$ARGD
Argo Group International Holdings, Inc. Stock $argd

$argd Overview Financials Valuation SEC Filings Company Website

2019 Q4 Form 10-Q Financial Statement

#000162828019013779 Filed on November 08, 2019

Income Statement

Concept	2019 Q4	2019 Q3	2018 Q3
Revenue	$484.6M	$487.4M	$498.9M
YoY Change	22976.19%	-2.31%	13.59%
Cost Of Revenue
YoY Change
Gross Profit
YoY Change
Gross Profit Margin
Selling, General & Admin
YoY Change
% of Gross Profit
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$6.900M	$6.600M	$9.300M
YoY Change	-21.59%	-29.03%	9.41%
% of Gross Profit
Operating Expenses	$567.5M	$507.7M	$447.4M
YoY Change	25.19%	13.48%	-10.07%
Operating Profit
YoY Change
Interest Expense	$8.400M	$7.700M	$7.900M
YoY Change	-157.14%	-2.53%	5.33%
% of Operating Profit
Other Income/Expense, Net
YoY Change
Pretax Income	-$102.2M	-$27.10M	$45.30M
YoY Change	71.19%	-159.82%	-168.74%
Income Tax	$500.0K	-$1.100M	$4.700M
% Of Pretax Income			10.38%
Net Earnings	-$102.7M	-$26.00M	$40.60M
YoY Change	135.55%	-164.04%	-166.23%
Net Earnings / Revenue	-21.19%	-5.33%	8.14%
Basic Earnings Per Share	-$2.99	-$0.76	$1.20
Diluted Earnings Per Share	-$2.99	-$0.76	$1.17
COMMON SHARES
Basic Shares Outstanding	34.32M shares	34.30M shares	33.96M shares
Diluted Shares Outstanding		34.30M shares	34.66M shares

Balance Sheet

Concept	2019 Q4	2019 Q3	2018 Q3
SHORT-TERM ASSETS
Cash & Short-Term Investments
YoY Change
Cash & Equivalents	$137.8M	$145.1M	$118.5M
Short-Term Investments
Other Short-Term Assets
YoY Change
Inventory
Prepaid Expenses
Receivables
Other Receivables
Total Short-Term Assets
YoY Change
LONG-TERM ASSETS
Property, Plant & Equipment	$140.4M	$109.0M
YoY Change	-9.3%
Goodwill	$161.4M	$177.0M	$161.4M
YoY Change	-8.81%	9.67%
Intangibles	$91.80M	$92.20M	$110.5M
YoY Change	-1.82%	-16.56%
Long-Term Investments	$5.098B	$5.127B	$4.865B
YoY Change	6.5%	5.39%	1.19%
Other Assets	$26.00M
YoY Change
Total Long-Term Assets
YoY Change
TOTAL ASSETS
Total Short-Term Assets
Total Long-Term Assets
Total Assets	$10.51B	$10.43B	$9.280B
YoY Change	9.95%	12.44%	2.45%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable
YoY Change
Accrued Expenses	$328.0M	$404.0M	$123.0M
YoY Change	132.62%	228.46%	25.51%
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	$342.0M	$404.0M	$131.0M
YoY Change	142.55%	208.4%	20.18%
LONG-TERM LIABILITIES
Long-Term Debt	$579.0M	$579.0M	$581.0M
YoY Change	-0.17%	-0.34%	0.0%
Other Long-Term Liabilities			$133.0M
YoY Change			121.67%
Total Long-Term Liabilities	$579.0M	$579.0M	$714.0M
YoY Change	-17.4%	-18.91%	11.39%
TOTAL LIABILITIES
Total Short-Term Liabilities	$342.0M	$404.0M	$131.0M
Total Long-Term Liabilities	$579.0M	$579.0M	$714.0M
Total Liabilities	$8.745B	$8.559B	$7.462B
YoY Change	11.95%	14.71%	2.92%
SHAREHOLDERS EQUITY
Retained Earnings	$793.7M	$907.0M	$915.7M
YoY Change	-7.99%	-0.95%
Common Stock	$1.422B	$1.419B	$1.414B
YoY Change	0.35%	0.35%
Preferred Stock
YoY Change
Treasury Stock (at cost)	$455.1M	$455.1M	$453.4M
YoY Change	0.0%	0.37%
Treasury Stock Shares	11.32M shares	11.32M shares	11.29M shares
Shareholders Equity	$1.764B	$1.875B	$1.818B
YoY Change
Total Liabilities & Shareholders Equity	$10.51B	$10.43B	$9.280B
YoY Change	9.95%	12.44%	2.45%

Cashflow Statement

Concept	2019 Q4	2019 Q3	2018 Q3
OPERATING ACTIVITIES
Net Income	-$102.7M	-$26.00M	$40.60M
YoY Change	135.55%	-164.04%	-166.23%
Depreciation, Depletion And Amortization	$6.900M	$6.600M	$9.300M
YoY Change	-21.59%	-29.03%	9.41%
Cash From Operating Activities	-$12.90M	$200.6M	$105.1M
YoY Change	-118.22%	90.87%	-51.14%
INVESTING ACTIVITIES
Capital Expenditures	-$7.000M	-$7.200M	-$24.80M
YoY Change	-294.44%	-70.97%	138.46%
Acquisitions
YoY Change
Other Investing Activities	$23.40M	-$222.3M	-$70.70M
YoY Change	-160.62%	214.43%	-49.89%
Cash From Investing Activities	$16.40M	-$229.5M	-$95.50M
YoY Change	-146.86%	140.31%	-36.96%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	-10.10M	-9.900M	-19.10M
YoY Change	-4.72%	-48.17%	-54.2%
NET CHANGE
Cash From Operating Activities	-12.90M	200.6M	105.1M
Cash From Investing Activities	16.40M	-229.5M	-95.50M
Cash From Financing Activities	-10.10M	-9.900M	-19.10M
Net Change In Cash	-6.600M	-38.80M	-9.500M
YoY Change	-126.19%	308.42%	-143.38%
FREE CASH FLOW
Cash From Operating Activities	-$12.90M	$200.6M	$105.1M
Capital Expenditures	-$7.000M	-$7.200M	-$24.80M
Free Cash Flow	-$5.900M	$207.8M	$129.9M
YoY Change	-108.78%	59.97%	-42.39%

Facts In Submission

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CY2018Q3	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	33956695	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	34161016	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	33921632	shares
CY2019Q3	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	34299999	shares
CY2018Q3	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	34656328	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	34769622	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	34688843	shares
CY2019Q3	us-gaap	Gain Loss On Investments Excluding Other Than Temporary Impairments GainLossOnInvestmentsExcludingOtherThanTemporaryImpairments	-1200000	USD
CY2018Q3	us-gaap	Gain Loss On Investments Excluding Other Than Temporary Impairments GainLossOnInvestmentsExcludingOtherThanTemporaryImpairments	14200000	USD
	us-gaap	Gain Loss On Investments Excluding Other Than Temporary Impairments GainLossOnInvestmentsExcludingOtherThanTemporaryImpairments	70100000	USD
	us-gaap	Gain Loss On Investments Excluding Other Than Temporary Impairments GainLossOnInvestmentsExcludingOtherThanTemporaryImpairments	10900000	USD
CY2019Q3	argo	Other Than Temporary Impairment Losses Fixed Maturities OtherThanTemporaryImpairmentLossesFixedMaturities	5000000.0	USD
CY2018Q3	argo	Other Than Temporary Impairment Losses Fixed Maturities OtherThanTemporaryImpairmentLossesFixedMaturities	0	USD
	argo	Other Than Temporary Impairment Losses Fixed Maturities OtherThanTemporaryImpairmentLossesFixedMaturities	11800000	USD
	argo	Other Than Temporary Impairment Losses Fixed Maturities OtherThanTemporaryImpairmentLossesFixedMaturities	1900000	USD
CY2019Q3	us-gaap	Other Than Temporary Impairment Loss Debt Securities Portion Recognized In Earnings OtherThanTemporaryImpairmentLossDebtSecuritiesPortionRecognizedInEarnings	5000000.0	USD
CY2018Q3	us-gaap	Other Than Temporary Impairment Loss Debt Securities Portion Recognized In Earnings OtherThanTemporaryImpairmentLossDebtSecuritiesPortionRecognizedInEarnings	0	USD
	us-gaap	Other Than Temporary Impairment Loss Debt Securities Portion Recognized In Earnings OtherThanTemporaryImpairmentLossDebtSecuritiesPortionRecognizedInEarnings	11800000	USD
	us-gaap	Other Than Temporary Impairment Loss Debt Securities Portion Recognized In Earnings OtherThanTemporaryImpairmentLossDebtSecuritiesPortionRecognizedInEarnings	1900000	USD
CY2019Q3	us-gaap	Realized Investment Gains Losses RealizedInvestmentGainsLosses	-6200000	USD
CY2018Q3	us-gaap	Realized Investment Gains Losses RealizedInvestmentGainsLosses	14200000	USD
	us-gaap	Realized Investment Gains Losses RealizedInvestmentGainsLosses	58300000	USD
	us-gaap	Realized Investment Gains Losses RealizedInvestmentGainsLosses	9000000.0	USD
CY2019Q3	us-gaap	Net Income Loss NetIncomeLoss	-25100000	USD
CY2018Q3	us-gaap	Net Income Loss NetIncomeLoss	40600000	USD
	us-gaap	Net Income Loss NetIncomeLoss	94900000	USD
	us-gaap	Net Income Loss NetIncomeLoss	107200000	USD
CY2019Q3	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Before Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax	0	USD
CY2018Q3	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Before Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax	-800000	USD
	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Before Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax	-100000	USD
	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Before Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax	-4800000	USD
CY2019Q3	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	-7400000	USD
CY2018Q3	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	-2400000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	91300000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	-63800000	USD
CY2019Q3	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	-2800000	USD
CY2018Q3	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	2400000	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	-7700000	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	-200000	USD
CY2019Q3	us-gaap	Other Comprehensive Income Loss Before Tax OtherComprehensiveIncomeLossBeforeTax	-4600000	USD
CY2018Q3	us-gaap	Other Comprehensive Income Loss Before Tax OtherComprehensiveIncomeLossBeforeTax	-5600000	USD
	us-gaap	Other Comprehensive Income Loss Before Tax OtherComprehensiveIncomeLossBeforeTax	98900000	USD
	us-gaap	Other Comprehensive Income Loss Before Tax OtherComprehensiveIncomeLossBeforeTax	-68400000	USD
CY2019Q3	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	-700000	USD
CY2018Q3	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	-1100000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	15100000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	-10400000	USD
CY2019Q3	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	-300000	USD
CY2018Q3	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	300000	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	-1000000.0	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	100000	USD
CY2019Q3	us-gaap	Other Comprehensive Income Loss Tax OtherComprehensiveIncomeLossTax	-400000	USD
CY2018Q3	us-gaap	Other Comprehensive Income Loss Tax OtherComprehensiveIncomeLossTax	-1400000	USD
	us-gaap	Other Comprehensive Income Loss Tax OtherComprehensiveIncomeLossTax	16100000	USD
	us-gaap	Other Comprehensive Income Loss Tax OtherComprehensiveIncomeLossTax	-10500000	USD
CY2019Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-4200000	USD
CY2018Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-4200000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	82800000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-57900000	USD
CY2019Q3	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	-29300000	USD
CY2018Q3	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	36400000	USD
	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	177700000	USD
	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	49300000	USD
CY2017Q4	us-gaap	Stockholders Equity StockholdersEquity	1819700000	USD
	us-gaap	Net Income Loss NetIncomeLoss	107200000	USD
	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	-58200000	USD
	us-gaap	Other Comprehensive Income Other Net Of Tax OtherComprehensiveIncomeOtherNetOfTax	300000	USD
	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	30000000.0	USD
	us-gaap	Stock Issued During Period Value Share Based Compensation StockIssuedDuringPeriodValueShareBasedCompensation	12700000	USD
	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	7000000.0	USD
	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	1400000	USD
	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	28000000.0	USD
CY2018Q3	us-gaap	Stockholders Equity StockholdersEquity	1818100000	USD
CY2018Q4	us-gaap	Stockholders Equity StockholdersEquity	1746700000	USD
	us-gaap	Net Income Loss NetIncomeLoss	94900000	USD
	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	82900000	USD
	us-gaap	Other Comprehensive Income Other Net Of Tax OtherComprehensiveIncomeOtherNetOfTax	-100000	USD
	us-gaap	Stock Issued During Period Value Share Based Compensation StockIssuedDuringPeriodValueShareBasedCompensation	11000000.0	USD
	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	11200000	USD
	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	1700000	USD
	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	32500000	USD
CY2019Q3	us-gaap	Stockholders Equity StockholdersEquity	1893400000	USD
	us-gaap	Net Income Loss NetIncomeLoss	94900000	USD
	us-gaap	Net Income Loss NetIncomeLoss	107200000	USD
	us-gaap	Depreciation And Amortization DepreciationAndAmortization	20400000	USD
	us-gaap	Depreciation And Amortization DepreciationAndAmortization	23100000	USD
	us-gaap	Share Based Compensation ShareBasedCompensation	11700000	USD
	us-gaap	Share Based Compensation ShareBasedCompensation	14400000	USD
	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-2200000	USD
	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-7400000	USD
	us-gaap	Realized Investment Gains Losses RealizedInvestmentGainsLosses	58300000	USD
	us-gaap	Realized Investment Gains Losses RealizedInvestmentGainsLosses	9000000.0	USD
	argo	Undistributed Earnings From Alternative Investment Portfolio UndistributedEarningsFromAlternativeInvestmentPortfolio	-19400000	USD
	argo	Undistributed Earnings From Alternative Investment Portfolio UndistributedEarningsFromAlternativeInvestmentPortfolio	-20700000	USD
	us-gaap	Increase Decrease In Accrued Interest Receivable Net IncreaseDecreaseInAccruedInterestReceivableNet	500000	USD
	us-gaap	Increase Decrease In Accrued Interest Receivable Net IncreaseDecreaseInAccruedInterestReceivableNet	2700000	USD
	us-gaap	Increase Decrease In Premiums Receivable IncreaseDecreaseInPremiumsReceivable	282600000	USD
	us-gaap	Increase Decrease In Premiums Receivable IncreaseDecreaseInPremiumsReceivable	148500000	USD
	us-gaap	Increase Decrease In Deferred Policy Acquisition Costs IncreaseDecreaseInDeferredPolicyAcquisitionCosts	-7500000	USD
	us-gaap	Increase Decrease In Deferred Policy Acquisition Costs IncreaseDecreaseInDeferredPolicyAcquisitionCosts	15200000	USD
	us-gaap	Increase Decrease In Prepaid Reinsurance Premiums IncreaseDecreaseInPrepaidReinsurancePremiums	147100000	USD
	us-gaap	Increase Decrease In Prepaid Reinsurance Premiums IncreaseDecreaseInPrepaidReinsurancePremiums	114600000	USD
	us-gaap	Increase Decrease In Future Policy Benefit Reserves IncreaseDecreaseInFuturePolicyBenefitReserves	194900000	USD
	us-gaap	Increase Decrease In Future Policy Benefit Reserves IncreaseDecreaseInFuturePolicyBenefitReserves	-19200000	USD
	us-gaap	Increase Decrease In Unearned Premiums IncreaseDecreaseInUnearnedPremiums	197700000	USD
	us-gaap	Increase Decrease In Unearned Premiums IncreaseDecreaseInUnearnedPremiums	179400000	USD
	argo	Increase Decrease In Reinsurance Payables And Funds Held IncreaseDecreaseInReinsurancePayablesAndFundsHeld	204800000	USD
	argo	Increase Decrease In Reinsurance Payables And Funds Held IncreaseDecreaseInReinsurancePayablesAndFundsHeld	151300000	USD
	us-gaap	Increase Decrease In Accrued Income Taxes Payable IncreaseDecreaseInAccruedIncomeTaxesPayable	7900000	USD
	us-gaap	Increase Decrease In Accrued Income Taxes Payable IncreaseDecreaseInAccruedIncomeTaxesPayable	8800000	USD
	argo	Increase Decrease In Accrued Underwriting Expenses IncreaseDecreaseInAccruedUnderwritingExpenses	8500000	USD
	argo	Increase Decrease In Accrued Underwriting Expenses IncreaseDecreaseInAccruedUnderwritingExpenses	85800000	USD
	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	42500000	USD
	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	1700000	USD
	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	195700000	USD
	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	231000000.0	USD
	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	1046300000	USD
	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	1158600000	USD
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	292200000	USD
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	375100000	USD
	argo	Proceedsfrom Sale And Maturity Of Equity Securities Fvni ProceedsfromSaleAndMaturityOfEquitySecuritiesFVNI	66300000	USD
	argo	Proceedsfrom Sale And Maturity Of Equity Securities Fvni ProceedsfromSaleAndMaturityOfEquitySecuritiesFVNI	165000000.0	USD
	us-gaap	Proceeds From Sale Of Other Investments ProceedsFromSaleOfOtherInvestments	67700000	USD
	us-gaap	Proceeds From Sale Of Other Investments ProceedsFromSaleOfOtherInvestments	93600000	USD
	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	1535000000.0	USD
	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	1787000000.0	USD
	argo	Payments To Acquire Equity Securities Fvni PaymentsToAcquireEquitySecuritiesFVNI	49900000	USD
	argo	Payments To Acquire Equity Securities Fvni PaymentsToAcquireEquitySecuritiesFVNI	156000000.0	USD
	us-gaap	Payments To Acquire Other Investments PaymentsToAcquireOtherInvestments	54600000	USD
	us-gaap	Payments To Acquire Other Investments PaymentsToAcquireOtherInvestments	34200000	USD
	argo	Payments For Proceeds From Change In Foreign Regulatory Deposits And Voluntary Pools PaymentsForProceedsFromChangeInForeignRegulatoryDepositsAndVoluntaryPools	-2300000	USD
	argo	Payments For Proceeds From Change In Foreign Regulatory Deposits And Voluntary Pools PaymentsForProceedsFromChangeInForeignRegulatoryDepositsAndVoluntaryPools	-13400000	USD
	us-gaap	Payments For Proceeds From Short Term Investments PaymentsForProceedsFromShortTermInvestments	0	USD
	us-gaap	Payments For Proceeds From Short Term Investments PaymentsForProceedsFromShortTermInvestments	47200000	USD
	argo	Increase Decrease In Settlements Of Foreign Currency Exchange Forward Contracts IncreaseDecreaseInSettlementsOfForeignCurrencyExchangeForwardContracts	-1200000	USD
	argo	Increase Decrease In Settlements Of Foreign Currency Exchange Forward Contracts IncreaseDecreaseInSettlementsOfForeignCurrencyExchangeForwardContracts	2000000.0	USD
	us-gaap	Cash Acquired From Acquisition CashAcquiredFromAcquisition	0	USD
	us-gaap	Cash Acquired From Acquisition CashAcquiredFromAcquisition	15600000	USD
	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	22900000	USD
	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	35800000	USD
	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	-29600000	USD
	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	-3600000	USD
	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-159200000	USD
	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-233300000	USD
	us-gaap	Repayments Of Notes Payable RepaymentsOfNotesPayable	600000	USD
	us-gaap	Repayments Of Notes Payable RepaymentsOfNotesPayable	0	USD
	us-gaap	Proceeds From Issuance Of Shares Under Incentive And Share Based Compensation Plans ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlans	1400000	USD
	us-gaap	Proceeds From Issuance Of Shares Under Incentive And Share Based Compensation Plans ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlans	1000000.0	USD
	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	0	USD
	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	30000000.0	USD
	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	32500000	USD
	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	28000000.0	USD
	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-31700000	USD
	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-57000000.0	USD
	us-gaap	Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	1100000	USD
	us-gaap	Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	1200000	USD
	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	5900000	USD
	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-58100000	USD
CY2018Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	139200000	USD
CY2017Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	176600000	USD
CY2019Q3	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	145100000	USD
CY2018Q3	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	118500000	USD
	us-gaap	Prior Period Reclassification Adjustment Description PriorPeriodReclassificationAdjustmentDescription	Certain reclassifications have been made to financial information presented for prior years to conform to the current year’s presentation.
CY2019Q3	argo	Fair Value Of Investments Assets Managed On Behalf Of Trade Capital Providers FairValueOfInvestmentsAssetsManagedOnBehalfOfTradeCapitalProviders	159600000	USD
CY2018Q4	argo	Fair Value Of Investments Assets Managed On Behalf Of Trade Capital Providers FairValueOfInvestmentsAssetsManagedOnBehalfOfTradeCapitalProviders	133400000	USD
CY2019Q3	us-gaap	Held To Maturity Securities Debt Maturities Within One Year Net Carrying Amount HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearNetCarryingAmount	242500000	USD
CY2019Q3	us-gaap	Held To Maturity Securities Debt Maturities Within One Year Fair Value HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearFairValue	242200000	USD
CY2019Q3	us-gaap	Held To Maturity Securities Debt Maturities After One Through Five Years Net Carrying Amount HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsNetCarryingAmount	1584300000	USD
CY2019Q3	us-gaap	Held To Maturity Securities Debt Maturities After One Through Five Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue	1577100000	USD
CY2019Q3	us-gaap	Held To Maturity Securities Debt Maturities After Five Through Ten Years Net Carrying Amount HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsNetCarryingAmount	669500000	USD
CY2019Q3	us-gaap	Held To Maturity Securities Debt Maturities After Five Through Ten Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue	683500000	USD
CY2019Q3	us-gaap	Held To Maturity Securities Debt Maturities After Ten Years Net Carrying Amount HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsNetCarryingAmount	105800000	USD
CY2019Q3	us-gaap	Held To Maturity Securities Debt Maturities After Ten Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsFairValue	111900000	USD
CY2019Q3	us-gaap	Held To Maturity Securities Debt Maturities Without Single Maturity Date Net Carrying Amount HeldToMaturitySecuritiesDebtMaturitiesWithoutSingleMaturityDateNetCarryingAmount	1114500000	USD
CY2019Q3	us-gaap	Held To Maturity Securities Debt Maturities Without Single Maturity Date Fair Value HeldToMaturitySecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue	1130900000	USD
CY2019Q3	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	3716600000	USD
CY2019Q3	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	3745600000	USD
CY2019Q3	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Number Of Positions DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions	9615	security
CY2019Q3	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Number Of Positions DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsNumberOfPositions	1219	security
CY2019Q3	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Number Of Positions DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerNumberOfPositions	424	security
CY2019Q3	us-gaap	Impairment Of Investments ImpairmentOfInvestments	5000000.0	USD
CY2018Q3	us-gaap	Impairment Of Investments ImpairmentOfInvestments	0	USD
	us-gaap	Impairment Of Investments ImpairmentOfInvestments	11800000	USD
	us-gaap	Impairment Of Investments ImpairmentOfInvestments	1900000	USD
CY2019Q3	argo	Gross Realized Investment On Fixed Maturities And Other Gains GrossRealizedInvestmentOnFixedMaturitiesAndOtherGains	11200000	USD
CY2018Q3	argo	Gross Realized Investment On Fixed Maturities And Other Gains GrossRealizedInvestmentOnFixedMaturitiesAndOtherGains	12200000	USD
	argo	Gross Realized Investment On Fixed Maturities And Other Gains GrossRealizedInvestmentOnFixedMaturitiesAndOtherGains	34900000	USD
	argo	Gross Realized Investment On Fixed Maturities And Other Gains GrossRealizedInvestmentOnFixedMaturitiesAndOtherGains	50700000	USD
CY2019Q3	argo	Gross Realized Investment On Fixed Maturities And Other Losses GrossRealizedInvestmentOnFixedMaturitiesAndOtherLosses	15000000.0	USD
CY2018Q3	argo	Gross Realized Investment On Fixed Maturities And Other Losses GrossRealizedInvestmentOnFixedMaturitiesAndOtherLosses	11600000	USD
	argo	Gross Realized Investment On Fixed Maturities And Other Losses GrossRealizedInvestmentOnFixedMaturitiesAndOtherLosses	42300000	USD
	argo	Gross Realized Investment On Fixed Maturities And Other Losses GrossRealizedInvestmentOnFixedMaturitiesAndOtherLosses	50500000	USD
CY2019Q3	us-gaap	Equity Securities Fv Ni Realized Gain Loss EquitySecuritiesFvNiRealizedGainLoss	6400000	USD
CY2018Q3	us-gaap	Equity Securities Fv Ni Realized Gain Loss EquitySecuritiesFvNiRealizedGainLoss	9100000	USD
	us-gaap	Equity Securities Fv Ni Realized Gain Loss EquitySecuritiesFvNiRealizedGainLoss	7700000	USD
	us-gaap	Equity Securities Fv Ni Realized Gain Loss EquitySecuritiesFvNiRealizedGainLoss	30900000	USD
CY2019Q3	us-gaap	Equity Securities Fv Ni Unrealized Gain Loss EquitySecuritiesFvNiUnrealizedGainLoss	-8800000	USD
CY2018Q3	us-gaap	Equity Securities Fv Ni Unrealized Gain Loss EquitySecuritiesFvNiUnrealizedGainLoss	4500000	USD
	us-gaap	Equity Securities Fv Ni Unrealized Gain Loss EquitySecuritiesFvNiUnrealizedGainLoss	58000000.0	USD
	us-gaap	Equity Securities Fv Ni Unrealized Gain Loss EquitySecuritiesFvNiUnrealizedGainLoss	-22100000	USD
CY2019Q3	us-gaap	Equity Securities Fv Ni Gain Loss EquitySecuritiesFvNiGainLoss	-2400000	USD
CY2018Q3	us-gaap	Equity Securities Fv Ni Gain Loss EquitySecuritiesFvNiGainLoss	13600000	USD
	us-gaap	Equity Securities Fv Ni Gain Loss EquitySecuritiesFvNiGainLoss	65700000	USD
	us-gaap	Equity Securities Fv Ni Gain Loss EquitySecuritiesFvNiGainLoss	8800000	USD
CY2019Q3	us-gaap	Realized Investment Gains Losses RealizedInvestmentGainsLosses	-6200000	USD
CY2018Q3	us-gaap	Realized Investment Gains Losses RealizedInvestmentGainsLosses	14200000	USD
	us-gaap	Realized Investment Gains Losses RealizedInvestmentGainsLosses	58300000	USD
	us-gaap	Realized Investment Gains Losses RealizedInvestmentGainsLosses	9000000.0	USD
CY2019Q3	argo	Income Tax Expense Benefit Related To Net Realized Investment And Other Gains IncomeTaxExpenseBenefitRelatedToNetRealizedInvestmentAndOtherGains	-300000	USD
CY2018Q3	argo	Income Tax Expense Benefit Related To Net Realized Investment And Other Gains IncomeTaxExpenseBenefitRelatedToNetRealizedInvestmentAndOtherGains	3300000	USD
	argo	Income Tax Expense Benefit Related To Net Realized Investment And Other Gains IncomeTaxExpenseBenefitRelatedToNetRealizedInvestmentAndOtherGains	11900000	USD
	argo	Income Tax Expense Benefit Related To Net Realized Investment And Other Gains IncomeTaxExpenseBenefitRelatedToNetRealizedInvestmentAndOtherGains	2800000	USD
CY2019Q3	argo	Net Realized Investment Gains Losses Net Of Income Taxes NetRealizedInvestmentGainsLossesNetOfIncomeTaxes	-5900000	USD
CY2018Q3	argo	Net Realized Investment Gains Losses Net Of Income Taxes NetRealizedInvestmentGainsLossesNetOfIncomeTaxes	10900000	USD
	argo	Net Realized Investment Gains Losses Net Of Income Taxes NetRealizedInvestmentGainsLossesNetOfIncomeTaxes	46400000	USD
	argo	Net Realized Investment Gains Losses Net Of Income Taxes NetRealizedInvestmentGainsLossesNetOfIncomeTaxes	6200000	USD
CY2019Q3	argo	Changes In Investment Unrealized Appreciation Depreciation Net Before Tax ChangesInInvestmentUnrealizedAppreciationDepreciationNetBeforeTax	4600000	USD
CY2018Q3	argo	Changes In Investment Unrealized Appreciation Depreciation Net Before Tax ChangesInInvestmentUnrealizedAppreciationDepreciationNetBeforeTax	4800000	USD
	argo	Changes In Investment Unrealized Appreciation Depreciation Net Before Tax ChangesInInvestmentUnrealizedAppreciationDepreciationNetBeforeTax	-99000000.0	USD
	argo	Changes In Investment Unrealized Appreciation Depreciation Net Before Tax ChangesInInvestmentUnrealizedAppreciationDepreciationNetBeforeTax	63600000	USD
CY2019Q3	argo	Changes In Investment Unrealized Appreciation Depreciation Net Tax Effects ChangesInInvestmentUnrealizedAppreciationDepreciationNetTaxEffects	-400000	USD
CY2018Q3	argo	Changes In Investment Unrealized Appreciation Depreciation Net Tax Effects ChangesInInvestmentUnrealizedAppreciationDepreciationNetTaxEffects	-1400000	USD
	argo	Changes In Investment Unrealized Appreciation Depreciation Net Tax Effects ChangesInInvestmentUnrealizedAppreciationDepreciationNetTaxEffects	16100000	USD
	argo	Changes In Investment Unrealized Appreciation Depreciation Net Tax Effects ChangesInInvestmentUnrealizedAppreciationDepreciationNetTaxEffects	-10500000	USD
CY2019Q3	argo	Changes In Investment Unrealized Appreciation Depreciation Net Of Tax Effect ChangesInInvestmentUnrealizedAppreciationDepreciationNetOfTaxEffect	4200000	USD
CY2018Q3	argo	Changes In Investment Unrealized Appreciation Depreciation Net Of Tax Effect ChangesInInvestmentUnrealizedAppreciationDepreciationNetOfTaxEffect	3400000	USD
	argo	Changes In Investment Unrealized Appreciation Depreciation Net Of Tax Effect ChangesInInvestmentUnrealizedAppreciationDepreciationNetOfTaxEffect	-82900000	USD
	argo	Changes In Investment Unrealized Appreciation Depreciation Net Of Tax Effect ChangesInInvestmentUnrealizedAppreciationDepreciationNetOfTaxEffect	53100000	USD
CY2019Q3	us-gaap	Pledged Assets Separately Reported Securities Pledged Under Letter Of Credit Facilities At Fair Value PledgedAssetsSeparatelyReportedSecuritiesPledgedUnderLetterOfCreditFacilitiesAtFairValue	129500000	USD
CY2018Q3	us-gaap	Pledged Assets Separately Reported Securities Pledged Under Letter Of Credit Facilities At Fair Value PledgedAssetsSeparatelyReportedSecuritiesPledgedUnderLetterOfCreditFacilitiesAtFairValue	76500000	USD
CY2019Q3	argo	Securities And Letters Of Credit Pledged SecuritiesAndLettersOfCreditPledged	403600000	USD
CY2018Q3	argo	Securities And Letters Of Credit Pledged SecuritiesAndLettersOfCreditPledged	418400000	USD
CY2019Q3	us-gaap	Pledged Assets Separately Reported Securities Pledged As Collateral At Fair Value PledgedAssetsSeparatelyReportedSecuritiesPledgedAsCollateralAtFairValue	731900000	USD
CY2018Q3	us-gaap	Pledged Assets Separately Reported Securities Pledged As Collateral At Fair Value PledgedAssetsSeparatelyReportedSecuritiesPledgedAsCollateralAtFairValue	675500000	USD
CY2018Q4	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	10400000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Into Level3 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersIntoLevel3	3500000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Out Of Level3 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersOutOfLevel3	0	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Earnings1 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1	300000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Other Comprehensive Income Loss FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeLoss	-500000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Purchases FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases	1900000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Issues FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetIssues	0	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Sales FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales	300000	USD
	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Settlements FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSettlements	0	USD
CY2019Q3	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	15300000	USD
	argo	Amount Of Gains Or Losses For Period Included In Net Income Attributable To Change In Unrealized Gains Or Losses Relating To Assets Held At End Of Period AmountOfGainsOrLossesForPeriodIncludedInNetIncomeAttributableToChangeInUnrealizedGainsOrLossesRelatingToAssetsHeldAtEndOfPeriod	0	USD
CY2017Q4	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	4200000	USD
CY2018	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Into Level3 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersIntoLevel3	0	USD
CY2018	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Out Of Level3 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersOutOfLevel3	0	USD
CY2018	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Earnings1 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1	200000	USD
CY2018	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Other Comprehensive Income Loss FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeLoss	300000	USD
CY2018	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Purchases FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases	7300000	USD
CY2018	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Issues FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetIssues	0	USD
CY2018	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Sales FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales	1600000	USD
CY2018	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Settlements FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSettlements	0	USD
CY2018Q4	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	10400000	USD
CY2018	argo	Amount Of Gains Or Losses For Period Included In Net Income Attributable To Change In Unrealized Gains Or Losses Relating To Assets Held At End Of Period AmountOfGainsOrLossesForPeriodIncludedInNetIncomeAttributableToChangeInUnrealizedGainsOrLossesRelatingToAssetsHeldAtEndOfPeriod	0	USD
CY2019Q3	us-gaap	Lease Cost LeaseCost	5000000.0	USD
	us-gaap	Lease Cost LeaseCost	17100000	USD
CY2018Q3	us-gaap	Lease Cost LeaseCost	5200000	USD
	us-gaap	Lease Cost LeaseCost	18200000	USD
CY2019Q3	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	108600000	USD
CY2019Q3	us-gaap	Operating Lease Liability OperatingLeaseLiability	120200000	USD
CY2019Q3	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P10Y3M21D
CY2019Q3	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.0393
CY2019Q3	us-gaap	Operating Lease Cost OperatingLeaseCost	5100000	USD
	us-gaap	Operating Lease Cost OperatingLeaseCost	15300000	USD
CY2019Q3	us-gaap	Variable Lease Cost VariableLeaseCost	0	USD
	us-gaap	Variable Lease Cost VariableLeaseCost	2100000	USD
CY2019Q3	us-gaap	Sublease Income SubleaseIncome	100000	USD
	us-gaap	Sublease Income SubleaseIncome	300000	USD
CY2019Q3	us-gaap	Lease Cost LeaseCost	5000000.0	USD
	us-gaap	Lease Cost LeaseCost	17100000	USD
	us-gaap	Operating Lease Payments OperatingLeasePayments	14100000	USD
	argo	Operating Lease Payments Liability Reduction OperatingLeasePaymentsLiabilityReduction	11500000	USD
CY2019Q3	us-gaap	Lessee Operating Lease Liability Payments Remainder Of Fiscal Year LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear	4700000	USD
CY2018Q4	us-gaap	Operating Leases Future Minimum Payments Remainder Of Fiscal Year OperatingLeasesFutureMinimumPaymentsRemainderOfFiscalYear	18700000	USD
CY2019Q3	us-gaap	Lessee Operating Lease Liability Payments Due Year Two LesseeOperatingLeaseLiabilityPaymentsDueYearTwo	18600000	USD
CY2018Q4	us-gaap	Operating Leases Future Minimum Payments Due In Two Years OperatingLeasesFutureMinimumPaymentsDueInTwoYears	18600000	USD
CY2019Q3	us-gaap	Lessee Operating Lease Liability Payments Due Year Three LesseeOperatingLeaseLiabilityPaymentsDueYearThree	17500000	USD
CY2018Q4	us-gaap	Operating Leases Future Minimum Payments Due In Three Years OperatingLeasesFutureMinimumPaymentsDueInThreeYears	17500000	USD
CY2019Q3	us-gaap	Lessee Operating Lease Liability Payments Due Year Four LesseeOperatingLeaseLiabilityPaymentsDueYearFour	14800000	USD
CY2018Q4	us-gaap	Operating Leases Future Minimum Payments Due In Four Years OperatingLeasesFutureMinimumPaymentsDueInFourYears	14700000	USD
CY2019Q3	us-gaap	Lessee Operating Lease Liability Payments Due Year Five LesseeOperatingLeaseLiabilityPaymentsDueYearFive	12300000	USD
CY2018Q4	us-gaap	Operating Leases Future Minimum Payments Due In Five Years OperatingLeasesFutureMinimumPaymentsDueInFiveYears	12300000	USD
CY2019Q3	us-gaap	Lessee Operating Lease Liability Payments Due After Year Five LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive	79400000	USD
CY2018Q4	us-gaap	Operating Leases Future Minimum Payments Due Thereafter OperatingLeasesFutureMinimumPaymentsDueThereafter	80100000	USD
CY2019Q3	us-gaap	Lessee Operating Lease Liability Payments Due LesseeOperatingLeaseLiabilityPaymentsDue	147300000	USD
CY2018Q4	us-gaap	Operating Leases Future Minimum Payments Due OperatingLeasesFutureMinimumPaymentsDue	161900000	USD
CY2019Q3	argo	Lessee Operating Lease Lease Notyet Commenced Liability LesseeOperatingLeaseLeaseNotyetCommencedLiability	500000	USD
CY2019Q3	us-gaap	Lessee Operating Lease Liability Undiscounted Excess Amount LesseeOperatingLeaseLiabilityUndiscountedExcessAmount	26600000	USD
CY2019Q3	us-gaap	Operating Lease Liability OperatingLeaseLiability	120200000	USD
	argo	Numberof Leased Properties Shortterm NumberofLeasedPropertiesShortterm	3	property
CY2019Q3	us-gaap	Operating Lease Lease Income OperatingLeaseLeaseIncome	700000	USD
	us-gaap	Operating Lease Lease Income OperatingLeaseLeaseIncome	2200000	USD
	us-gaap	Schedule Of Liability For Unpaid Claims And Claims Adjustment Expense ScheduleOfLiabilityForUnpaidClaimsAndClaimsAdjustmentExpense	<div style="line-height:120%;padding-top:8px;text-align:justify;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">The following table provides a reconciliation of reserves for losses and loss adjustment expenses (“LAE”):</span></div><div style="line-height:120%;text-align:center;font-size:10pt;"><div style="padding-left:0px;text-indent:0px;line-height:normal;padding-top:10px;"><table cellpadding="0" cellspacing="0" style="font-family:Times New Roman;font-size:10pt;margin-left:auto;margin-right:auto;width:100%;border-collapse:collapse;text-align:left;"><tr><td colspan="9"/></tr><tr><td style="width:70%;"/><td style="width:1%;"/><td style="width:1%;"/><td style="width:12%;"/><td style="width:1%;"/><td style="width:1%;"/><td style="width:1%;"/><td style="width:12%;"/><td style="width:1%;"/></tr><tr><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="7" style="vertical-align:bottom;border-bottom:1px solid #000000;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:center;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;font-weight:bold;">For the Nine Months Ended<br/>September 30,</span></div></td></tr><tr><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="text-align:left;padding-left:12px;text-indent:-12px;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;">(in millions)</span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="3" style="vertical-align:bottom;border-bottom:1px solid #000000;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;border-top:1px solid #000000;"><div style="text-align:center;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;font-weight:bold;">2019</span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="3" style="vertical-align:bottom;border-bottom:1px solid #000000;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;border-top:1px solid #000000;"><div style="text-align:center;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;font-weight:bold;">2018</span></div></td></tr><tr><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="text-align:left;padding-left:12px;text-indent:-12px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">Net reserves beginning of the year</span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;background-color:#cceeff;border-top:1px solid #000000;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">$</span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-top:2px;padding-bottom:2px;border-top:1px solid #000000;"><div style="text-align:right;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><span>2,562.9</span></span></div></td><td style="vertical-align:bottom;background-color:#cceeff;border-top:1px solid #000000;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;background-color:#cceeff;border-top:1px solid #000000;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">$</span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-top:2px;padding-bottom:2px;border-top:1px solid #000000;"><div style="text-align:right;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><span>2,488.0</span></span></div></td><td style="vertical-align:bottom;background-color:#cceeff;border-top:1px solid #000000;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td></tr><tr><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="text-align:left;padding-left:12px;text-indent:-12px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">Net reserves acquired</span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><span>—</span></span></div></td><td style="vertical-align:bottom;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><span>49.4</span></span></div></td><td style="vertical-align:bottom;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td></tr><tr><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="text-align:left;padding-left:12px;text-indent:-12px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">Add:</span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="3" style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="3" style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td></tr><tr><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="text-align:left;padding-left:12px;text-indent:-12px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">Losses and LAE incurred during current calendar year, net of reinsurance:</span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="3" style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="3" style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td></tr><tr><td style="vertical-align:bottom;background-color:#cceeff;padding-left:20px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="text-align:left;padding-left:12px;text-indent:-12px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">Current accident year</span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><span>799.9</span></span></div></td><td style="vertical-align:bottom;background-color:#cceeff;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><span>764.3</span></span></div></td><td style="vertical-align:bottom;background-color:#cceeff;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td></tr><tr><td style="vertical-align:bottom;padding-left:20px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="text-align:left;padding-left:12px;text-indent:-12px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">Prior accident years</span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;border-bottom:1px solid #000000;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><span>61.6</span></span></div></td><td style="vertical-align:bottom;border-bottom:1px solid #000000;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;border-bottom:1px solid #000000;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><span>(4.1</span></span></div></td><td style="vertical-align:bottom;border-bottom:1px solid #000000;padding-right:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">)</span></div></td></tr><tr><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="text-align:left;padding-left:12px;text-indent:-12px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">Losses and LAE incurred during calendar year, net of reinsurance</span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;border-bottom:1px solid #000000;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;border-top:1px solid #000000;"><div style="text-align:right;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><span>861.5</span></span></div></td><td style="vertical-align:bottom;border-bottom:1px solid #000000;background-color:#cceeff;border-top:1px solid #000000;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;border-bottom:1px solid #000000;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;border-top:1px solid #000000;"><div style="text-align:right;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><span>760.2</span></span></div></td><td style="vertical-align:bottom;border-bottom:1px solid #000000;background-color:#cceeff;border-top:1px solid #000000;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td></tr><tr><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="text-align:left;padding-left:12px;text-indent:-12px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">Deduct:</span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="3" style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;border-top:1px solid #000000;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="3" style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;border-top:1px solid #000000;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td></tr><tr><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="text-align:left;padding-left:12px;text-indent:-12px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">Losses and LAE payments made during current calendar year, net of reinsurance:</span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="3" style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="3" style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td></tr><tr><td style="vertical-align:bottom;padding-left:20px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="text-align:left;padding-left:12px;text-indent:-12px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">Current accident year</span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><span>163.6</span></span></div></td><td style="vertical-align:bottom;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><span>223.2</span></span></div></td><td style="vertical-align:bottom;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td></tr><tr><td style="vertical-align:bottom;background-color:#cceeff;padding-left:20px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="text-align:left;padding-left:12px;text-indent:-12px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">Prior accident years</span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;border-bottom:1px solid #000000;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><span>615.8</span></span></div></td><td style="vertical-align:bottom;border-bottom:1px solid #000000;background-color:#cceeff;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;border-bottom:1px solid #000000;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><span>469.0</span></span></div></td><td style="vertical-align:bottom;border-bottom:1px solid #000000;background-color:#cceeff;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td></tr><tr><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="text-align:left;padding-left:12px;text-indent:-12px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">Losses and LAE payments made during current calendar year, net of reinsurance:</span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;border-bottom:1px solid #000000;padding-left:2px;padding-top:2px;padding-bottom:2px;border-top:1px solid #000000;"><div style="text-align:right;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><span>779.4</span></span></div></td><td style="vertical-align:bottom;border-bottom:1px solid #000000;border-top:1px solid #000000;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;border-bottom:1px solid #000000;padding-left:2px;padding-top:2px;padding-bottom:2px;border-top:1px solid #000000;"><div style="text-align:right;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><span>692.2</span></span></div></td><td style="vertical-align:bottom;border-bottom:1px solid #000000;border-top:1px solid #000000;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td></tr><tr><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="padding-left:12px;text-indent:-12px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">Change in participation interest </span><span style="font-family:inherit;font-size:10pt;"><sup style="vertical-align:top;line-height:120%;font-size:7pt">(1)</sup></span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;border-top:1px solid #000000;"><div style="text-align:right;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><span>(14.4</span></span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-right:2px;padding-top:2px;padding-bottom:2px;border-top:1px solid #000000;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">)</span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;border-top:1px solid #000000;"><div style="text-align:right;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><span>(29.4</span></span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-right:2px;padding-top:2px;padding-bottom:2px;border-top:1px solid #000000;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">)</span></div></td></tr><tr><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="text-align:left;padding-left:12px;text-indent:-12px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">Foreign exchange adjustments</span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;border-bottom:1px solid #000000;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><span>(26.3</span></span></div></td><td style="vertical-align:bottom;border-bottom:1px solid #000000;padding-right:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">)</span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;border-bottom:1px solid #000000;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><span>(20.8</span></span></div></td><td style="vertical-align:bottom;border-bottom:1px solid #000000;padding-right:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">)</span></div></td></tr><tr><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="text-align:left;padding-left:12px;text-indent:-12px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">Net reserves - end of period</span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;border-top:1px solid #000000;"><div style="text-align:right;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><span>2,604.3</span></span></div></td><td style="vertical-align:bottom;background-color:#cceeff;border-top:1px solid #000000;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;border-top:1px solid #000000;"><div style="text-align:right;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><span>2,555.2</span></span></div></td><td style="vertical-align:bottom;background-color:#cceeff;border-top:1px solid #000000;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td></tr><tr><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="text-align:left;padding-left:12px;text-indent:-12px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">Add:</span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="3" style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="3" style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td></tr><tr><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="text-align:left;padding-left:12px;text-indent:-12px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">Reinsurance recoverables on unpaid losses and LAE, end of period</span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;border-bottom:1px solid #000000;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><span>2,238.2</span></span></div></td><td style="vertical-align:bottom;border-bottom:1px solid #000000;background-color:#cceeff;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td><td style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td colspan="2" style="vertical-align:bottom;border-bottom:1px solid #000000;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;"><div style="text-align:right;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><span>1,736.5</span></span></div></td><td style="vertical-align:bottom;border-bottom:1px solid #000000;background-color:#cceeff;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td></tr><tr><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="text-align:left;padding-left:12px;text-indent:-12px;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">Gross reserves - end of period</span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td style="vertical-align:bottom;border-bottom:3px double #000000;padding-left:2px;padding-top:2px;padding-bottom:2px;border-top:1px solid #000000;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">$</span></div></td><td style="vertical-align:bottom;border-bottom:3px double #000000;padding-top:2px;padding-bottom:2px;border-top:1px solid #000000;"><div style="text-align:right;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><span>4,842.5</span></span></div></td><td style="vertical-align:bottom;border-bottom:3px double #000000;border-top:1px solid #000000;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td><td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;"><div style="overflow:hidden;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"> </span></div></td><td style="vertical-align:bottom;border-bottom:3px double #000000;padding-left:2px;padding-top:2px;padding-bottom:2px;border-top:1px solid #000000;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">$</span></div></td><td style="vertical-align:bottom;border-bottom:3px double #000000;padding-top:2px;padding-bottom:2px;border-top:1px solid #000000;"><div style="text-align:right;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><span>4,291.7</span></span></div></td><td style="vertical-align:bottom;border-bottom:3px double #000000;border-top:1px solid #000000;"><div style="text-align:left;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;"><br/></span></div></td></tr></table></div></div><div style="line-height:120%;font-size:8pt;padding-left:0px;"><span style="font-family:inherit;font-size:8pt;"><sup style="vertical-align:top;line-height:120%;font-size:5pt">(1)</sup> </span></div><div style="line-height:120%;text-align:justify;font-size:8pt;"><span style="font-family:inherit;font-size:8pt;">Amount represents the change in reserves due to changing our participation in Syndicates 1200 and 1910.</span></div>
CY2018Q4	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	2562900000	USD
CY2017Q4	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	2488000000.0	USD
	argo	Liability For Unpaid Claims And Claims Adjustment Expense Net Reserves Acquired LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNetReservesAcquired	0	USD
	argo	Liability For Unpaid Claims And Claims Adjustment Expense Net Reserves Acquired LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNetReservesAcquired	49400000	USD
	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Current Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersCurrentYearClaimsAndClaimsAdjustmentExpense	799900000	USD
	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Current Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersCurrentYearClaimsAndClaimsAdjustmentExpense	764300000	USD
	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Prior Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense	61600000	USD
	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Prior Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense	-4100000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Incurred Claims1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaims1	861500000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Incurred Claims1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaims1	760200000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Current Year1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidCurrentYear1	163600000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Current Year1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidCurrentYear1	223200000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Prior Years1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidPriorYears1	615800000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Claims Paid Prior Years1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidPriorYears1	469000000.0	USD
	us-gaap	Payments For Losses And Loss Adjustment Expense PaymentsForLossesAndLossAdjustmentExpense	779400000	USD
	us-gaap	Payments For Losses And Loss Adjustment Expense PaymentsForLossesAndLossAdjustmentExpense	692200000	USD
	argo	Liability For Unpaid Claims And Claims Adjustment Expense Change In Participation Interest LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseChangeInParticipationInterest	-14400000	USD
	argo	Liability For Unpaid Claims And Claims Adjustment Expense Change In Participation Interest LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseChangeInParticipationInterest	-29400000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Foreign Currency Translation Gain Loss LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseForeignCurrencyTranslationGainLoss	26300000	USD
	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Foreign Currency Translation Gain Loss LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseForeignCurrencyTranslationGainLoss	20800000	USD
CY2019Q3	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	2604300000	USD
CY2018Q3	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Net LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet	2555200000	USD
CY2019Q3	us-gaap	Reinsurance Receivables Incurred But Not Reported Claims ReinsuranceReceivablesIncurredButNotReportedClaims	2238200000	USD
CY2018Q3	us-gaap	Reinsurance Receivables Incurred But Not Reported Claims ReinsuranceReceivablesIncurredButNotReportedClaims	1736500000	USD
CY2019Q3	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	4842500000	USD
CY2018Q3	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	4291700000	USD
	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Prior Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense	61600000	USD
	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Prior Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense	-4100000	USD
	argo	Other Comprehensive Income Loss Netof Tax Including Cumulative Effectof Adoption OtherComprehensiveIncomeLossNetofTaxIncludingCumulativeEffectofAdoption	82800000	USD
	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	-58200000	USD
	us-gaap	Reclassification From Aoci Current Period Net Of Tax Attributable To Parent ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent	-300000	USD
	argo	Other Comprehensive Income Loss Netof Tax Including Cumulative Effectof Adoption OtherComprehensiveIncomeLossNetofTaxIncludingCumulativeEffectofAdoption	-57900000	USD
CY2019Q3	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.31
CY2019Q3	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	10900000	USD
CY2019Q2	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.31
CY2019Q2	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	10800000	USD
CY2018Q2	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.27
CY2018Q2	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	9400000	USD
	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	76100000	USD
	us-gaap	Reclassification From Aoci Current Period Net Of Tax Attributable To Parent ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent	-6700000	USD
CY2019Q3	us-gaap	Net Income Loss NetIncomeLoss	-25100000	USD
CY2018Q3	us-gaap	Net Income Loss NetIncomeLoss	40600000	USD
	us-gaap	Net Income Loss NetIncomeLoss	94900000	USD
	us-gaap	Net Income Loss NetIncomeLoss	107200000	USD
CY2019Q3	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	34299999	shares
CY2018Q3	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	33956695	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	34161016	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	33921632	shares
CY2019Q3	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	0	shares
CY2018Q3	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	699633	shares
	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	608606	shares
	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	767211	shares
CY2019Q3	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	34299999	shares
CY2018Q3	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	34656328	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	34769622	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	34688843	shares
CY2019Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	-0.73
CY2018Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.20
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.78
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.16
CY2019Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-0.73
CY2018Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.17
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.73
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.09
CY2019Q3	us-gaap	Treasury Stock Shares TreasuryStockShares	11315889	shares
CY2018Q3	us-gaap	Treasury Stock Shares TreasuryStockShares	11285996	shares
CY2019Q3	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	489376	shares
	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	2331	shares
CY2018Q3	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	0	shares
	us-gaap	Interest Paid InterestPaid	26500000	USD
	us-gaap	Interest Paid InterestPaid	23100000	USD
	us-gaap	Income Taxes Paid IncomeTaxesPaid	4800000	USD
	us-gaap	Income Taxes Paid IncomeTaxesPaid	18100000	USD
	us-gaap	Proceeds From Income Tax Refunds ProceedsFromIncomeTaxRefunds	100000	USD
	us-gaap	Proceeds From Income Tax Refunds ProceedsFromIncomeTaxRefunds	0	USD
	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	4700000	USD
	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	18100000	USD
	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Award Vesting Period1 ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1	P5Y
	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Fair Value Assumptions Expected Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1	P4Y6M
	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate	0.0166
	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate	0.0296
	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Dividend Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate	0.0176
	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Dividend Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate	0.0184
	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Fair Value Assumptions Expected Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1	P4Y5M26D
	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate	0.1873
	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate	0.1782
CY2019Q3	us-gaap	Noninterest Expense Commission Expense NoninterestExpenseCommissionExpense	58000000.0	USD
CY2018Q3	us-gaap	Noninterest Expense Commission Expense NoninterestExpenseCommissionExpense	88000000.0	USD
	us-gaap	Noninterest Expense Commission Expense NoninterestExpenseCommissionExpense	178000000.0	USD
	us-gaap	Noninterest Expense Commission Expense NoninterestExpenseCommissionExpense	212700000	USD
CY2019Q3	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	92900000	USD
CY2018Q3	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	83200000	USD
	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	281000000.0	USD
	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	261600000	USD
CY2019Q3	argo	Premium Taxes Boards And Bureaus PremiumTaxesBoardsAndBureaus	10800000	USD
CY2018Q3	argo	Premium Taxes Boards And Bureaus PremiumTaxesBoardsAndBureaus	9800000	USD
	argo	Premium Taxes Boards And Bureaus PremiumTaxesBoardsAndBureaus	27000000.0	USD
	argo	Premium Taxes Boards And Bureaus PremiumTaxesBoardsAndBureaus	27200000	USD
CY2019Q3	argo	Underwriting Acquisition And Insurance Expense Gross UnderwritingAcquisitionAndInsuranceExpenseGross	161700000	USD
CY2018Q3	argo	Underwriting Acquisition And Insurance Expense Gross UnderwritingAcquisitionAndInsuranceExpenseGross	181000000.0	USD
	argo	Underwriting Acquisition And Insurance Expense Gross UnderwritingAcquisitionAndInsuranceExpenseGross	486000000.0	USD
	argo	Underwriting Acquisition And Insurance Expense Gross UnderwritingAcquisitionAndInsuranceExpenseGross	501500000	USD
CY2019Q3	argo	Net Supplementary Insurance Information Amortization Deferral Of Deferred Policy Acquisition Costs NetSupplementaryInsuranceInformationAmortizationDeferralOfDeferredPolicyAcquisitionCosts	-6000000.0	USD
CY2018Q3	argo	Net Supplementary Insurance Information Amortization Deferral Of Deferred Policy Acquisition Costs NetSupplementaryInsuranceInformationAmortizationDeferralOfDeferredPolicyAcquisitionCosts	13000000.0	USD
	argo	Net Supplementary Insurance Information Amortization Deferral Of Deferred Policy Acquisition Costs NetSupplementaryInsuranceInformationAmortizationDeferralOfDeferredPolicyAcquisitionCosts	-11300000	USD
	argo	Net Supplementary Insurance Information Amortization Deferral Of Deferred Policy Acquisition Costs NetSupplementaryInsuranceInformationAmortizationDeferralOfDeferredPolicyAcquisitionCosts	16500000	USD
CY2019Q3	argo	Underwriting Acquisition And Insurance Expenses UnderwritingAcquisitionAndInsuranceExpenses	167700000	USD
CY2018Q3	argo	Underwriting Acquisition And Insurance Expenses UnderwritingAcquisitionAndInsuranceExpenses	168000000.0	USD
	argo	Underwriting Acquisition And Insurance Expenses UnderwritingAcquisitionAndInsuranceExpenses	497300000	USD
	argo	Underwriting Acquisition And Insurance Expenses UnderwritingAcquisitionAndInsuranceExpenses	485000000.0	USD
CY2019Q3	argo	Proxy Solicitationand Related Expense ProxySolicitationandRelatedExpense	3700000	USD
	argo	Proxy Solicitationand Related Expense ProxySolicitationandRelatedExpense	11700000	USD
	argo	Numberof Subsidiaries Subjectto Corporate Tax NumberofSubsidiariesSubjecttoCorporateTax	8	subsidiary
CY2019Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	-26200000	USD
CY2019Q3	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.041
CY2018Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	45300000	USD
CY2018Q3	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.102
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	103500000	USD
	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.084
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	127400000	USD
	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.158
CY2019Q3	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	-4100000	USD
CY2018Q3	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	8400000	USD
	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	14400000	USD
	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	26800000	USD
CY2019Q3	us-gaap	Income Tax Reconciliation Tax Exempt Income IncomeTaxReconciliationTaxExemptIncome	400000	USD
CY2018Q3	us-gaap	Income Tax Reconciliation Tax Exempt Income IncomeTaxReconciliationTaxExemptIncome	400000	USD
	us-gaap	Income Tax Reconciliation Tax Exempt Income IncomeTaxReconciliationTaxExemptIncome	1100000	USD
	us-gaap	Income Tax Reconciliation Tax Exempt Income IncomeTaxReconciliationTaxExemptIncome	1400000	USD
CY2019Q3	argo	Income Tax Reconciliation Foreign Exchange Adjustments IncomeTaxReconciliationForeignExchangeAdjustments	700000	USD
CY2018Q3	argo	Income Tax Reconciliation Foreign Exchange Adjustments IncomeTaxReconciliationForeignExchangeAdjustments	-1000000.0	USD
	argo	Income Tax Reconciliation Foreign Exchange Adjustments IncomeTaxReconciliationForeignExchangeAdjustments	1300000	USD
	argo	Income Tax Reconciliation Foreign Exchange Adjustments IncomeTaxReconciliationForeignExchangeAdjustments	-1200000	USD
CY2019Q3	argo	Income Tax Reconciliation Withholding Taxes IncomeTaxReconciliationWithholdingTaxes	0	USD
CY2018Q3	argo	Income Tax Reconciliation Withholding Taxes IncomeTaxReconciliationWithholdingTaxes	200000	USD
	argo	Income Tax Reconciliation Withholding Taxes IncomeTaxReconciliationWithholdingTaxes	200000	USD
	argo	Income Tax Reconciliation Withholding Taxes IncomeTaxReconciliationWithholdingTaxes	500000	USD
CY2019Q3	us-gaap	Income Tax Reconciliation Prior Year Income Taxes IncomeTaxReconciliationPriorYearIncomeTaxes	0	USD
CY2018Q3	us-gaap	Income Tax Reconciliation Prior Year Income Taxes IncomeTaxReconciliationPriorYearIncomeTaxes	-2200000	USD
	us-gaap	Income Tax Reconciliation Prior Year Income Taxes IncomeTaxReconciliationPriorYearIncomeTaxes	-1800000	USD
	us-gaap	Income Tax Reconciliation Prior Year Income Taxes IncomeTaxReconciliationPriorYearIncomeTaxes	-2100000	USD
CY2019Q3	us-gaap	Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance	2200000	USD
CY2018Q3	us-gaap	Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance	-200000	USD
	us-gaap	Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance	1600000	USD
	us-gaap	Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance	-3600000	USD
CY2019Q3	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	500000	USD
CY2018Q3	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	-100000	USD
	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	-6000000.0	USD
	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	1200000	USD
CY2019Q3	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	-1100000	USD
CY2018Q3	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	4700000	USD
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	8600000	USD
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	20200000	USD
	argo	Net Operating Losses Carry Back Period NetOperatingLossesCarryBackPeriod	P2Y
	argo	Capital Losses Carry Back Period CapitalLossesCarryBackPeriod	P3Y
	us-gaap	Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance	1600000	USD
CY2019Q3	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	0	USD
CY2019Q3	us-gaap	Contractual Obligation ContractualObligation	94200000	USD
	argo	Contractual Obligation Period ContractualObligationPeriod	P13Y
	us-gaap	Revenues Revenues	1485200000	USD
	us-gaap	Number Of Reportable Segments NumberOfReportableSegments	2	segment
CY2019Q3	us-gaap	Premiums Earned Net PremiumsEarnedNet	451500000	USD
CY2018Q3	us-gaap	Premiums Earned Net PremiumsEarnedNet	446900000	USD
	us-gaap	Premiums Earned Net PremiumsEarnedNet	1303700000	USD
	us-gaap	Premiums Earned Net PremiumsEarnedNet	1279300000	USD
CY2019Q3	us-gaap	Net Investment Income NetInvestmentIncome	40200000	USD
CY2018Q3	us-gaap	Net Investment Income NetInvestmentIncome	34500000	USD
	us-gaap	Net Investment Income NetInvestmentIncome	116900000	USD
	us-gaap	Net Investment Income NetInvestmentIncome	103700000	USD
CY2019Q3	argo	Fee And Other Income FeeAndOtherIncome	1900000	USD
CY2018Q3	argo	Fee And Other Income FeeAndOtherIncome	3300000	USD
	argo	Fee And Other Income FeeAndOtherIncome	6300000	USD
	argo	Fee And Other Income FeeAndOtherIncome	7200000	USD
CY2019Q3	us-gaap	Realized Investment Gains Losses RealizedInvestmentGainsLosses	-6200000	USD
CY2018Q3	us-gaap	Realized Investment Gains Losses RealizedInvestmentGainsLosses	14200000	USD
	us-gaap	Realized Investment Gains Losses RealizedInvestmentGainsLosses	58300000	USD
	us-gaap	Realized Investment Gains Losses RealizedInvestmentGainsLosses	9000000.0	USD
CY2019Q3	us-gaap	Revenues Revenues	487400000	USD
CY2018Q3	us-gaap	Revenues Revenues	498900000	USD
	us-gaap	Revenues Revenues	1399200000	USD
CY2019Q3	us-gaap	Realized Investment Gains Losses RealizedInvestmentGainsLosses	-6200000	USD
CY2018Q3	us-gaap	Realized Investment Gains Losses RealizedInvestmentGainsLosses	14200000	USD
	us-gaap	Realized Investment Gains Losses RealizedInvestmentGainsLosses	58300000	USD
	us-gaap	Realized Investment Gains Losses RealizedInvestmentGainsLosses	9000000.0	USD
CY2019Q3	us-gaap	Foreign Currency Transaction Gain Loss Before Tax ForeignCurrencyTransactionGainLossBeforeTax	1600000	USD
CY2018Q3	us-gaap	Foreign Currency Transaction Gain Loss Before Tax ForeignCurrencyTransactionGainLossBeforeTax	1700000	USD
	us-gaap	Foreign Currency Transaction Gain Loss Before Tax ForeignCurrencyTransactionGainLossBeforeTax	6200000	USD
	us-gaap	Foreign Currency Transaction Gain Loss Before Tax ForeignCurrencyTransactionGainLossBeforeTax	2300000	USD
CY2019Q3	us-gaap	Other Nonoperating Expense OtherNonoperatingExpense	3700000	USD
CY2018Q3	us-gaap	Other Nonoperating Expense OtherNonoperatingExpense	0	USD
	us-gaap	Other Nonoperating Expense OtherNonoperatingExpense	11700000	USD
	us-gaap	Other Nonoperating Expense OtherNonoperatingExpense	0	USD
CY2019Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	-26200000	USD
CY2018Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	45300000	USD
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	103500000	USD
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	127400000	USD
CY2019Q3	us-gaap	Premiums Earned Net PremiumsEarnedNet	451500000	USD
CY2018Q3	us-gaap	Premiums Earned Net PremiumsEarnedNet	446900000	USD
	us-gaap	Premiums Earned Net PremiumsEarnedNet	1303700000	USD
	us-gaap	Premiums Earned Net PremiumsEarnedNet	1279300000	USD
CY2019Q3	us-gaap	Assets Assets	10445800000	USD
CY2018Q4	us-gaap	Assets Assets	9558200000	USD
CY2019Q3	argo	Assets Associated With Trade Capital Providers AssetsAssociatedWithTradeCapitalProviders	884600000	USD
CY2018Q4	argo	Assets Associated With Trade Capital Providers AssetsAssociatedWithTradeCapitalProviders	880400000	USD
CY2019Q3	us-gaap	Debt Instrument Face Amount DebtInstrumentFaceAmount	143800000	USD
CY2018Q4	us-gaap	Debt Instrument Face Amount DebtInstrumentFaceAmount	143800000	USD
CY2019Q3	us-gaap	Unamortized Debt Issuance Expense UnamortizedDebtIssuanceExpense	3900000	USD
CY2018Q4	us-gaap	Unamortized Debt Issuance Expense UnamortizedDebtIssuanceExpense	4000000.0	USD
CY2018Q4	us-gaap	Accrued Investment Income Receivable AccruedInvestmentIncomeReceivable	27200000	USD
CY2019Q3	us-gaap	Senior Notes SeniorNotes	139900000	USD
CY2018Q4	us-gaap	Senior Notes SeniorNotes	139800000	USD
CY2019Q3	us-gaap	Investments Investments	5127000000.0	USD
CY2019Q3	us-gaap	Cash Cash	145100000	USD
CY2019Q3	us-gaap	Accrued Investment Income Receivable AccruedInvestmentIncomeReceivable	27700000	USD
CY2019Q3	us-gaap	Premiums Receivable At Carrying Value PremiumsReceivableAtCarryingValue	740300000	USD
CY2019Q3	us-gaap	Reinsurance Recoverables ReinsuranceRecoverables	2873800000	USD
CY2019Q3	us-gaap	Intangible Assets Net Including Goodwill IntangibleAssetsNetIncludingGoodwill	269200000	USD
CY2019Q3	us-gaap	Income Tax Receivable IncomeTaxReceivable	200000	USD
CY2019Q3	us-gaap	Deferred Policy Acquisition Costs DeferredPolicyAcquisitionCosts	159500000	USD
CY2019Q3	us-gaap	Prepaid Reinsurance Premiums PrepaidReinsurancePremiums	603800000	USD
CY2019Q3	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	108600000	USD
CY2019Q3	us-gaap	Other Assets OtherAssets	390600000	USD
CY2019Q3	us-gaap	Due From Affiliates DueFromAffiliates	0	USD
CY2019Q3	us-gaap	Investments In Affiliates Subsidiaries Associates And Joint Ventures InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures	0	USD
CY2019Q3	us-gaap	Assets Assets	10445800000	USD
CY2019Q3	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	4842500000	USD
CY2019Q3	us-gaap	Unearned Premiums UnearnedPremiums	1495500000	USD
CY2019Q3	argo	Funds Held And Ceded Reinsurance Payable Net FundsHeldAndCededReinsurancePayableNet	1211800000	USD
CY2019Q3	us-gaap	Long Term Debt LongTermDebt	578600000	USD
CY2019Q3	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	19900000	USD
CY2019Q3	argo	Accrued Underwriting Expenses And Other Liabilities AccruedUnderwritingExpensesAndOtherLiabilities	283900000	USD
CY2019Q3	us-gaap	Operating Lease Liability OperatingLeaseLiability	120200000	USD
CY2019Q3	us-gaap	Related Party Transaction Due From To Related Party RelatedPartyTransactionDueFromToRelatedParty	0	USD
CY2019Q3	us-gaap	Liabilities Liabilities	8552400000	USD
CY2019Q3	us-gaap	Stockholders Equity StockholdersEquity	1893400000	USD
CY2019Q3	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	10445800000	USD
CY2018Q4	us-gaap	Investments Investments	4787000000.0	USD
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CY2018Q4	us-gaap	Premiums Receivable At Carrying Value PremiumsReceivableAtCarryingValue	649900000	USD
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CY2018Q4	us-gaap	Intangible Assets Net Including Goodwill IntangibleAssetsNetIncludingGoodwill	270500000	USD
CY2018Q4	us-gaap	Income Tax Receivable IncomeTaxReceivable	8200000	USD
CY2018Q4	us-gaap	Deferred Policy Acquisition Costs DeferredPolicyAcquisitionCosts	167300000	USD
CY2018Q4	us-gaap	Prepaid Reinsurance Premiums PrepaidReinsurancePremiums	457700000	USD
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CY2018Q4	us-gaap	Investments In Affiliates Subsidiaries Associates And Joint Ventures InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures	0	USD
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CY2018Q4	us-gaap	Assets Assets	9558200000	USD
CY2018Q4	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	4654600000	USD
CY2018Q4	us-gaap	Unearned Premiums UnearnedPremiums	1300900000	USD
CY2018Q4	argo	Funds Held And Ceded Reinsurance Payable Net FundsHeldAndCededReinsurancePayableNet	1007700000	USD
CY2018Q3	us-gaap	Realized Investment Gains Losses RealizedInvestmentGainsLosses	14200000	USD
CY2018Q3	us-gaap	Revenues Revenues	498900000	USD
CY2018Q3	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Incurred Claims1 LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaims1	277500000	USD
CY2018Q3	argo	Underwriting Acquisition And Insurance Expenses UnderwritingAcquisitionAndInsuranceExpenses	168000000.0	USD
CY2018Q4	us-gaap	Long Term Debt LongTermDebt	580200000	USD
CY2018Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	6200000	USD
CY2018Q4	argo	Accrued Underwriting Expenses And Other Liabilities AccruedUnderwritingExpensesAndOtherLiabilities	261900000	USD
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CY2019Q3	us-gaap	Net Income Loss NetIncomeLoss	-25100000	USD
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CY2018Q3	us-gaap	Net Investment Income NetInvestmentIncome	34500000	USD
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CY2018Q4	us-gaap	Stockholders Equity StockholdersEquity	1746700000	USD
CY2018Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	9558200000	USD
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CY2019Q3	argo	Underwriting Acquisition And Insurance Expenses UnderwritingAcquisitionAndInsuranceExpenses	167700000	USD
CY2019Q3	us-gaap	Interest Expense InterestExpense	7500000	USD
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CY2019Q3	us-gaap	Benefits Losses And Expenses BenefitsLossesAndExpenses	513600000	USD
CY2019Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	-26200000	USD
CY2019Q3	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	-1100000	USD
CY2019Q3	argo	Net Income Loss Before Equity In Earnings Of Subsidiaries NetIncomeLossBeforeEquityInEarningsOfSubsidiaries	-25100000	USD
CY2019Q3	argo	Equity In Undistributed Net Income Loss Of Subsidiaries EquityInUndistributedNetIncomeLossOfSubsidiaries	0	USD
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CY2018Q3	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	4700000	USD
CY2018Q3	argo	Net Income Loss Before Equity In Earnings Of Subsidiaries NetIncomeLossBeforeEquityInEarningsOfSubsidiaries	40600000	USD
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	us-gaap	Net Investment Income NetInvestmentIncome	116900000	USD
	argo	Fee And Other Income FeeAndOtherIncome	6300000	USD
	us-gaap	Realized Investment Gains Losses RealizedInvestmentGainsLosses	58300000	USD
	argo	Underwriting Acquisition And Insurance Expenses UnderwritingAcquisitionAndInsuranceExpenses	497300000	USD
	us-gaap	Interest Expense InterestExpense	25300000	USD
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	us-gaap	Benefits Losses And Expenses BenefitsLossesAndExpenses	1381700000	USD
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	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	8600000	USD
	argo	Net Income Loss Before Equity In Earnings Of Subsidiaries NetIncomeLossBeforeEquityInEarningsOfSubsidiaries	94900000	USD
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	us-gaap	Net Income Loss NetIncomeLoss	94900000	USD
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	us-gaap	Interest Expense InterestExpense	23400000	USD
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	us-gaap	Foreign Currency Transaction Gain Loss Before Tax ForeignCurrencyTransactionGainLossBeforeTax	2300000	USD
	us-gaap	Benefits Losses And Expenses BenefitsLossesAndExpenses	1271800000	USD
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	127400000	USD
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	20200000	USD
	argo	Net Income Loss Before Equity In Earnings Of Subsidiaries NetIncomeLossBeforeEquityInEarningsOfSubsidiaries	107200000	USD
	argo	Equity In Undistributed Net Income Loss Of Subsidiaries EquityInUndistributedNetIncomeLossOfSubsidiaries	0	USD
	us-gaap	Net Income Loss NetIncomeLoss	107200000	USD
	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	195700000	USD
	argo	Proceeds From Sale Of Investments ProceedsFromSaleOfInvestments	1180300000	USD
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	292200000	USD
	us-gaap	Payments To Acquire Investments PaymentsToAcquireInvestments	1639500000	USD
	argo	Payments For Proceeds From Change In Foreign Regulatory Deposits Voluntary Pools Shortterm Investments PaymentsForProceedsFromChangeInForeignRegulatoryDepositsVoluntaryPoolsShorttermInvestments	-2300000	USD
	argo	Increase Decrease In Settlements Of Foreign Currency Exchange Forward Contracts IncreaseDecreaseInSettlementsOfForeignCurrencyExchangeForwardContracts	-1200000	USD
	argo	Payments For Proceeds From Purchases Of Fixed Asset And Other Investing Activities PaymentsForProceedsFromPurchasesOfFixedAssetAndOtherInvestingActivities	-6700000	USD
	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-159200000	USD
	argo	Paymentfor Intercompany Note PaymentforIntercompanyNote	0	USD
	us-gaap	Repayments Of Notes Payable RepaymentsOfNotesPayable	600000	USD
	us-gaap	Proceeds From Issuance Of Shares Under Incentive And Share Based Compensation Plans ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlans	1400000	USD
	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	32500000	USD
	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-31700000	USD
	us-gaap	Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	1100000	USD
	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	5900000	USD
CY2018Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	139200000	USD
CY2019Q3	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	145100000	USD
	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	231000000.0	USD
	argo	Proceeds From Sale Of Investments ProceedsFromSaleOfInvestments	1417200000	USD
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	375100000	USD
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	argo	Payments For Proceeds From Change In Foreign Regulatory Deposits Voluntary Pools Shortterm Investments PaymentsForProceedsFromChangeInForeignRegulatoryDepositsVoluntaryPoolsShorttermInvestments	33800000	USD
	argo	Increase Decrease In Settlements Of Foreign Currency Exchange Forward Contracts IncreaseDecreaseInSettlementsOfForeignCurrencyExchangeForwardContracts	2000000.0	USD
	us-gaap	Cash Acquired From Acquisition CashAcquiredFromAcquisition	15600000	USD
	argo	Payments For Proceeds From Purchases Of Fixed Asset And Other Investing Activities PaymentsForProceedsFromPurchasesOfFixedAssetAndOtherInvestingActivities	32200000	USD
	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-233300000	USD
	argo	Payments For Proceeds From Inter Company Advances PaymentsForProceedsFromInterCompanyAdvances	0	USD
	us-gaap	Proceeds From Issuance Of Shares Under Incentive And Share Based Compensation Plans ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlans	1000000.0	USD
	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	30000000.0	USD
	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	28000000.0	USD
	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-57000000.0	USD
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	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-58100000	USD
CY2017Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	176600000	USD
CY2018Q3	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	118500000	USD

Files In Submission

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report.css	Edgar Link	pending
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Argo Group International Holdings, Inc. Stock $argd

2019 Q4 Form 10-Q Financial Statement

#000162828019013779 Filed on November 08, 2019

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$ARGD Argo Group International Holdings, Inc. Stock $argd

2019 Q4 Form 10-Q Financial Statement

#000162828019013779 Filed on November 08, 2019

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$ARGD
Argo Group International Holdings, Inc. Stock $argd