CY2019Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	6118342000	USD
CY2020Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	28606913000	USD
CY2019Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	26662144000	USD
CY2020	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.47
CY2019	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	1.68
CY2018	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	1.39
CY2020	us-gaap	Net Income Loss NetIncomeLoss	530670000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	681944000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	640749000	USD
CY2020	us-gaap	Gain Loss On Investments GainLossOnInvestments	103000000	USD
CY2019	us-gaap	Gain Loss On Investments GainLossOnInvestments	120703000	USD
CY2018	us-gaap	Gain Loss On Investments GainLossOnInvestments	154488000	USD
CY2020	us-gaap	Depreciation And Amortization DepreciationAndAmortization	135065000	USD
CY2019	us-gaap	Depreciation And Amortization DepreciationAndAmortization	113387000	USD
CY2018	us-gaap	Depreciation And Amortization DepreciationAndAmortization	131108000	USD
CY2020	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	2315000	USD
CY2019	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	2041000	USD
CY2018	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	8317000	USD
CY2020	us-gaap	Income Loss From Equity Method Investments Net Of Dividends Or Distributions IncomeLossFromEquityMethodInvestmentsNetOfDividendsOrDistributions	54253000	USD
CY2019	us-gaap	Income Loss From Equity Method Investments Net Of Dividends Or Distributions IncomeLossFromEquityMethodInvestmentsNetOfDividendsOrDistributions	69194000	USD
CY2018	us-gaap	Income Loss From Equity Method Investments Net Of Dividends Or Distributions IncomeLossFromEquityMethodInvestmentsNetOfDividendsOrDistributions	109349000	USD
CY2020	us-gaap	Share Based Compensation ShareBasedCompensation	49658000	USD
CY2019	us-gaap	Share Based Compensation ShareBasedCompensation	49274000	USD
CY2018	us-gaap	Share Based Compensation ShareBasedCompensation	36591000	USD
CY2020	us-gaap	Increase Decrease In Trading Securities IncreaseDecreaseInTradingSecurities	67943000	USD
CY2019	us-gaap	Increase Decrease In Trading Securities IncreaseDecreaseInTradingSecurities	26553000	USD
CY2018	us-gaap	Increase Decrease In Trading Securities IncreaseDecreaseInTradingSecurities	19093000	USD
CY2020	us-gaap	Increase Decrease In Premiums Receivable IncreaseDecreaseInPremiumsReceivable	173618000	USD
CY2019	us-gaap	Increase Decrease In Premiums Receivable IncreaseDecreaseInPremiumsReceivable	189151000	USD
CY2018	us-gaap	Increase Decrease In Premiums Receivable IncreaseDecreaseInPremiumsReceivable	43813000	USD
CY2020	us-gaap	Increase Decrease In Reinsurance Recoverable IncreaseDecreaseInReinsuranceRecoverable	313525000	USD
CY2019	us-gaap	Increase Decrease In Reinsurance Recoverable IncreaseDecreaseInReinsuranceRecoverable	165898000	USD
CY2018	us-gaap	Increase Decrease In Reinsurance Recoverable IncreaseDecreaseInReinsuranceRecoverable	165287000	USD
CY2020	us-gaap	Increase Decrease In Deferred Policy Acquisition Costs IncreaseDecreaseInDeferredPolicyAcquisitionCosts	38691000	USD
CY2019	us-gaap	Increase Decrease In Deferred Policy Acquisition Costs IncreaseDecreaseInDeferredPolicyAcquisitionCosts	20057000	USD
CY2018	us-gaap	Increase Decrease In Deferred Policy Acquisition Costs IncreaseDecreaseInDeferredPolicyAcquisitionCosts	-7788000	USD
CY2020	us-gaap	Increase Decrease In Income Taxes IncreaseDecreaseInIncomeTaxes	49021000	USD
CY2019	us-gaap	Increase Decrease In Income Taxes IncreaseDecreaseInIncomeTaxes	-12530000	USD
CY2018	us-gaap	Increase Decrease In Income Taxes IncreaseDecreaseInIncomeTaxes	-11950000	USD
CY2020	us-gaap	Increase Decrease In Deferred Income Taxes IncreaseDecreaseInDeferredIncomeTaxes	34057000	USD
CY2019	us-gaap	Increase Decrease In Deferred Income Taxes IncreaseDecreaseInDeferredIncomeTaxes	-7130000	USD
CY2018	us-gaap	Increase Decrease In Deferred Income Taxes IncreaseDecreaseInDeferredIncomeTaxes	74761000	USD
CY2020	us-gaap	Increase Decrease In Liability For Claims And Claims Adjustment Expense Reserve IncreaseDecreaseInLiabilityForClaimsAndClaimsAdjustmentExpenseReserve	1176049000	USD
CY2019	us-gaap	Increase Decrease In Liability For Claims And Claims Adjustment Expense Reserve IncreaseDecreaseInLiabilityForClaimsAndClaimsAdjustmentExpenseReserve	612254000	USD
CY2018	us-gaap	Increase Decrease In Liability For Claims And Claims Adjustment Expense Reserve IncreaseDecreaseInLiabilityForClaimsAndClaimsAdjustmentExpenseReserve	339015000	USD
CY2020	us-gaap	Increase Decrease In Unearned Premiums IncreaseDecreaseInUnearnedPremiums	415956000	USD
CY2019	us-gaap	Increase Decrease In Unearned Premiums IncreaseDecreaseInUnearnedPremiums	301355000	USD
CY2018	us-gaap	Increase Decrease In Unearned Premiums IncreaseDecreaseInUnearnedPremiums	84142000	USD
CY2020	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	43039000	USD
CY2019	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	-19506000	USD
CY2018	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	-48770000	USD
CY2020	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	1616686000	USD
CY2019	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	1143793000	USD
CY2018	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	620199000	USD
CY2020	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	3832555000	USD
CY2019	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	2093271000	USD
CY2018	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	3525149000	USD
CY2020	us-gaap	Proceeds From Sale Of Available For Sale Securities Equity ProceedsFromSaleOfAvailableForSaleSecuritiesEquity	114763000	USD
CY2019	us-gaap	Proceeds From Sale Of Available For Sale Securities Equity ProceedsFromSaleOfAvailableForSaleSecuritiesEquity	79963000	USD
CY2018	us-gaap	Proceeds From Sale Of Available For Sale Securities Equity ProceedsFromSaleOfAvailableForSaleSecuritiesEquity	497989000	USD
CY2020	wrb	Proceeds From Payments To Equity Method Investments ProceedsFromPaymentsToEquityMethodInvestments	-3042000	USD
CY2019	wrb	Proceeds From Payments To Equity Method Investments ProceedsFromPaymentsToEquityMethodInvestments	194663000	USD
CY2018	wrb	Proceeds From Payments To Equity Method Investments ProceedsFromPaymentsToEquityMethodInvestments	-79635000	USD
CY2020	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	3864327000	USD
CY2019	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	2933980000	USD
CY2018	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	2676455000	USD
CY2020	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	7551591000	USD
CY2019	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	5352886000	USD
CY2018	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	6677753000	USD
CY2020	us-gaap	Payments To Acquire Available For Sale Securities Equity PaymentsToAcquireAvailableForSaleSecuritiesEquity	253031000	USD
CY2019	us-gaap	Payments To Acquire Available For Sale Securities Equity PaymentsToAcquireAvailableForSaleSecuritiesEquity	172978000	USD
CY2018	us-gaap	Payments To Acquire Available For Sale Securities Equity PaymentsToAcquireAvailableForSaleSecuritiesEquity	85610000	USD
CY2020	wrb	Payments For Proceeds From Real Estate PaymentsForProceedsFromRealEstate	-178934000	USD
CY2019	wrb	Payments For Proceeds From Real Estate PaymentsForProceedsFromRealEstate	146752000	USD
CY2018	wrb	Payments For Proceeds From Real Estate PaymentsForProceedsFromRealEstate	514064000	USD
CY2020	us-gaap	Payments For Proceeds From Loans Receivable PaymentsForProceedsFromLoansReceivable	-1467000	USD
CY2019	us-gaap	Payments For Proceeds From Loans Receivable PaymentsForProceedsFromLoansReceivable	-3481000	USD
CY2018	us-gaap	Payments For Proceeds From Loans Receivable PaymentsForProceedsFromLoansReceivable	13204000	USD
CY2020	wrb	Paymentsto Acquire Property Plantand Equipment Net PaymentstoAcquirePropertyPlantandEquipmentNet	38171000	USD
CY2019	wrb	Paymentsto Acquire Property Plantand Equipment Net PaymentstoAcquirePropertyPlantandEquipmentNet	60457000	USD
CY2018	wrb	Paymentsto Acquire Property Plantand Equipment Net PaymentstoAcquirePropertyPlantandEquipmentNet	49860000	USD
CY2020	us-gaap	Increase Decrease In Broker Dealer Related Receivables Payables Net IncreaseDecreaseInBrokerDealerRelatedReceivablesPayablesNet	26515000	USD
CY2019	us-gaap	Increase Decrease In Broker Dealer Related Receivables Payables Net IncreaseDecreaseInBrokerDealerRelatedReceivablesPayablesNet	-2844000	USD
CY2018	us-gaap	Increase Decrease In Broker Dealer Related Receivables Payables Net IncreaseDecreaseInBrokerDealerRelatedReceivablesPayablesNet	-4262000	USD
CY2020	us-gaap	Proceeds From Divestiture Of Businesses Net Of Cash Divested ProceedsFromDivestitureOfBusinessesNetOfCashDivested	0	USD
CY2019	us-gaap	Proceeds From Divestiture Of Businesses Net Of Cash Divested ProceedsFromDivestitureOfBusinessesNetOfCashDivested	0	USD
CY2018	us-gaap	Proceeds From Divestiture Of Businesses Net Of Cash Divested ProceedsFromDivestitureOfBusinessesNetOfCashDivested	8664000	USD
CY2020	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	0	USD
CY2019	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	0	USD
CY2018	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	6637000	USD
CY2020	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	119696000	USD
CY2019	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-424871000	USD
CY2018	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-714244000	USD
CY2020	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	741637000	USD
CY2019	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	290974000	USD
CY2018	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	294562000	USD
CY2020	us-gaap	Repayments Of Debt RepaymentsOfDebt	652751000	USD
CY2019	us-gaap	Repayments Of Debt RepaymentsOfDebt	456360000	USD
CY2018	us-gaap	Repayments Of Debt RepaymentsOfDebt	4524000	USD
CY2020	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	84147000	USD
CY2019	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	308191000	USD
CY2018	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	254951000	USD
CY2020	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	346357000	USD
CY2019	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	18225000	USD
CY2018	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	24750000	USD
CY2020	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	-56225000	USD
CY2019	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	-21391000	USD
CY2018	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	-17740000	USD
CY2020	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-397843000	USD
CY2019	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-513193000	USD
CY2018	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-7403000	USD
CY2020	us-gaap	Effect Of Exchange Rate On Cash And Cash Equivalents EffectOfExchangeRateOnCashAndCashEquivalents	10117000	USD
CY2019	us-gaap	Effect Of Exchange Rate On Cash And Cash Equivalents EffectOfExchangeRateOnCashAndCashEquivalents	379000	USD
CY2018	us-gaap	Effect Of Exchange Rate On Cash And Cash Equivalents EffectOfExchangeRateOnCashAndCashEquivalents	-31421000	USD
CY2020	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	1348656000	USD
CY2019	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	206108000	USD
CY2018	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-132869000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	1023710000	USD
CY2018Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	817602000	USD
CY2017Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	950471000	USD
CY2020Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	2372366000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	1023710000	USD
CY2018Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	817602000	USD
CY2020Q4	wrb	Increase Decrease In Earned Unbilled Audit Premiums IncreaseDecreaseInEarnedUnbilledAuditPremiums	-27000000	USD
CY2019Q4	wrb	Increase Decrease In Earned Unbilled Audit Premiums IncreaseDecreaseInEarnedUnbilledAuditPremiums	4000000	USD
CY2018Q4	wrb	Increase Decrease In Earned Unbilled Audit Premiums IncreaseDecreaseInEarnedUnbilledAuditPremiums	-4000000	USD
CY2020Q4	us-gaap	Deposit Contracts Liabilities DepositContractsLiabilities	38000000	USD
CY2019Q4	us-gaap	Deposit Contracts Liabilities DepositContractsLiabilities	41000000	USD
CY2020	us-gaap	Depreciation Depreciation	53000000	USD
CY2019	us-gaap	Depreciation Depreciation	54000000	USD
CY2018	us-gaap	Depreciation Depreciation	54000000	USD
CY2020	us-gaap	Interest Paid Net InterestPaidNet	155000000	USD
CY2019	us-gaap	Interest Paid Net InterestPaidNet	160000000	USD
CY2018	us-gaap	Interest Paid Net InterestPaidNet	155000000	USD
CY2020	us-gaap	Income Taxes Paid IncomeTaxesPaid	103000000	USD
CY2019	us-gaap	Income Taxes Paid IncomeTaxesPaid	125000000	USD
CY2018	us-gaap	Income Taxes Paid IncomeTaxesPaid	186000000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Before Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeTax	164645000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Before Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax	29927000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Before Tax OtherComprehensiveIncomeLossBeforeTax	194572000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesTax	24395000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax	0	USD
CY2020	us-gaap	Other Comprehensive Income Loss Tax OtherComprehensiveIncomeLossTax	24395000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	140250000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	29927000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	170177000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Before Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeTax	261970000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Before Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax	37166000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Before Tax OtherComprehensiveIncomeLossBeforeTax	299136000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesTax	46068000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax	0	USD
CY2019	us-gaap	Other Comprehensive Income Loss Tax OtherComprehensiveIncomeLossTax	46068000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	215902000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	37166000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	253068000	USD
CY2020Q4	us-gaap	Held To Maturity Securities Amortized Cost Before Other Than Temporary Impairment HeldToMaturitySecuritiesAmortizedCostBeforeOtherThanTemporaryImpairment	73572000	USD
CY2020Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss DebtSecuritiesHeldToMaturityAllowanceForCreditLoss	798000	USD
CY2020Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Gain HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain	14260000	USD
CY2020Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	0	USD
CY2020Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	87034000	USD
CY2020Q4	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	72774000	USD
CY2020Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	13682286000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss DebtSecuritiesAvailableForSaleAllowanceForCreditLoss	1782000	USD
CY2020Q4	wrb	Available For Sale Securities Debt Securities Gross Unrealized Gain AvailableForSaleSecuritiesDebtSecuritiesGrossUnrealizedGain	500283000	USD
CY2020Q4	wrb	Available For Sale Securities Debt Securities Gross Unrealized Losses AvailableForSaleSecuritiesDebtSecuritiesGrossUnrealizedLosses	94192000	USD
CY2020Q4	wrb	Available For Sale Securities Debt Securities Fair Value AvailableForSaleSecuritiesDebtSecuritiesFairValue	14086595000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	14086595000	USD
CY2020Q4	wrb	Debt Securities Availableforsaleand Heldtomaturity Amortized Cost DebtSecuritiesAvailableforsaleandHeldtomaturityAmortizedCost	13755858000	USD
CY2020Q4	wrb	Debt Securities Allowancefor Credit Loss DebtSecuritiesAllowanceforCreditLoss	2580000	USD
CY2020Q4	wrb	Debt Securities Availableforsaleand Heldtomaturity Gross Unrealized Gains DebtSecuritiesAvailableforsaleandHeldtomaturityGrossUnrealizedGains	514543000	USD
CY2020Q4	wrb	Debt Securities Availableforsaleand Heldtomaturity Gross Unrealized Losses DebtSecuritiesAvailableforsaleandHeldtomaturityGrossUnrealizedLosses	94192000	USD
CY2020Q4	wrb	Debt Securities Availableforsaleand Heldtomaturity Fair Value DebtSecuritiesAvailableforsaleandHeldtomaturityFairValue	14173629000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale And Held To Maturity DebtSecuritiesAvailableForSaleAndHeldToMaturity	14159369000	USD
CY2019Q4	us-gaap	Held To Maturity Securities Amortized Cost Before Other Than Temporary Impairment HeldToMaturitySecuritiesAmortizedCostBeforeOtherThanTemporaryImpairment	78683000	USD
CY2019Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Gain HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain	13994000	USD
CY2019Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	0	USD
CY2019Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	92677000	USD
CY2019Q4	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	78683000	USD
CY2019Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	13897964000	USD
CY2019Q4	wrb	Available For Sale Securities Debt Securities Gross Unrealized Gain AvailableForSaleSecuritiesDebtSecuritiesGrossUnrealizedGain	340700000	USD
CY2019Q4	wrb	Available For Sale Securities Debt Securities Gross Unrealized Losses AvailableForSaleSecuritiesDebtSecuritiesGrossUnrealizedLosses	136386000	USD
CY2019Q4	wrb	Available For Sale Securities Debt Securities Fair Value AvailableForSaleSecuritiesDebtSecuritiesFairValue	14102278000	USD
CY2019Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	14102278000	USD
CY2019Q4	wrb	Debt Securities Availableforsaleand Heldtomaturity Amortized Cost DebtSecuritiesAvailableforsaleandHeldtomaturityAmortizedCost	13976647000	USD
CY2019Q4	wrb	Debt Securities Availableforsaleand Heldtomaturity Gross Unrealized Gains DebtSecuritiesAvailableforsaleandHeldtomaturityGrossUnrealizedGains	354694000	USD
CY2019Q4	wrb	Debt Securities Availableforsaleand Heldtomaturity Gross Unrealized Losses DebtSecuritiesAvailableforsaleandHeldtomaturityGrossUnrealizedLosses	136386000	USD
CY2019Q4	wrb	Debt Securities Availableforsaleand Heldtomaturity Fair Value DebtSecuritiesAvailableforsaleandHeldtomaturityFairValue	14194955000	USD
CY2019Q4	us-gaap	Debt Securities Available For Sale And Held To Maturity DebtSecuritiesAvailableForSaleAndHeldToMaturity	14180961000	USD
CY2019Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss DebtSecuritiesHeldToMaturityAllowanceForCreditLoss	0	USD
CY2020	us-gaap	Debt Securities Held To Maturity Credit Loss Expense Reversal DebtSecuritiesHeldToMaturityCreditLossExpenseReversal	729000	USD
CY2020Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss DebtSecuritiesHeldToMaturityAllowanceForCreditLoss	798000	USD
CY2019Q4	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss DebtSecuritiesAvailableForSaleAllowanceForCreditLoss	0	USD
CY2020	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss Not Previously Recorded DebtSecuritiesAvailableForSaleAllowanceForCreditLossNotPreviouslyRecorded	19648000	USD
CY2020	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss Not To Sell Before Recovery Credit Loss Previously Recorded Expense Reversal DebtSecuritiesAvailableForSaleAllowanceForCreditLossNotToSellBeforeRecoveryCreditLossPreviouslyRecordedExpenseReversal	-3468000	USD
CY2020	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss Securities Sold DebtSecuritiesAvailableForSaleAllowanceForCreditLossSecuritiesSold	50043000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss DebtSecuritiesAvailableForSaleAllowanceForCreditLoss	1782000	USD
CY2020Q4	wrb	Marketable Securities Fixed Maturities Within One Year Amortized Cost MarketableSecuritiesFixedMaturitiesWithinOneYearAmortizedCost	1618794000	USD
CY2020Q4	wrb	Marketable Securities Fixed Maturities Within One Year Fair Value MarketableSecuritiesFixedMaturitiesWithinOneYearFairValue	1612652000	USD
CY2020Q4	wrb	Marketable Securities Fixed Maturities After One Through Five Years Amortized Cost MarketableSecuritiesFixedMaturitiesAfterOneThroughFiveYearsAmortizedCost	5319638000	USD
CY2020Q4	wrb	Marketable Securities Fixed Maturities After One Through Five Years Fair Value MarketableSecuritiesFixedMaturitiesAfterOneThroughFiveYearsFairValue	5511880000	USD
CY2020Q4	wrb	Marketable Securities Fixed Maturities After Five Through Ten Years Amortized Cost MarketableSecuritiesFixedMaturitiesAfterFiveThroughTenYearsAmortizedCost	3382528000	USD
CY2020Q4	wrb	Marketable Securities Fixed Maturities After Five Through Ten Years Fair Value MarketableSecuritiesFixedMaturitiesAfterFiveThroughTenYearsFairValue	3550286000	USD
CY2020Q4	wrb	Marketable Securities Fixed Maturities After Ten Years Amortized Cost MarketableSecuritiesFixedMaturitiesAfterTenYearsAmortizedCost	2433353000	USD
CY2020Q4	wrb	Marketable Securities Fixed Maturities After Ten Years Fair Value MarketableSecuritiesFixedMaturitiesAfterTenYearsFairValue	2470983000	USD
CY2020Q4	wrb	Marketable Securities Debt Maturities Without Single Maturity Date Amortized Cost MarketableSecuritiesDebtMaturitiesWithoutSingleMaturityDateAmortizedCost	1000747000	USD
CY2020Q4	wrb	Marketable Securities Debt Maturities Without Single Maturity Date Fair Value MarketableSecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue	1027828000	USD
CY2020Q4	wrb	Marketable Securities Fixed Maturities Amortized Cost MarketableSecuritiesFixedMaturitiesAmortizedCost	13755060000	USD
CY2020Q4	wrb	Marketable Securities Fixed Maturities Fair Value MarketableSecuritiesFixedMaturitiesFairValue	14173629000	USD
CY2020Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss DebtSecuritiesHeldToMaturityAllowanceForCreditLoss	798000	USD
CY2020Q4	us-gaap	Held To Maturity Securities Restricted HeldToMaturitySecuritiesRestricted	1223000000	USD
CY2020Q4	us-gaap	Trading Securities TradingSecurities	341000000	USD
CY2019Q4	us-gaap	Trading Securities TradingSecurities	401000000	USD
CY2020	us-gaap	Investment Income Interest And Dividend InvestmentIncomeInterestAndDividend	592946000	USD
CY2019	us-gaap	Investment Income Interest And Dividend InvestmentIncomeInterestAndDividend	651361000	USD
CY2018	us-gaap	Investment Income Interest And Dividend InvestmentIncomeInterestAndDividend	678596000	USD
CY2020	us-gaap	Investment Income Investment Expense InvestmentIncomeInvestmentExpense	9125000	USD
CY2019	us-gaap	Investment Income Investment Expense InvestmentIncomeInvestmentExpense	5747000	USD
CY2018	us-gaap	Investment Income Investment Expense InvestmentIncomeInvestmentExpense	4361000	USD
CY2020	us-gaap	Net Investment Income NetInvestmentIncome	583821000	USD
CY2019	us-gaap	Net Investment Income NetInvestmentIncome	645614000	USD
CY2018	us-gaap	Net Investment Income NetInvestmentIncome	674235000	USD
CY2020Q4	us-gaap	Variable Interest Entity Entity Maximum Loss Exposure Amount VariableInterestEntityEntityMaximumLossExposureAmount	124000000	USD
CY2020Q4	us-gaap	Equity Method Investments EquityMethodInvestments	1309430000	USD
CY2019Q4	us-gaap	Equity Method Investments EquityMethodInvestments	1213535000	USD
CY2020	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	54253000	USD
CY2019	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	69194000	USD
CY2018	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	109349000	USD
CY2020Q4	wrb	Buildingand Lease Obligations BuildingandLeaseObligations	1738144000	USD
CY2019Q4	wrb	Buildingand Lease Obligations BuildingandLeaseObligations	1351249000	USD
CY2020Q4	us-gaap	Development In Process DevelopmentInProcess	222770000	USD
CY2019Q4	us-gaap	Development In Process DevelopmentInProcess	754701000	USD
CY2020Q4	us-gaap	Real Estate Investment Property Net RealEstateInvestmentPropertyNet	1960914000	USD
CY2019Q4	us-gaap	Real Estate Investment Property Net RealEstateInvestmentPropertyNet	2105950000	USD
CY2020Q4	us-gaap	Real Estate Investment Property Accumulated Depreciation RealEstateInvestmentPropertyAccumulatedDepreciation	86970000	USD
CY2019Q4	us-gaap	Real Estate Investment Property Accumulated Depreciation RealEstateInvestmentPropertyAccumulatedDepreciation	59832000	USD
CY2020	us-gaap	Sec Schedule Iii Real Estate Accumulated Depreciation Depreciation Expense SECScheduleIIIRealEstateAccumulatedDepreciationDepreciationExpense	27090000	USD
CY2019	us-gaap	Sec Schedule Iii Real Estate Accumulated Depreciation Depreciation Expense SECScheduleIIIRealEstateAccumulatedDepreciationDepreciationExpense	15033000	USD
CY2020Q4	us-gaap	Operating Leases Future Minimum Payments Receivable Current OperatingLeasesFutureMinimumPaymentsReceivableCurrent	66558703	USD
CY2020Q4	us-gaap	Operating Leases Future Minimum Payments Receivable In Two Years OperatingLeasesFutureMinimumPaymentsReceivableInTwoYears	68750145	USD
CY2020Q4	us-gaap	Operating Leases Future Minimum Payments Receivable In Three Years OperatingLeasesFutureMinimumPaymentsReceivableInThreeYears	62144246	USD
CY2020Q4	us-gaap	Operating Leases Future Minimum Payments Receivable In Four Years OperatingLeasesFutureMinimumPaymentsReceivableInFourYears	59270828	USD
CY2020Q4	us-gaap	Operating Leases Future Minimum Payments Receivable In Five Years OperatingLeasesFutureMinimumPaymentsReceivableInFiveYears	55265048	USD
CY2020Q4	us-gaap	Operating Leases Future Minimum Payments Receivable Thereafter OperatingLeasesFutureMinimumPaymentsReceivableThereafter	643109471	USD
CY2020Q4	us-gaap	Mortgage Loans On Real Estate Commercial And Consumer Net MortgageLoansOnRealEstateCommercialAndConsumerNet	84913000	USD
CY2019Q4	us-gaap	Mortgage Loans On Real Estate Commercial And Consumer Net MortgageLoansOnRealEstateCommercialAndConsumerNet	91799000	USD
CY2020Q4	us-gaap	Loans Receivable Fair Value Disclosure LoansReceivableFairValueDisclosure	86596000	USD
CY2019Q4	us-gaap	Loans Receivable Fair Value Disclosure LoansReceivableFairValueDisclosure	94613000	USD
CY2019Q4	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	200000	USD
CY2020Q4	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	200000	USD
CY2019Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	2146000	USD
CY2020	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	3648000	USD
CY2020Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	5437000	USD
CY2020	wrb	Availablefor Saleand Heldto Maturity Realized Gains Debt Securities Excluding Otherthan Temporary Impairmentsand Allowances AvailableforSaleandHeldtoMaturityRealizedGainsDebtSecuritiesExcludingOtherthanTemporaryImpairmentsandAllowances	27819000	USD
CY2019	wrb	Availablefor Saleand Heldto Maturity Realized Gains Debt Securities Excluding Otherthan Temporary Impairmentsand Allowances AvailableforSaleandHeldtoMaturityRealizedGainsDebtSecuritiesExcludingOtherthanTemporaryImpairmentsandAllowances	23900000	USD
CY2018	wrb	Availablefor Saleand Heldto Maturity Realized Gains Debt Securities Excluding Otherthan Temporary Impairmentsand Allowances AvailableforSaleandHeldtoMaturityRealizedGainsDebtSecuritiesExcludingOtherthanTemporaryImpairmentsandAllowances	26752000	USD
CY2020	wrb	Availablefor Saleand Heldto Maturity Realized Losses Debt Securities Excluding Otherthan Temporary Impairmentsand Allowances AvailableforSaleandHeldtoMaturityRealizedLossesDebtSecuritiesExcludingOtherthanTemporaryImpairmentsandAllowances	56096000	USD
CY2019	wrb	Availablefor Saleand Heldto Maturity Realized Losses Debt Securities Excluding Otherthan Temporary Impairmentsand Allowances AvailableforSaleandHeldtoMaturityRealizedLossesDebtSecuritiesExcludingOtherthanTemporaryImpairmentsandAllowances	13636000	USD
CY2018	wrb	Availablefor Saleand Heldto Maturity Realized Losses Debt Securities Excluding Otherthan Temporary Impairmentsand Allowances AvailableforSaleandHeldtoMaturityRealizedLossesDebtSecuritiesExcludingOtherthanTemporaryImpairmentsandAllowances	13733000	USD
CY2020	us-gaap	Equity Securities Fv Ni Realized Gain EquitySecuritiesFvNiRealizedGain	32647000	USD
CY2019	us-gaap	Equity Securities Fv Ni Realized Gain EquitySecuritiesFvNiRealizedGain	23306000	USD
CY2018	us-gaap	Equity Securities Fv Ni Realized Gain EquitySecuritiesFvNiRealizedGain	435150000	USD
CY2020	us-gaap	Equity Securities Fv Ni Unrealized Gain Loss EquitySecuritiesFvNiUnrealizedGainLoss	-25868000	USD
CY2019	us-gaap	Equity Securities Fv Ni Unrealized Gain Loss EquitySecuritiesFvNiUnrealizedGainLoss	85292000	USD
CY2018	us-gaap	Equity Securities Fv Ni Unrealized Gain Loss EquitySecuritiesFvNiUnrealizedGainLoss	-320413000	USD
CY2020	us-gaap	Equity Method Investment Realized Gain Loss On Disposal EquityMethodInvestmentRealizedGainLossOnDisposal	31481000	USD
CY2019	us-gaap	Equity Method Investment Realized Gain Loss On Disposal EquityMethodInvestmentRealizedGainLossOnDisposal	-2825000	USD
CY2018	us-gaap	Equity Method Investment Realized Gain Loss On Disposal EquityMethodInvestmentRealizedGainLossOnDisposal	-212000	USD
CY2020	us-gaap	Gain Loss On Sale Of Properties GainLossOnSaleOfProperties	101554000	USD
CY2019	us-gaap	Gain Loss On Sale Of Properties GainLossOnSaleOfProperties	5965000	USD
CY2018	us-gaap	Gain Loss On Sale Of Properties GainLossOnSaleOfProperties	27816000	USD
CY2020	us-gaap	Gain Loss On Sale Of Loans And Leases GainLossOnSaleOfLoansAndLeases	0	USD
CY2019	us-gaap	Gain Loss On Sale Of Loans And Leases GainLossOnSaleOfLoansAndLeases	-970000	USD
CY2018	us-gaap	Gain Loss On Sale Of Loans And Leases GainLossOnSaleOfLoansAndLeases	2838000	USD
CY2020	us-gaap	Gain Loss On Sale Of Other Investments GainLossOnSaleOfOtherInvestments	-38023000	USD
CY2019	us-gaap	Gain Loss On Sale Of Other Investments GainLossOnSaleOfOtherInvestments	-329000	USD
CY2018	us-gaap	Gain Loss On Sale Of Other Investments GainLossOnSaleOfOtherInvestments	1977000	USD
CY2020	wrb	Realized Gain Losson Investments Including Equity Method Investments Excluding Otherthan Temporary Impairmentsand Allowances RealizedGainLossonInvestmentsIncludingEquityMethodInvestmentsExcludingOtherthanTemporaryImpairmentsandAllowances	73514000	USD
CY2019	wrb	Realized Gain Losson Investments Including Equity Method Investments Excluding Otherthan Temporary Impairmentsand Allowances RealizedGainLossonInvestmentsIncludingEquityMethodInvestmentsExcludingOtherthanTemporaryImpairmentsandAllowances	120703000	USD
CY2018	wrb	Realized Gain Losson Investments Including Equity Method Investments Excluding Otherthan Temporary Impairmentsand Allowances RealizedGainLossonInvestmentsIncludingEquityMethodInvestmentsExcludingOtherthanTemporaryImpairmentsandAllowances	160175000	USD
CY2020	wrb	Debt Securities Allowancefor Credit Loss Period Increase Decrease DebtSecuritiesAllowanceforCreditLossPeriodIncreaseDecrease	33134000	USD
CY2019	wrb	Debt Securities Allowancefor Credit Loss Period Increase Decrease DebtSecuritiesAllowanceforCreditLossPeriodIncreaseDecrease	0	USD
CY2018	wrb	Debt Securities Allowancefor Credit Loss Period Increase Decrease DebtSecuritiesAllowanceforCreditLossPeriodIncreaseDecrease	-5687000	USD
CY2020	us-gaap	Financing Receivable Allowance For Credit Losses Period Increase Decrease FinancingReceivableAllowanceForCreditLossesPeriodIncreaseDecrease	-3648000	USD
CY2019	us-gaap	Financing Receivable Allowance For Credit Losses Period Increase Decrease FinancingReceivableAllowanceForCreditLossesPeriodIncreaseDecrease	0	USD
CY2018	us-gaap	Financing Receivable Allowance For Credit Losses Period Increase Decrease FinancingReceivableAllowanceForCreditLossesPeriodIncreaseDecrease	0	USD
CY2020	wrb	Investments Allowancefor Credit Loss Period Increase Decrease InvestmentsAllowanceforCreditLossPeriodIncreaseDecrease	29486000	USD
CY2019	wrb	Investments Allowancefor Credit Loss Period Increase Decrease InvestmentsAllowanceforCreditLossPeriodIncreaseDecrease	0	USD
CY2018	wrb	Investments Allowancefor Credit Loss Period Increase Decrease InvestmentsAllowanceforCreditLossPeriodIncreaseDecrease	-5687000	USD
CY2020	wrb	Realized Gain Losson Marketable Securities Equity Method Investmentsand Other Investments Before Tax RealizedGainLossonMarketableSecuritiesEquityMethodInvestmentsandOtherInvestmentsBeforeTax	103000000	USD
CY2019	wrb	Realized Gain Losson Marketable Securities Equity Method Investmentsand Other Investments Before Tax RealizedGainLossonMarketableSecuritiesEquityMethodInvestmentsandOtherInvestmentsBeforeTax	120703000	USD
CY2018	wrb	Realized Gain Losson Marketable Securities Equity Method Investmentsand Other Investments Before Tax RealizedGainLossonMarketableSecuritiesEquityMethodInvestmentsandOtherInvestmentsBeforeTax	154488000	USD
CY2020	wrb	Realized Gain Losson Marketable Securities Equity Method Investmentsand Other Investments Tax RealizedGainLossonMarketableSecuritiesEquityMethodInvestmentsandOtherInvestmentsTax	21630000	USD
CY2019	wrb	Realized Gain Losson Marketable Securities Equity Method Investmentsand Other Investments Tax RealizedGainLossonMarketableSecuritiesEquityMethodInvestmentsandOtherInvestmentsTax	25348000	USD
CY2018	wrb	Realized Gain Losson Marketable Securities Equity Method Investmentsand Other Investments Tax RealizedGainLossonMarketableSecuritiesEquityMethodInvestmentsandOtherInvestmentsTax	32442000	USD
CY2020	wrb	Realized Gain Losson Marketable Securities Equity Method Investmentsand Other Investments Netof Tax RealizedGainLossonMarketableSecuritiesEquityMethodInvestmentsandOtherInvestmentsNetofTax	81370000	USD
CY2019	wrb	Realized Gain Losson Marketable Securities Equity Method Investmentsand Other Investments Netof Tax RealizedGainLossonMarketableSecuritiesEquityMethodInvestmentsandOtherInvestmentsNetofTax	95355000	USD
CY2018	wrb	Realized Gain Losson Marketable Securities Equity Method Investmentsand Other Investments Netof Tax RealizedGainLossonMarketableSecuritiesEquityMethodInvestmentsandOtherInvestmentsNetofTax	122046000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Before Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeTax	164645000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Before Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeTax	261970000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Before Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeTax	-302737000	USD
CY2020	wrb	Changein Unrealized Gainlosson Investmentstax ChangeinUnrealizedGainlossonInvestmentstax	24395000	USD
CY2018	wrb	Liabilityfor Unpaid Claimsand Claims Adjustment Expense Incurred Claims Adjustment LiabilityforUnpaidClaimsandClaimsAdjustmentExpenseIncurredClaimsAdjustment	-6831000	USD
CY2020	wrb	Liability For Unpaid Claims And Claims Adjustment Expense Incurred Loss Reserve Discount Accretion LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredLossReserveDiscountAccretion	-35142000	USD
CY2019	wrb	Changein Unrealized Gainlosson Investmentstax ChangeinUnrealizedGainlossonInvestmentstax	46068000	USD
CY2018	wrb	Changein Unrealized Gainlosson Investmentstax ChangeinUnrealizedGainlossonInvestmentstax	-50410000	USD
CY2020	wrb	Changein Unrealized Gainlosson Investments Including Portion Attributableto Noncontrolling Interest ChangeinUnrealizedGainlossonInvestmentsIncludingPortionAttributabletoNoncontrollingInterest	2000	USD
CY2019	wrb	Changein Unrealized Gainlosson Investments Including Portion Attributableto Noncontrolling Interest ChangeinUnrealizedGainlossonInvestmentsIncludingPortionAttributabletoNoncontrollingInterest	-103000	USD
CY2018	wrb	Changein Unrealized Gainlosson Investments Including Portion Attributableto Noncontrolling Interest ChangeinUnrealizedGainlossonInvestmentsIncludingPortionAttributabletoNoncontrollingInterest	46000	USD
CY2020	wrb	Changein Unrealized Gainlosson Investments Including Portion Attributableto Noncontrolling Interest Netof Tax ChangeinUnrealizedGainlossonInvestmentsIncludingPortionAttributabletoNoncontrollingInterestNetofTax	140248000	USD
CY2019	wrb	Changein Unrealized Gainlosson Investments Including Portion Attributableto Noncontrolling Interest Netof Tax ChangeinUnrealizedGainlossonInvestmentsIncludingPortionAttributabletoNoncontrollingInterestNetofTax	216005000	USD
CY2018	wrb	Changein Unrealized Gainlosson Investments Including Portion Attributableto Noncontrolling Interest Netof Tax ChangeinUnrealizedGainlossonInvestmentsIncludingPortionAttributabletoNoncontrollingInterestNetofTax	-252373000	USD
CY2019Q1	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Into Level3 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersIntoLevel3	2	USD
CY2020Q4	us-gaap	Shortduration Insurance Contracts Liability For Unpaid Claims And Allocated Claim Adjustment Expense Net ShortdurationInsuranceContractsLiabilityForUnpaidClaimsAndAllocatedClaimAdjustmentExpenseNet	12103860000	USD
CY2020Q4	us-gaap	Reinsurance Recoverable For Unpaid Claims And Claims Adjustments ReinsuranceRecoverableForUnpaidClaimsAndClaimsAdjustments	2164037000	USD
CY2020Q4	us-gaap	Shortduration Insurance Contracts Discounted Liabilities Aggregate Discount ShortdurationInsuranceContractsDiscountedLiabilitiesAggregateDiscount	483467000	USD
CY2020Q4	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	13784430000	USD
CY2020	us-gaap	Schedule Of Liability For Unpaid Claims And Claims Adjustment Expense ScheduleOfLiabilityForUnpaidClaimsAndClaimsAdjustmentExpense	<div style="margin-bottom:6pt;margin-top:6pt;text-indent:36pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">The table below provides a reconciliation of the beginning and ending reserve balances:</span></div><div style="margin-bottom:5pt;margin-top:11pt"><table style="border-collapse:collapse;display:inline-table;vertical-align:top;width:98.739%"><tr><td style="width:1.0%"/><td style="width:55.212%"/><td style="width:0.1%"/><td style="width:1.0%"/><td style="width:13.651%"/><td style="width:0.1%"/><td style="width:0.1%"/><td style="width:0.509%"/><td style="width:0.1%"/><td style="width:1.0%"/><td style="width:12.375%"/><td style="width:0.1%"/><td style="width:0.1%"/><td style="width:0.509%"/><td style="width:0.1%"/><td style="width:1.0%"/><td style="width:12.944%"/><td style="width:0.1%"/></tr><tr><td colspan="3" style="padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:700;line-height:100%;text-decoration:underline">(In thousands)</span></td><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:700;line-height:100%">2020</span></td><td colspan="3" style="padding:0 1pt"/><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:700;line-height:100%">2019</span></td><td colspan="3" style="padding:0 1pt"/><td colspan="3" style="padding:2px 1pt;text-align:center;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:700;line-height:100%">2018</span></td></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">Net reserves at beginning of year</span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">$</span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">10,697,998 </span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">$</span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">10,248,883 </span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">$</span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">10,056,914 </span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt 2px 7.75pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">Cumulative effect adjustment resulting from changes in accounting principles (1)</span></td><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">5,927 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">— </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">— </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt 2px 7.75pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">Restated net reserves at beginning of period</span></td><td colspan="2" style="background-color:#cceeff;border-top:1pt solid #000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">10,703,925 </span></td><td style="background-color:#cceeff;border-top:1pt solid #000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;border-top:1pt solid #000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">10,248,883 </span></td><td style="background-color:#cceeff;border-top:1pt solid #000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;border-top:1pt solid #000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">10,056,914 </span></td><td style="background-color:#cceeff;border-top:1pt solid #000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">Net provision for losses and loss expenses:</span></td><td colspan="3" style="background-color:#ffffff;border-top:1pt solid #000;padding:0 1pt"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="3" style="background-color:#ffffff;border-top:1pt solid #000;padding:0 1pt"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="3" style="background-color:#ffffff;border-top:1pt solid #000;padding:0 1pt"/></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt 2px 7.75pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">Claims occurring during the current year (2)</span></td><td colspan="2" style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">4,432,937 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">4,057,989 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">3,926,489 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt 2px 7.75pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">Increase in estimates for claims occurring in prior years (3)</span></td><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">627 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">34,079 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">6,831 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt 2px 7.75pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">Loss reserve discount accretion</span></td><td colspan="2" style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">35,142 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">39,048 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">41,382 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt 2px 12.25pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">Total</span></td><td colspan="2" style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">4,468,706 </span></td><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">4,131,116 </span></td><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">3,974,702 </span></td><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">Net payments for claims:</span></td><td colspan="3" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%"> </span></td><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="3" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%"> </span></td><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="3" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%"> </span></td></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt 2px 7.75pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">Current year</span></td><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">921,054 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">985,599 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">964,808 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt 2px 7.75pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">Prior year</span></td><td colspan="2" style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">2,677,595 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">2,673,803 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">2,700,077 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt 2px 12.25pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">Total</span></td><td colspan="2" style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">3,598,649 </span></td><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">3,659,402 </span></td><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">3,664,885 </span></td><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">Foreign currency translation</span></td><td colspan="2" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">46,411 </span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">(22,599)</span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">(117,848)</span></td><td style="background-color:#cceeff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">Net reserves at end of year</span></td><td colspan="2" style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">11,620,393 </span></td><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">10,697,998 </span></td><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">10,248,883 </span></td><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">Ceded reserve at end of year</span></td><td colspan="2" style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">2,164,037 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">1,885,251 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="2" style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">1,717,565 </span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">Gross reserves at end of year</span></td><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">$</span></td><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">13,784,430 </span></td><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">$</span></td><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">12,583,249 </span></td><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">$</span></td><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">11,966,448 </span></td><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr style="height:15pt"><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="3" style="background-color:#cceeff;border-top:3pt double #000000;padding:0 1pt"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="3" style="background-color:#cceeff;border-top:3pt double #000000;padding:0 1pt"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td colspan="3" style="background-color:#cceeff;border-top:3pt double #000000;padding:0 1pt"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">Net change in premiums and losses occurring in prior years:</span></td><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt;text-align:left;text-indent:9pt;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">Increase in estimates for claims occurring in prior years (3)</span></td><td style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">$</span></td><td style="background-color:#cceeff;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">(627)</span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">$</span></td><td style="background-color:#cceeff;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">(34,079)</span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td style="background-color:#cceeff;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">$</span></td><td style="background-color:#cceeff;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">(6,831)</span></td><td style="background-color:#cceeff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt;text-align:left;text-indent:9pt;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">Retrospective premium adjustments for claims occurring in prior years (4)</span></td><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">16,807 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">53,511 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">45,638 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#cceeff;padding:2px 1pt;text-align:left;vertical-align:bottom"><div style="text-indent:9pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">Net favorable premium and reserve development on prior years</span></div></td><td style="background-color:#cceeff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">$</span></td><td style="background-color:#cceeff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">16,180 </span></td><td style="background-color:#cceeff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td style="background-color:#cceeff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">$</span></td><td style="background-color:#cceeff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">19,432 </span></td><td style="background-color:#cceeff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#cceeff;padding:0 1pt"/><td style="background-color:#cceeff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">$</span></td><td style="background-color:#cceeff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8.5pt;font-weight:400;line-height:100%">38,807 </span></td><td style="background-color:#cceeff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr></table></div><div><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-weight:400;line-height:120%">_______________________________________</span></div><div style="padding-left:18pt;text-indent:-18pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">(1)</span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;padding-left:6.34pt">The cumulative effect adjustment resulting from changes in accounting principals relates to the allowance for expected credit losses on reinsurance recoverables that commenced on January 1, 2020 due to the adoption of ASU 2016-13. See Note 1 for more details.</span></div><div style="padding-left:18pt;text-indent:-18pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">(2)</span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;padding-left:6.34pt">Claims occurring during the current year are net of loss reserve discounts of $10 million, $20 million and $24 million in 2020, 2019, and 2018, respectively.</span></div><div style="padding-left:18pt;text-indent:-18pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">(3)</span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;padding-left:6.34pt">The change in estimates for claims occurring in prior years is net of loss reserve discount. On an undiscounted basis, the estimates for claims occurring in prior years decreased by $21 million in 2020, increased by $19 million in 2019, and decreased by $4 million in 2018, respectively.</span></div>(4)For certain retrospectively rated insurance polices and reinsurance agreements, changes in loss and loss expenses for prior years are offset by additional or return premiums.
CY2019Q4	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	10697998000	USD
CY2018Q4	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	10248883000	USD
CY2017Q4	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	10056914000	USD
CY2020	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Current Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersCurrentYearClaimsAndClaimsAdjustmentExpense	4432937000	USD
CY2019	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Current Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersCurrentYearClaimsAndClaimsAdjustmentExpense	4057989000	USD
CY2018	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Current Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersCurrentYearClaimsAndClaimsAdjustmentExpense	3926489000	USD
CY2020	wrb	Liabilityfor Unpaid Claimsand Claims Adjustment Expense Incurred Claims Adjustment LiabilityforUnpaidClaimsandClaimsAdjustmentExpenseIncurredClaimsAdjustment	-627000	USD
CY2019	wrb	Liabilityfor Unpaid Claimsand Claims Adjustment Expense Incurred Claims Adjustment LiabilityforUnpaidClaimsandClaimsAdjustmentExpenseIncurredClaimsAdjustment	-34079000	USD
CY2019	wrb	Liability For Unpaid Claims And Claims Adjustment Expense Incurred Loss Reserve Discount Accretion LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredLossReserveDiscountAccretion	-39048000	USD
CY2018	wrb	Liability For Unpaid Claims And Claims Adjustment Expense Incurred Loss Reserve Discount Accretion LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredLossReserveDiscountAccretion	-41382000	USD
CY2020	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Incurred Claims1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaims1	4468706000	USD
CY2019	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Incurred Claims1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaims1	4131116000	USD
CY2018	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Incurred Claims1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaims1	3974702000	USD
CY2020	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Current Year1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidCurrentYear1	921054000	USD
CY2019	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Current Year1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidCurrentYear1	985599000	USD
CY2018	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Current Year1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidCurrentYear1	964808000	USD
CY2020	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Prior Years1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidPriorYears1	2677595000	USD
CY2019	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Prior Years1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidPriorYears1	2673803000	USD
CY2018	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Prior Years1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidPriorYears1	2700077000	USD
CY2020	us-gaap	Payments For Losses And Loss Adjustment Expense PaymentsForLossesAndLossAdjustmentExpense	3598649000	USD
CY2019	us-gaap	Payments For Losses And Loss Adjustment Expense PaymentsForLossesAndLossAdjustmentExpense	3659402000	USD
CY2018	us-gaap	Payments For Losses And Loss Adjustment Expense PaymentsForLossesAndLossAdjustmentExpense	3664885000	USD
CY2020	wrb	Liabilityfor Unpaid Claimsand Claims Adjustment Expense Foreign Exchange Translation LiabilityforUnpaidClaimsandClaimsAdjustmentExpenseForeignExchangeTranslation	46411000	USD
CY2019	wrb	Liabilityfor Unpaid Claimsand Claims Adjustment Expense Foreign Exchange Translation LiabilityforUnpaidClaimsandClaimsAdjustmentExpenseForeignExchangeTranslation	-22599000	USD
CY2020	wrb	Favorable Reserve Development Net Of Premium Offsets FavorableReserveDevelopmentNetOfPremiumOffsets	16180000	USD
CY2019	wrb	Favorable Reserve Development Net Of Premium Offsets FavorableReserveDevelopmentNetOfPremiumOffsets	19432000	USD
CY2018	wrb	Favorable Reserve Development Net Of Premium Offsets FavorableReserveDevelopmentNetOfPremiumOffsets	38807000	USD
CY2020Q4	us-gaap	Workers Compensation Discount Amount WorkersCompensationDiscountAmount	10000000	USD
CY2019Q4	us-gaap	Workers Compensation Discount Amount WorkersCompensationDiscountAmount	20000000	USD
CY2018	wrb	Liabilityfor Unpaid Claimsand Claims Adjustment Expense Foreign Exchange Translation LiabilityforUnpaidClaimsandClaimsAdjustmentExpenseForeignExchangeTranslation	-117848000	USD
CY2020Q4	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	11620393000	USD
CY2019Q4	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	10697998000	USD
CY2018Q4	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	10248883000	USD
CY2020Q4	us-gaap	Reinsurance Recoverables Gross ReinsuranceRecoverablesGross	2164037000	USD
CY2019Q4	us-gaap	Reinsurance Recoverables Gross ReinsuranceRecoverablesGross	1885251000	USD
CY2018Q4	us-gaap	Reinsurance Recoverables Gross ReinsuranceRecoverablesGross	1717565000	USD
CY2020Q4	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	13784430000	USD
CY2019Q4	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	12583249000	USD
CY2018Q4	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	11966448000	USD
CY2020	wrb	Increase Decreasein Estimatesfor Claims Occurringin Prior Years Premiumsand Losses IncreaseDecreaseinEstimatesforClaimsOccurringinPriorYearsPremiumsandLosses	-627000	USD
CY2019	wrb	Increase Decreasein Estimatesfor Claims Occurringin Prior Years Premiumsand Losses IncreaseDecreaseinEstimatesforClaimsOccurringinPriorYearsPremiumsandLosses	-34079000	USD
CY2018	wrb	Increase Decreasein Estimatesfor Claims Occurringin Prior Years Premiumsand Losses IncreaseDecreaseinEstimatesforClaimsOccurringinPriorYearsPremiumsandLosses	-6831000	USD
CY2020	wrb	Retrospective Premium Adjustmentsin Estimatesfor Claims Occurringin Prior Years Premiumsand Losses RetrospectivePremiumAdjustmentsinEstimatesforClaimsOccurringinPriorYearsPremiumsandLosses	16807000	USD
CY2019	wrb	Retrospective Premium Adjustmentsin Estimatesfor Claims Occurringin Prior Years Premiumsand Losses RetrospectivePremiumAdjustmentsinEstimatesforClaimsOccurringinPriorYearsPremiumsandLosses	53511000	USD
CY2018	wrb	Retrospective Premium Adjustmentsin Estimatesfor Claims Occurringin Prior Years Premiumsand Losses RetrospectivePremiumAdjustmentsinEstimatesforClaimsOccurringinPriorYearsPremiumsandLosses	45638000	USD
CY2018Q4	us-gaap	Workers Compensation Discount Amount WorkersCompensationDiscountAmount	24000000	USD
CY2020	wrb	Liability For Unpaid Claims And Claims Adjustment Expense Incurred Claims Undiscounted Basis Prior Years Increase Decrease LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaimsUndiscountedBasisPriorYearsIncreaseDecrease	21000000	USD
CY2019	wrb	Liability For Unpaid Claims And Claims Adjustment Expense Incurred Claims Undiscounted Basis Prior Years Increase Decrease LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaimsUndiscountedBasisPriorYearsIncreaseDecrease	-19000000	USD
CY2018	wrb	Liability For Unpaid Claims And Claims Adjustment Expense Incurred Claims Undiscounted Basis Prior Years Increase Decrease LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaimsUndiscountedBasisPriorYearsIncreaseDecrease	-4000000	USD
CY2020Q4	wrb	Liabilityfor Claimsand Claims Adjustment Expense Net Of Reinsurance LiabilityforClaimsandClaimsAdjustmentExpenseNetOfReinsurance	171000000	USD
CY2020Q4	wrb	Liabilityfor Claimsand Claims Adjustment Expense Net Of Reinsurance LiabilityforClaimsandClaimsAdjustmentExpenseNetOfReinsurance	171000000	USD
CY2020Q4	wrb	Liability For Claims And Claims Adjustment Expense Net Of Reinsurance Reported Claims Amount LiabilityForClaimsAndClaimsAdjustmentExpenseNetOfReinsuranceReportedClaimsAmount	95000000	USD
CY2020Q4	wrb	Liability For Claims And Claims Adjustment Expense Net Of Reinsurance Incurred But Not Reported Ibnr Claims Amount LiabilityForClaimsAndClaimsAdjustmentExpenseNetOfReinsuranceIncurredButNotReportedIBNRClaimsAmount	76000000	USD
CY2020	wrb	Favorable Reserve Development Net Of Premium Offsets FavorableReserveDevelopmentNetOfPremiumOffsets	16000000	USD
CY2019	wrb	Favorable Reserve Development Net Of Premium Offsets FavorableReserveDevelopmentNetOfPremiumOffsets	19000000	USD
CY2018	wrb	Favorable Reserve Development Net Of Premium Offsets FavorableReserveDevelopmentNetOfPremiumOffsets	39000000	USD
CY2020Q4	us-gaap	Liability For Asbestos And Environmental Claims Net LiabilityForAsbestosAndEnvironmentalClaimsNet	19000000	USD
CY2019Q4	us-gaap	Liability For Asbestos And Environmental Claims Net LiabilityForAsbestosAndEnvironmentalClaimsNet	24000000	USD
CY2019Q4	us-gaap	Workers Compensation Discount Prior Year Amount WorkersCompensationDiscountPriorYearAmount	1731000000	USD
CY2020Q4	wrb	Workers Compensation Discount After Effects Of Ceded Reinsurance Amount WorkersCompensationDiscountAfterEffectsOfCededReinsuranceAmount	483000000	USD
CY2019Q4	wrb	Workers Compensation Discount After Effects Of Ceded Reinsurance Amount WorkersCompensationDiscountAfterEffectsOfCededReinsuranceAmount	530000000	USD
CY2020	us-gaap	Direct Premiums Written DirectPremiumsWritten	7874050000	USD
CY2019	us-gaap	Direct Premiums Written DirectPremiumsWritten	7386759000	USD
CY2018	us-gaap	Direct Premiums Written DirectPremiumsWritten	6973216000	USD
CY2020	us-gaap	Assumed Premiums Written AssumedPremiumsWritten	973597000	USD
CY2019	us-gaap	Assumed Premiums Written AssumedPremiumsWritten	875459000	USD
CY2018	us-gaap	Assumed Premiums Written AssumedPremiumsWritten	729278000	USD
CY2020	us-gaap	Ceded Premiums Written CededPremiumsWritten	1585210000	USD
CY2019	us-gaap	Ceded Premiums Written CededPremiumsWritten	1398719000	USD
CY2018	us-gaap	Ceded Premiums Written CededPremiumsWritten	1269267000	USD
CY2020	us-gaap	Premiums Written Net PremiumsWrittenNet	7262437000	USD
CY2019	us-gaap	Premiums Written Net PremiumsWrittenNet	6863499000	USD
CY2018	us-gaap	Premiums Written Net PremiumsWrittenNet	6433227000	USD
CY2020	us-gaap	Direct Premiums Earned DirectPremiumsEarned	7489470000	USD
CY2019	us-gaap	Direct Premiums Earned DirectPremiumsEarned	7141427000	USD
CY2018	us-gaap	Direct Premiums Earned DirectPremiumsEarned	6851795000	USD
CY2020	us-gaap	Assumed Premiums Earned AssumedPremiumsEarned	941321000	USD
CY2019	us-gaap	Assumed Premiums Earned AssumedPremiumsEarned	820705000	USD
CY2018	us-gaap	Assumed Premiums Earned AssumedPremiumsEarned	755759000	USD
CY2020	us-gaap	Ceded Premiums Earned CededPremiumsEarned	1499948000	USD
CY2020Q4	us-gaap	Reinsurance Recoverables Allowance ReinsuranceRecoverablesAllowance	7800649	USD
CY2019	us-gaap	Ceded Premiums Earned CededPremiumsEarned	1328844000	USD
CY2018	us-gaap	Ceded Premiums Earned CededPremiumsEarned	1236049000	USD
CY2020	us-gaap	Premiums Earned Net PremiumsEarnedNet	6930843000	USD
CY2019	us-gaap	Premiums Earned Net PremiumsEarnedNet	6633288000	USD
CY2018	us-gaap	Premiums Earned Net PremiumsEarnedNet	6371505000	USD
CY2020	us-gaap	Reinsurance Effect On Claims And Benefits Incurred Amount Ceded ReinsuranceEffectOnClaimsAndBenefitsIncurredAmountCeded	955630000	USD
CY2019	us-gaap	Reinsurance Effect On Claims And Benefits Incurred Amount Ceded ReinsuranceEffectOnClaimsAndBenefitsIncurredAmountCeded	836831000	USD
CY2018	us-gaap	Reinsurance Effect On Claims And Benefits Incurred Amount Ceded ReinsuranceEffectOnClaimsAndBenefitsIncurredAmountCeded	829742000	USD
CY2020	us-gaap	Revenue From Contract With Customer Including Assessed Tax RevenueFromContractWithCustomerIncludingAssessedTax	358253000	USD
CY2019	us-gaap	Revenue From Contract With Customer Including Assessed Tax RevenueFromContractWithCustomerIncludingAssessedTax	314191000	USD
CY2018	us-gaap	Revenue From Contract With Customer Including Assessed Tax RevenueFromContractWithCustomerIncludingAssessedTax	268037000	USD
CY2019Q4	us-gaap	Premiums Receivable Allowance For Doubtful Accounts PremiumsReceivableAllowanceForDoubtfulAccounts	19823000	USD
CY2020	us-gaap	Premium Receivable Credit Loss Expense Reversal PremiumReceivableCreditLossExpenseReversal	1790000	USD
CY2020Q4	us-gaap	Premiums Receivable Allowance For Doubtful Accounts PremiumsReceivableAllowanceForDoubtfulAccounts	22883000	USD
CY2019Q4	us-gaap	Reinsurance Recoverables Allowance ReinsuranceRecoverablesAllowance	690127	USD
CY2018Q4	us-gaap	Reinsurance Recoverables Allowance ReinsuranceRecoverablesAllowance	946965	USD
CY2019Q4	us-gaap	Reinsurance Recoverables Allowance ReinsuranceRecoverablesAllowance	690000	USD
CY2020	us-gaap	Reinsurance Recoverable Credit Loss Expense Reversal ReinsuranceRecoverableCreditLossExpenseReversal	1184000	USD
CY2020Q4	us-gaap	Reinsurance Recoverables Allowance ReinsuranceRecoverablesAllowance	7801000	USD
CY2020Q4	us-gaap	Reinsurance Recoverables Allowance ReinsuranceRecoverablesAllowance	7801000	USD
CY2020Q4	us-gaap	Reinsurance Recoverables ReinsuranceRecoverables	2424502000	USD
CY2020	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	162305000	USD
CY2020	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	17000	USD
CY2020	us-gaap	Federal Income Tax Expense Benefit Continuing Operations FederalIncomeTaxExpenseBenefitContinuingOperations	162322000	USD
CY2020	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	23375000	USD
CY2020	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	-13880000	USD
CY2020	us-gaap	Foreign Income Tax Expense Benefit Continuing Operations ForeignIncomeTaxExpenseBenefitContinuingOperations	9495000	USD
CY2020	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	185680000	USD
CY2020	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-13863000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	171817000	USD
CY2019	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	124231000	USD
CY2019	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	27616000	USD
CY2019	us-gaap	Federal Income Tax Expense Benefit Continuing Operations FederalIncomeTaxExpenseBenefitContinuingOperations	151847000	USD
CY2019	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	9030000	USD
CY2019	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	8058000	USD
CY2019	us-gaap	Foreign Income Tax Expense Benefit Continuing Operations ForeignIncomeTaxExpenseBenefitContinuingOperations	17088000	USD
CY2019	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	133261000	USD
CY2019	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	35674000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	168935000	USD
CY2018	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	188712000	USD
CY2018	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	-63134000	USD
CY2018	us-gaap	Federal Income Tax Expense Benefit Continuing Operations FederalIncomeTaxExpenseBenefitContinuingOperations	125578000	USD
CY2018	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	13963000	USD
CY2018	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	23487000	USD
CY2018	us-gaap	Foreign Income Tax Expense Benefit Continuing Operations ForeignIncomeTaxExpenseBenefitContinuingOperations	37450000	USD
CY2018	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	202675000	USD
CY2018	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-39647000	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	163028000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	831000000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	739000000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	755000000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	-126000000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	114000000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	57000000	USD
CY2020	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	148008000	USD
CY2019	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	179113000	USD
CY2018	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	170540000	USD
CY2020	us-gaap	Income Tax Reconciliation Tax Exempt Income IncomeTaxReconciliationTaxExemptIncome	12770000	USD
CY2019	us-gaap	Income Tax Reconciliation Tax Exempt Income IncomeTaxReconciliationTaxExemptIncome	14666000	USD
CY2018	us-gaap	Income Tax Reconciliation Tax Exempt Income IncomeTaxReconciliationTaxExemptIncome	18833000	USD
CY2020	us-gaap	Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance	46238000	USD
CY2019	us-gaap	Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance	-1945000	USD
CY2018	us-gaap	Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance	18576000	USD
CY2020	us-gaap	Income Tax Reconciliation Foreign Income Tax Rate Differential IncomeTaxReconciliationForeignIncomeTaxRateDifferential	6753000	USD
CY2019	us-gaap	Income Tax Reconciliation Foreign Income Tax Rate Differential IncomeTaxReconciliationForeignIncomeTaxRateDifferential	7700000	USD
CY2018	us-gaap	Income Tax Reconciliation Foreign Income Tax Rate Differential IncomeTaxReconciliationForeignIncomeTaxRateDifferential	7683000	USD
CY2020	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	2561000	USD
CY2019	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	4842000	USD
CY2018	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	3901000	USD
CY2020	us-gaap	Income Tax Reconciliation Change In Enacted Tax Rate IncomeTaxReconciliationChangeInEnactedTaxRate	0	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	-10950000	USD
CY2020	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	-18973000	USD
CY2019	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	-6109000	USD
CY2018	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	-7889000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	171817000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	168935000	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	163028000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Loss Reserves DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsLossReserves	141877000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Loss Reserves DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsLossReserves	136100000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Unearned Premiums Reserve DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsUnearnedPremiumsReserve	134971000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Unearned Premiums Reserve DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsUnearnedPremiumsReserve	120246000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards DeferredTaxAssetsOperatingLossCarryforwards	64494000	USD
CY2019Q4	wrb	Tax Cutsand Jobs Act Incomplete Accounting Deferred Tax Liabilities Provisional Undistributed Foreign Earnings TaxCutsandJobsActIncompleteAccountingDeferredTaxLiabilitiesProvisionalUndistributedForeignEarnings	29697000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Deferred Expense Deferred Policy Acquisition Cost DeferredTaxLiabilitiesDeferredExpenseDeferredPolicyAcquisitionCost	113084000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards DeferredTaxAssetsOperatingLossCarryforwards	37147000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Impairment Losses DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsImpairmentLosses	5973000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Impairment Losses DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsImpairmentLosses	8049000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Share Based Compensation Cost DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost	60551000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Share Based Compensation Cost DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost	60552000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	85327000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	63633000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	493193000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	425727000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	79488000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	33250000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	413705000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	392477000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets Intangible Assets DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets	12761000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets Intangible Assets DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets	12832000	USD
CY2020Q4	wrb	Tax Cutsand Jobs Act Incomplete Accounting Deferred Tax Liabilities Provisional Undistributed Foreign Earnings TaxCutsandJobsActIncompleteAccountingDeferredTaxLiabilitiesProvisionalUndistributedForeignEarnings	24747000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Deferred Expense Deferred Policy Acquisition Cost DeferredTaxLiabilitiesDeferredExpenseDeferredPolicyAcquisitionCost	103947000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Unrealized Gains On Trading Securities DeferredTaxLiabilitiesUnrealizedGainsOnTradingSecurities	100241000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Unrealized Gains On Trading Securities DeferredTaxLiabilitiesUnrealizedGainsOnTradingSecurities	93330000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	48235000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	47082000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Investments DeferredTaxLiabilitiesInvestments	64944000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Investments DeferredTaxLiabilitiesInvestments	73083000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	62809000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	50212000	USD
CY2020Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	426821000	USD
CY2019Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	410183000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	13116000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	17706000	USD
CY2020Q4	us-gaap	Income Tax Receivable IncomeTaxReceivable	35400000	USD
CY2019Q4	us-gaap	Taxes Payable Current And Noncurrent TaxesPayableCurrentAndNoncurrent	13400000	USD
CY2020Q4	us-gaap	Tax Credit Carryforward Valuation Allowance TaxCreditCarryforwardValuationAllowance	79500000	USD
CY2019Q4	us-gaap	Tax Credit Carryforward Valuation Allowance TaxCreditCarryforwardValuationAllowance	33300000	USD
CY2020Q4	us-gaap	Undistributed Earnings Of Foreign Subsidiaries UndistributedEarningsOfForeignSubsidiaries	111000000	USD
CY2020Q4	us-gaap	Statutory Accounting Practices Statutory Amount Available For Dividend Payments Without Regulatory Approval StatutoryAccountingPracticesStatutoryAmountAvailableForDividendPaymentsWithoutRegulatoryApproval	721000000	USD
CY2020	us-gaap	Statutory Accounting Practices Statutory Net Income Amount StatutoryAccountingPracticesStatutoryNetIncomeAmount	771990000	USD
CY2019	us-gaap	Statutory Accounting Practices Statutory Net Income Amount StatutoryAccountingPracticesStatutoryNetIncomeAmount	601564000	USD
CY2018	us-gaap	Statutory Accounting Practices Statutory Net Income Amount StatutoryAccountingPracticesStatutoryNetIncomeAmount	1099953000	USD
CY2020Q4	us-gaap	Statutory Accounting Practices Statutory Capital And Surplus Balance StatutoryAccountingPracticesStatutoryCapitalAndSurplusBalance	6188121000	USD
CY2019Q4	us-gaap	Statutory Accounting Practices Statutory Capital And Surplus Balance StatutoryAccountingPracticesStatutoryCapitalAndSurplusBalance	6013062000	USD
CY2018Q4	us-gaap	Statutory Accounting Practices Statutory Capital And Surplus Balance StatutoryAccountingPracticesStatutoryCapitalAndSurplusBalance	5587930000	USD
CY2020Q4	wrb	Statutory Accounting Practices Statutory Capitaland Surplus Total Increase Decrease Effecton Balance StatutoryAccountingPracticesStatutoryCapitalandSurplusTotalIncreaseDecreaseEffectonBalance	200000000	USD
CY2020Q4	wrb	Statutory Accounting Practices Statutory Capitaland Surplus Adjusted Capital Balance Remedial Threshold Percent StatutoryAccountingPracticesStatutoryCapitalandSurplusAdjustedCapitalBalanceRemedialThresholdPercent	2
CY2020Q4	wrb	Statutory Accounting Practices Statutory Capitaland Surplus Adjusted Capital Balance StatutoryAccountingPracticesStatutoryCapitalandSurplusAdjustedCapitalBalance	5989000000	USD
CY2020Q4	wrb	Statutory Accounting Practices Statutory Capitaland Surplus Adjusted Capital Balance Percent StatutoryAccountingPracticesStatutoryCapitalandSurplusAdjustedCapitalBalancePercent	3.88
CY2020	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	186924	shares
CY2019	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	190722	shares
CY2018	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	190048	shares
CY2020	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	188763	shares
CY2019	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	193521	shares
CY2018	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	192395	shares
CY2019Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	183411907	shares
CY2018Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	182993640	shares
CY2017Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	182272278	shares
CY2020	us-gaap	Stock Issued During Period Shares New Issues StockIssuedDuringPeriodSharesNewIssues	776544	shares
CY2019	us-gaap	Stock Issued During Period Shares New Issues StockIssuedDuringPeriodSharesNewIssues	687339	shares
CY2018	us-gaap	Stock Issued During Period Shares New Issues StockIssuedDuringPeriodSharesNewIssues	1257762	shares
CY2020	us-gaap	Treasury Stock Shares Acquired TreasuryStockSharesAcquired	6363301	shares
CY2019	us-gaap	Treasury Stock Shares Acquired TreasuryStockSharesAcquired	269072	shares
CY2018	us-gaap	Treasury Stock Shares Acquired TreasuryStockSharesAcquired	536400	shares
CY2020Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	177825150	shares
CY2019Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	183411907	shares
CY2018Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	182993640	shares
CY2020Q4	wrb	Due To Broker DueToBroker	0	USD
CY2020Q4	wrb	Due To Broker Fair Value DueToBrokerFairValue	0	USD
CY2019Q4	wrb	Due To Broker DueToBroker	27116000	USD
CY2019Q4	wrb	Due To Broker Fair Value DueToBrokerFairValue	27116000	USD
CY2020	wrb	Commitmentto Investin Certain Investment Funds CommitmenttoInvestinCertainInvestmentFunds	124000000	USD
CY2020	wrb	Commitmentto Investin Real Estate Construction Projects CommitmenttoInvestinRealEstateConstructionProjects	200000000	USD
CY2020	us-gaap	Operating Lease Cost OperatingLeaseCost	44291000	USD
CY2019	us-gaap	Operating Lease Cost OperatingLeaseCost	44107000	USD
CY2020	us-gaap	Operating Lease Payments OperatingLeasePayments	45348000	USD
CY2019	us-gaap	Operating Lease Payments OperatingLeasePayments	40083000	USD
CY2020	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	8870000	USD
CY2019	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	32881000	USD
CY2020Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	164476000	USD
CY2019Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	193311000	USD
CY2020Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	203643000	USD
CY2019Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	230338000	USD
CY2020Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P6Y9M25D
CY2019Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P7Y1M9D
CY2020Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.0594
CY2019Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.0597
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due Next Twelve Months LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths	47477000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Two LesseeOperatingLeaseLiabilityPaymentsDueYearTwo	41442000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Three LesseeOperatingLeaseLiabilityPaymentsDueYearThree	37843000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Four LesseeOperatingLeaseLiabilityPaymentsDueYearFour	31283000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Five LesseeOperatingLeaseLiabilityPaymentsDueYearFive	22452000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due After Year Five LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive	58124000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due LesseeOperatingLeaseLiabilityPaymentsDue	238621000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Undiscounted Excess Amount LesseeOperatingLeaseLiabilityUndiscountedExcessAmount	34978000	USD
CY2020Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	203643000	USD
CY2020	us-gaap	Deferred Compensation Arrangement With Individual Shares Issued DeferredCompensationArrangementWithIndividualSharesIssued	7519447	shares
CY2020	us-gaap	Deferred Compensation Arrangement With Individual Compensation Expense DeferredCompensationArrangementWithIndividualCompensationExpense	13464000	USD
CY2019	us-gaap	Deferred Compensation Arrangement With Individual Compensation Expense DeferredCompensationArrangementWithIndividualCompensationExpense	16119000	USD
CY2018	us-gaap	Deferred Compensation Arrangement With Individual Compensation Expense DeferredCompensationArrangementWithIndividualCompensationExpense	21438000	USD
CY2020	us-gaap	Deferred Policy Acquisition Cost Amortization Expense DeferredPolicyAcquisitionCostAmortizationExpense	904955000	USD
CY2019	us-gaap	Deferred Policy Acquisition Cost Amortization Expense DeferredPolicyAcquisitionCostAmortizationExpense	1001611000	USD
CY2018	us-gaap	Deferred Policy Acquisition Cost Amortization Expense DeferredPolicyAcquisitionCostAmortizationExpense	915246000	USD
CY2020	us-gaap	Other Underwriting Expense OtherUnderwritingExpense	1206058000	USD
CY2019	us-gaap	Other Underwriting Expense OtherUnderwritingExpense	1088690000	USD
CY2018	us-gaap	Other Underwriting Expense OtherUnderwritingExpense	1183635000	USD
CY2020	wrb	Service Company Expenses ServiceCompanyExpenses	85724000	USD
CY2019	wrb	Service Company Expenses ServiceCompanyExpenses	101317000	USD
CY2018	wrb	Service Company Expenses ServiceCompanyExpenses	118357000	USD
CY2020	us-gaap	Foreign Currency Transaction Gain Loss Before Tax ForeignCurrencyTransactionGainLossBeforeTax	-363000	USD
CY2019	us-gaap	Foreign Currency Transaction Gain Loss Before Tax ForeignCurrencyTransactionGainLossBeforeTax	30715000	USD
CY2018	us-gaap	Foreign Currency Transaction Gain Loss Before Tax ForeignCurrencyTransactionGainLossBeforeTax	27067000	USD
CY2020	us-gaap	Write Off Of Deferred Debt Issuance Cost WriteOffOfDeferredDebtIssuanceCost	8440000	USD
CY2019	us-gaap	Write Off Of Deferred Debt Issuance Cost WriteOffOfDeferredDebtIssuanceCost	0	USD
CY2018	us-gaap	Write Off Of Deferred Debt Issuance Cost WriteOffOfDeferredDebtIssuanceCost	0	USD
CY2020	wrb	Other Costs And Expense Operating Other OtherCostsAndExpenseOperatingOther	184852000	USD
CY2019	wrb	Other Costs And Expense Operating Other OtherCostsAndExpenseOperatingOther	201179000	USD
CY2018	wrb	Other Costs And Expense Operating Other OtherCostsAndExpenseOperatingOther	193050000	USD
CY2020	us-gaap	Other Cost And Expense Operating OtherCostAndExpenseOperating	2390392000	USD
CY2019	us-gaap	Other Cost And Expense Operating OtherCostAndExpenseOperating	2362082000	USD
CY2018	us-gaap	Other Cost And Expense Operating OtherCostAndExpenseOperating	2383221000	USD
CY2020	us-gaap	Number Of Reportable Segments NumberOfReportableSegments	2	segment
CY2020	us-gaap	Gain Loss On Investments GainLossOnInvestments	103000000	USD
CY2020	us-gaap	Gain Loss On Investments GainLossOnInvestments	103000000	USD
CY2020	us-gaap	Gain Loss On Investments GainLossOnInvestments	103000000	USD
CY2020	us-gaap	Income Loss From Subsidiaries Net Of Tax IncomeLossFromSubsidiariesNetOfTax	93181000	USD
CY2020	us-gaap	Premiums Earned Net PremiumsEarnedNet	6930843000	USD
CY2020	us-gaap	Net Investment Income NetInvestmentIncome	583821000	USD
CY2020	wrb	Other Revenues OtherRevenues	584261000	USD
CY2020	us-gaap	Revenues Revenues	8098925000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	704802000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	530670000	USD
CY2019	us-gaap	Gain Loss On Investments GainLossOnInvestments	120703000	USD
CY2019	us-gaap	Gain Loss On Investments GainLossOnInvestments	120703000	USD
CY2019	us-gaap	Gain Loss On Investments GainLossOnInvestments	120703000	USD
CY2019	us-gaap	Income Loss From Subsidiaries Net Of Tax IncomeLossFromSubsidiariesNetOfTax	95355000	USD
CY2019	us-gaap	Premiums Earned Net PremiumsEarnedNet	6633288000	USD
CY2019	us-gaap	Net Investment Income NetInvestmentIncome	645614000	USD
CY2019	wrb	Other Revenues OtherRevenues	623294000	USD
CY2019	us-gaap	Revenues Revenues	7902196000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	852920000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	681944000	USD
CY2018	us-gaap	Gain Loss On Investments GainLossOnInvestments	154488000	USD
CY2018	us-gaap	Gain Loss On Investments GainLossOnInvestments	154488000	USD
CY2018	us-gaap	Gain Loss On Investments GainLossOnInvestments	154488000	USD
CY2018	us-gaap	Income Loss From Subsidiaries Net Of Tax IncomeLossFromSubsidiariesNetOfTax	122046000	USD
CY2018	us-gaap	Premiums Earned Net PremiumsEarnedNet	6371505000	USD
CY2018	us-gaap	Net Investment Income NetInvestmentIncome	674235000	USD
CY2018	wrb	Other Revenues OtherRevenues	645911000	USD
CY2018	us-gaap	Revenues Revenues	7691651000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	812094000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	640749000	USD
CY2020Q4	us-gaap	Assets Assets	28606913000	USD
CY2019Q4	us-gaap	Assets Assets	26662144000	USD
CY2020	us-gaap	Premiums Earned Net PremiumsEarnedNet	6930843000	USD
CY2019	us-gaap	Premiums Earned Net PremiumsEarnedNet	6633288000	USD
CY2018	us-gaap	Premiums Earned Net PremiumsEarnedNet	6371505000	USD
CY2020	us-gaap	Cash Dividends Paid To Parent Company CashDividendsPaidToParentCompany	617424000	USD
CY2019	us-gaap	Cash Dividends Paid To Parent Company CashDividendsPaidToParentCompany	416027000	USD
CY2018	us-gaap	Cash Dividends Paid To Parent Company CashDividendsPaidToParentCompany	639477000	USD
CY2020Q4	us-gaap	Supplementary Insurance Information Deferred Policy Acquisition Costs SupplementaryInsuranceInformationDeferredPolicyAcquisitionCosts	556168000	USD
CY2020Q4	us-gaap	Supplementary Insurance Information Liability For Future Policy Benefits Losses Claims And Loss Expense Reserves SupplementaryInsuranceInformationLiabilityForFuturePolicyBenefitsLossesClaimsAndLossExpenseReserves	13784430000	USD
CY2020Q4	us-gaap	Supplementary Insurance Information Unearned Premiums SupplementaryInsuranceInformationUnearnedPremiums	4073191000	USD
CY2020	us-gaap	Supplementary Insurance Information Premium Revenue SupplementaryInsuranceInformationPremiumRevenue	6930843000	USD
CY2020	us-gaap	Supplementary Insurance Information Net Investment Income SupplementaryInsuranceInformationNetInvestmentIncome	583821000	USD
CY2020	us-gaap	Supplementary Insurance Information Benefits Claims Losses And Settlement Expense SupplementaryInsuranceInformationBenefitsClaimsLossesAndSettlementExpense	4468706000	USD
CY2018Q4	us-gaap	Supplementary Insurance Information Deferred Policy Acquisition Costs SupplementaryInsuranceInformationDeferredPolicyAcquisitionCosts	497629000	USD
CY2020	us-gaap	Supplementary Insurance Information Amortization Of Deferred Policy Acquisition Costs SupplementaryInsuranceInformationAmortizationOfDeferredPolicyAcquisitionCosts	904955000	USD
CY2020	us-gaap	Supplementary Insurance Information Other Operating Expense SupplementaryInsuranceInformationOtherOperatingExpense	1485437000	USD
CY2020	us-gaap	Supplementary Insurance Information Premiums Written SupplementaryInsuranceInformationPremiumsWritten	7262437000	USD
CY2019Q4	us-gaap	Supplementary Insurance Information Deferred Policy Acquisition Costs SupplementaryInsuranceInformationDeferredPolicyAcquisitionCosts	517364000	USD
CY2019Q4	us-gaap	Supplementary Insurance Information Liability For Future Policy Benefits Losses Claims And Loss Expense Reserves SupplementaryInsuranceInformationLiabilityForFuturePolicyBenefitsLossesClaimsAndLossExpenseReserves	12583249000	USD
CY2019Q4	us-gaap	Supplementary Insurance Information Unearned Premiums SupplementaryInsuranceInformationUnearnedPremiums	3656507000	USD
CY2019	us-gaap	Supplementary Insurance Information Premium Revenue SupplementaryInsuranceInformationPremiumRevenue	6633288000	USD
CY2019	us-gaap	Supplementary Insurance Information Net Investment Income SupplementaryInsuranceInformationNetInvestmentIncome	645614000	USD
CY2019	us-gaap	Supplementary Insurance Information Benefits Claims Losses And Settlement Expense SupplementaryInsuranceInformationBenefitsClaimsLossesAndSettlementExpense	4131116000	USD
CY2019	us-gaap	Supplementary Insurance Information Amortization Of Deferred Policy Acquisition Costs SupplementaryInsuranceInformationAmortizationOfDeferredPolicyAcquisitionCosts	1001611000	USD
CY2019	us-gaap	Supplementary Insurance Information Other Operating Expense SupplementaryInsuranceInformationOtherOperatingExpense	1360471000	USD
CY2019	us-gaap	Supplementary Insurance Information Premiums Written SupplementaryInsuranceInformationPremiumsWritten	6863499000	USD
CY2018Q4	us-gaap	Supplementary Insurance Information Liability For Future Policy Benefits Losses Claims And Loss Expense Reserves SupplementaryInsuranceInformationLiabilityForFuturePolicyBenefitsLossesClaimsAndLossExpenseReserves	11966448000	USD
CY2018Q4	us-gaap	Supplementary Insurance Information Unearned Premiums SupplementaryInsuranceInformationUnearnedPremiums	3359991000	USD
CY2018	us-gaap	Supplementary Insurance Information Premium Revenue SupplementaryInsuranceInformationPremiumRevenue	6371505000	USD
CY2019	us-gaap	Ceded Premiums Written CededPremiumsWritten	1398719000	USD
CY2018	us-gaap	Supplementary Insurance Information Net Investment Income SupplementaryInsuranceInformationNetInvestmentIncome	674235000	USD
CY2018	us-gaap	Supplementary Insurance Information Benefits Claims Losses And Settlement Expense SupplementaryInsuranceInformationBenefitsClaimsLossesAndSettlementExpense	3974702000	USD
CY2018	us-gaap	Supplementary Insurance Information Amortization Of Deferred Policy Acquisition Costs SupplementaryInsuranceInformationAmortizationOfDeferredPolicyAcquisitionCosts	915246000	USD
CY2018	us-gaap	Supplementary Insurance Information Other Operating Expense SupplementaryInsuranceInformationOtherOperatingExpense	1467975000	USD
CY2018	us-gaap	Supplementary Insurance Information Premiums Written SupplementaryInsuranceInformationPremiumsWritten	6433227000	USD
CY2020	us-gaap	Direct Premiums Written DirectPremiumsWritten	7874050000	USD
CY2020	us-gaap	Ceded Premiums Written CededPremiumsWritten	1585210000	USD
CY2020	us-gaap	Assumed Premiums Written AssumedPremiumsWritten	973597000	USD
CY2020	us-gaap	Premiums Written Net PremiumsWrittenNet	7262437000	USD
CY2020	us-gaap	Premiums Percentage Assumed To Net PremiumsPercentageAssumedToNet	0.134
CY2019	us-gaap	Direct Premiums Written DirectPremiumsWritten	7386759000	USD
CY2019	us-gaap	Assumed Premiums Written AssumedPremiumsWritten	875459000	USD
CY2019	us-gaap	Premiums Written Net PremiumsWrittenNet	6863499000	USD
CY2019	us-gaap	Premiums Percentage Assumed To Net PremiumsPercentageAssumedToNet	0.128
CY2018	us-gaap	Direct Premiums Written DirectPremiumsWritten	6973216000	USD
CY2018	us-gaap	Ceded Premiums Written CededPremiumsWritten	1269267000	USD
CY2018	us-gaap	Assumed Premiums Written AssumedPremiumsWritten	729278000	USD
CY2018	us-gaap	Premiums Written Net PremiumsWrittenNet	6433227000	USD
CY2018	us-gaap	Premiums Percentage Assumed To Net PremiumsPercentageAssumedToNet	0.113
CY2020Q4	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Deferred Policy Acquisition Costs SupplementalInformationForPropertyCasualtyInsuranceUnderwritersDeferredPolicyAcquisitionCosts	556168000	USD
CY2019Q4	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Deferred Policy Acquisition Costs SupplementalInformationForPropertyCasualtyInsuranceUnderwritersDeferredPolicyAcquisitionCosts	517364000	USD
CY2018Q4	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Deferred Policy Acquisition Costs SupplementalInformationForPropertyCasualtyInsuranceUnderwritersDeferredPolicyAcquisitionCosts	497629000	USD
CY2020Q4	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Reserves For Unpaid Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersReservesForUnpaidClaimsAndClaimsAdjustmentExpense	13784430000	USD
CY2019Q4	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Reserves For Unpaid Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersReservesForUnpaidClaimsAndClaimsAdjustmentExpense	12583249000	USD
CY2018Q4	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Reserves For Unpaid Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersReservesForUnpaidClaimsAndClaimsAdjustmentExpense	11966448000	USD
CY2020Q4	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Unearned Premiums SupplementalInformationForPropertyCasualtyInsuranceUnderwritersUnearnedPremiums	4073191000	USD
CY2019Q4	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Unearned Premiums SupplementalInformationForPropertyCasualtyInsuranceUnderwritersUnearnedPremiums	3656507000	USD
CY2018Q4	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Unearned Premiums SupplementalInformationForPropertyCasualtyInsuranceUnderwritersUnearnedPremiums	3359991000	USD
CY2020	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Earned Premiums SupplementalInformationForPropertyCasualtyInsuranceUnderwritersEarnedPremiums	6930843000	USD
CY2019	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Earned Premiums SupplementalInformationForPropertyCasualtyInsuranceUnderwritersEarnedPremiums	6633288000	USD
CY2018	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Earned Premiums SupplementalInformationForPropertyCasualtyInsuranceUnderwritersEarnedPremiums	6371505000	USD
CY2020	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Net Investment Income SupplementalInformationForPropertyCasualtyInsuranceUnderwritersNetInvestmentIncome	583821000	USD
CY2019	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Net Investment Income SupplementalInformationForPropertyCasualtyInsuranceUnderwritersNetInvestmentIncome	645614000	USD
CY2018	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Net Investment Income SupplementalInformationForPropertyCasualtyInsuranceUnderwritersNetInvestmentIncome	674235000	USD
CY2020	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Current Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersCurrentYearClaimsAndClaimsAdjustmentExpense	4432937000	USD
CY2019	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Current Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersCurrentYearClaimsAndClaimsAdjustmentExpense	4057989000	USD
CY2018	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Current Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersCurrentYearClaimsAndClaimsAdjustmentExpense	3926489000	USD
CY2020	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Prior Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense	627000	USD
CY2019	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Prior Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense	34079000	USD
CY2018	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Prior Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense	6831000	USD
CY2020	wrb	Supplemental Informationfor Property Casualty Insurance Underwriters Loss Reserve Discount Accretion SupplementalInformationforPropertyCasualtyInsuranceUnderwritersLossReserveDiscountAccretion	35142000	USD
CY2019	wrb	Supplemental Informationfor Property Casualty Insurance Underwriters Loss Reserve Discount Accretion SupplementalInformationforPropertyCasualtyInsuranceUnderwritersLossReserveDiscountAccretion	39048000	USD
CY2018	wrb	Supplemental Informationfor Property Casualty Insurance Underwriters Loss Reserve Discount Accretion SupplementalInformationforPropertyCasualtyInsuranceUnderwritersLossReserveDiscountAccretion	41382000	USD
CY2020	us-gaap	Deferred Policy Acquisition Cost Amortization Expense DeferredPolicyAcquisitionCostAmortizationExpense	904955000	USD
CY2019	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Amortization Of Deferred Policy Acquisition Costs SupplementalInformationForPropertyCasualtyInsuranceUnderwritersAmortizationOfDeferredPolicyAcquisitionCosts	1001611000	USD
CY2018	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Amortization Of Deferred Policy Acquisition Costs SupplementalInformationForPropertyCasualtyInsuranceUnderwritersAmortizationOfDeferredPolicyAcquisitionCosts	915246000	USD
CY2020	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Paid Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPaidClaimsAndClaimsAdjustmentExpense	3598649000	USD
CY2019	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Paid Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPaidClaimsAndClaimsAdjustmentExpense	3659402000	USD
CY2018	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Paid Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPaidClaimsAndClaimsAdjustmentExpense	3664885000	USD
CY2020	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Premiums Written SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPremiumsWritten	7262437000	USD
CY2019	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Premiums Written SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPremiumsWritten	6863499000	USD
CY2018	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Premiums Written SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPremiumsWritten	6433227000	USD

Files In Submission

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wrb1231202010-kex41.htm	Edgar Link	pending

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$WRB
BERKLEY W R CORP Stock $wrb

2020 Form 10-K Financial Statement

#000001154421000013 Filed on February 18, 2021

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$WRB BERKLEY W R CORP Stock $wrb

2020 Form 10-K Financial Statement

#000001154421000013 Filed on February 18, 2021

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$WRB
BERKLEY W R CORP Stock $wrb