ACGL


Line plots across dimensions of each concept
Line plots across concepts
Tables

Table of contents



us-gaap:CommonStockValue
us-gaap:ConsolidatedEntities

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic

us-gaap:EarningsPerShareBasic

us-gaap:EarningsPerShareDiluted

us-gaap:BenefitsLossesAndExpenses

us-gaap:ComprehensiveIncomeNetOfTax

us-gaap:ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest

us-gaap:DeferredPolicyAcquisitionCostAmortizationExpense
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments

us-gaap:GeneralAndAdministrativeExpense

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:StatementEquityComponents
us-gaap:StatementBusinessSegments

us-gaap:IncomeTaxExpenseBenefit
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:StatementEquityComponents
us-gaap:StatementBusinessSegments

us-gaap:IncomeTaxesPaidNet

us-gaap:InsuranceCommissionsAndFees

us-gaap:InterestExpense
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments

us-gaap:InterestExpenseDebt

us-gaap:InterestPaidNet

us-gaap:NetIncomeLoss
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:StatementEquityComponents
us-gaap:StatementBusinessSegments

us-gaap:NetIncomeLossAttributableToNoncontrollingInterest
us-gaap:StatementEquityComponents

us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments

us-gaap:OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax

us-gaap:OtherComprehensiveIncomeLossNetOfTax

us-gaap:PolicyholderBenefitsAndClaimsIncurredNet
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments

us-gaap:PreferredStockDividendsIncomeStatementImpact

us-gaap:PremiumsEarnedNet

us-gaap:ProfitLoss
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments
us-gaap:StatementEquityComponents

us-gaap:Revenues

us-gaap:Assets
dei:LegalEntity, us-gaap:ConsolidatedEntities
dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities
us-gaap:ConsolidatedEntities
us-gaap:ConsolidationItems
us-gaap:EquityMethodInvestmentNonconsolidatedInvestee
us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities
us-gaap:StatementBusinessSegments

us-gaap:Liabilities
dei:LegalEntity, us-gaap:ConsolidatedEntities
dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities
us-gaap:ConsolidatedEntities
us-gaap:ConsolidationItems
us-gaap:EquityMethodInvestmentNonconsolidatedInvestee
us-gaap:StatementBusinessSegments

us-gaap:LiabilitiesAndStockholdersEquity
us-gaap:ConsolidatedEntities

us-gaap:StockholdersEquity
us-gaap:CumulativeEffectPeriodOfAdoption, us-gaap:StatementEquityComponents
us-gaap:StatementEquityComponents

us-gaap:CashAndCashEquivalentsAtCarryingValue
dei:LegalEntity, us-gaap:ConsolidatedEntities
dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities
us-gaap:ConsolidatedEntities

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents
us-gaap:ConsolidatedEntities

us-gaap:AmortizationOfIntangibleAssets
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:Goodwill
us-gaap:FairValueByAssetClass

us-gaap:IndefiniteLivedIntangibleAssetsExcludingGoodwill
us-gaap:FairValueByAssetClass

us-gaap:FiniteLivedIntangibleAssetsNet
us-gaap:FairValueByAssetClass

us-gaap:IntangibleAssetsNetIncludingGoodwill
dei:LegalEntity, us-gaap:ConsolidatedEntities
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments

us-gaap:DeferredTaxAssetsLiabilitiesNet
us-gaap:BalanceSheetLocation
us-gaap:OperatingLeaseRightOfUseAsset

us-gaap:EquitySecuritiesFvNi
dei:LegalEntity, us-gaap:ConsolidatedEntities
dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities

us-gaap:OtherAssets
dei:LegalEntity, us-gaap:ConsolidatedEntities
dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities
us-gaap:ConsolidatedEntities

us-gaap:AccruedIncomeTaxesCurrent

us-gaap:MinorityInterest
dei:LegalEntity
dei:LegalEntity, us-gaap:StatementEquityComponents

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearThree

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFive

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive

us-gaap:OperatingLeaseLiability
us-gaap:BalanceSheetLocation

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDue

us-gaap:LesseeOperatingLeaseLiabilityUndiscountedExcessAmount

us-gaap:StockholdersEquity
us-gaap:CumulativeEffectPeriodOfAdoption, us-gaap:StatementEquityComponents
us-gaap:StatementEquityComponents

us-gaap:StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
us-gaap:ConsolidatedEntities

us-gaap:CommonStockValue
us-gaap:ConsolidatedEntities

us-gaap:AdditionalPaidInCapitalCommonStock
us-gaap:ConsolidatedEntities

us-gaap:RetainedEarningsAccumulatedDeficit
us-gaap:ConsolidatedEntities

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax
us-gaap:ConsolidatedEntities
us-gaap:StatementEquityComponents

us-gaap:TreasuryStockValue
us-gaap:ConsolidatedEntities

us-gaap:MinorityInterest
dei:LegalEntity
dei:LegalEntity, us-gaap:StatementEquityComponents
us-gaap:StatementClassOfStock
us-gaap:StockIssuedDuringPeriodValueNewIssues
us-gaap:StatementEquityComponents
us-gaap:StatementEquityComponents
us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue

us-gaap:NetCashProvidedByUsedInOperatingActivities
dei:LegalEntity, us-gaap:ConsolidatedEntities
dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities

us-gaap:NetCashProvidedByUsedInInvestingActivities
dei:LegalEntity, us-gaap:ConsolidatedEntities
dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities

us-gaap:NetCashProvidedByUsedInFinancingActivities
dei:LegalEntity, us-gaap:ConsolidatedEntities
dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect

us-gaap:IncreaseDecreaseInOtherOperatingCapitalNet

us-gaap:NetCashProvidedByUsedInOperatingActivities
dei:LegalEntity, us-gaap:ConsolidatedEntities
dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities

us-gaap:NetIncomeLoss
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:StatementEquityComponents
us-gaap:StatementBusinessSegments

us-gaap:ProfitLoss
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments
us-gaap:StatementEquityComponents

us-gaap:ShareBasedCompensation

us-gaap:NetCashProvidedByUsedInInvestingActivities
dei:LegalEntity, us-gaap:ConsolidatedEntities
dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities

us-gaap:PaymentsToAcquireProductiveAssets

us-gaap:NetCashProvidedByUsedInFinancingActivities
dei:LegalEntity, us-gaap:ConsolidatedEntities
dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities

us-gaap:PaymentsForRepurchaseOfCommonStock

us-gaap:EffectiveIncomeTaxRateContinuingOperations
us-gaap:AwardType
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice

us-gaap:DeferredTaxAssetsNet

us-gaap:UnrecognizedTaxBenefits

us-gaap:DeferredTaxAssetsValuationAllowance

acgl:AcquisitionExpenseRatioPercentage
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments

acgl:CombinedRatioPercentage
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments

acgl:ContractholderReceivablesCreditLossExpenseReversal
dei:LegalEntity, us-gaap:ConsolidatedEntities, us-gaap:SubsequentEventType
acgl:DeconsolidationGainLossAmountNet

acgl:EquityInNetIncomeLossOfInvestmentFundsAccountedForUsingEquityMethodAndOtherIncomeLoss

acgl:IncomeLossFromOperatingAffiliatesEquityMethod
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:EquityMethodInvestmentNonconsolidatedInvestee

acgl:IncreaseDecreaseInLossAndLossAdjustmentExpensesNetOfRecoverables

acgl:IncreaseDecreaseInUnearnedPremiumsNetOfPrepaidReinsurancePremiums
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
acgl:LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaimsPriorYearsPercentage

acgl:LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaimsRetroactiveReinsurance
dei:LegalEntity
acgl:MinorityInterestOtherAdjustmentstoAdditionalPaidinCapital

acgl:NetRealizedGainsLosses
dei:LegalEntity
acgl:NoncontrollingInterestPeriodIncreaseDecreaseOther

acgl:OtherOperatingExpenseRatioPercentage
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments

acgl:OtherUnderwritingIncomeLoss
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments

acgl:ProceedsFromCommonSharesIssuedNet

acgl:ProceedsFromPaymentsToNonredeemableNoncontrollingInterests
dei:LegalEntity
acgl:RedeemableNoncontrollingInterestAccretionofIssuanceCosts

acgl:SegmentOtherCostAndExpenseOperating
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:StatementEquityComponents
acgl:StockGrantedDuringPeriodValueNetOfTaxWithholdingsSharebasedCompensation
us-gaap:StatementClassOfStock
acgl:TreasuryStockSharesAcquiredCumulativeSinceInception
us-gaap:StatementClassOfStock
acgl:TreasuryStockValueAcquiredCumulativeSinceInception

acgl:UnderwritingIncomeLossSegment
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments

acgl:UnderwritingRelatedAllowanceForCreditLossesCreditLossExpenseReversal
us-gaap:StatementEquityComponents
us-gaap:AdjustmentsToAdditionalPaidInCapitalOther
us-gaap:StatementEquityComponents
us-gaap:AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts

us-gaap:BusinessCombinationAcquisitionRelatedCosts
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments
us-gaap:BusinessAcquisition, us-gaap:SubsequentEventType
us-gaap:BusinessCombinationStepAcquisitionEquityInterestInAcquireeFairValue1

us-gaap:CededPremiumsWritten
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments
us-gaap:ConcentrationRiskByBenchmark, us-gaap:ConcentrationRiskByType
us-gaap:ConcentrationRiskPercentage1
us-gaap:CreditRatingAMBest, us-gaap:Collateral, us-gaap:ConcentrationRiskByBenchmark, us-gaap:ConcentrationRiskByType
us-gaap:CreditRatingAMBest, us-gaap:ConcentrationRiskByBenchmark, us-gaap:ConcentrationRiskByType

us-gaap:DebtSecuritiesAvailableForSaleAllowanceForCreditLossNotPreviouslyRecorded
us-gaap:FinancialInstrument, us-gaap:InvestmentType

us-gaap:DebtSecuritiesAvailableForSaleAllowanceForCreditLossNotToSellBeforeRecoveryCreditLossPreviouslyRecordedExpenseReversal
us-gaap:FinancialInstrument, us-gaap:InvestmentType

us-gaap:DebtSecuritiesAvailableForSaleAllowanceForCreditLossSecuritiesSold
us-gaap:FinancialInstrument, us-gaap:InvestmentType

us-gaap:DebtSecuritiesAvailableForSaleChangeInPresentValueExpenseReversal
us-gaap:FinancialInstrument, us-gaap:InvestmentType
us-gaap:InvestmentType
us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:StatementEquityComponents

us-gaap:DebtSecuritiesAvailableForSaleRealizedGain

us-gaap:DebtSecuritiesAvailableForSaleRealizedLoss

us-gaap:DerivativeGainLossOnDerivativeNet
us-gaap:DerivativeInstrumentRisk, us-gaap:HedgingDesignation
us-gaap:HedgingDesignation

us-gaap:DividendsPreferredStock
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:StatementEquityComponents

us-gaap:EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

us-gaap:EquitySecuritiesFvNiRealizedGainLoss

us-gaap:EquitySecuritiesFvNiUnrealizedGainLoss
us-gaap:FairValueByAssetClass, us-gaap:FairValueByMeasurementFrequency, us-gaap:InvestmentType
us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1
us-gaap:FairValueByMeasurementFrequency, us-gaap:InvestmentType
us-gaap:FairValueByAssetClass, us-gaap:FairValueByMeasurementFrequency, us-gaap:InvestmentType
us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeLoss
us-gaap:FairValueByAssetClass, us-gaap:FairValueByMeasurementFrequency, us-gaap:InvestmentType
us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases
us-gaap:FairValueByMeasurementFrequency, us-gaap:InvestmentType
us-gaap:FairValueByAssetClass, us-gaap:FairValueByMeasurementFrequency, us-gaap:InvestmentType
us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales
us-gaap:FairValueByMeasurementFrequency, us-gaap:InvestmentType
us-gaap:FairValueByAssetClass, us-gaap:FairValueByMeasurementFrequency, us-gaap:InvestmentType
us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSettlements
us-gaap:FairValueByAssetClass, us-gaap:FairValueByMeasurementFrequency, us-gaap:InvestmentType
us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersNet
us-gaap:FairValueByLiabilityClass, us-gaap:FairValueByMeasurementFrequency
us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings
us-gaap:FairValueByLiabilityClass, us-gaap:FairValueByMeasurementFrequency
us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements
us-gaap:InvestmentType
us-gaap:FairValueOptionChangesInFairValueGainLoss1

us-gaap:ForeignCurrencyTransactionGainLossBeforeTax
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments
us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:StatementEquityComponents
us-gaap:GainLossOnInvestmentsExcludingOtherThanTemporaryImpairments

us-gaap:GainLossOnSaleOfOtherInvestments

us-gaap:ImpairmentOfInvestments
us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:StatementEquityComponents

us-gaap:IncomeLossFromEquityMethodInvestments
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:IncreaseDecreaseInCashCollateralForBorrowedSecurities

us-gaap:IncreaseDecreaseInCashCollateralForLoanedSecurities

us-gaap:IncreaseDecreaseInDeferredPolicyAcquisitionCosts

us-gaap:IncreaseDecreaseInPremiumsReceivable

us-gaap:IncreaseDecreaseInReinsurancePayables

us-gaap:IncreaseDecreaseInUnearnedPremiumsNet
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments

us-gaap:InvestmentIncomeInterestAndDividend
us-gaap:InvestmentType

us-gaap:InvestmentIncomeInvestmentExpense

us-gaap:InvestmentIncomeNet
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments

us-gaap:LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidCurrentYear1

us-gaap:LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidPriorYears1

us-gaap:LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseForeignCurrencyTranslationGainLoss

us-gaap:LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaims1

us-gaap:LossRatio
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments

us-gaap:MarketableSecuritiesGainLossExcludingOtherThanTemporaryImpairments

us-gaap:MarketableSecuritiesRealizedGainLoss
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments
dei:LegalEntity
us-gaap:MinorityInterestDecreaseFromRedemptions

us-gaap:NetIncomeLossAttributableToNonredeemableNoncontrollingInterest
dei:LegalEntity
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments

us-gaap:NetIncomeLossAttributableToRedeemableNoncontrollingInterest
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments
us-gaap:StatementEquityComponents
us-gaap:OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToNoncontrollingInterest
us-gaap:StatementEquityComponents
us-gaap:OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToNoncontrollingInterest

us-gaap:OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossArisingDuringPeriodNetOfTax
us-gaap:StatementEquityComponents
us-gaap:StatementEquityComponents
us-gaap:OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax

us-gaap:OtherComprehensiveIncomeLossBeforeTax

us-gaap:OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax

us-gaap:OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax

us-gaap:OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToNoncontrollingInterest
dei:LegalEntity

us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax

us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax

us-gaap:OtherComprehensiveIncomeLossTax

us-gaap:OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax

us-gaap:OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax

us-gaap:OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax

us-gaap:OtherCostAndExpenseOperating

us-gaap:OtherExpenses
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments

us-gaap:OtherOperatingIncomeExpenseNet
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:PaymentsForLossesAndLossAdjustmentExpense

us-gaap:PaymentsForProceedsFromDerivativeInstrumentInvestingActivities

us-gaap:PaymentsForProceedsFromOtherInvestingActivities

us-gaap:PaymentsForProceedsFromShortTermInvestments

us-gaap:PaymentsOfDividendsMinorityInterest

us-gaap:PaymentsOfDividendsPreferredStockAndPreferenceStock

us-gaap:PaymentsToAcquireAvailableForSaleSecuritiesDebt
us-gaap:Ownership, us-gaap:SubsequentEventType
us-gaap:PaymentsToAcquireBusinessesGross

us-gaap:PaymentsToAcquireInterestInSubsidiariesAndAffiliates
us-gaap:EquityMethodInvestmentNonconsolidatedInvestee

us-gaap:PaymentsToAcquireOtherInvestments

us-gaap:PaymentsToAcquireTradingSecuritiesHeldforinvestment

us-gaap:PremiumReceivableCreditLossExpenseReversal

us-gaap:PremiumsReceivableAllowanceForDoubtfulAccountsWriteOffsAgainstAllowance

us-gaap:PremiumsWrittenGross
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments

us-gaap:PremiumsWrittenNet
us-gaap:StatementClassOfStock
us-gaap:ProceedsFromIssuanceOfPreferredStockAndPreferenceStock

us-gaap:ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities

us-gaap:ProceedsFromOtherDebt

us-gaap:ProceedsFromPaymentsForOtherFinancingActivities

us-gaap:ProceedsFromSaleOfAvailableForSaleSecuritiesDebt

us-gaap:ProceedsFromSaleOfOtherInvestments

us-gaap:ProceedsFromSaleOfTradingSecuritiesHeldforinvestment

us-gaap:ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodBeforeTax

us-gaap:ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax

us-gaap:ReinsuranceRecoverableCreditLossExpenseReversal

us-gaap:RepaymentsOfOtherDebt
us-gaap:Ownership, us-gaap:SubsequentEventType
us-gaap:SaleOfStockPercentageOfOwnershipAfterTransaction
us-gaap:AwardType
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
us-gaap:AwardType
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
us-gaap:StatementClassOfStock
us-gaap:StockIssuedDuringPeriodSharesNewIssues
us-gaap:SubsequentEventType
us-gaap:StockRepurchasedDuringPeriodShares
us-gaap:SubsequentEventType
us-gaap:StockRepurchasedDuringPeriodValue

us-gaap:SupplementalInformationForPropertyCasualtyInsuranceUnderwritersCurrentYearClaimsAndClaimsAdjustmentExpense

us-gaap:SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense

us-gaap:TreasuryStockSharesAcquired

us-gaap:TreasuryStockValueAcquiredCostMethod
us-gaap:StatementEquityComponents
dei:LegalEntity, us-gaap:ConsolidatedEntities
us-gaap:VariableInterestEntityOwnershipPercentage
dei:LegalEntity, us-gaap:ConsolidatedEntities, us-gaap:StatementClassOfStock
dei:LegalEntity, us-gaap:ConsolidatedEntities, us-gaap:SubsequentEventType
dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities
dei:LegalEntity, us-gaap:ConsolidatedEntities
acgl:AggregateExcessOfLossReinsuranceAgreement
dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities, us-gaap:SubsequentEventType
us-gaap:ConsolidatedEntities

acgl:AvailableForSaleInvestmentsCostOrAmortizedCostFixedMaturitiesAndShortTerm

acgl:AvailableForSaleInvestmentsFairValueFixedMaturitiesAndShortTerm

acgl:AvailableForSaleSecuritiesQualitativeDisclosureLargestSingleLoss

acgl:AvailableforSaleInvestmentsCostOrAmortizedCostFixedMaturitiesAndShortTerm

acgl:ContractHolderPayables

acgl:ContractholderDeductiblesReceivable

acgl:ContractholderReceivablesAllowanceForCreditLoss

acgl:DeferredTaxAssetLeaseLiability

acgl:DeferredTaxLIabilitiesRightOfUseAsset

acgl:DeferredTaxLiabilityContingencyReserve
us-gaap:EquityMethodInvestmentNonconsolidatedInvestee
acgl:EquityMethodInvestmentSummarizedFinancialInformationInvestedAssets
dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities, us-gaap:SubsequentEventType
acgl:ExcessOfLossAgreementAggregateLosses

acgl:FixedMaturitiesAndShortTermInvestmentsPledgedUnderSecuritiesLendingFairValue
us-gaap:FairValueByAssetClass
acgl:IndefinitelivedIntangibleAssetsExcludingGoodwillGrossAmount
acgl:SourcesOfFunding, dei:LegalEntity, us-gaap:ConsolidatedEntities
acgl:InitialCoverageAmount
acgl:SourcesOfFunding, dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities
acgl:SourcesOfFunding, dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities, us-gaap:SubsequentEventType
dei:LegalEntity, us-gaap:ConsolidatedEntities
us-gaap:ConsolidatedEntities

acgl:IntangibleAssetsGrossIncludingGoodwill

acgl:IntangibleAssetsIncludingGoodwillAccumulatedForeignCurrencyAndOtherAdjustments
us-gaap:FairValueByAssetClass
us-gaap:FairValueByAssetClass, us-gaap:FiniteLivedIntangibleAssetsByMajorClass
us-gaap:FairValueByAssetClass, us-gaap:IndefiniteLivedIntangibleAssetsByMajorClass

acgl:IntangibleAssetsLiabilitiesandGoodwillGross
us-gaap:FairValueByAssetClass
us-gaap:FairValueByAssetClass, us-gaap:FiniteLivedIntangibleAssetsByMajorClass
us-gaap:FairValueByAssetClass, us-gaap:IndefiniteLivedIntangibleAssetsByMajorClass

acgl:IntangibleAssetsLiabilitiesandGoodwillNet
us-gaap:FairValueByAssetClass
us-gaap:FairValueByAssetClass, us-gaap:FiniteLivedIntangibleAssetsByMajorClass
us-gaap:FairValueByAssetClass, us-gaap:IndefiniteLivedIntangibleAssetsByMajorClass
us-gaap:FairValueByLiabilityClass

acgl:InvestableAssets
us-gaap:ConsolidatedEntities
us-gaap:ConsolidationItems
us-gaap:StatementBusinessSegments

acgl:InvestmentCommitments
us-gaap:InvestmentType

acgl:InvestmentInOperatingAffiliateEquityMethod
us-gaap:EquityMethodInvestmentNonconsolidatedInvestee
us-gaap:ConsolidatedEntities
acgl:InvestmentInSubsidiaries

acgl:InvestmentsAccountedForUsingFairValueOption
dei:LegalEntity, us-gaap:ConsolidatedEntities
dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities
us-gaap:FinancialInstrument
us-gaap:FinancialInstrument, us-gaap:InvestmentSecondaryCategorization, us-gaap:InvestmentType
us-gaap:FinancialInstrument, us-gaap:InvestmentType
us-gaap:CreditFacility
acgl:LineOfCreditFacilityOptionalIncreasedCapacity

acgl:LloydsSyndicateUncrystallizedLossesDeferredTaxAsset
us-gaap:BusinessAcquisition, us-gaap:SubsequentEventType
acgl:NetReinsuranceToClosePortfolioTransfer
us-gaap:IncomeTaxAuthority
acgl:OperatingLossCarryforwardAnnualUtilizationLimit
us-gaap:IncomeTaxAuthority
acgl:OperatingLossCarryforwardPortionSubjecttoUtilizationLimits

acgl:OtherInvestmentsAndOtherFairValueOptionInvestments
us-gaap:InvestmentSecondaryCategorization, us-gaap:InvestmentType

acgl:PercentageOfTotalAssetsAndLiabilitiesMeasuredAtFairValuePricedUsingNonBindingBrokerQuotes
dei:LegalEntity, us-gaap:ConsolidatedEntities
acgl:RemainingRetentionNet
us-gaap:ConsolidatedEntities

acgl:RestrictedAssets
acgl:RestrictedAssetsRestrictionType
dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities, us-gaap:SubsequentEventType
acgl:SPVIssuanceOfInsuranceLinkedNotes

acgl:SecuritiesLendingInvestmentsPledgedAmortizedCost

acgl:SecuritiesReceivedAsCollateralAmortizedCost

acgl:ShortTermInvestmentsCostAmount
us-gaap:InvestmentType

acgl:TotalAssetsAndLiabilitiesMeasuredAtFairValue

acgl:TotalAssetsAndLiabilitiesMeasuredAtFairValuePricedUsingNonBindingBrokerQuotes

acgl:UnpaidReinsuranceRecoverablesandDeferredCharges
dei:LegalEntity, us-gaap:ConsolidatedEntities
acgl:VariableInterestEntityMaximumExposureToLossOffBalanceSheet
us-gaap:ConsolidatedEntities
dei:LegalEntity, us-gaap:ConsolidatedEntities
acgl:VariableInterestEntityMaximumExposureToLossOnBalanceSheetAssetLiabilityNet
us-gaap:ConsolidatedEntities
dei:LegalEntity, us-gaap:ConsolidatedEntities
acgl:VariableInterestEntityMaximumExposuretoLossOffBalanceSheet
dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities
us-gaap:ConsolidatedEntities
us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities
dei:LegalEntity, us-gaap:ConsolidatedEntities
acgl:VariableInterestEntityMaximumExposuretoLossOnBalanceSheetAssetLiabilityNet
dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities
us-gaap:ConsolidatedEntities
us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities

srt:PayablesToBrokerDealersAndClearingOrganizations
dei:LegalEntity, us-gaap:ConsolidatedEntities
dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities

us-gaap:AccruedInvestmentIncomeReceivable
dei:LegalEntity, us-gaap:ConsolidatedEntities
dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities
us-gaap:EquityMethodInvestmentNonconsolidatedInvestee
us-gaap:AssetsNet

us-gaap:AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
us-gaap:FinancialInstrument, us-gaap:InvestmentType
us-gaap:InvestmentType
us-gaap:FinancialInstrument, us-gaap:InvestmentType
us-gaap:AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
us-gaap:InvestmentType

us-gaap:AvailableForSaleDebtSecuritiesAmortizedCostBasis
us-gaap:FinancialInstrument, us-gaap:InvestmentType
us-gaap:InvestmentType

us-gaap:AvailableForSaleSecurities
us-gaap:FinancialInstrument, us-gaap:InvestmentType
us-gaap:InvestmentType

us-gaap:AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
us-gaap:InvestmentType

us-gaap:AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
us-gaap:FinancialInstrument, us-gaap:InvestmentType
us-gaap:InvestmentType

us-gaap:AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss
us-gaap:FinancialInstrument, us-gaap:InvestmentType
us-gaap:InvestmentType

us-gaap:AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLoss
us-gaap:FinancialInstrument, us-gaap:InvestmentType
us-gaap:InvestmentType

us-gaap:AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue
us-gaap:FinancialInstrument, us-gaap:InvestmentType
us-gaap:InvestmentType

us-gaap:AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss
us-gaap:FinancialInstrument, us-gaap:InvestmentType
us-gaap:InvestmentType

us-gaap:AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
us-gaap:FinancialInstrument, us-gaap:InvestmentType
us-gaap:InvestmentType

us-gaap:AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
us-gaap:FinancialInstrument, us-gaap:InvestmentType
us-gaap:InvestmentType
us-gaap:InvestmentType
us-gaap:AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost
us-gaap:InvestmentType
us-gaap:AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue
us-gaap:InvestmentType
us-gaap:AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost
us-gaap:InvestmentType
us-gaap:AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue
us-gaap:InvestmentType
us-gaap:AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost
us-gaap:InvestmentType
us-gaap:AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue
us-gaap:InvestmentType
us-gaap:AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate
us-gaap:InvestmentType
us-gaap:AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis
us-gaap:InvestmentType
us-gaap:AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost
us-gaap:InvestmentType
us-gaap:AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue
us-gaap:FinancialInstrument, us-gaap:InvestmentType
us-gaap:AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateAmortizedCost
us-gaap:FinancialInstrument, us-gaap:InvestmentType
us-gaap:AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue

us-gaap:AvailableForSaleSecuritiesDebtSecurities
dei:LegalEntity, us-gaap:ConsolidatedEntities
dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities
us-gaap:FinancialInstrument, us-gaap:InvestmentType
us-gaap:InvestmentType

us-gaap:ContractWithCustomerAssetAccumulatedAllowanceForCreditLoss
us-gaap:DebtInstrument, us-gaap:LongtermDebtType
us-gaap:DebtInstrumentFaceAmount
us-gaap:LongtermDebtType

us-gaap:DebtSecuritiesAvailableForSaleAllowanceForCreditLoss
us-gaap:FinancialInstrument, us-gaap:InvestmentType
us-gaap:InvestmentType

us-gaap:DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger
us-gaap:FinancialInstrument, us-gaap:InvestmentType
us-gaap:InvestmentType

us-gaap:DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss
us-gaap:FinancialInstrument, us-gaap:InvestmentType
us-gaap:InvestmentType

us-gaap:DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months
us-gaap:FinancialInstrument, us-gaap:InvestmentType
us-gaap:InvestmentType

us-gaap:DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss
us-gaap:FinancialInstrument, us-gaap:InvestmentType
us-gaap:InvestmentType

us-gaap:DebtSecuritiesAvailableForSaleUnrealizedLossPosition
us-gaap:FinancialInstrument, us-gaap:InvestmentType
us-gaap:InvestmentType

us-gaap:DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss
us-gaap:FinancialInstrument, us-gaap:InvestmentType
us-gaap:InvestmentType

us-gaap:DeferredIncomeTaxLiabilities

us-gaap:DeferredPolicyAcquisitionCosts
dei:LegalEntity, us-gaap:ConsolidatedEntities
dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities

us-gaap:DeferredTaxAssetsGoodwillAndIntangibleAssets

us-gaap:DeferredTaxAssetsGross

us-gaap:DeferredTaxAssetsOperatingLossCarryforwards
us-gaap:IncomeTaxAuthority
us-gaap:DeferredTaxAssetsTaxCreditCarryforwardsAlternativeMinimumTax

us-gaap:DeferredTaxAssetsTaxCreditCarryforwardsForeign
us-gaap:IncomeTaxAuthority

us-gaap:DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits

us-gaap:DeferredTaxAssetsTaxDeferredExpenseOther

us-gaap:DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsLossReserves

us-gaap:DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsOther

us-gaap:DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsReserves

us-gaap:DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsUnearnedPremiumsReserve

us-gaap:DeferredTaxAssetsUnrealizedCurrencyLosses

us-gaap:DeferredTaxLiabilitiesDeferredExpenseOtherCapitalizedCosts

us-gaap:DeferredTaxLiabilitiesInvestments

us-gaap:DeferredTaxLiabilitiesOther

us-gaap:DeferredTaxLiabilitiesOtherFiniteLivedAssets

us-gaap:DeferredTaxLiabilitiesTaxDeferredIncome
us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk, us-gaap:HedgingDesignation
us-gaap:DerivativeFairValueOfDerivativeAsset
us-gaap:HedgingDesignation

us-gaap:DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral
us-gaap:BalanceSheetLocation, us-gaap:DerivativeInstrumentRisk, us-gaap:HedgingDesignation
us-gaap:DerivativeFairValueOfDerivativeLiability
us-gaap:HedgingDesignation

us-gaap:DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral
us-gaap:DerivativeInstrumentRisk, us-gaap:HedgingDesignation
us-gaap:DerivativeNotionalAmount
us-gaap:AwardType
us-gaap:EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized

us-gaap:EquityMethodInvestments
us-gaap:InvestmentType
us-gaap:FairValueByAssetClass
us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue
us-gaap:FairValueByAssetClass, us-gaap:FairValueByMeasurementFrequency, us-gaap:InvestmentType
us-gaap:FairValueByAssetClass, us-gaap:InvestmentType
us-gaap:FairValueByMeasurementFrequency, us-gaap:InvestmentType
us-gaap:FairValueByLiabilityClass
us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue
us-gaap:FairValueByLiabilityClass, us-gaap:FairValueByMeasurementFrequency

us-gaap:FinanceLeaseLiabilityPaymentsDueNextTwelveMonths

us-gaap:FiniteLivedIntangibleAssetsAccumulatedAmortization
us-gaap:FairValueByAssetClass
us-gaap:FairValueByAssetClass, us-gaap:FiniteLivedIntangibleAssetsByMajorClass
us-gaap:FairValueByLiabilityClass

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseYearFive

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseYearFour

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseYearThree

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo
us-gaap:FairValueByAssetClass
us-gaap:FiniteLivedIntangibleAssetsGross
us-gaap:ConsolidatedEntities, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:FundsHeldUnderReinsuranceAgreementsLiability
us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:FairValueByAssetClass
us-gaap:GoodwillGross

us-gaap:Investments
us-gaap:ConsolidatedEntities

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByLiabilityClass, us-gaap:FairValueByMeasurementFrequency
us-gaap:LiabilitiesFairValueDisclosure
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency
us-gaap:FairValueByLiabilityClass, us-gaap:FairValueByMeasurementBasis, us-gaap:FairValueByMeasurementFrequency
us-gaap:FairValueByMeasurementBasis, us-gaap:FairValueByMeasurementFrequency

us-gaap:LiabilityForClaimsAndClaimsAdjustmentExpense
dei:LegalEntity, us-gaap:ConsolidatedEntities
dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities

us-gaap:LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet

us-gaap:LineOfCredit
dei:LegalEntity, us-gaap:ConsolidatedEntities
dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities
us-gaap:ConsolidatedEntities
us-gaap:ConsolidatedEntities, us-gaap:CreditFacility
us-gaap:CreditFacility
us-gaap:ConsolidatedEntities, us-gaap:CreditFacility
us-gaap:LineOfCreditFacilityCapacityAvailableForSpecificPurposeOtherThanForTradePurchases
us-gaap:ConsolidatedEntities, us-gaap:CreditFacility
us-gaap:LineOfCreditFacilityMaximumBorrowingCapacity
us-gaap:CreditFacility
us-gaap:LineOfCreditFacilityRemainingBorrowingCapacity

us-gaap:LongTermDebtFairValue
us-gaap:DebtInstrument, us-gaap:LongtermDebtType
dei:LegalEntity, us-gaap:ConsolidatedEntities, us-gaap:Ownership
us-gaap:MinorityInterestOwnershipPercentageByNoncontrollingOwners
dei:LegalEntity, us-gaap:Ownership
dei:LegalEntity, us-gaap:Ownership, us-gaap:StatementClassOfStock
dei:LegalEntity, us-gaap:Ownership, us-gaap:StatementClassOfStock, us-gaap:StatementEquityComponents
us-gaap:Ownership, us-gaap:OtherOwnershipInterestsByName, us-gaap:SubsequentEventType

us-gaap:ObligationToReturnSecuritiesReceivedAsCollateral
us-gaap:AssetsSoldUnderAgreementsToRepurchaseMaturityPeriods
us-gaap:AssetsSoldUnderAgreementsToRepurchaseMaturityPeriods, us-gaap:FinancialInstrument
us-gaap:FinancialInstrument

us-gaap:OperatingLeaseWeightedAverageDiscountRatePercent
us-gaap:IncomeTaxAuthority
us-gaap:OperatingLossCarryforwards

us-gaap:OtherInvestments
us-gaap:InvestmentSecondaryCategorization, us-gaap:InvestmentType
us-gaap:InvestmentType

us-gaap:OtherInvestmentsAndSecuritiesAtCost

us-gaap:OtherLiabilities
dei:LegalEntity, us-gaap:ConsolidatedEntities
dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities
us-gaap:ConsolidatedEntities
dei:LegalEntity
us-gaap:OtherRestrictedAssets

us-gaap:OtherShortTermInvestments
us-gaap:InvestmentType

us-gaap:PolicyholderContractDeposits

us-gaap:PreferredStockValue

us-gaap:PremiumsReceivableAllowanceForDoubtfulAccounts

us-gaap:PremiumsReceivableAtCarryingValue
dei:LegalEntity, us-gaap:ConsolidatedEntities
dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities

us-gaap:PrepaidReinsurancePremiums
dei:LegalEntity, us-gaap:ConsolidatedEntities
dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities

us-gaap:PurchaseCommitmentRemainingMinimumAmountCommitted

us-gaap:ReceivablesFromBrokersDealersAndClearingOrganizations
dei:LegalEntity, us-gaap:ConsolidatedEntities
dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities

us-gaap:RedeemableNoncontrollingInterestEquityFairValue

us-gaap:RedeemableNoncontrollingInterestEquityPreferredCarryingAmount
dei:LegalEntity
dei:LegalEntity, us-gaap:ConsolidatedEntities
dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities

us-gaap:ReinsurancePayable
dei:LegalEntity, us-gaap:ConsolidatedEntities
dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities

us-gaap:ReinsuranceRecoverableForUnpaidClaimsAndClaimsAdjustments
us-gaap:ConsolidationItems
us-gaap:MajorCustomers, us-gaap:ProductOrService
us-gaap:ProductOrService
us-gaap:ProductOrService, us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments
dei:LegalEntity, us-gaap:ConsolidatedEntities
us-gaap:ReinsuranceRecoverables
us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:ReinsuranceRecoverablesAllowance

us-gaap:ReinsuranceRecoverablesGross

us-gaap:ReinsuranceRecoverablesOnPaidAndUnpaidLosses
dei:LegalEntity, us-gaap:ConsolidatedEntities
dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities
us-gaap:ConsolidatedEntities, us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:RestrictedCashAndCashEquivalents

us-gaap:SecuredBorrowingsGrossIncludingNotSubjectToMasterNettingArrangement

us-gaap:SecuritiesLoanedCollateralRightToReclaimCash

us-gaap:SecuritiesLoanedCollateralRightToReclaimSecurities

us-gaap:SecuritiesReceivedAsCollateral
us-gaap:Collateral

us-gaap:SecurityOwnedAndPledgedAsCollateralFairValue

us-gaap:SeniorLongTermNotes
dei:LegalEntity, us-gaap:ConsolidatedEntities
dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities
us-gaap:ConsolidatedEntities
us-gaap:DebtInstrument, us-gaap:LongtermDebtType
us-gaap:LongtermDebtType
us-gaap:AwardType
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue
us-gaap:AwardType
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice
us-gaap:AwardType
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableAggregateIntrinsicValue
us-gaap:AwardType
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue
us-gaap:AwardType
us-gaap:SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue

us-gaap:ShortdurationInsuranceContractsDiscountedLiabilitiesAggregateDiscount
us-gaap:ProductOrService, us-gaap:StatementBusinessSegments
us-gaap:ShortdurationInsuranceContractsHistoricalClaimsDurationYearEight
us-gaap:StatementBusinessSegments
us-gaap:ProductOrService, us-gaap:StatementBusinessSegments
us-gaap:ShortdurationInsuranceContractsHistoricalClaimsDurationYearFive
us-gaap:StatementBusinessSegments
us-gaap:ProductOrService, us-gaap:StatementBusinessSegments
us-gaap:ShortdurationInsuranceContractsHistoricalClaimsDurationYearFour
us-gaap:StatementBusinessSegments
us-gaap:ProductOrService, us-gaap:StatementBusinessSegments
us-gaap:ShortdurationInsuranceContractsHistoricalClaimsDurationYearNine
us-gaap:ProductOrService, us-gaap:StatementBusinessSegments
us-gaap:ShortdurationInsuranceContractsHistoricalClaimsDurationYearOne
us-gaap:StatementBusinessSegments
us-gaap:ProductOrService, us-gaap:StatementBusinessSegments
us-gaap:ShortdurationInsuranceContractsHistoricalClaimsDurationYearSeven
us-gaap:StatementBusinessSegments
us-gaap:ProductOrService, us-gaap:StatementBusinessSegments
us-gaap:ShortdurationInsuranceContractsHistoricalClaimsDurationYearSix
us-gaap:StatementBusinessSegments
us-gaap:ProductOrService, us-gaap:StatementBusinessSegments
us-gaap:ShortdurationInsuranceContractsHistoricalClaimsDurationYearTen
us-gaap:StatementBusinessSegments
us-gaap:ProductOrService, us-gaap:StatementBusinessSegments
us-gaap:ShortdurationInsuranceContractsHistoricalClaimsDurationYearThree
us-gaap:StatementBusinessSegments
us-gaap:ProductOrService, us-gaap:StatementBusinessSegments
us-gaap:ShortdurationInsuranceContractsHistoricalClaimsDurationYearTwo
us-gaap:StatementBusinessSegments

us-gaap:ShortdurationInsuranceContractsLiabilityForUnpaidClaimsAndAllocatedClaimAdjustmentExpenseNet
us-gaap:ProductOrService
us-gaap:ProductOrService, us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments
us-gaap:ProductOrService, us-gaap:StatementBusinessSegments
us-gaap:ShortdurationInsuranceContractsLiabilityForUnpaidClaimsAndAllocatedClaimAdjustmentExpenseNetNotSeparatelyPresented
us-gaap:StatementBusinessSegments

us-gaap:ShortdurationInsuranceContractsLiabilityForUnpaidClaimsAndClaimAdjustmentExpenseAggregateReconcilingItems

us-gaap:ShortdurationInsuranceContractsLiabilityForUnpaidClaimsAndClaimAdjustmentExpenseOtherReconcilingItem

us-gaap:ShortdurationInsuranceContractsLiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseAccumulatedUnallocatedClaimAdjustmentExpense
us-gaap:ConsolidatedEntities, us-gaap:StatutoryAccountingPracticesByJurisdiction
us-gaap:StatutoryAccountingPracticesStatutoryAmountAvailableForDividendPayments
us-gaap:ConsolidatedEntities, us-gaap:StatutoryAccountingPracticesByJurisdiction
us-gaap:StatutoryAccountingPracticesStatutoryAmountAvailableForDividendPaymentsWithoutRegulatoryApproval
us-gaap:StatutoryAccountingPracticesByJurisdiction
us-gaap:StatutoryAccountingPracticesStatutoryCapitalAndSurplusBalance
us-gaap:StatutoryAccountingPracticesByJurisdiction
us-gaap:StatutoryAccountingPracticesStatutoryCapitalAndSurplusRequired
us-gaap:StatementClassOfStock
us-gaap:StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1
us-gaap:SubsequentEventType
us-gaap:SupplementalInformationForPropertyCasualtyInsuranceUnderwritersByAffiliationWithRegistrant
us-gaap:SupplementalInformationForPropertyCasualtyInsuranceUnderwritersDeferredPolicyAcquisitionCosts
us-gaap:SupplementalInformationForPropertyCasualtyInsuranceUnderwritersByAffiliationWithRegistrant
us-gaap:SupplementalInformationForPropertyCasualtyInsuranceUnderwritersDiscountDeductedFromReserves
us-gaap:SupplementalInformationForPropertyCasualtyInsuranceUnderwritersByAffiliationWithRegistrant
us-gaap:SupplementalInformationForPropertyCasualtyInsuranceUnderwritersReservesForUnpaidClaimsAndClaimsAdjustmentExpense
us-gaap:SupplementalInformationForPropertyCasualtyInsuranceUnderwritersByAffiliationWithRegistrant
us-gaap:SupplementalInformationForPropertyCasualtyInsuranceUnderwritersUnearnedPremiums

us-gaap:SupplementaryInsuranceInformationDeferredPolicyAcquisitionCosts
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments

us-gaap:SupplementaryInsuranceInformationLiabilityForFuturePolicyBenefitsLossesClaimsAndLossExpenseReserves
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments

us-gaap:SupplementaryInsuranceInformationUnearnedPremiums
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:StatementBusinessSegments

us-gaap:TreasuryStockShares
us-gaap:BalanceSheetLocation, us-gaap:FinancialInstrument
us-gaap:USGovernmentAgenciesSecuritiesAtCarryingValue

us-gaap:UnearnedPremiums
dei:LegalEntity, us-gaap:ConsolidatedEntities
dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities

us-gaap:VariableInterestEntityEntityMaximumLossExposureAmount
dei:LegalEntity, us-gaap:ConsolidatedEntities
dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities
us-gaap:ConsolidatedEntities
us-gaap:InvestmentType
us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities

Plots across concepts


IncomeStatement
Other Comprehensive Income Loss Net Of Tax
Expenses
General And Administrative Expense
Balance Sheet
Operating Lease Liability
Assets
Cash And Cash Equivalents At Carrying Value
Current Assets
Cash And Cash Equivalents At Carrying Value
NonCurrent Assets
Finite Lived Intangible Assets Net
Liabilities
Operating Lease Liability
Noncurrent Liabilities
Minority Interest
Stockholders Equity
Common Stock Value
CashFlow
Net Cash Provided By Used In Investing Activities
NetCashProvidedByUsedInOperatingActivities
Share Based Compensation
NetCashProvidedByUsedInInvestingActivities
Net Cash Provided By Used In Investing Activities
NetCashProvidedByUsedInFinancingActivities
Proceeds From Payments For Other Financing Activities
Shares
Treasury Stock Shares
DividendsAndRepurchase
Dividends Preferred Stock
LesseeOperatingLeaseLiabilityPaymentsDue
Lessee Operating Lease Liability Undiscounted Excess Amount
FiniteLivedIntangibleAssets
Finite Lived Intangible Assets Net

Tables

  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:CommonStockValue ██████▇▇▇▇▇▇▇▇▆▆▆▄▄▄▄▄▄▄▄▃▃▃▃▃▃▃▃▃▃▂▂▂▂▂▁▁▁0.6470.6450.6430.6420.6420.6420.6380.6380.6380.6360.6340.6330.6330.630.6110.610.6090.5830.5820.5820.5810.5790.5770.5760.5760.5730.5720.5710.570.5670.5650.5650.5640.5610.5610.5560.5560.5520.5490.5440.5410.5350.534NANANA
us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding ▁█406.485994409.223253NA409.194657408.119681414.03357NA413.180201410.899483408.971029NA411.721214413.111205139.297934NA134.885451139.244646139.047672NA124.931653124.365596124.496496NA125.011773125.88542128.451054NA135.876605136.889944136.562717NA136.034413135.84905135.409288NA138.696934138.211736137.814906NA137.140929137.97559946.820172NA153.546027159.79590955.513827
us-gaap:WeightedAverageNumberOfSharesOutstandingBasic ▁█397.743402400.807895NA402.850485402.503687403.892161NA402.564121401.482784400.184404NA402.939092404.800421135.846576NA134.885451134.486664134.034927NA120.938916120.59906120.428179NA120.56741121.719214124.209276NA131.945962132.650634131.85791NA131.495296131.377274130.907902NA135.06736134.529129133.954623NA131.560851131.23226944.499747NA146.993373152.9626253.039026
us-gaap:EarningsPerShareBasic ▄▃▄▃▃▂▃▃▃▃▂▂▃▃▄▁▄▅▂▅▄▄▂▃▃▅▄▄▄▄▄▃▄▅▂▄▄▄▃▄▃▂▄▃▄█1.671.071.321.010.720.330.780.951.141.090.310.540.581.011.5-0.391.291.80.512.051.71.240.440.620.912.241.651.691.531.341.190.831.311.920.11.361.581.181.031.240.70.431.590.961.553.97
us-gaap:EarningsPerShareDiluted ▄▃▄▃▃▂▃▃▄▃▂▃▃▃▄▁▄▅▂▅▄▄▂▃▃▅▄▄▄▄▄▃▄▅▂▄▄▄▃▄▃▂▄▃▄█1.631.051.31.00.710.320.760.921.121.070.310.530.560.991.46-0.391.251.740.51.981.651.20.420.60.882.161.61.641.481.31.140.81.261.850.11.331.541.141.01.190.670.411.510.921.483.79
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:BenefitsLossesAndExpenses █████▇▆▅▅▅▅▄▄▄▄▆▄▄▃▃▃▃▃▃▃▂▂▂▃▂▂▂▂▂▃▂▁▂▁▁▂▂▁▂▁▁1824.6291826.6831753.0691800.7811799.3191594.5571403.451245.3551248.8231181.4621260.6841121.6621130.7941095.6561162.5031516.5821174.2691016.744904.951880.65927.664894.739862.548858.886887.053760.909801.803762.821816.654763.348746.134738.927669.779628.812913.009709.702621.433648.85609.379598.272678.957749.687594.906646.121531.444621.14
us-gaap:ComprehensiveIncomeNetOfTax █▄█▆▇▂▅▆▇█▄▄▄▃▄▂▅▅▁▄▅▅▃▂▃▅▄▃▅▄▄▄▁▄▂▅▄▄699.705155.089646.082455.907626.366-46.03326.76397.34637.458665.571178.817200.524183.548.162203.00217.585279.285351.991-160.28208.79273.26272.92932.26823.40124.208312.503241.83496.978318.18231.255194.499206.102-101.945199.022-17.898320.691178.897244.801NANANANANANANANA
us-gaap:ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest █▄▇▆█▁▅▅▇▇▄▄▄▃▄▃▅▅▂▅▅▅▃▃▃▅▄▄▅▄▄▄▂▄▃▅▄▄▄▃▄▃▃▅▅▄742.893188.071713.041536.37814.045-311.879316.008403.312657.24716.6898.209220.724195.12463.45190.1035.613293.141372.907-138.646259.597311.52293.61.5267.27234.237337.924233.80491.567321.881227.9194.499206.102-101.945199.022-17.898320.691178.897244.801150.61951.98136.52146.65850.245363.17275.72219.43
us-gaap:DeferredPolicyAcquisitionCostAmortizationExpense █▇▆▅▆▅▅▄▄▄▄▄▄▄▄▄▄▃▃▃▃▃▃▃▃▃▃▃▃▃▃▂▂▂▂▂▂▁▂▁▁▁▁▁▁▁335.143304.481254.828247.942254.789247.283221.888211.12210.089197.848209.319201.602202.838191.376208.879193.854190.436182.289168.426163.861175.281170.465171.409171.566175.425163.076175.215163.547158.158160.342157.521147.313131.677127.592133.568128.065128.289118.962123.339120.205110.639108.754104.824111.279107.475117.624
us-gaap:GeneralAndAdministrativeExpense ▃▅▅▃▃▄▅▃▃▃▅▂▄▃▂▃▅▆█▃▃▁▂▁▃15.95125.38425.33517.93717.9220.79626.83717.06118.25117.96226.83514.33522.51215.31213.98617.09824.87627.79236.67818.48517.29.38312.24310.73917.418NANANANANANANANANANANANANANANANANANANANANA
us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest █▅▇▆▆▁▄▅▆▆▂▄▄▃▄▁▄▄▂▄▄▃▂▂▃▄▃▄▃▃▃▃▃▄▂▃▃▃▃▃▂▂▄▃▄745.367439.111633.373512.389492.516-60.729340.104437.305530.317541.38491.336282.122280.015188.299258.605-37.028233.268302.43283.276316.851263.488191.93739.45673.704132.599321.435212.648229.71219.006182.883176.944122.221182.011261.3297.097195.097221.035166.158138.295166.72196.61124.923230.607151.231244.871NA
us-gaap:IncomeTaxExpenseBenefit ▇▆▆▅▅▅▅▆▇▇▆▆▅▄█▃▆▅▁▄▄▄▃▃▃▄▃▃▃▃▄▃▃▃▁▃▂▂▂▂▂▂▂▃▂▃51.17938.8634.05923.70726.12727.94527.33638.11644.47245.88635.01233.35623.66821.91556.8138.18934.16928.397-12.29813.23114.13116.3111.459.7046.7812.6785.5146.4467.2893.73815.4547.3965.0714.853-12.125.4410.7671.902-4.977-2.267-1.731-0.371-3.5053.21.426.753
us-gaap:IncomeTaxesPaidNet █▃▅█▃▃▅▃▆▂▄▃▃▁▃▅▃▃▃▃▄▃134.07.156.14136.43.07.462.3633.676.2-32.733.0212.53.4-49.93.88144.03.20.79.92114.124.12.5NA9.522.43.6NA5.06.71.67.72.83.51.3-2.3-0.21.52.8-7.73.62.33.73.12.0NANA
us-gaap:InsuranceCommissionsAndFees ▃▃▃▂▃▃▃▂▃▃▁▃▂▂▅▃▂▂▆▃█▂▃▃▃▄▂▁▂▁▃▁▁▁▃▁▁▁▁▁▁▁▂▁▁▁5.5296.117.8525.4136.6676.8526.7573.3265.9538.8250.0275.8233.8745.34914.7346.0644.8224.63318.9227.9825.2245.0478.6217.6237.71711.5364.8251.7022.0331.5825.6730.5260.9020.5385.6641.0770.8060.5430.9820.8480.7840.8152.8140.8740.8830.794
us-gaap:InterestExpense ▇▇▇█▆▆▆▆▆▆▆▆▆▆▆▆▆▆▄▃▃▃▃▃▁▃▃▁▃▃▂▁▁▁▁▂▂▂▂▂▂▂▂▂▂▂35.738.34638.41941.34331.13932.55531.19931.32829.2829.06529.77429.7330.34430.63630.49629.5128.74928.67618.53915.94315.66316.10715.82713.34.01112.73612.7444.15214.33414.4049.3735.9375.8525.8986.1877.3787.4397.5218.0878.1257.7587.7217.467.3717.9167.26
us-gaap:InterestExpenseDebt NANANA3.250.86.6NA7.754.76.2NA67.660.97.9NA64.658.05.8NANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:InterestPaidNet █▁73.71.0NANA50.86.6NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:NetIncomeLoss █▆▇▅▄▃▅▅▆▆▃▄▄▃▃▁▃▄▂▄▃▃▂▂▂▄▃▄▃▃▃▂▃▄▂▃▄▃▃▃▂▂▄▃▄▃675.486438.156543.544419.039298.821144.117326.384392.453468.954448.528136.494227.408243.646150.423214.64-33.656185.167253.12774.013252.872211.055154.79858.57980.033115.79283.336215.164228.675208.016182.5161.49114.825176.94256.47619.217189.656220.268164.256143.272168.98898.34225.756234.112148.031243.451216.994
us-gaap:NetIncomeLossAttributableToNoncontrollingInterest ▆▆▆▆█▁▅▅▅▆▄▅▅▅▅▅▅▅▅▆▆▅▅▅▅▆▅▅▅▅▅▅▅▅43.17837.55255.7769.643167.568-232.791-13.6166.73616.89146.97-80.1721.35812.70115.961-12.848-11.56113.93220.90821.56150.74838.30220.829-30.573-16.03310.02925.421-8.03-5.4113.701-3.3550.00.00.00.0NANANANANANANANANANANANA
us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic █▆▇▆▄▃▅▅▆▆▃▄▄▃▄▁▃▄▂▄▄▃▂▂▃▄▄▄▃▃▃▃▃▄▂▃▄▃▃▃▂▂▄▃▄▄663.82427.753533.141408.636288.418133.714315.981382.05458.551438.125126.091217.006233.243137.276203.535-52.76173.818241.90962.396247.388205.57149.31453.09474.549110.305277.852209.679223.191202.531177.016156.005109.341171.455250.99213.732184.172212.619157.795136.811162.52791.88119.295227.651141.57236.99210.533
us-gaap:OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax ▅▂█▆▇▁▇▃▅▅▃▅▄▅▆▅▆▅▄▄▃▆▄▄▆▃▄▃▆▅▅▇▄▂▅▆▃▆6.205-28.58439.06516.70922.251-44.68924.751-16.4244.2675.516-15.582.063-12.5951.28217.3138.2818.2973.124-14.231-5.312-18.15117.313-10.851-12.08211.58-22.757-12.091-23.59510.021-1.3491.31729.523-5.407-28.2225.73113.978-15.13613.201NANANANANANANANA
us-gaap:OtherComprehensiveIncomeLossNetOfTax ▄▁▅▅█▂▄▄▆▇▅▄▃▃▄▅▅▅▂▄▅▅▄▄▃▄▄▃▅▅▅▅▁▄▄▆▄▅24.229-287.637113.72747.688347.656-223.2053.244.123171.395221.18241.885-28.042-61.223-102.934-11.68950.8394.04298.872-234.22-44.02362.163117.973-26.48-56.728-91.58229.16726.67-131.697110.16448.75533.00991.277-278.885-57.454-37.115131.035-41.37180.545NANANANANANANANA
us-gaap:PolicyholderBenefitsAndClaimsIncurredNet ▇█▇██▇▅▅▄▄▅▄▄▃▄▇▄▃▃▂▃▂▂▂▂▂▂▂▂▂▂▂▁▁▃▂▁▁▁▂▂▂▁▁▁▂1159.8311203.11127.3851216.2731230.5221115.419844.922802.455767.543718.532827.673699.42726.153636.86678.8751046.141689.86552.57553.875524.183584.592522.949506.02531.741519.426493.716495.819501.673485.518436.24434.323427.045418.653399.403622.506443.871399.693395.207378.067423.984431.622493.88367.326359.193363.145428.051
us-gaap:PreferredStockDividendsIncomeStatementImpact NANA10.40310.40310.40310.40310.40310.40310.40310.40310.40310.40210.40310.43711.10512.36911.34911.21811.6175.4845.4855.4845.4855.4845.4855.484NANANANANANANANANANANANANANANANANANANANA
us-gaap:PremiumsEarnedNet █▇▇▆▆▆▅▅▅▄▄▄▄▄▄▄▄▃▃▃▃▃▂▂▂▂▂▂▂▂▂▂▂▂▂▂▁▁▁▁▁▁▁▁▁▁2120.9091948.4221811.0451771.0921665.3541744.4441515.8821438.0231463.7271368.8661369.4351290.8781336.7631234.8991224.7551261.8861240.8741117.017968.855958.4031005.985951.579943.52936.683943.438910.264923.165903.651907.152859.78839.366795.0758.816752.77779.481748.691726.656680.312673.192682.049642.879633.695632.146627.409623.011669.917
us-gaap:ProfitLoss █▆▇▆▆▁▅▅▆▆▃▄▄▃▄▁▃▄▂▄▄▃▂▂▃▄▄▄▄▃▃▃▃▄718.664475.708599.314488.682466.389-88.674326.384399.189485.845495.498136.494248.766256.347166.384214.64-45.217199.099274.03574.013303.62249.357175.62758.57964.0125.819308.757207.134223.264211.717179.145161.49114.825176.94256.476NANANANANANANA25.756NANANA216.994
us-gaap:Revenues █▇▇▇▇▄▅▅▅▅▃▄▄▃▄▄▄▃▂▃▃▂▂▂▂▂▂▂▂▂▂▁▁▂▂▂▁▁▁▁▁▁▁▁▁▁2569.9962265.7942386.4422313.172291.8351533.8281743.5541682.661779.141722.8461352.021403.7841410.8091283.9551421.1081479.5541407.5371319.176988.2271197.5011191.1521086.676902.004932.591019.6521082.3441014.451992.5311035.66946.231923.078861.148851.79890.141920.106904.799842.468815.008747.674764.993775.568775.072825.513797.352776.315844.887
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:Assets █▇▇▇▇▆▆▆▅▅▅▅▅▅▅▅▄▄▄▃▃▃▃▃▃▃▂▃▃▂▂▂▂▂▁▂▂▁▁▁▁▁▁46481.88644204.26743282.29742716.03541199.64838416.12637885.36135572.60334851.6733977.03732218.32932252.53431853.1232131.95532051.65832624.79730862.63930092.22629372.10925643.23124411.91724541.36923177.2723770.59223084.92522849.6822009.54322610.68522573.51521800.35819566.09418930.82318917.68318757.06117816.76218889.75718496.72317812.78317141.76917430.02817213.80617191.96615770.792NANANA
us-gaap:Liabilities ██▇▇▇▆▆▅▅▅▅▅▅▅▅▅▄▄▄▃▃▃▃▃▃▂▂▂▂▂▂▂▂▂▁▂▂▂▁▂▂▂▁31519.40730173.26129294.85629448.28328472.74826500.72125569.80923510.79423032.49622817.97721780.6521814.43321622.10721921.45821805.72322646.92620880.5620412.55220060.98417250.64216714.0417167.59316028.37616628.52615947.53415551.7814890.89715528.215332.4514895.49513918.59813487.53813683.36513421.53112647.88413540.96313476.40712973.32712513.28312955.65712772.53712866.43111257.789NANANA
us-gaap:LiabilitiesAndStockholdersEquity █▇▇▇▇▆▆▆▅▅▅▅▅▅▅▅▄▄▄▃▃▃▃▃▃▃▂▃▃▂▂▂▂▂▁▂▂▁▁▁▁▁▁46481.88644204.26743282.29742716.03541199.64838416.12637885.36135572.60334851.6733977.03732218.32932252.53431853.1232131.95532051.65832624.79730862.63930092.22629372.10925643.23124411.91724541.36923177.2723770.59223084.92522849.6822009.54322610.68522573.51521800.35819566.09418930.82318917.68318757.06117816.76218889.75718496.72317812.78317141.76917430.02817213.80617191.96615770.792NANANA
us-gaap:StockholdersEquity █▇▇▇▇▆▆▆▆▅▅▅▄▄▄▄▄▄▄▃▃▂▂▂▂▂▂▂▂▂▂▂▁▂▁▂▁▁▁13986.07213096.47213105.88612451.99711991.82511367.24411497.37111158.09610757.35210114.5969439.8279355.1489163.7559150.3729196.6028911.1448898.8878605.8448253.7187352.3226703.9226413.5876204.8816162.8156137.5156288.7026130.0536081.0466229.3995892.1335647.4965443.2855234.3185335.535168.8785348.7945020.3164839.4564592.074NANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:CashAndCashEquivalentsAtCarryingValue ▆▄▄▅▄▄▃▄▃▃▃▃▂▃▃▄▃▃▄▂▂▂▂▃▂▂▂▃▄█▂▂▁▁▁▁▁▁▁▁▁▁▁▁▁▁1234.059941.951906.448976.398854.259882.284726.23880.099605.316633.1646.556651.037526.628680.891606.199862.361740.32703.754842.942578.816516.591557.961553.326649.779525.074471.012485.702663.726926.4431569.605434.057436.141375.119356.767371.041422.44355.392422.806351.699369.895411.001406.877362.74365.997341.469338.708
us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents █▅▅▄▄▄▃▃▂▂▂▂▁▂▂▃▃▂▃1818.4631367.5141290.5441186.9731064.6831070.437903.698962.475683.075710.216724.643709.819583.109732.256727.284980.614895.815809.763969.569NANANA681.095NANANANANANANANANANANANANANANANANANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:AmortizationOfIntangibleAssets ▄▃▅▄▄▄▅▅▅▅▇▇▇▇████▁▁▁▁15.28614.40219.19616.71516.48916.63121.8920.00319.79420.41726.14726.31526.47226.73631.83631.82430.82431.2944.8424.8654.884.748NANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:Goodwill NANA314.629NANANA326.551NANANA249.62NANANA198.236NANANA204.021NANANA15.536NANANA14.946NANANA0.0NANANA0.0NANANANANANANANANANANA
 us-gaap:Goodwill us-gaap:FairValueByAssetClass us-gaap:GoodwillNANA314.629NANANA326.551NANANA249.62NANANA198.236NANANA204.021NANANA15.536NANANA14.946NANANANANANANANANANANANANANANANANANANA
us-gaap:IndefiniteLivedIntangibleAssetsExcludingGoodwill NANA79.219NANANA85.91NANANA61.874NANANA68.174NANANA68.174NANANA33.524NANANA33.524NANANA16.666NANANA16.666NANANANANANANANANANANA
 us-gaap:IndefiniteLivedIntangibleAssetsExcludingGoodwill us-gaap:FairValueByAssetClass us-gaap:IndefinitelivedIntangibleAssetsNANA79.219NANANA85.91NANANA61.874NANANA68.174NANANA68.174NANANA33.524NANANA33.524NANANANANANANANANANANANANANANANANANANA
us-gaap:FiniteLivedIntangibleAssetsNet NANA299.015NANANA325.621NANANA323.426NANANA386.201NANANA509.358NANANA48.471NANANA61.069NANANA10.653NANANA21.593NANANANANANANANANANANA
 us-gaap:FiniteLivedIntangibleAssetsNet us-gaap:FairValueByAssetClass us-gaap:FiniteLivedIntangibleAssetsNANA299.015NANANA325.621NANANA323.426NANANA386.201NANANA509.358NANANA48.471NANANA61.069NANANANANANANANANANANANANANANANANANANA
us-gaap:IntangibleAssetsNetIncludingGoodwill ▇▇▇▇▇▇█▇▇▇▇▆▆▇▇▇▇██▂▂▂▂▂▂▂▂▂▂▂▁▁▁667.153679.509692.863713.777688.49705.45738.083624.5641.01659.215634.92566.662593.008626.004652.611684.405712.975750.315781.55390.94188.32792.6797.531103.62102.518106.745109.539111.528118.721120.87527.328.9630.96NA38.3NANANANANANANANANANANA
us-gaap:DeferredTaxAssetsLiabilitiesNet █▄▁▂93.048.115.72229.7NANANANANANA22.50217.29.728.139.562248.3221.1227.5221.237124.1113.0123.7135.694139.9143.9124.7130.992155.8151.5151.2128.561143.8140.7112.298.58293.699.297.667.45766.755.480.766.0NANANA
 us-gaap:OperatingLeaseRightOfUseAsset us-gaap:BalanceSheetLocation us-gaap:OtherAssetsNANA115.911NA119.494127.766131.661131.424134.061140.741NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:EquitySecuritiesFvNi █▇▇▇▆▅▄▂▃▂▁▂1693.5521532.9061444.831502.0151257.3171181.903838.925550.485670.943495.895338.899444.118NANA495.804NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:AccruedIncomeTaxesCurrent NANA9.2NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:MinorityInterest ██▇▇▆▅▇██▇▇███▇███▇▇▇▇▇▇▇▇▇▇▇▇▁▁▁▁▁918.874876.864823.007757.92679.089492.785762.777854.924855.347838.081791.56876.754861.153854.112843.411860.898877.456868.186851.854834.808788.589754.915738.831774.162794.88789.594769.081782.02792.34793.4960.00.00.00.00.0NANANANANANANANANANANA
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo NANA30.357NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearThree NANA25.828NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour NANA19.48NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFive NANA13.017NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive NANA31.318NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:StockholdersEquity █▇▇▇▇▆▆▆▆▅▅▅▄▄▄▄▄▄▄▃▃▂▂▂▂▂▂▂▂▂▂▂▁▂▁▂▁▁▁13986.07213096.47213105.88612451.99711991.82511367.24411497.37111158.09610757.35210114.5969439.8279355.1489163.7559150.3729196.6028911.1448898.8878605.8448253.7187352.3226703.9226413.5876204.8816162.8156137.5156288.7026130.0536081.0466229.3995892.1335647.4965443.2855234.3185335.535168.8785348.7945020.3164839.4564592.074NANANANANANANA
us-gaap:StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest █▇▇▇▇▆▆▆▆▅▅▅▅▅▅▅▅▄▄▄▃▃▃▃▃▃▃▃▃▃▂▂▂▂▂▂▁▁▁▁▁▁▁14904.94613973.33613928.89313209.91712670.91411860.02912260.14812013.0211612.69910952.67710231.38710231.90210024.90810004.48410040.0139772.0429776.3439474.039105.5728187.137492.5117168.5026943.7126936.9776932.3957078.2966899.1346863.0667021.7396685.6295647.4965443.2855234.3185335.535168.8785348.7945020.3164839.4564628.4864474.3714441.2694325.5354513.003NANANA
us-gaap:CommonStockValue ██████▇▇▇▇▇▇▇▇▆▆▆▄▄▄▄▄▄▄▄▃▃▃▃▃▃▃▃▃▃▂▂▂▂▂▁▁▁0.6470.6450.6430.6420.6420.6420.6380.6380.6380.6360.6340.6330.6330.630.6110.610.6090.5830.5820.5820.5810.5790.5770.5760.5760.5730.5720.5710.570.5670.5650.5650.5640.5610.5610.5560.5560.5520.5490.5440.5410.5350.534NANANA
us-gaap:AdditionalPaidInCapitalCommonStock ██████▇▇▇▇▇▇▇▇▅▅▅▃▃▂▂▂▂▂▂▂▂▂▂▂▂▂▂▁▁▁▁▁▁▁▁▁▁2028.9192014.7411977.7941950.7821935.5141921.4871889.6831864.4681847.9491819.6051793.7811775.4991760.6061737.9781230.6171212.961196.884548.053531.687516.204517.942485.943467.339450.948437.533399.757383.073366.408353.208320.503299.517283.449272.955242.492227.778200.607187.013170.694161.419150.882142.001120.109110.325NANANA
us-gaap:RetainedEarningsAccumulatedDeficit █▇▇▇▆▆▆▆▆▅▅▅▅▄▄▄▄▄▄▄▄▃▃▃▃▃▃▃▃▂▂▂▂▂▂▂▂▁▁▁▁▁▁13454.03612790.21612362.46311829.32211420.68611132.26811021.00610705.02510322.9759864.4249426.2999300.2089083.2028849.9598562.8898359.3548412.1148238.2967996.7017972.6437725.2557519.6857370.3717317.2777242.7287132.4236854.5716644.8926421.7016219.176042.1545886.1495776.8085605.3535354.3615351.2415167.0694954.454833.0674696.2564533.7294441.8484422.553NANANA
us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax ▅▅█▇▇▃▅▅▅▄▁▁▁▂▄▄▄▃▂▄▅▄▃▃▄▅▄▄▅▄▄▄▃▅▆▆▅▅▅▅▆▅▅230.048205.827488.895386.357349.48821.944212.091211.714206.82738.323-178.72-221.041-194.157-134.009118.044129.68278.441-15.677-114.541119.752163.834101.629-16.5029.80966.441158.023128.856102.186233.883123.71974.96441.955-49.322229.563287.017324.132193.097234.468153.923146.576263.584225.405204.503NANANA
us-gaap:TreasuryStockValue █▇▇▇▇▇▆▆▆▆▆▆▆▅▅▅▅▅▅▅▅▅▅▅▅▄▄▃▃▃▃▃▃▂▂▂▂▂▂▂▂▂▁3007.5782694.9572500.02495.1062494.5052489.0972406.0472403.7492401.0372388.3922382.1672280.1512266.5292084.1862077.7412053.6442051.3432039.272034.572031.8592028.692019.2491941.9041940.7951934.7631727.0741562.0191358.0111104.9631096.8261094.7041093.8331091.6871067.4391025.839852.742852.419845.708845.472844.887823.586787.362549.912NANANA
us-gaap:MinorityInterest ██▇▇▆▅▇██▇▇███▇███▇▇▇▇▇▇▇▇▇▇▇▇▁▁▁▁▁918.874876.864823.007757.92679.089492.785762.777854.924855.347838.081791.56876.754861.153854.112843.411860.898877.456868.186851.854834.808788.589754.915738.831774.162794.88789.594769.081782.02792.34793.4960.00.00.00.00.0NANANANANANANANANANANA
 us-gaap:StockIssuedDuringPeriodValueNewIssues us-gaap:StatementClassOfStock us-gaap:SeriesGPreferredStock500.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:StockIssuedDuringPeriodValueNewIssues us-gaap:StatementEquityComponents us-gaap:PreferredStock500.0NANANANANANANANANA0.00.0NANA100.0230.0NANA0.0NANANA0.0NANANANANANANANANANANA0.00.0NANA0.00.0NANANANANANA
 us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue us-gaap:StatementEquityComponents us-gaap:AdditionalPaidInCapital▂█▂▂▁▅▁▁▁▄16.4940.57314.66314.66213.1628.60211.86212.77513.60725.908NANANANANANA27.08215.65710.2710.54221.50414.2659.52110.53122.80613.2389.6719.49121.45214.1758.9328.83919.92311.5437.64410.72916.5197.4115.75.78113.8775.6285.6156.07412.287.096
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:NetCashProvidedByUsedInOperatingActivities ▇▆▄█▅▄▃▆▃▁▃849.727762.845555.0551009.87711.126610.454505.32830.615477.126235.398438.335NANANANANANANANANANANANANANANANANANANA223.82238.694182.695205.659189.652334.683252.447144.821109.641309.924221.967224.58144.513267.424205.514184.623
us-gaap:NetCashProvidedByUsedInInvestingActivities ▆▆▇▅▁▇▆▆▇▇█-600.489-493.189-434.808-798.228-1531.694-278.496-556.007-503.532-452.151-294.793-163.937NANANANANANANANANANANANANANANANANANANA-821.841-179.96-95.28-210.43297.173-177.82-318.7023.381-106.363-232.919-131.125-68.013276.028-186.45527.003-100.479
 us-gaap:NetCashProvidedByUsedInInvestingActivities dei:LegalEntity,us-gaap:ConsolidatedEntities acgl:WatfordHoldingsLtd,us-gaap:VariableInterestEntityPrimaryBeneficiary█▁74.921.4NANA113.7-35.7NANANA-105.9NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:NetCashProvidedByUsedInInvestingActivities dei:LegalEntity,us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities acgl:WatfordHoldingsLtd,us-gaap:VariableInterestEntityPrimaryBeneficiaryNANANA164.0NANANA-45.5NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:NetCashProvidedByUsedInFinancingActivities ▄▁▂▂█▂▂▂▂▃▁209.017-186.602-44.812-105.247805.833-134.496-34.166-37.411-50.60441.519-252.066NANANANANANANANANANANANANANANANANANANA595.521-5.375-63.063-3.065-339.567-94.7212.531-81.278-22.116-109.468-87.715-117.836-423.272-65.711-222.69-73.964
us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect █▄▅▅▃▅▃▆▃▃▄▅▂▄▁▄▄▂450.94976.97103.571122.29-5.754166.739-58.777279.4-27.141-14.42714.824126.71-149.1474.972-253.3384.79986.052-159.806NANANANANANANANANANANANANANANANANANANANANANANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:IncreaseDecreaseInOtherOperatingCapitalNet ▇▆▄▁▄█▃▄▆▅▃▃▆▃▇▃▄▅▅▄▅▃▅▅▂▅▅▅▄▄▃▄▄▄▄▃▅▄▄▄▄▄▄▃▄▅134.73396.574-7.444-194.732-31.058223.124-83.146-22.249109.19437.253-63.331-54.64113.933-56.143165.163-97.707-25.57151.98533.873-38.49555.194-46.66439.06619.651-121.26570.08526.73451.29-19.847-19.041-54.907-43.988-0.9673.179-26.089-64.86337.864-22.5730.217-2.109-32.075-42.701-19.741-54.5744.25233.023
us-gaap:NetCashProvidedByUsedInOperatingActivities ▇▆▄█▅▄▃▆▃▁▃849.727762.845555.0551009.87711.126610.454505.32830.615477.126235.398438.335NANANANANANANANANANANANANANANANANANANA223.82238.694182.695205.659189.652334.683252.447144.821109.641309.924221.967224.58144.513267.424205.514184.623
us-gaap:NetIncomeLoss █▆▇▅▄▃▅▅▆▆▃▄▄▃▃▁▃▄▂▄▃▃▂▂▂▄▃▄▃▃▃▂▃▄▂▃▄▃▃▃▂▂▄▃▄▃675.486438.156543.544419.039298.821144.117326.384392.453468.954448.528136.494227.408243.646150.423214.64-33.656185.167253.12774.013252.872211.055154.79858.57980.033115.79283.336215.164228.675208.016182.5161.49114.825176.94256.47619.217189.656220.268164.256143.272168.98898.34225.756234.112148.031243.451216.994
us-gaap:ProfitLoss █▆▇▆▆▁▅▅▆▆▃▄▄▃▄▁▃▄▂▄▄▃▂▂▃▄▄▄▄▃▃▃▃▄718.664475.708599.314488.682466.389-88.674326.384399.189485.845495.498136.494248.766256.347166.384214.64-45.217199.099274.03574.013303.62249.357175.62758.57964.0125.819308.757207.134223.264211.717179.145161.49114.825176.94256.476NANANANANANANA25.756NANANA216.994
us-gaap:ShareBasedCompensation ▃█▃▃▃▆▂▂▃▅▂▂▄▃▂▃▅▃▂▂▄▃▂▂▄▃▂▂▄▃▂▂▄▂▁▂▃▁▁▁▃▁▁▁▂▁16.75240.81214.82914.52113.36328.54911.98512.89515.64625.8919.9710.38720.75514.6649.4915.56927.08215.65710.2710.54221.50414.2659.52110.53122.80613.2389.6719.49121.45214.1758.9328.83919.92311.5437.64410.72916.5197.4115.75.78113.8775.6285.6156.07412.287.096
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:NetCashProvidedByUsedInInvestingActivities ▆▆▇▅▁▇▆▆▇▇█-600.489-493.189-434.808-798.228-1531.694-278.496-556.007-503.532-452.151-294.793-163.937NANANANANANANANANANANANANANANANANANANA-821.841-179.96-95.28-210.43297.173-177.82-318.7023.381-106.363-232.919-131.125-68.013276.028-186.45527.003-100.479
 us-gaap:NetCashProvidedByUsedInInvestingActivities dei:LegalEntity,us-gaap:ConsolidatedEntities acgl:WatfordHoldingsLtd,us-gaap:VariableInterestEntityPrimaryBeneficiary█▁74.921.4NANA113.7-35.7NANANA-105.9NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:NetCashProvidedByUsedInInvestingActivities dei:LegalEntity,us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities acgl:WatfordHoldingsLtd,us-gaap:VariableInterestEntityPrimaryBeneficiaryNANANA164.0NANANA-45.5NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:PaymentsToAcquireProductiveAssets ▆▆▆▅▅▅▆▆▅▅▆▅▅▅▅▅▅▅▅▅▅▅▅▁▆█▅▅▅▅▅▅▅▅▅▅▅▅▅▅▅▅▅▅▅▅11.09512.4913.1559.039.2178.4710.20211.2766.9369.42310.7595.8089.0024.245.9795.7595.9095.1943.7383.2814.3323.9524.835-32.26410.26832.8975.3084.2154.9785.3826.5463.8613.353.7424.6383.6863.716.4983.4613.1784.2668.0821.5532.2516.0571.803
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:NetCashProvidedByUsedInFinancingActivities ▄▁▂▂█▂▂▂▂▃▁209.017-186.602-44.812-105.247805.833-134.496-34.166-37.411-50.60441.519-252.066NANANANANANANANANANANANANANANANANANANA595.521-5.375-63.063-3.065-339.567-94.7212.531-81.278-22.116-109.468-87.715-117.836-423.272-65.711-222.69-73.964
us-gaap:PaymentsForRepurchaseOfCommonStock █▁306.049179.266NA0.00.075.4860.00.00.02.87198.23310.954170.2763.2990.00.00.00.00.00.00.075.2560.03.506198.979162.898202.218251.9190.00.00.01.33315.49940.964172.0560.00.00.00.00320.83329.552237.173258.1553.398269.054181.272
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31

Common Stock Value

us-gaap:CommonStockValue

us-gaap:CommonStockValue


Common
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value647000.0645000.0643000.0642000.0642000.0642000.0638000.0638000.0638000.0636000.0634000.0633000.0633000.0630000.0611000.0610000.0609000.0583000.0582000.0582000.0581000.0579000.0577000.0576000.0576000.0573000.0572000.0571000.0570000.0567000.0565000.0565000.0564000.0561000.0561000.0556000.0556000.0552000.0549000.0544000.0541000.0535000.0534000.0548000.0
Percentage of CommonStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CommonStockValue us-gaap:ConsolidatedEntities

srt:ParentCompany


Common
Period End2020-12-312019-12-31
Value643000.0638000.0
Percentage of CommonStockValue100.0100.0
Percentage of Assets0.00.0
Percentage of Assets srt:ParentCompany0.00.0

Weighted Average Number Of Diluted Shares Outstanding

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding


Weighted
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-31
Value4064094094084144134104084114131391341391391241241241251251281351361361361351351381381371371374615315955
Percentage of WeightedAverageNumberOfDilutedSharesOutstanding100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Weighted Average Number Of Shares Outstanding Basic

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic


Weighted
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-31
Value3974004024024034024014004024041351341341341201201201201211241311321311311311301351341331311314414615253
Percentage of WeightedAverageNumberOfSharesOutstandingBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Earnings Per Share Basic

us-gaap:EarningsPerShareBasic

us-gaap:EarningsPerShareBasic


Earnings
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value1.671.071.321.010.720.330.780.951.141.090.310.540.581.011.5-0.391.291.80.512.051.71.240.440.620.912.241.651.691.531.341.190.831.311.920.11.361.581.181.031.240.70.431.590.961.553.97
Percentage of EarningsPerShareBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Earnings Per Share Diluted

us-gaap:EarningsPerShareDiluted

us-gaap:EarningsPerShareDiluted


Earnings
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value1.631.051.31.00.710.320.760.921.121.070.310.530.560.991.46-0.391.251.740.51.981.651.20.420.60.882.161.61.641.481.31.140.81.261.850.11.331.541.141.01.190.670.411.510.921.483.79
Percentage of EarningsPerShareDiluted100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Benefits Losses And Expenses

us-gaap:BenefitsLossesAndExpenses

us-gaap:BenefitsLossesAndExpenses


Benefits
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value182418261753180017991594140312451248118112601121113010951162151611741016904880927894862858887760801762816763746738669628913709621648609598678749594646531621
Percentage of BenefitsLossesAndExpenses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues71.080.673.577.878.5104.080.574.070.268.693.279.980.285.381.8102.583.477.191.673.577.982.395.692.187.070.379.076.978.980.780.885.878.670.699.278.473.879.681.578.287.596.772.181.068.573.5

Comprehensive Income Net Of Tax

us-gaap:ComprehensiveIncomeNetOfTax

us-gaap:ComprehensiveIncomeNetOfTax


Comprehensive
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-31
Value699155646455626-46.033263976376651782001834820317279351-160.2820827327232232431224196318231194206-101.945199-17.898320178244
Percentage of ComprehensiveIncomeNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues27.26.827.119.727.3-3.018.723.635.838.613.214.313.03.814.31.219.826.7-16.217.422.925.13.62.52.428.923.89.830.724.421.123.9-12.022.4-1.935.421.230.0

Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest

us-gaap:ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest

us-gaap:ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest


Comprehensive
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value742188713536814-311.87931640365771698220195631905.613293372-138.6462593112931.5267.2723433723391321227194206-101.945199-17.898320178244150511364650363275219
Percentage of ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues28.98.329.923.235.5-20.318.124.036.941.67.315.713.84.913.40.420.828.3-14.021.726.227.00.20.83.431.223.09.231.124.121.123.9-12.022.4-1.935.421.230.020.16.817.66.06.145.535.526.0

Deferred Policy Acquisition Cost Amortization Expense

us-gaap:DeferredPolicyAcquisitionCostAmortizationExpense

us-gaap:DeferredPolicyAcquisitionCostAmortizationExpense


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value335304254247254247221211210197209201202191208193190182168163175170171171175163175163158160157147131127133128128118123120110108104111107117
Percentage of DeferredPolicyAcquisitionCostAmortizationExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues13.013.410.710.711.116.112.712.511.811.515.514.414.414.914.713.113.513.817.013.714.715.719.018.417.215.117.316.515.316.917.117.115.514.314.514.215.214.616.515.714.314.012.714.013.813.9

us-gaap:DeferredPolicyAcquisitionCostAmortizationExpense us-gaap:ConsolidationItems

us-gaap:OperatingSegments


Deferred
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value276225223232225197188180168178171168160178161155149134135141137137142145142159153153159157147131127
Percentage of DeferredPolicyAcquisitionCostAmortizationExpense90.888.590.291.291.289.089.185.985.385.585.383.183.685.383.581.882.279.782.580.880.780.383.382.887.191.294.197.399.5100.0100.0100.0100.0
Percentage of Revenues12.29.59.710.114.711.311.210.19.813.212.311.912.512.510.911.111.413.611.311.912.715.315.314.213.115.715.514.916.917.117.115.514.3
Percentage of Revenues us-gaap:OperatingSegments0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:DeferredPolicyAcquisitionCostAmortizationExpense us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, acgl:InsuranceSegment


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value13612810110210710796919182858890858782787475777774707776758181767684827470
Percentage of DeferredPolicyAcquisitionCostAmortizationExpense40.842.139.741.342.343.443.543.243.441.940.943.844.744.541.842.641.441.144.747.144.143.641.144.943.746.046.350.048.348.053.456.256.455.5
Percentage of Revenues5.35.74.24.44.77.05.55.45.14.86.36.36.46.66.15.65.65.77.66.46.56.87.88.37.56.98.08.27.48.19.19.68.77.9
Percentage of Revenues us-gaap:OperatingSegments acgl:InsuranceSegment0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, acgl:MortgageSegment


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value3030253534383534323130332726242125287.47.7578.5238.385141010101611119.1546.5473.4514.1373.691
Percentage of DeferredPolicyAcquisitionCostAmortizationExpense9.09.910.214.413.415.616.016.315.516.014.816.513.713.911.711.213.515.84.44.74.94.98.26.15.86.49.67.37.35.74.22.33.12.9
Percentage of Revenues1.21.31.11.51.52.52.02.01.81.82.32.42.02.11.71.51.82.20.70.60.70.81.61.11.01.01.71.21.11.00.70.40.50.4
Percentage of Revenues us-gaap:OperatingSegments acgl:MortgageSegment0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, acgl:ReinsuranceSegment


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value1331189885907965625654625050486657514651505554535558566160667366615353
Percentage of DeferredPolicyAcquisitionCostAmortizationExpense39.938.838.734.435.532.229.529.627.027.529.825.024.725.231.929.626.925.330.630.631.832.131.132.333.334.735.336.841.845.842.541.540.541.7
Percentage of Revenues5.25.24.13.73.95.23.83.73.23.24.63.63.63.84.73.93.63.55.24.24.75.05.95.95.75.26.16.16.47.87.27.16.36.0
Percentage of Revenues us-gaap:OperatingSegments acgl:ReinsuranceSegment0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, acgl:UnderwritingSegments


Deferred
Period End2021-06-302020-06-30
Value300232
Percentage of DeferredPolicyAcquisitionCostAmortizationExpense89.791.2
Percentage of Revenues11.710.1
Percentage of Revenues us-gaap:OperatingSegments acgl:UnderwritingSegments0.00.0

us-gaap:OperatingSegments, us-gaap:AllOtherSegments


Deferred
Period End2021-06-302020-06-30
Value3422
Percentage of DeferredPolicyAcquisitionCostAmortizationExpense10.38.8
Percentage of Revenues1.31.0
Percentage of Revenues us-gaap:OperatingSegments us-gaap:AllOtherSegments0.00.0

us-gaap:DeferredPolicyAcquisitionCostAmortizationExpense us-gaap:StatementBusinessSegments

us-gaap:CorporateAndOther


Deferred
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-30
Value282924222124232929302934313032343234283332332830
Percentage of DeferredPolicyAcquisitionCostAmortizationExpense9.211.59.88.88.811.010.914.114.714.514.716.916.414.716.518.217.820.317.519.219.319.716.717.2
Percentage of Revenues1.21.21.11.01.41.41.41.71.72.22.12.42.42.22.22.52.53.52.42.83.03.73.13.0
Percentage of Revenues us-gaap:CorporateAndOther0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

General And Administrative Expense

us-gaap:GeneralAndAdministrativeExpense

us-gaap:GeneralAndAdministrativeExpense


General
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-30
Value1525251717202617181726142215131724273618179.383121017
Percentage of GeneralAndAdministrativeExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues0.61.11.10.80.81.41.51.01.01.02.01.01.61.21.01.21.82.13.71.51.40.91.41.21.7

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

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value745439633512492-60.72934043753054191282280188258-37.0282333028331626319139731323212122292191821761221822617.0971952211661381669624230151244
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues29.019.426.522.221.5-4.019.526.029.831.46.820.119.814.718.2-2.516.622.98.426.522.117.74.47.913.029.721.023.121.119.319.214.221.429.40.821.626.220.418.521.812.53.227.919.031.5

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest us-gaap:ConsolidationItems

us-gaap:OperatingSegments


Income
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value397570433302205355430511489182258266170273-23.487218279592602211697492121293222236215186176122182261
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest90.590.184.761.4-339.1104.698.596.590.4199.391.795.190.8105.863.493.592.471.682.283.988.1188.5125.291.991.3104.5102.998.4102.0100.0100.0100.0100.0
Percentage of Revenues17.523.918.813.213.420.425.628.828.413.518.418.913.319.3-1.615.521.26.021.718.615.68.29.912.027.121.923.820.819.719.214.221.429.4
Percentage of Revenues us-gaap:OperatingSegments0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, us-gaap:AllOtherSegments


Income
Period End2021-06-302020-06-30
Value47190
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest6.438.6
Percentage of Revenues1.98.3
Percentage of Revenues us-gaap:OperatingSegments us-gaap:AllOtherSegments0.00.0

us-gaap:OperatingSegments, us-gaap:Corporate


Income
Period End2021-06-302020-06-30
Value697305
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest93.662.1
Percentage of Revenues27.213.3
Percentage of Revenues us-gaap:OperatingSegments us-gaap:Corporate0.00.0

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:StatementEquityComponents

us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value650.357638918513615415910-25.118-24.38-39.405-67.7482125226.006-55.902572636-9.732-10.92223520198.986232.044-22.7261342
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest8.80.110.017.437.7-224.64.69.611.31.9-27.5-8.6-14.1-36.08.3-69.39.62.0-67.118.29.919.3-24.7-14.816.710.99.78.34.112.61.2-18.67.616.1
Percentage of Revenues2.60.02.73.98.18.90.92.53.40.6-1.9-1.7-2.8-5.31.51.71.60.5-5.74.82.23.4-1.1-1.22.23.32.01.90.92.40.2-2.61.64.7
Percentage of Revenues us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest us-gaap:StatementBusinessSegments

us-gaap:CorporateAndOther


Income
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-30
Value416278190-266.682-15.7336.7511852-90.671231317-15.006-13.541152223564222-34.928-18.58910
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest9.59.915.338.6439.1-4.61.53.59.6-99.38.34.99.2-5.836.66.57.628.417.816.111.9-88.5-25.28.1
Percentage of Revenues1.82.63.48.3-17.4-0.90.41.03.0-6.71.71.01.4-1.1-0.91.11.72.44.73.62.1-3.9-2.01.0
Percentage of Revenues us-gaap:CorporateAndOther0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Income Tax Expense Benefit

us-gaap:IncomeTaxExpenseBenefit

us-gaap:IncomeTaxExpenseBenefit


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value5138342326272738444535332321568.1893428-12.298131416119.7046.78125.5146.4467.2893.738157.3965.0714.853-12.125.4410.7671.902-4.977-2.267-1.731-0.371-3.5053.21.426.753
Percentage of IncomeTaxExpenseBenefit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues2.01.71.41.01.11.81.62.32.52.72.62.41.71.74.00.62.42.2-1.21.11.21.51.31.00.71.20.50.60.70.41.70.90.60.5-1.30.60.10.2-0.7-0.3-0.2-0.0-0.40.40.20.8

us-gaap:IncomeTaxExpenseBenefit us-gaap:ConsolidationItems

us-gaap:OperatingSegments


Income
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value38332326272738444535332321568.1683428-12.298131416119.7046.78125.5146.4467.2893.738157.3965.0714.853
Percentage of IncomeTaxExpenseBenefit100.098.999.7101.5100.0100.0100.0100.0100.0100.0100.099.9100.0100.099.7100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues1.71.41.01.21.81.62.32.52.72.62.41.71.74.00.62.42.2-1.21.11.21.51.31.00.71.20.50.60.70.41.70.90.60.5
Percentage of Revenues us-gaap:OperatingSegments0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:IncomeTaxExpenseBenefit us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, us-gaap:AllOtherSegments


Income
Period End2021-06-302020-06-30
Value0.226-0.402
Percentage of IncomeTaxExpenseBenefit0.4-1.5
Percentage of Revenues0.0-0.0
Percentage of Revenues us-gaap:OperatingSegments us-gaap:AllOtherSegments0.00.0

us-gaap:OperatingSegments, us-gaap:Corporate


Income
Period End2021-06-302020-06-30
Value5026
Percentage of IncomeTaxExpenseBenefit99.6101.5
Percentage of Revenues2.01.2
Percentage of Revenues us-gaap:OperatingSegments us-gaap:Corporate0.00.0

us-gaap:IncomeTaxExpenseBenefit us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:StatementEquityComponents

us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value5.2633.0545.6289.40118151.1253.2184.4150.179-2.852-1.177-2.762-5.287-0.3381.765.1570.962-2.9542.6053.9154.7271.9031.3580.9194.2522.4911.6390.7011.8181.274-2.025-0.0063.418
Percentage of IncomeTaxExpenseBenefit10.37.916.539.769.554.24.18.49.90.4-8.1-3.5-11.7-24.1-0.621.515.13.424.019.727.729.016.614.013.633.545.225.49.648.68.2-27.4-0.170.4
Percentage of Revenues0.20.10.20.40.81.00.10.20.20.0-0.2-0.1-0.2-0.4-0.00.10.40.1-0.30.20.30.40.20.10.10.40.20.20.10.20.1-0.2-0.00.4
Percentage of Revenues us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:IncomeTaxExpenseBenefit us-gaap:StatementBusinessSegments

us-gaap:CorporateAndOther


Income
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-30
Value0.0080.3590.069-0.4020.00.00.00.020.00.00.00.0240.0030.00.0210.00.00.0-0.0010.00.00.00.00.0
Percentage of IncomeTaxExpenseBenefit0.01.10.3-1.50.00.00.00.00.00.00.00.10.00.00.30.00.0-0.0-0.00.00.00.00.00.0
Percentage of Revenues0.00.00.0-0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0-0.00.00.00.00.00.0
Percentage of Revenues us-gaap:CorporateAndOther0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Income Taxes Paid Net

us-gaap:IncomeTaxesPaidNet

us-gaap:IncomeTaxesPaidNet


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value1347.1561363.07.4623.676-32.733123.4-49.93.881443.20.79.92114242.59.5223.65.06.71.67.72.83.51.3-2.3-0.21.52.8-7.73.62.33.73.12.0
Percentage of IncomeTaxesPaidNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues5.20.32.45.90.10.53.60.24.3-1.92.40.90.2-3.90.33.00.20.11.01.22.00.21.02.20.30.50.60.20.80.30.40.1-0.2-0.00.20.3-1.00.50.30.50.40.3

Insurance Commissions And Fees

us-gaap:InsuranceCommissionsAndFees

us-gaap:InsuranceCommissionsAndFees


Insurance
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value5.5296.117.8525.4136.6676.8526.7573.3265.9538.8250.0275.8233.8745.349146.0644.8224.633187.98255.0478.6217.6237.717114.8251.7022.0331.5825.6730.5260.9020.5385.6641.0770.8060.5430.9820.8480.7840.8152.8140.8740.8830.794
Percentage of InsuranceCommissionsAndFees100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues0.20.30.30.20.30.40.40.20.30.50.00.40.30.41.00.40.30.41.90.72.10.51.00.80.81.10.50.20.20.20.60.10.10.10.60.10.10.10.10.10.10.10.30.10.10.1

Interest Expense

us-gaap:InterestExpense

us-gaap:InterestExpense


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value3538384131323131292929293030302928281815151615134.01112124.15214149.3735.9375.8525.8986.1877.3787.4397.5218.0878.1257.7587.7217.467.3717.9167.26
Percentage of InterestExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues1.41.71.61.81.42.11.81.91.61.72.22.12.22.42.12.02.02.21.91.31.31.51.81.40.41.21.30.41.41.51.00.70.70.70.70.80.90.91.11.11.01.00.90.91.00.9

us-gaap:InterestExpense us-gaap:ConsolidationItems

us-gaap:OperatingSegments


Interest
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value34333625252323232324242625252625251512121212124.01112124.15214149.3735.9375.8525.898
Percentage of InterestExpense89.287.587.680.777.575.874.279.880.881.983.085.984.684.189.090.189.883.581.179.478.480.690.3100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues1.51.41.61.11.61.41.41.31.41.81.81.82.01.81.81.82.01.61.11.01.21.41.30.41.21.30.41.41.51.00.70.70.7
Percentage of Revenues us-gaap:OperatingSegments0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:InterestExpense us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, us-gaap:AllOtherSegments


Interest
Period End2021-06-302020-06-30
Value4.2616.009
Percentage of InterestExpense11.919.3
Percentage of Revenues0.20.3
Percentage of Revenues us-gaap:OperatingSegments us-gaap:AllOtherSegments0.00.0

us-gaap:OperatingSegments, us-gaap:Corporate


Interest
Period End2021-06-302020-06-30
Value3125
Percentage of InterestExpense88.180.7
Percentage of Revenues1.21.1
Percentage of Revenues us-gaap:OperatingSegments us-gaap:Corporate0.00.0

us-gaap:InterestExpense us-gaap:StatementBusinessSegments

us-gaap:CorporateAndOther


Interest
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-30
Value4.1494.8045.1196.0097.317.5588.0915.9055.5835.3865.0644.2864.7294.8363.2462.8372.923.0583.0193.2313.483.071.2860.0
Percentage of InterestExpense10.812.512.419.322.524.225.820.219.218.117.014.115.415.911.09.910.216.518.920.621.619.49.70.0
Percentage of Revenues0.20.20.20.30.50.40.50.30.30.40.40.30.40.30.20.20.20.30.30.30.30.30.10.0
Percentage of Revenues us-gaap:CorporateAndOther0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Interest Expense Debt

us-gaap:InterestExpenseDebt

us-gaap:InterestExpenseDebt


Interest
Period End2020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-31
Value3.2506.67.7546.267607.964585.8
Percentage of InterestExpenseDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues0.12.20.40.53.10.44.84.30.64.44.10.4

Interest Paid Net

us-gaap:InterestPaidNet

us-gaap:InterestPaidNet


Interest
Period End2021-06-302021-03-312020-06-302020-03-31
Value731.0506.6
Percentage of InterestPaidNet100.0100.0100.0100.0
Percentage of Revenues2.90.02.20.4

Net Income Loss

us-gaap:NetIncomeLoss

us-gaap:NetIncomeLoss


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value675438543419298144326392468448136227243150214-33.656185253742522111545880115283215228208182161114176256191892201641431689825234148243216
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues26.319.322.818.113.09.418.723.326.426.010.116.217.311.715.1-2.313.219.27.521.117.714.26.58.611.426.221.223.020.119.317.513.320.828.82.121.026.120.219.222.112.73.328.418.631.425.7

us-gaap:NetIncomeLoss us-gaap:ConsolidationItems

us-gaap:OperatingSegments


Net
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value433535409275177328392467443146225242149216-31.655184251712472061526282115280216229208182161114176256
Percentage of NetIncomeLoss99.098.697.792.0123.5100.6100.099.798.8107.799.199.699.1101.094.199.499.297.297.798.098.7107.4103.299.499.1100.7100.6100.1100.2100.0100.0100.0100.0
Percentage of Revenues19.222.517.712.011.618.823.326.325.710.916.117.211.615.3-2.113.119.07.320.617.414.17.08.911.325.921.423.220.119.317.513.320.828.8
Percentage of Revenues us-gaap:OperatingSegments0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NetIncomeLoss us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, us-gaap:AllOtherSegments


Net
Period End2021-06-302020-06-30
Value4.74423
Percentage of NetIncomeLoss0.78.0
Percentage of Revenues0.21.0
Percentage of Revenues us-gaap:OperatingSegments us-gaap:AllOtherSegments0.00.0

us-gaap:OperatingSegments, us-gaap:Corporate


Net
Period End2021-06-302020-06-30
Value670275
Percentage of NetIncomeLoss99.392.0
Percentage of Revenues26.112.0
Percentage of Revenues us-gaap:OperatingSegments us-gaap:Corporate0.00.0

us-gaap:NetIncomeLoss us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:StatementEquityComponents

us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value60-2.697577916712114385510-22.266-23.203-36.643-62.4612123175.044-52.948542232-11.635-12.278213018178.285210.77-20.7011338
Percentage of NetIncomeLoss9.0-0.610.619.056.084.14.59.911.82.3-16.3-10.2-15.0-41.510.1-71.09.32.0-71.521.710.520.8-19.9-15.318.310.98.47.64.011.60.5-18.07.915.1
Percentage of Revenues2.4-0.12.43.47.37.90.82.33.10.6-1.6-1.7-2.6-4.91.51.61.20.4-5.44.61.93.0-1.3-1.32.12.91.81.80.82.20.1-2.41.64.3
Percentage of Revenues us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NetIncomeLoss us-gaap:StatementBusinessSegments

us-gaap:CorporateAndOther


Net
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-30
Value4.197.7189.74423-33.834-2.1170.0151.5235.251-10.5012.0781.0071.407-2.158-2.0011.1592.0212.1045.7194.1762.01-4.355-2.5560.657
Percentage of NetIncomeLoss1.01.42.38.0-23.5-0.60.00.31.2-7.70.90.40.9-1.05.90.60.82.82.32.01.3-7.4-3.20.6
Percentage of Revenues0.20.30.41.0-2.2-0.10.00.10.3-0.80.10.10.1-0.2-0.10.10.20.20.50.40.2-0.5-0.30.1
Percentage of Revenues us-gaap:CorporateAndOther0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Net Income Loss Attributable To Noncontrolling Interest

us-gaap:NetIncomeLossAttributableToNoncontrollingInterest

us-gaap:NetIncomeLossAttributableToNoncontrollingInterest


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value43375569167-232.791-13.6166.7361646-80.17211215-12.848-11.561132021503820-30.573-16.0331025-8.03-5.4113.701-3.3550.00.00.00.0
Percentage of NetIncomeLossAttributableToNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.00.0
Percentage of Revenues1.71.72.33.07.3-15.2-0.80.40.92.7-5.91.50.91.2-0.9-0.81.01.62.24.23.21.9-3.4-1.71.02.3-0.8-0.50.4-0.40.00.00.00.0

us-gaap:NetIncomeLossAttributableToNoncontrollingInterest us-gaap:StatementEquityComponents

us-gaap:RetainedEarnings


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value43375569167-232.791-13.6166.7361646-80.17211215-12.848-11.561132021503820-30.573-16.0331025-8.03-5.4113.701-3.3550.00.00.00.0
Percentage of NetIncomeLossAttributableToNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.00.0
Percentage of Revenues1.71.72.33.07.3-15.2-0.80.40.92.7-5.91.50.91.2-0.9-0.81.01.62.24.23.21.9-3.4-1.71.02.3-0.8-0.50.4-0.40.00.00.00.0
Percentage of Revenues us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Net Income Loss Available To Common Stockholders Basic

us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic

us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value663427533408288133315382458438126217233137203-52.76173241622472051495374110277209223202177156109171250131842121571361629119227141236210
Percentage of NetIncomeLossAvailableToCommonStockholdersBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues25.818.922.317.712.68.718.122.725.825.49.315.516.510.714.3-3.612.318.36.320.717.313.75.98.010.825.720.722.519.618.716.912.720.128.21.520.425.219.418.321.211.82.527.617.830.524.9

us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic us-gaap:ConsolidationItems

us-gaap:OperatingSegments


Net
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value423525398264167318382457432136214232135205-50.759172239602412011475777109275211224202177156109171250
Percentage of NetIncomeLossAvailableToCommonStockholdersBasic99.098.697.691.7125.3100.7100.099.798.8108.399.099.699.0101.196.299.399.296.697.798.098.7108.2103.499.499.1100.8100.6100.1100.2100.0100.0100.0100.0
Percentage of Revenues18.722.017.211.510.918.222.725.725.110.115.316.510.614.5-3.412.318.26.120.216.913.66.48.310.825.420.822.619.618.716.912.720.128.2
Percentage of Revenues us-gaap:OperatingSegments0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, us-gaap:AllOtherSegments


Net
Period End2021-06-302020-06-30
Value4.74423
Percentage of NetIncomeLossAvailableToCommonStockholdersBasic0.78.3
Percentage of Revenues0.21.0
Percentage of Revenues us-gaap:OperatingSegments us-gaap:AllOtherSegments0.00.0

us-gaap:OperatingSegments, us-gaap:Corporate


Net
Period End2021-06-302020-06-30
Value659264
Percentage of NetIncomeLossAvailableToCommonStockholdersBasic99.391.7
Percentage of Revenues25.611.5
Percentage of Revenues us-gaap:OperatingSegments us-gaap:Corporate0.00.0

us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic us-gaap:StatementBusinessSegments

us-gaap:CorporateAndOther


Net
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-30
Value4.197.7189.74423-33.834-2.1170.0151.5235.251-10.5012.0781.0071.407-2.158-2.0011.1592.0212.1045.7194.1762.01-4.355-2.5560.657
Percentage of NetIncomeLossAvailableToCommonStockholdersBasic1.01.42.48.3-25.3-0.70.00.31.2-8.31.00.41.0-1.13.80.70.83.42.32.01.3-8.2-3.40.6
Percentage of Revenues0.20.30.41.0-2.2-0.10.00.10.3-0.80.10.10.1-0.2-0.10.10.20.20.50.40.2-0.5-0.30.1
Percentage of Revenues us-gaap:CorporateAndOther0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

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

us-gaap:OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax

us-gaap:OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-31
Value6.205-28.584391622-44.68924-16.4244.2675.516-15.582.063-12.5951.282178.28183.124-14.231-5.312-18.15117-10.851-12.08211-22.757-12.091-23.59510-1.3491.31729-5.407-28.2225.73113-15.13613
Percentage of OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues0.2-1.31.60.71.0-2.91.4-1.00.20.3-1.20.1-0.90.11.20.61.30.2-1.4-0.4-1.51.6-1.2-1.31.1-2.1-1.2-2.41.0-0.10.13.4-0.6-3.20.61.5-1.81.6

Other Comprehensive Income Loss Net Of Tax

us-gaap:OtherComprehensiveIncomeLossNetOfTax

us-gaap:OtherComprehensiveIncomeLossNetOfTax


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-31
Value24-287.63711347347-223.2053.244.12317122141-28.042-61.223-102.934-11.689509498-234.22-44.02362117-26.48-56.728-91.5822926-131.697110483391-278.885-57.454-37.115131-41.37180
Percentage of OtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues0.9-12.74.82.115.2-14.60.20.29.612.83.1-2.0-4.3-8.0-0.83.46.77.5-23.7-3.75.210.9-2.9-6.1-9.02.72.6-13.310.65.23.610.6-32.7-6.5-4.014.5-4.99.9

Policyholder Benefits And Claims Incurred Net

us-gaap:PolicyholderBenefitsAndClaimsIncurredNet

us-gaap:PolicyholderBenefitsAndClaimsIncurredNet


Policyholder
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value1159120311271216123011158448027677188276997266366781046689552553524584522506531519493495501485436434427418399622443399395378423431493367359363428
Percentage of PolicyholderBenefitsAndClaimsIncurredNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues45.153.147.252.653.772.748.547.743.141.761.249.851.549.647.870.749.041.956.043.849.148.156.157.050.945.648.950.546.946.147.149.649.144.967.749.147.448.550.655.455.763.744.545.046.850.7

us-gaap:PolicyholderBenefitsAndClaimsIncurredNet us-gaap:ConsolidationItems

us-gaap:OperatingSegments


Policyholder
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value10841018110011251004710706656607698602609538562922579467469449501443422465441444458478477434434427418399
Percentage of PolicyholderBenefitsAndClaimsIncurredNet90.190.390.591.590.184.188.085.584.684.486.183.984.682.888.284.084.584.785.885.784.983.487.585.090.092.595.398.399.7100.0100.0100.0100.0
Percentage of Revenues47.942.747.649.165.540.742.036.935.351.742.943.242.039.662.441.235.447.537.642.140.846.849.943.341.045.248.246.146.047.149.649.144.9
Percentage of Revenues us-gaap:OperatingSegments0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:PolicyholderBenefitsAndClaimsIncurredNet us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, acgl:InsuranceSegment


Policyholder
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value545535541525518507446422389356400409357353370568350332348332354323313339320317324338311286307305291283
Percentage of PolicyholderBenefitsAndClaimsIncurredNet47.144.548.143.242.145.552.952.750.749.648.358.549.255.554.554.450.960.262.963.560.761.962.063.961.864.465.467.464.265.770.971.669.671.0
Percentage of Revenues21.223.622.722.722.633.125.625.121.920.729.629.225.327.626.038.424.925.235.227.829.829.834.836.431.529.432.034.130.130.333.435.534.231.8
Percentage of Revenues us-gaap:OperatingSegments acgl:InsuranceSegment0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, acgl:MortgageSegment


Policyholder
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value9.886383153224673.2871325116.6179.6152143493520298.841110.3668.6297.2379.5629.639131515158.478-1.5312.0172.1782.079
Percentage of PolicyholderBenefitsAndClaimsIncurredNet0.95.37.412.618.26.10.41.63.41.60.81.43.06.87.33.43.05.31.62.10.11.71.41.81.92.83.23.23.21.9-0.40.50.50.5
Percentage of Revenues0.42.83.56.69.84.40.20.81.50.60.50.71.53.43.52.41.52.20.90.90.00.80.81.00.91.31.61.61.50.9-0.20.20.30.2
Percentage of Revenues us-gaap:OperatingSegments acgl:MortgageSegment0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, acgl:ReinsuranceSegment


Policyholder
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value463484392422383430260270240239291183229141142318207105112105146111100115111112118123150139127119125113
Percentage of PolicyholderBenefitsAndClaimsIncurredNet40.040.334.834.731.238.630.833.731.433.435.326.231.722.221.030.530.119.120.220.225.021.319.921.821.422.823.924.731.032.029.527.929.928.5
Percentage of Revenues18.021.416.518.216.728.014.916.113.513.921.613.116.311.010.021.514.78.011.38.812.310.311.212.410.910.411.712.514.514.813.913.814.712.8
Percentage of Revenues us-gaap:OperatingSegments acgl:ReinsuranceSegment0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, acgl:UnderwritingSegments


Policyholder
Period End2021-06-302020-06-30
Value10191125
Percentage of PolicyholderBenefitsAndClaimsIncurredNet87.991.5
Percentage of Revenues39.749.1
Percentage of Revenues us-gaap:OperatingSegments acgl:UnderwritingSegments0.00.0

us-gaap:OperatingSegments, us-gaap:AllOtherSegments


Policyholder
Period End2021-06-302020-06-30
Value140104
Percentage of PolicyholderBenefitsAndClaimsIncurredNet12.18.5
Percentage of Revenues5.54.6
Percentage of Revenues us-gaap:OperatingSegments us-gaap:AllOtherSegments0.00.0

us-gaap:PolicyholderBenefitsAndClaimsIncurredNet us-gaap:StatementBusinessSegments

us-gaap:CorporateAndOther


Policyholder
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-30
Value1181091151041101349611111012996117971161231108584748379836677
Percentage of PolicyholderBenefitsAndClaimsIncurredNet9.99.79.58.59.915.912.014.515.415.613.916.115.417.211.816.015.515.314.214.315.116.612.515.0
Percentage of Revenues5.24.65.04.67.27.75.76.36.49.66.98.37.68.28.47.96.58.66.27.07.39.37.17.6
Percentage of Revenues us-gaap:CorporateAndOther0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Preferred Stock Dividends Income Statement Impact

us-gaap:PreferredStockDividendsIncomeStatementImpact

us-gaap:PreferredStockDividendsIncomeStatementImpact


Preferred
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value10101010101010101010101011121111115.4845.4855.4845.4855.4845.4855.484
Percentage of PreferredStockDividendsIncomeStatementImpact100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues0.40.40.50.70.60.60.60.60.80.70.70.80.80.80.80.91.20.50.50.50.60.60.50.5

Premiums Earned Net

us-gaap:PremiumsEarnedNet

us-gaap:PremiumsEarnedNet


Premiums
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value2120194818111771166517441515143814631368136912901336123412241261124011179689581005951943936943910923903907859839795758752779748726680673682642633632627623669
Percentage of PremiumsEarnedNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues82.586.075.976.672.7113.786.985.582.379.5101.392.094.896.286.285.388.284.798.080.084.587.6104.6100.492.584.191.091.087.690.990.992.389.184.684.782.786.383.590.089.282.981.876.678.780.379.3

Profit Loss

us-gaap:ProfitLoss

us-gaap:ProfitLoss


Profit
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312011-03-312010-03-31
Value718475599488466-88.674326399485495136248256166214-45.21719927474303249175586412530820722321117916111417625625216
Percentage of ProfitLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues28.021.025.121.120.4-5.818.723.727.328.810.117.718.213.015.1-3.114.120.87.525.420.916.26.56.912.328.520.422.520.418.917.513.320.828.83.325.7

us-gaap:ProfitLoss us-gaap:ConsolidationItems

us-gaap:OperatingSegments


Profit
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value433536410275178328392467443146225242149216-31.655184251712472061526282115280216229208182161114176256
Percentage of ProfitLoss91.289.683.959.2-200.7100.698.396.289.5107.790.694.789.6101.070.092.491.697.281.483.087.0107.4129.091.590.9104.7103.098.4102.1100.0100.0100.0100.0
Percentage of Revenues19.122.517.712.011.618.823.326.325.710.916.117.211.615.3-2.113.119.07.320.617.414.17.08.911.325.921.423.220.119.317.513.320.828.8
Percentage of Revenues us-gaap:OperatingSegments0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:ProfitLoss us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, us-gaap:AllOtherSegments


Profit
Period End2021-06-302020-06-30
Value47190
Percentage of ProfitLoss6.640.8
Percentage of Revenues1.88.3
Percentage of Revenues us-gaap:OperatingSegments us-gaap:AllOtherSegments0.00.0

us-gaap:OperatingSegments, us-gaap:Corporate


Profit
Period End2021-06-302020-06-30
Value671275
Percentage of ProfitLoss93.459.2
Percentage of Revenues26.112.0
Percentage of Revenues us-gaap:OperatingSegments us-gaap:Corporate0.00.0

us-gaap:ProfitLoss us-gaap:StatementBusinessSegments

us-gaap:CorporateAndOther


Profit
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-30
Value416278190-266.682-15.7336.7511852-90.671231317-15.006-13.562152223564222-34.928-18.58910
Percentage of ProfitLoss8.810.416.140.8300.7-4.81.73.810.5-66.49.45.310.4-7.030.07.68.432.018.617.013.0-59.6-29.08.5
Percentage of Revenues1.82.63.48.3-17.4-0.90.41.03.0-6.71.71.01.4-1.1-0.91.11.72.44.73.62.1-3.9-2.01.0
Percentage of Revenues us-gaap:CorporateAndOther0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:ProfitLoss us-gaap:StatementEquityComponents

us-gaap:RetainedEarnings


Profit
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312011-03-312010-03-31
Value718475599488466-88.67431239948549556248256166201-45.21719927495303249175286412530820722321117916111417625625216
Percentage of ProfitLoss100.0100.0100.0100.0100.0100.095.8100.0100.0100.041.3100.0100.0100.094.0100.0100.0100.0129.1100.0100.0100.047.8100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues28.021.025.121.120.4-5.817.923.727.328.84.217.718.213.014.2-3.114.120.89.725.420.916.23.16.912.328.520.422.520.418.917.513.320.828.83.325.7
Percentage of Revenues us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Revenues

us-gaap:Revenues

us-gaap:Revenues


Revenues
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value2569226523862313229115331743168217791722135214031410128314211479140713199881197119110869029321019108210149921035946923861851890920904842815747764775775825797776844
Percentage of Revenues100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Assets

us-gaap:Assets

us-gaap:Assets


Assets
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value4648144204432824271641199384163788535572348513397732218322523185332131320513262430862300922937225643244112454123177237702308422849220092261022573218001956618930189171875717816188891849617812171411743017213171911577015375
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:Assets dei:LegalEntity, us-gaap:ConsolidatedEntities

acgl:Bellemeade20171Ltd, us-gaap:VariableInterestEntityNotPrimaryBeneficiary


Assetsdei:
Period End2021-06-302021-03-312020-12-312019-12-31
Value145145145216
Percentage of Assets0.30.30.30.6
Percentage of Assets0.30.30.30.6
Percentage of Assets acgl:Bellemeade20171Ltd us-gaap:VariableInterestEntityNotPrimaryBeneficiary100.0100.0100.0100.0

acgl:Bellemeade20182, us-gaap:VariableInterestEntityNotPrimaryBeneficiary


Assetsdei:
Period End2021-03-312020-12-312019-12-31
Value66108437
Percentage of Assets0.20.31.2
Percentage of Assets0.20.31.2
Percentage of Assets acgl:Bellemeade20182 us-gaap:VariableInterestEntityNotPrimaryBeneficiary100.0100.0100.0

acgl:Bellemeade20183, us-gaap:VariableInterestEntityNotPrimaryBeneficiary


Assetsdei:
Period End2021-06-302021-03-312020-12-312019-12-31
Value302302302426
Percentage of Assets0.70.70.71.1
Percentage of Assets0.70.70.71.1
Percentage of Assets acgl:Bellemeade20183 us-gaap:VariableInterestEntityNotPrimaryBeneficiary100.0100.0100.0100.0

acgl:Bellemeade20191Ltd, us-gaap:VariableInterestEntityNotPrimaryBeneficiary


Assetsdei:
Period End2021-06-302021-03-312020-12-312019-12-31
Value219219219257
Percentage of Assets0.50.50.50.7
Percentage of Assets0.50.50.50.7
Percentage of Assets acgl:Bellemeade20191Ltd us-gaap:VariableInterestEntityNotPrimaryBeneficiary100.0100.0100.0100.0

acgl:Bellemeade20192Ltd, us-gaap:VariableInterestEntityNotPrimaryBeneficiary


Assetsdei:
Period End2021-06-302021-03-312020-12-312019-12-31
Value398398398525
Percentage of Assets0.90.90.91.4
Percentage of Assets0.90.90.91.4
Percentage of Assets acgl:Bellemeade20192Ltd us-gaap:VariableInterestEntityNotPrimaryBeneficiary100.0100.0100.0100.0

acgl:Bellemeade20193Ltd, us-gaap:VariableInterestEntityNotPrimaryBeneficiary


Assetsdei:
Period End2021-06-302021-03-312020-12-312019-12-31
Value528528528656
Percentage of Assets1.11.21.21.7
Percentage of Assets1.11.21.21.7
Percentage of Assets acgl:Bellemeade20193Ltd us-gaap:VariableInterestEntityNotPrimaryBeneficiary100.0100.0100.0100.0

acgl:Bellemeade20201Ltd, us-gaap:VariableInterestEntityNotPrimaryBeneficiary


Assetsdei:
Period End2020-12-31
Value275
Percentage of Assets0.6
Percentage of Assets0.6
Percentage of Assets acgl:Bellemeade20201Ltd us-gaap:VariableInterestEntityNotPrimaryBeneficiary100.0

acgl:Bellemeade20201Ltd., us-gaap:VariableInterestEntityNotPrimaryBeneficiary


Assetsdei:
Period End2021-06-302021-03-312020-12-31
Value18132275
Percentage of Assets0.00.30.6
Percentage of Assets0.00.30.6
Percentage of Assets acgl:Bellemeade20201Ltd. us-gaap:VariableInterestEntityNotPrimaryBeneficiary100.0100.0100.0

acgl:Bellemeade20202Ltd, us-gaap:VariableInterestEntityNotPrimaryBeneficiary


Assetsdei:
Period End2021-06-302021-03-312020-12-31
Value325368423
Percentage of Assets0.70.81.0
Percentage of Assets0.70.81.0
Percentage of Assets acgl:Bellemeade20202Ltd us-gaap:VariableInterestEntityNotPrimaryBeneficiary100.0100.0100.0

acgl:Bellemeade20203Ltd, us-gaap:VariableInterestEntityNotPrimaryBeneficiary


Assetsdei:
Period End2020-12-31
Value418
Percentage of Assets1.0
Percentage of Assets1.0
Percentage of Assets acgl:Bellemeade20203Ltd us-gaap:VariableInterestEntityNotPrimaryBeneficiary100.0

acgl:Bellemeade20204Ltd, us-gaap:VariableInterestEntityNotPrimaryBeneficiary


Assetsdei:
Period End2020-12-31
Value321
Percentage of Assets0.7
Percentage of Assets0.7
Percentage of Assets acgl:Bellemeade20204Ltd us-gaap:VariableInterestEntityNotPrimaryBeneficiary100.0

acgl:Bellemeade20204LtdMember, us-gaap:VariableInterestEntityNotPrimaryBeneficiary


Assetsdei:
Period End2021-06-302021-03-312020-12-31
Value268321321
Percentage of Assets0.60.70.7
Percentage of Assets0.60.70.7
Percentage of Assets acgl:Bellemeade20204LtdMember us-gaap:VariableInterestEntityNotPrimaryBeneficiary100.0100.0100.0

acgl:Bellemeade20212Ltd, us-gaap:VariableInterestEntityNotPrimaryBeneficiary


Assetsdei:
Period End2021-06-30
Value522
Percentage of Assets1.1
Percentage of Assets1.1
Percentage of Assets acgl:Bellemeade20212Ltd us-gaap:VariableInterestEntityNotPrimaryBeneficiary100.0

acgl:BellemeadeRe20181Ltd, us-gaap:VariableInterestEntityNotPrimaryBeneficiary


Assetsdei:
Period End2021-06-302021-03-312020-12-312019-12-31
Value250250250328
Percentage of Assets0.50.60.60.9
Percentage of Assets0.50.60.60.9
Percentage of Assets acgl:BellemeadeRe20181Ltd us-gaap:VariableInterestEntityNotPrimaryBeneficiary100.0100.0100.0100.0

acgl:BellemeadeRe20194Ltd, us-gaap:VariableInterestEntityNotPrimaryBeneficiary


Assetsdei:
Period End2021-06-302021-03-312020-12-312019-12-31
Value468468468577
Percentage of Assets1.01.11.11.5
Percentage of Assets1.01.11.11.5
Percentage of Assets acgl:BellemeadeRe20194Ltd us-gaap:VariableInterestEntityNotPrimaryBeneficiary100.0100.0100.0100.0

acgl:WatfordHoldingsLtd, us-gaap:VariableInterestEntityPrimaryBeneficiary


Assetsdei:
Period End2021-06-302021-03-312020-12-312020-03-312019-12-31
Value43493703353234063550
Percentage of Assets9.48.48.28.99.4
Percentage of Assets9.48.48.28.99.4
Percentage of Assets acgl:WatfordHoldingsLtd us-gaap:VariableInterestEntityPrimaryBeneficiary100.0100.0100.0100.0100.0

us-gaap:Assets dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities

acgl:Bellemeade20171Ltd, us-gaap:VariableInterestEntityNotPrimaryBeneficiary


Assetsdei:
Period End2020-09-302020-06-302019-12-31
Value145145216
Percentage of Assets0.30.40.6
Percentage of Assets0.30.40.6
Percentage of Assets acgl:Bellemeade20171Ltd us-gaap:VariableInterestEntityNotPrimaryBeneficiary100.0100.0100.0

acgl:Bellemeade20182, us-gaap:VariableInterestEntityNotPrimaryBeneficiary


Assetsdei:
Period End2020-09-302020-06-302019-12-31
Value187272437
Percentage of Assets0.40.71.2
Percentage of Assets0.40.71.2
Percentage of Assets acgl:Bellemeade20182 us-gaap:VariableInterestEntityNotPrimaryBeneficiary100.0100.0100.0

acgl:Bellemeade20183, us-gaap:VariableInterestEntityNotPrimaryBeneficiary


Assetsdei:
Period End2020-09-302020-06-302019-12-31
Value302302426
Percentage of Assets0.70.71.1
Percentage of Assets0.70.71.1
Percentage of Assets acgl:Bellemeade20183 us-gaap:VariableInterestEntityNotPrimaryBeneficiary100.0100.0100.0

acgl:Bellemeade20191Ltd, us-gaap:VariableInterestEntityNotPrimaryBeneficiary


Assetsdei:
Period End2020-09-302020-06-302019-12-31
Value219219257
Percentage of Assets0.50.50.7
Percentage of Assets0.50.50.7
Percentage of Assets acgl:Bellemeade20191Ltd us-gaap:VariableInterestEntityNotPrimaryBeneficiary100.0100.0100.0

acgl:Bellemeade20192Ltd, us-gaap:VariableInterestEntityNotPrimaryBeneficiary


Assetsdei:
Period End2020-09-302020-06-302019-12-31
Value398398525
Percentage of Assets0.91.01.4
Percentage of Assets0.91.01.4
Percentage of Assets acgl:Bellemeade20192Ltd us-gaap:VariableInterestEntityNotPrimaryBeneficiary100.0100.0100.0

acgl:Bellemeade20193Ltd, us-gaap:VariableInterestEntityNotPrimaryBeneficiary


Assetsdei:
Period End2020-09-302020-06-302019-12-31
Value528528656
Percentage of Assets1.21.31.7
Percentage of Assets1.21.31.7
Percentage of Assets acgl:Bellemeade20193Ltd us-gaap:VariableInterestEntityNotPrimaryBeneficiary100.0100.0100.0

acgl:Bellemeade20201Ltd., us-gaap:VariableInterestEntityNotPrimaryBeneficiary


Assetsdei:
Period End2020-09-302020-06-30
Value406450
Percentage of Assets1.01.1
Percentage of Assets1.01.1
Percentage of Assets acgl:Bellemeade20201Ltd. us-gaap:VariableInterestEntityNotPrimaryBeneficiary100.0100.0

acgl:Bellemeade20202Ltd, us-gaap:VariableInterestEntityNotPrimaryBeneficiary


Assetsdei:
Period End2020-09-30
Value423
Percentage of Assets1.0
Percentage of Assets1.0
Percentage of Assets acgl:Bellemeade20202Ltd us-gaap:VariableInterestEntityNotPrimaryBeneficiary100.0

acgl:BellemeadeRe20181Ltd, us-gaap:VariableInterestEntityNotPrimaryBeneficiary


Assetsdei:
Period End2020-09-302020-06-302019-12-31
Value250250328
Percentage of Assets0.60.60.9
Percentage of Assets0.60.60.9
Percentage of Assets acgl:BellemeadeRe20181Ltd us-gaap:VariableInterestEntityNotPrimaryBeneficiary100.0100.0100.0

acgl:BellemeadeRe20194Ltd, us-gaap:VariableInterestEntityNotPrimaryBeneficiary


Assetsdei:
Period End2020-09-302020-06-302019-12-31
Value468468577
Percentage of Assets1.11.11.5
Percentage of Assets1.11.11.5
Percentage of Assets acgl:BellemeadeRe20194Ltd us-gaap:VariableInterestEntityNotPrimaryBeneficiary100.0100.0100.0

acgl:WatfordHoldingsLtd, us-gaap:VariableInterestEntityPrimaryBeneficiary


Assetsdei:
Period End2020-09-302020-06-302019-12-31
Value365335473550
Percentage of Assets8.68.69.4
Percentage of Assets8.68.69.4
Percentage of Assets acgl:WatfordHoldingsLtd us-gaap:VariableInterestEntityPrimaryBeneficiary100.0100.0100.0

us-gaap:Assets us-gaap:ConsolidatedEntities

srt:ParentCompany


Assetsus-gaap:
Period End2020-12-312019-12-31
Value1441511825
Percentage of Assets33.331.2
Percentage of Assets33.331.2
Percentage of Assets srt:ParentCompany100.0100.0

us-gaap:VariableInterestEntityNotPrimaryBeneficiary


Assetsus-gaap:
Period End2021-06-302021-03-312020-12-312019-12-31
Value4446420038593425
Percentage of Assets9.69.58.99.0
Percentage of Assets9.69.58.99.0
Percentage of Assets us-gaap:VariableInterestEntityNotPrimaryBeneficiary100.0100.0100.0100.0

us-gaap:Assets us-gaap:ConsolidationItems

us-gaap:OperatingSegments


Assetsus-gaap:
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-31
Value39791343742884529037269892221721054216792132321227205272120721210206531956618930189171875717816
Percentage of Assets91.990.789.590.691.990.590.891.292.492.993.393.894.094.7100.0100.0100.0100.0100.0
Percentage of Assets91.990.789.590.691.990.590.891.292.492.993.393.894.094.7100.0100.0100.0100.0100.0
Percentage of Assets us-gaap:OperatingSegments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:Assets us-gaap:EquityMethodInvestmentNonconsolidatedInvestee

us-gaap:EquityMethodInvestmentNonconsolidatedInvesteeOrGroupOfInvestees


Assetsus-gaap:
Period End2020-12-312019-12-31
Value4907828039
Percentage of Assets113.474.0
Percentage of Assets113.474.0
Percentage of Assets us-gaap:EquityMethodInvestmentNonconsolidatedInvesteeOrGroupOfInvestees100.0100.0

us-gaap:Assets us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities

us-gaap:VariableInterestEntityNotPrimaryBeneficiary


Assetsus-gaap:
Period End2020-09-302020-06-302019-12-31
Value332930353425
Percentage of Assets7.87.49.0
Percentage of Assets7.87.49.0
Percentage of Assets us-gaap:VariableInterestEntityNotPrimaryBeneficiary100.0100.0100.0

us-gaap:Assets us-gaap:StatementBusinessSegments

us-gaap:CorporateAndOther


Assetsus-gaap:
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-31
Value34903510337230142382212214820.00.0
Percentage of Assets8.19.310.59.48.19.26.70.00.0
Percentage of Assets8.19.310.59.48.19.26.70.00.0
Percentage of Assets us-gaap:CorporateAndOther100.0100.0100.0100.0100.0100.0100.00.00.0

Liabilities

us-gaap:Liabilities

us-gaap:Liabilities


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value3151930173292942944828472265002556923510230322281721780218142162221921218052264620880204122006017250167141716716028166281594715551148901552815332148951391813487136831342112647135401347612973125131295512772128661125711052
Percentage of Liabilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets67.868.367.768.969.169.067.566.166.167.267.667.667.968.268.069.467.767.868.367.368.570.069.270.069.168.167.768.767.968.371.171.272.371.671.071.772.972.873.074.374.274.871.471.9

us-gaap:Liabilities dei:LegalEntity, us-gaap:ConsolidatedEntities

acgl:WatfordHoldingsLtd, us-gaap:VariableInterestEntityPrimaryBeneficiary


Liabilitiesdei:
Period End2021-06-302021-03-312020-12-312020-03-312019-12-31
Value32732674253827902626
Percentage of Liabilities10.48.98.710.510.3
Percentage of Assets7.06.05.97.36.9
Percentage of Assets acgl:WatfordHoldingsLtd us-gaap:VariableInterestEntityPrimaryBeneficiary75.372.271.981.974.0

us-gaap:Liabilities dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities

acgl:WatfordHoldingsLtd, us-gaap:VariableInterestEntityPrimaryBeneficiary


Liabilitiesdei:
Period End2020-09-302020-06-302019-12-31
Value273327182626
Percentage of Liabilities9.39.510.3
Percentage of Assets6.46.66.9
Percentage of Assets acgl:WatfordHoldingsLtd us-gaap:VariableInterestEntityPrimaryBeneficiary74.876.674.0

us-gaap:Liabilities us-gaap:ConsolidatedEntities

srt:ParentCompany


Liabilitiesus-gaap:
Period End2020-12-312019-12-31
Value1309328
Percentage of Liabilities4.51.3
Percentage of Assets3.00.9
Percentage of Assets srt:ParentCompany9.12.8

us-gaap:Liabilities us-gaap:ConsolidationItems

us-gaap:OperatingSegments


Liabilitiesus-gaap:
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-31
Value26789229771951819959188551591214956156271529915036144921522315078148601391813487136831342112647
Percentage of Liabilities91.489.989.691.594.092.793.394.095.996.797.398.098.399.8100.0100.0100.0100.0100.0
Percentage of Assets61.960.760.662.364.264.864.565.766.365.865.867.366.868.271.171.272.371.671.0
Percentage of Assets us-gaap:OperatingSegments67.366.867.768.769.971.671.072.171.770.870.671.871.171.971.171.272.371.671.0

us-gaap:Liabilities us-gaap:EquityMethodInvestmentNonconsolidatedInvestee

us-gaap:EquityMethodInvestmentNonconsolidatedInvesteeOrGroupOfInvestees


Liabilitiesus-gaap:
Period End2020-12-312019-12-31
Value60543595
Percentage of Liabilities20.714.1
Percentage of Assets14.09.5
Percentage of Assets us-gaap:EquityMethodInvestmentNonconsolidatedInvesteeOrGroupOfInvestees12.312.8

us-gaap:Liabilities us-gaap:StatementBusinessSegments

us-gaap:CorporateAndOther


Liabilitiesus-gaap:
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-31
Value2505259222621846120510723980.00.0
Percentage of Liabilities8.610.110.48.56.06.72.70.00.0
Percentage of Assets5.86.87.05.84.14.61.80.00.0
Percentage of Assets us-gaap:CorporateAndOther71.873.867.161.250.650.526.90.00.0

Liabilities And Stockholders Equity

us-gaap:LiabilitiesAndStockholdersEquity

us-gaap:LiabilitiesAndStockholdersEquity


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value4648144204432824271641199384163788535572348513397732218322523185332131320513262430862300922937225643244112454123177237702308422849220092261022573218001956618930189171875717816188891849617812171411743017213171911577015375
Percentage of LiabilitiesAndStockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:LiabilitiesAndStockholdersEquity us-gaap:ConsolidatedEntities

srt:ParentCompany


Liabilities
Period End2020-12-312019-12-31
Value1441511825
Percentage of LiabilitiesAndStockholdersEquity33.331.2
Percentage of Assets33.331.2
Percentage of Assets srt:ParentCompany100.0100.0

Stockholders Equity

us-gaap:StockholdersEquity

us-gaap:StockholdersEquity


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-31
Value1398613096131051245111991113671149711158107571011494399355916391509196891188988605825373526703641362046162613762886130608162295892564754435234533551685348502048394592
Percentage of StockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets30.129.630.329.229.129.630.331.430.929.829.329.028.828.528.727.328.828.628.128.727.526.126.825.926.627.527.926.927.627.028.928.827.728.429.028.327.127.226.8

us-gaap:StockholdersEquity us-gaap:CumulativeEffectPeriodOfAdoption, us-gaap:StatementEquityComponents

srt:CumulativeEffectPeriodOfAdoptionAdjustedBalance, us-gaap:RetainedEarnings


Stockholders
Period End2021-03-312020-12-312020-06-302020-03-312019-12-312019-06-302019-03-312018-12-312017-12-31
Value127901236211420111321099810322986494268712
Percentage of StockholdersEquity97.794.395.297.995.796.097.599.994.7
Percentage of Assets28.928.627.729.029.029.629.029.327.2
Percentage of Assets srt:CumulativeEffectPeriodOfAdoptionAdjustedBalance us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.0

us-gaap:StockholdersEquity us-gaap:StatementEquityComponents

us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312011-12-31
Value26424650143841811325828326197-114.178-172.22-143.353-96.23815718614368-27.64119223115050651102131611222301308049-12.754260289174
Percentage of StockholdersEquity1.91.93.83.53.51.02.22.52.41.0-1.2-1.8-1.6-1.11.72.11.60.8-0.32.63.42.40.81.11.83.42.62.03.72.21.40.9-0.24.95.63.8
Percentage of Assets0.60.61.21.01.00.30.70.80.80.3-0.4-0.5-0.5-0.30.50.60.50.2-0.10.80.90.60.20.30.50.90.70.51.00.60.40.3-0.11.41.61.0
Percentage of Assets us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AccumulatedOtherComprehensiveIncome


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312010-12-31
Value2302054883863492121221120638-178.72-221.041-194.157-134.00911812978-15.677-114.541119163101-16.5029.809661581281022331237441-49.322229287324193234153204
Percentage of StockholdersEquity1.61.63.73.12.90.21.81.91.90.4-1.9-2.4-2.1-1.51.31.50.9-0.2-1.41.62.41.6-0.30.21.12.52.11.73.82.11.30.8-0.94.35.66.13.84.83.40.0
Percentage of Assets0.50.51.10.90.80.10.60.60.60.1-0.6-0.7-0.6-0.40.40.40.3-0.1-0.40.50.70.4-0.10.00.30.70.60.51.00.60.40.2-0.31.21.61.71.01.30.91.3
Percentage of Assets us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AccumulatedTranslationAdjustment


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312011-12-31
Value-34.654-40.884-12.4-51.93-68.999-91.205-46.395-71.479-54.8-58.879-64.542-48.821-50.804-37.771-39.356-56.72-65.411-83.784-86.9-72.596-67.225-49.116-66.587-55.905-43.919-55.499-32.742-20.6512.944-7.077-5.728-7.045-36.568-31.161-2.939-20.713
Percentage of StockholdersEquity-0.2-0.3-0.1-0.4-0.6-0.8-0.4-0.6-0.5-0.6-0.7-0.5-0.6-0.4-0.4-0.6-0.7-1.0-1.1-1.0-1.0-0.8-1.1-0.9-0.7-0.9-0.5-0.30.0-0.1-0.1-0.1-0.7-0.6-0.1-0.5
Percentage of Assets-0.1-0.1-0.0-0.1-0.2-0.2-0.1-0.2-0.2-0.2-0.2-0.2-0.2-0.1-0.1-0.2-0.2-0.3-0.3-0.3-0.3-0.2-0.3-0.2-0.2-0.2-0.1-0.10.0-0.0-0.0-0.0-0.2-0.2-0.0-0.1
Percentage of Assets us-gaap:AccumulatedTranslationAdjustment0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AdditionalPaidInCapital


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312010-12-31
Value20282014197719501935192118891864184718191793177517601737123012121196548531516517485467450437399383366353320299283272242227211197170161110
Percentage of StockholdersEquity14.515.415.115.716.116.916.416.717.218.019.019.019.219.013.413.613.46.46.47.07.77.67.57.37.16.46.26.05.75.45.35.25.24.54.43.93.93.53.50.0
Percentage of Assets4.44.64.64.64.75.05.05.25.35.45.65.55.55.43.83.73.91.81.82.02.12.02.01.91.91.71.71.61.61.51.51.51.41.31.31.11.11.00.90.7
Percentage of Assets us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CommonStock


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312010-12-31
Value0.6470.6450.6430.6420.6420.6420.6380.6380.6380.6360.6340.6330.6330.630.6110.610.6090.5830.5820.5820.5810.5790.5770.5760.5760.5730.5720.5710.570.5670.5650.5650.5640.5610.5610.5560.5560.5520.5490.534
Percentage of StockholdersEquity0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:CommonStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:PreferredStock


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312010-12-31
Value1280780780780780780780780780780780780780780872772772772772775325325325325325325325325325325325325325325325325325325325325
Percentage of StockholdersEquity9.26.06.06.36.56.96.87.07.37.78.38.38.58.59.58.78.79.09.410.54.85.15.25.35.35.25.35.35.25.55.86.06.26.16.36.16.56.77.10.0
Percentage of Assets2.81.81.81.81.92.02.12.22.22.32.42.42.42.42.72.42.52.62.63.01.31.31.41.41.41.41.51.41.41.51.71.71.71.71.81.71.81.81.92.1
Percentage of Assets us-gaap:PreferredStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:RetainedEarnings


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312010-12-31
Value1345412790123621182911420111321102110705103229864942693009083884985628359841282387996797277257519737073177242713268546644642162196042588657765605535453405156495447964386
Percentage of StockholdersEquity96.297.794.395.095.297.995.995.996.097.599.999.499.196.793.193.894.595.796.9108.4115.2117.2118.8118.7118.0113.4111.8109.3103.1105.6107.0108.1110.4105.1103.699.8102.7102.4104.50.0
Percentage of Assets28.928.928.627.727.729.029.130.129.629.029.328.828.527.526.725.627.327.427.231.131.630.631.830.831.431.231.129.428.428.530.931.130.529.930.128.327.927.828.027.8
Percentage of Assets us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:TreasuryStock


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312010-12-31
Value-3007.578-2694.957-2503.909-2495.106-2494.505-2489.097-2406.047-2403.749-2401.037-2388.392-2382.167-2280.151-2266.529-2084.186-2077.741-2053.644-2051.343-2039.27-2034.57-2031.859-2028.69-2019.249-1941.904-1940.795-1934.763-1727.074-1562.019-1358.011-1104.963-1096.826-1094.704-1093.833-1091.687-1067.439-1025.839-852.742-852.419-845.708-845.472-549.912
Percentage of StockholdersEquity-21.5-20.6-19.1-20.0-20.8-21.9-20.9-21.5-22.3-23.6-25.2-24.4-24.7-22.8-22.6-23.0-23.1-23.7-24.7-27.6-30.3-31.5-31.3-31.5-31.5-27.5-25.5-22.3-17.7-18.6-19.4-20.1-20.9-20.0-19.8-15.9-17.0-17.5-18.40.0
Percentage of Assets-6.5-6.1-5.8-5.8-6.1-6.5-6.4-6.8-6.9-7.0-7.4-7.1-7.1-6.5-6.5-6.3-6.6-6.8-6.9-7.9-8.3-8.2-8.4-8.2-8.4-7.6-7.1-6.0-4.9-5.0-5.6-5.8-5.8-5.7-5.8-4.5-4.6-4.7-4.9-3.5
Percentage of Assets us-gaap:TreasuryStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Cash And Cash Equivalents At Carrying Value

us-gaap:CashAndCashEquivalentsAtCarryingValue

us-gaap:CashAndCashEquivalentsAtCarryingValue


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312008-12-312007-12-31
Value12349419069768548827268806056336466515266806068627407038425785165575536495254714856639261569434436375356371422355422351369411406362365341338334251239
Percentage of CashAndCashEquivalentsAtCarryingValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets2.72.12.12.32.12.31.92.51.71.92.02.01.72.11.92.62.42.32.92.32.12.32.42.72.32.12.22.94.17.22.22.32.01.92.12.21.92.42.12.12.42.42.30.00.00.02.20.00.0

us-gaap:CashAndCashEquivalentsAtCarryingValue dei:LegalEntity, us-gaap:ConsolidatedEntities

acgl:WatfordHoldingsLtd, us-gaap:VariableInterestEntityPrimaryBeneficiary


Cash
Period End2021-06-302021-03-312020-12-312020-03-312019-12-31
Value34923621196102
Percentage of CashAndCashEquivalentsAtCarryingValue28.325.123.310.914.1
Percentage of Assets0.80.50.50.30.3
Percentage of Assets acgl:WatfordHoldingsLtd us-gaap:VariableInterestEntityPrimaryBeneficiary8.06.46.02.82.9

us-gaap:CashAndCashEquivalentsAtCarryingValue dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities

acgl:WatfordHoldingsLtd, us-gaap:VariableInterestEntityPrimaryBeneficiary


Cash
Period End2020-09-302020-06-302019-12-31
Value195107102
Percentage of CashAndCashEquivalentsAtCarryingValue20.012.614.1
Percentage of Assets0.50.30.3
Percentage of Assets acgl:WatfordHoldingsLtd us-gaap:VariableInterestEntityPrimaryBeneficiary5.33.02.9

us-gaap:CashAndCashEquivalentsAtCarryingValue us-gaap:ConsolidatedEntities

srt:ParentCompany


Cash
Period End2020-12-312019-12-31
Value1818
Percentage of CashAndCashEquivalentsAtCarryingValue2.12.5
Percentage of Assets0.00.0
Percentage of Assets srt:ParentCompany0.10.2

Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312015-12-31
Value181813671290118610641070903962683710724709583732727980895809969681
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets3.93.13.02.82.62.82.42.72.02.12.22.21.82.32.33.02.92.73.32.9

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents us-gaap:ConsolidatedEntities

us-gaap:Parent


Cash
Period End2020-12-312019-12-312018-12-312017-12-31
Value18186.15910
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents1.52.00.81.4
Percentage of Assets0.00.00.00.0
Percentage of Assets us-gaap:Parent0.00.00.00.0

Amortization Of Intangible Assets

us-gaap:AmortizationOfIntangibleAssets

us-gaap:AmortizationOfIntangibleAssets


Amortization
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value1514191616162120192026262626313130314.8424.8654.884.748
Percentage of AmortizationOfIntangibleAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AmortizationOfIntangibleAssets us-gaap:ConsolidationItems

us-gaap:OperatingSegments


Amortization
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value14191616162120192026262626313130314.854.8654.884.748
Percentage of AmortizationOfIntangibleAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.2100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:OperatingSegments0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AmortizationOfIntangibleAssets us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, us-gaap:AllOtherSegments


Amortization
Period End2021-06-30
Value0.898
Percentage of AmortizationOfIntangibleAssets5.9
Percentage of Assets0.0
Percentage of Assets us-gaap:OperatingSegments us-gaap:AllOtherSegments0.0

us-gaap:OperatingSegments, us-gaap:Corporate


Amortization
Period End2021-06-302020-06-30
Value1416
Percentage of AmortizationOfIntangibleAssets94.1100.0
Percentage of Assets0.00.0
Percentage of Assets us-gaap:OperatingSegments us-gaap:Corporate0.00.0

Goodwill

us-gaap:Goodwill

us-gaap:Goodwill


Goodwill
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-31
Value31432624919820415140.00.0
Percentage of Goodwill100.0100.0100.0100.0100.0100.0100.00.00.0
Percentage of Assets0.70.90.80.60.70.10.10.00.0

us-gaap:Goodwill us-gaap:FairValueByAssetClass

us-gaap:Goodwill


Goodwillus-gaap:
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-31
Value3143262491982041514
Percentage of Goodwill100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.70.90.80.60.70.10.1
Percentage of Assets us-gaap:Goodwill0.00.00.00.00.00.00.0

Indefinite Lived Intangible Assets Excluding Goodwill

us-gaap:IndefiniteLivedIntangibleAssetsExcludingGoodwill

us-gaap:IndefiniteLivedIntangibleAssetsExcludingGoodwill


Indefinite
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-31
Value798561686833331616
Percentage of IndefiniteLivedIntangibleAssetsExcludingGoodwill100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.20.20.20.20.20.10.20.10.1

us-gaap:IndefiniteLivedIntangibleAssetsExcludingGoodwill us-gaap:FairValueByAssetClass

us-gaap:IndefinitelivedIntangibleAssets


Indefinite
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-31
Value79856168683333
Percentage of IndefiniteLivedIntangibleAssetsExcludingGoodwill100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.20.20.20.20.20.10.2
Percentage of Assets us-gaap:IndefinitelivedIntangibleAssets0.00.00.00.00.00.00.0

Finite Lived Intangible Assets Net

us-gaap:FiniteLivedIntangibleAssetsNet

us-gaap:FiniteLivedIntangibleAssetsNet


Finite
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-31
Value29932532338650948611021
Percentage of FiniteLivedIntangibleAssetsNet100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.70.91.01.21.70.20.30.10.1

us-gaap:FiniteLivedIntangibleAssetsNet us-gaap:FairValueByAssetClass

us-gaap:FiniteLivedIntangibleAssets


Finite
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-31
Value2993253233865094861
Percentage of FiniteLivedIntangibleAssetsNet100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.70.91.01.21.70.20.3
Percentage of Assets us-gaap:FiniteLivedIntangibleAssets0.00.00.00.00.00.00.0

Intangible Assets Net Including Goodwill

us-gaap:IntangibleAssetsNetIncludingGoodwill

us-gaap:IntangibleAssetsNetIncludingGoodwill


Intangible
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302012-12-31
Value6676796927136887057386246416596345665936266526847127507819088929710310210610911111812027283038
Percentage of IntangibleAssetsNetIncludingGoodwill100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets1.41.51.61.71.71.81.91.81.81.92.01.81.91.92.02.12.32.52.70.40.40.40.40.40.40.50.50.50.50.60.10.20.20.2

us-gaap:IntangibleAssetsNetIncludingGoodwill dei:LegalEntity, us-gaap:ConsolidatedEntities

acgl:WatfordHoldingsLtd, us-gaap:VariableInterestEntityPrimaryBeneficiary


Intangible
Period End2021-06-302021-03-312020-12-312020-03-312019-12-31
Value107.657.657.657.65
Percentage of IntangibleAssetsNetIncludingGoodwill1.51.11.11.11.0
Percentage of Assets0.00.00.00.00.0
Percentage of Assets acgl:WatfordHoldingsLtd us-gaap:VariableInterestEntityPrimaryBeneficiary0.20.20.20.20.2

us-gaap:IntangibleAssetsNetIncludingGoodwill us-gaap:ConsolidationItems

us-gaap:OperatingSegments


Intangible
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302012-12-31
Value6716857066806977306166336516275595856186446767057427738388929710310210610911111812027283038
Percentage of IntangibleAssetsNetIncludingGoodwill98.998.998.998.998.999.098.898.898.898.898.698.798.898.898.998.999.099.091.6100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.1100.0100.099.9
Percentage of Assets1.51.61.71.71.81.91.71.81.91.91.71.81.92.02.12.32.52.60.30.40.40.40.40.40.50.50.50.50.60.10.20.20.2
Percentage of Assets us-gaap:OperatingSegments0.01.70.00.00.02.10.00.00.02.20.00.00.02.20.00.00.02.90.00.00.40.50.50.50.50.50.50.60.60.10.20.20.2

us-gaap:IntangibleAssetsNetIncludingGoodwill us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, acgl:InsuranceSegment


Intangible
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302012-12-31
Value2702762802822632682891581571561142020212223242425262727282930302824242020202021
Percentage of IntangibleAssetsNetIncludingGoodwill40.540.640.639.538.238.039.225.524.623.818.03.63.53.53.43.43.43.23.229.031.130.029.528.830.228.625.921.520.616.774.871.367.555.8
Percentage of Assets0.60.60.60.70.60.70.80.40.50.50.40.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.1
Percentage of Assets us-gaap:OperatingSegments acgl:InsuranceSegment0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, acgl:MortgageSegment


Intangible
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302012-12-31
Value37037738540341542643845747549451353856459662265268071774755596366716973778389940.00.00.00.0
Percentage of IntangibleAssetsNetIncludingGoodwill55.555.655.656.660.360.559.573.374.275.180.895.195.295.395.495.495.495.695.761.267.368.168.569.167.468.971.174.975.278.50.00.00.00.0
Percentage of Assets0.80.90.90.91.01.11.21.31.41.51.61.71.81.91.92.02.22.42.50.20.20.30.30.30.30.30.40.40.40.40.00.00.00.0
Percentage of Assets us-gaap:OperatingSegments acgl:MortgageSegment0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, acgl:ReinsuranceSegment


Intangible
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302012-12-31
Value161718202.5162.5162.5160.00.00.00.00.00.00.00.2110.4170.6090.7730.9561.2281.441.7131.8752.1492.422.6873.3333.9394.9425.8036.98.3071016
Percentage of IntangibleAssetsNetIncludingGoodwill2.42.62.72.80.40.40.30.00.00.00.00.00.00.00.00.10.10.10.11.41.61.81.92.12.42.53.03.54.24.825.328.732.544.1
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.10.1
Percentage of Assets us-gaap:OperatingSegments acgl:ReinsuranceSegment0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, acgl:UnderwritingSegments


Intangible
Period End2021-06-302020-06-30
Value656680
Percentage of IntangibleAssetsNetIncludingGoodwill98.598.9
Percentage of Assets1.41.7
Percentage of Assets us-gaap:OperatingSegments acgl:UnderwritingSegments0.00.0

us-gaap:OperatingSegments, us-gaap:AllOtherSegments


Intangible
Period End2021-06-302020-06-30
Value107.65
Percentage of IntangibleAssetsNetIncludingGoodwill1.51.1
Percentage of Assets0.00.0
Percentage of Assets us-gaap:OperatingSegments us-gaap:AllOtherSegments0.00.0

us-gaap:IntangibleAssetsNetIncludingGoodwill us-gaap:StatementBusinessSegments

us-gaap:CorporateAndOther


Intangible
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302014-12-312013-12-312012-12-31
Value7.657.657.657.657.657.657.657.657.657.657.657.657.657.657.657.657.657.657.650.00.00.00.00.00.00.00.0
Percentage of IntangibleAssetsNetIncludingGoodwill1.11.11.11.11.11.01.21.21.21.21.41.31.21.21.11.11.01.08.40.00.00.00.00.00.00.00.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:CorporateAndOther0.00.20.00.00.00.20.00.00.00.20.00.00.00.30.00.00.00.30.00.00.00.00.00.00.00.00.0

Deferred Tax Assets Liabilities Net

us-gaap:DeferredTaxAssetsLiabilitiesNet

us-gaap:DeferredTaxAssetsLiabilitiesNet


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-31
Value9348152922179.72839248221227221124113123135139143124130155151151128143140112989399976766558066
Percentage of DeferredTaxAssetsLiabilitiesNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.20.10.00.10.10.10.00.10.10.80.70.80.80.50.50.50.60.60.60.50.60.70.70.70.70.80.70.60.60.50.50.50.40.40.30.50.4

Operating Lease Right Of Use Asset

us-gaap:OperatingLeaseRightOfUseAsset us-gaap:BalanceSheetLocation

us-gaap:OperatingLeaseRightOfUseAsset

us-gaap:OtherAssets


Operating
Period End2020-12-312020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value115119127131131134140
Percentage of OperatingLeaseRightOfUseAsset100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.30.30.30.30.40.40.4
Percentage of Assets us-gaap:OtherAssets0.00.00.00.00.00.00.0

Equity Securities Fv Ni

us-gaap:EquitySecuritiesFvNi

us-gaap:EquitySecuritiesFvNi


Equity
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-31
Value169315321444150212571181838550670495338444495
Percentage of EquitySecuritiesFvNi100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets3.63.53.33.53.13.12.21.51.91.51.11.41.5

us-gaap:EquitySecuritiesFvNi dei:LegalEntity, us-gaap:ConsolidatedEntities

acgl:WatfordHoldingsLtd, us-gaap:VariableInterestEntityPrimaryBeneficiary


Equity
Period End2021-06-302021-03-312020-12-312020-03-312019-12-31
Value9762526365
Percentage of EquitySecuritiesFvNi5.84.13.65.37.8
Percentage of Assets0.20.10.10.20.2
Percentage of Assets acgl:WatfordHoldingsLtd us-gaap:VariableInterestEntityPrimaryBeneficiary2.21.71.51.91.8

us-gaap:EquitySecuritiesFvNi dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities

acgl:WatfordHoldingsLtd, us-gaap:VariableInterestEntityPrimaryBeneficiary


Equity
Period End2020-09-302020-06-302019-12-31
Value526265
Percentage of EquitySecuritiesFvNi3.55.07.8
Percentage of Assets0.10.20.2
Percentage of Assets acgl:WatfordHoldingsLtd us-gaap:VariableInterestEntityPrimaryBeneficiary1.41.81.8

Other Assets

us-gaap:OtherAssets

us-gaap:OtherAssets


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value23572135185317711632150913831192113510359299741000922105310121014930889679680898968899905933927840888926899570566540519509518497445727746734669609
Percentage of OtherAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets5.14.84.34.14.03.93.73.43.33.02.93.03.12.93.33.13.33.13.02.62.83.74.23.83.94.14.23.73.94.24.63.03.02.92.92.72.82.82.64.24.34.34.24.0

us-gaap:OtherAssets dei:LegalEntity, us-gaap:ConsolidatedEntities

acgl:WatfordHoldingsLtd, us-gaap:VariableInterestEntityPrimaryBeneficiary


Other
Period End2021-06-302021-03-312020-12-312020-03-312019-12-31
Value11287756760
Percentage of OtherAssets4.84.14.14.54.3
Percentage of Assets0.20.20.20.20.2
Percentage of Assets acgl:WatfordHoldingsLtd us-gaap:VariableInterestEntityPrimaryBeneficiary2.62.42.12.01.7

us-gaap:OtherAssets dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities

acgl:WatfordHoldingsLtd, us-gaap:VariableInterestEntityPrimaryBeneficiary


Other
Period End2020-09-302020-06-302019-12-31
Value756360
Percentage of OtherAssets4.23.94.3
Percentage of Assets0.20.20.2
Percentage of Assets acgl:WatfordHoldingsLtd us-gaap:VariableInterestEntityPrimaryBeneficiary2.11.81.7

us-gaap:OtherAssets us-gaap:ConsolidatedEntities

srt:ParentCompany


Other
Period End2020-12-312019-12-31
Value1820
Percentage of OtherAssets1.01.5
Percentage of Assets0.00.1
Percentage of Assets srt:ParentCompany0.10.2

Accrued Income Taxes Current

us-gaap:AccruedIncomeTaxesCurrent

us-gaap:AccruedIncomeTaxesCurrent


Accrued
Period End2020-12-31
Value9200000.0
Percentage of AccruedIncomeTaxesCurrent100.0
Percentage of Assets0.0

Minority Interest

us-gaap:MinorityInterest

us-gaap:MinorityInterest


Minority
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-31
Value9188768237576794927628548558387918768618548438608778688518347887547387747947897697827927930.00.00.00.00.0
Percentage of MinorityInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.00.00.0
Percentage of Assets2.02.01.91.81.61.32.02.42.52.52.52.72.72.72.62.62.82.92.93.33.23.13.23.33.43.53.53.53.53.60.00.00.00.00.0

us-gaap:MinorityInterest dei:LegalEntity

acgl:WatfordHoldingsLtd


Minority
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value918876823757679492762854855838791876861843
Percentage of MinorityInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets2.02.01.91.81.61.32.02.42.52.52.52.72.72.6
Percentage of Assets acgl:WatfordHoldingsLtd0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:MinorityInterest dei:LegalEntity, us-gaap:StatementEquityComponents

acgl:WatfordHoldingsLtd, us-gaap:NoncontrollingInterest


Minority
Period End2020-12-312019-12-312018-12-312017-12-312014-06-302014-03-312013-12-31
Value8237627918437927930.0
Percentage of MinorityInterest100.0100.0100.0100.0100.0100.00.0
Percentage of Assets1.92.02.52.63.53.60.0
Percentage of Assets acgl:WatfordHoldingsLtd us-gaap:NoncontrollingInterest0.00.00.00.00.00.00.0

Lessee Operating Lease Liability Payments Due Year Two

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo


Lessee
Period End2020-12-31
Value30
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearTwo100.0
Percentage of Assets0.1

Lessee Operating Lease Liability Payments Due Year Three

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearThree

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearThree


Lessee
Period End2020-12-31
Value25
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearThree100.0
Percentage of Assets0.1

Lessee Operating Lease Liability Payments Due Year Four

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour


Lessee
Period End2020-12-31
Value19
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearFour100.0
Percentage of Assets0.0

Lessee Operating Lease Liability Payments Due Year Five

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFive

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFive


Lessee
Period End2020-12-31
Value13
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearFive100.0
Percentage of Assets0.0

Lessee Operating Lease Liability Payments Due After Year Five

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive


Lessee
Period End2020-12-31
Value31
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive100.0
Percentage of Assets0.1

Operating Lease Liability

us-gaap:OperatingLeaseLiability

us-gaap:OperatingLeaseLiability


Operating
Period End2020-12-312020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value136139145150147150157
Percentage of OperatingLeaseLiability100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.30.30.40.40.40.40.5

us-gaap:OperatingLeaseLiability us-gaap:BalanceSheetLocation

us-gaap:OtherLiabilities


Operating
Period End2020-12-312020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value136139145150147150157
Percentage of OperatingLeaseLiability100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.30.30.40.40.40.40.5
Percentage of Assets us-gaap:OtherLiabilities0.00.00.00.00.00.00.0

Lessee Operating Lease Liability Payments Due

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDue

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDue


Lessee
Period End2020-12-31
Value152
Percentage of LesseeOperatingLeaseLiabilityPaymentsDue100.0
Percentage of Assets0.4

Lessee Operating Lease Liability Undiscounted Excess Amount

us-gaap:LesseeOperatingLeaseLiabilityUndiscountedExcessAmount

us-gaap:LesseeOperatingLeaseLiabilityUndiscountedExcessAmount


Lessee
Period End2020-12-31
Value16
Percentage of LesseeOperatingLeaseLiabilityUndiscountedExcessAmount100.0
Percentage of Assets0.0

Stockholders Equity

us-gaap:StockholdersEquity

us-gaap:StockholdersEquity


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-31
Value1398613096131051245111991113671149711158107571011494399355916391509196891188988605825373526703641362046162613762886130608162295892564754435234533551685348502048394592
Percentage of StockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets30.129.630.329.229.129.630.331.430.929.829.329.028.828.528.727.328.828.628.128.727.526.126.825.926.627.527.926.927.627.028.928.827.728.429.028.327.127.226.8

us-gaap:StockholdersEquity us-gaap:CumulativeEffectPeriodOfAdoption, us-gaap:StatementEquityComponents

srt:CumulativeEffectPeriodOfAdoptionAdjustedBalance, us-gaap:RetainedEarnings


Stockholders
Period End2021-03-312020-12-312020-06-302020-03-312019-12-312019-06-302019-03-312018-12-312017-12-31
Value127901236211420111321099810322986494268712
Percentage of StockholdersEquity97.794.395.297.995.796.097.599.994.7
Percentage of Assets28.928.627.729.029.029.629.029.327.2
Percentage of Assets srt:CumulativeEffectPeriodOfAdoptionAdjustedBalance us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.0

us-gaap:StockholdersEquity us-gaap:StatementEquityComponents

us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312011-12-31
Value26424650143841811325828326197-114.178-172.22-143.353-96.23815718614368-27.64119223115050651102131611222301308049-12.754260289174
Percentage of StockholdersEquity1.91.93.83.53.51.02.22.52.41.0-1.2-1.8-1.6-1.11.72.11.60.8-0.32.63.42.40.81.11.83.42.62.03.72.21.40.9-0.24.95.63.8
Percentage of Assets0.60.61.21.01.00.30.70.80.80.3-0.4-0.5-0.5-0.30.50.60.50.2-0.10.80.90.60.20.30.50.90.70.51.00.60.40.3-0.11.41.61.0
Percentage of Assets us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AccumulatedOtherComprehensiveIncome


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312010-12-31
Value2302054883863492121221120638-178.72-221.041-194.157-134.00911812978-15.677-114.541119163101-16.5029.809661581281022331237441-49.322229287324193234153204
Percentage of StockholdersEquity1.61.63.73.12.90.21.81.91.90.4-1.9-2.4-2.1-1.51.31.50.9-0.2-1.41.62.41.6-0.30.21.12.52.11.73.82.11.30.8-0.94.35.66.13.84.83.40.0
Percentage of Assets0.50.51.10.90.80.10.60.60.60.1-0.6-0.7-0.6-0.40.40.40.3-0.1-0.40.50.70.4-0.10.00.30.70.60.51.00.60.40.2-0.31.21.61.71.01.30.91.3
Percentage of Assets us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AccumulatedTranslationAdjustment


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312011-12-31
Value-34.654-40.884-12.4-51.93-68.999-91.205-46.395-71.479-54.8-58.879-64.542-48.821-50.804-37.771-39.356-56.72-65.411-83.784-86.9-72.596-67.225-49.116-66.587-55.905-43.919-55.499-32.742-20.6512.944-7.077-5.728-7.045-36.568-31.161-2.939-20.713
Percentage of StockholdersEquity-0.2-0.3-0.1-0.4-0.6-0.8-0.4-0.6-0.5-0.6-0.7-0.5-0.6-0.4-0.4-0.6-0.7-1.0-1.1-1.0-1.0-0.8-1.1-0.9-0.7-0.9-0.5-0.30.0-0.1-0.1-0.1-0.7-0.6-0.1-0.5
Percentage of Assets-0.1-0.1-0.0-0.1-0.2-0.2-0.1-0.2-0.2-0.2-0.2-0.2-0.2-0.1-0.1-0.2-0.2-0.3-0.3-0.3-0.3-0.2-0.3-0.2-0.2-0.2-0.1-0.10.0-0.0-0.0-0.0-0.2-0.2-0.0-0.1
Percentage of Assets us-gaap:AccumulatedTranslationAdjustment0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AdditionalPaidInCapital


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312010-12-31
Value20282014197719501935192118891864184718191793177517601737123012121196548531516517485467450437399383366353320299283272242227211197170161110
Percentage of StockholdersEquity14.515.415.115.716.116.916.416.717.218.019.019.019.219.013.413.613.46.46.47.07.77.67.57.37.16.46.26.05.75.45.35.25.24.54.43.93.93.53.50.0
Percentage of Assets4.44.64.64.64.75.05.05.25.35.45.65.55.55.43.83.73.91.81.82.02.12.02.01.91.91.71.71.61.61.51.51.51.41.31.31.11.11.00.90.7
Percentage of Assets us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CommonStock


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312010-12-31
Value0.6470.6450.6430.6420.6420.6420.6380.6380.6380.6360.6340.6330.6330.630.6110.610.6090.5830.5820.5820.5810.5790.5770.5760.5760.5730.5720.5710.570.5670.5650.5650.5640.5610.5610.5560.5560.5520.5490.534
Percentage of StockholdersEquity0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:CommonStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:PreferredStock


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312010-12-31
Value1280780780780780780780780780780780780780780872772772772772775325325325325325325325325325325325325325325325325325325325325
Percentage of StockholdersEquity9.26.06.06.36.56.96.87.07.37.78.38.38.58.59.58.78.79.09.410.54.85.15.25.35.35.25.35.35.25.55.86.06.26.16.36.16.56.77.10.0
Percentage of Assets2.81.81.81.81.92.02.12.22.22.32.42.42.42.42.72.42.52.62.63.01.31.31.41.41.41.41.51.41.41.51.71.71.71.71.81.71.81.81.92.1
Percentage of Assets us-gaap:PreferredStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:RetainedEarnings


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312010-12-31
Value1345412790123621182911420111321102110705103229864942693009083884985628359841282387996797277257519737073177242713268546644642162196042588657765605535453405156495447964386
Percentage of StockholdersEquity96.297.794.395.095.297.995.995.996.097.599.999.499.196.793.193.894.595.796.9108.4115.2117.2118.8118.7118.0113.4111.8109.3103.1105.6107.0108.1110.4105.1103.699.8102.7102.4104.50.0
Percentage of Assets28.928.928.627.727.729.029.130.129.629.029.328.828.527.526.725.627.327.427.231.131.630.631.830.831.431.231.129.428.428.530.931.130.529.930.128.327.927.828.027.8
Percentage of Assets us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:TreasuryStock


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312010-12-31
Value-3007.578-2694.957-2503.909-2495.106-2494.505-2489.097-2406.047-2403.749-2401.037-2388.392-2382.167-2280.151-2266.529-2084.186-2077.741-2053.644-2051.343-2039.27-2034.57-2031.859-2028.69-2019.249-1941.904-1940.795-1934.763-1727.074-1562.019-1358.011-1104.963-1096.826-1094.704-1093.833-1091.687-1067.439-1025.839-852.742-852.419-845.708-845.472-549.912
Percentage of StockholdersEquity-21.5-20.6-19.1-20.0-20.8-21.9-20.9-21.5-22.3-23.6-25.2-24.4-24.7-22.8-22.6-23.0-23.1-23.7-24.7-27.6-30.3-31.5-31.3-31.5-31.5-27.5-25.5-22.3-17.7-18.6-19.4-20.1-20.9-20.0-19.8-15.9-17.0-17.5-18.40.0
Percentage of Assets-6.5-6.1-5.8-5.8-6.1-6.5-6.4-6.8-6.9-7.0-7.4-7.1-7.1-6.5-6.5-6.3-6.6-6.8-6.9-7.9-8.3-8.2-8.4-8.2-8.4-7.6-7.1-6.0-4.9-5.0-5.6-5.8-5.8-5.7-5.8-4.5-4.6-4.7-4.9-3.5
Percentage of Assets us-gaap:TreasuryStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Stockholders Equity Including Portion Attributable To Noncontrolling Interest

us-gaap:StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest

us-gaap:StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-312008-12-31
Value149041397313928132091267011860122601201311612109521023110231100241000410040977297769474910581877492716869436936693270786899686370216685564754435234533551685348502048394628447444414325451343233432
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets32.131.632.230.930.830.932.433.833.332.231.831.731.531.131.330.031.731.531.031.930.729.230.029.230.031.031.330.431.130.728.928.827.728.429.028.327.127.227.025.725.825.228.628.10.0

us-gaap:StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest us-gaap:ConsolidatedEntities

srt:ParentCompany


Stockholders
Period End2020-12-312019-12-31
Value1310511497
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest94.193.8
Percentage of Assets30.330.3
Percentage of Assets srt:ParentCompany90.997.2

Common Stock Value

us-gaap:CommonStockValue

us-gaap:CommonStockValue


Common
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value647000.0645000.0643000.0642000.0642000.0642000.0638000.0638000.0638000.0636000.0634000.0633000.0633000.0630000.0611000.0610000.0609000.0583000.0582000.0582000.0581000.0579000.0577000.0576000.0576000.0573000.0572000.0571000.0570000.0567000.0565000.0565000.0564000.0561000.0561000.0556000.0556000.0552000.0549000.0544000.0541000.0535000.0534000.0548000.0
Percentage of CommonStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CommonStockValue us-gaap:ConsolidatedEntities

srt:ParentCompany


Common
Period End2020-12-312019-12-31
Value643000.0638000.0
Percentage of CommonStockValue100.0100.0
Percentage of Assets0.00.0
Percentage of Assets srt:ParentCompany0.00.0

Additional Paid In Capital Common Stock

us-gaap:AdditionalPaidInCapitalCommonStock

us-gaap:AdditionalPaidInCapitalCommonStock


Additional
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value20282014197719501935192118891864184718191793177517601737123012121196548531516517485467450437399383366353320299283272242227200187170161150142120110253
Percentage of AdditionalPaidInCapitalCommonStock100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets4.44.64.64.64.75.05.05.25.35.45.65.55.55.43.83.73.91.81.82.02.12.02.01.91.91.71.71.61.61.51.51.51.41.31.31.11.01.00.90.90.80.70.71.6

us-gaap:AdditionalPaidInCapitalCommonStock us-gaap:ConsolidatedEntities

srt:ParentCompany


Additional
Period End2020-12-312019-12-31
Value19771889
Percentage of AdditionalPaidInCapitalCommonStock100.0100.0
Percentage of Assets4.65.0
Percentage of Assets srt:ParentCompany13.716.0

Retained Earnings Accumulated Deficit

us-gaap:RetainedEarningsAccumulatedDeficit

us-gaap:RetainedEarningsAccumulatedDeficit


Retained
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value13454127901236211829114201113211021107051032298649426930090838849856283598412823879967972772575197370731772427132685466446421621960425886577656055354535151674954483346964533444144223605
Percentage of RetainedEarningsAccumulatedDeficit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets28.928.928.627.727.729.029.130.129.629.029.328.828.527.526.725.627.327.427.231.131.630.631.830.831.431.231.129.428.428.530.931.130.529.930.128.327.927.828.226.926.325.828.023.5

us-gaap:RetainedEarningsAccumulatedDeficit us-gaap:ConsolidatedEntities

srt:ParentCompany


Retained
Period End2020-12-312019-12-31
Value1236211021
Percentage of RetainedEarningsAccumulatedDeficit100.0100.0
Percentage of Assets28.629.1
Percentage of Assets srt:ParentCompany85.893.2

Accumulated Other Comprehensive Income Loss Net Of Tax

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax


Accumulated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value2302054883863492121221120638-178.72-221.041-194.157-134.00911812978-15.677-114.541119163101-16.5029.809661581281022331237441-49.322229287324193234153146263225204138
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.50.51.10.90.80.10.60.60.60.1-0.6-0.7-0.6-0.40.40.40.3-0.1-0.40.50.70.4-0.10.00.30.70.60.51.00.60.40.2-0.31.21.61.71.01.30.90.81.51.31.30.9

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax us-gaap:ConsolidatedEntities

srt:ParentCompany


Accumulated
Period End2020-12-312019-12-31
Value488212
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax100.0100.0
Percentage of Assets1.10.6
Percentage of Assets srt:ParentCompany3.41.8

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax us-gaap:StatementEquityComponents

us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss


Accumulated
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312013-09-302013-06-302013-03-312012-12-312011-12-312010-12-31
Value501258-114.178157-27.641501618049-12.753260289174213
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax102.5121.963.9133.324.1-303.5125.4107.6116.825.9113.6101.0113.5104.6
Percentage of Assets1.20.7-0.40.5-0.10.20.70.40.3-0.11.41.61.01.4
Percentage of Assets us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AccumulatedTranslationAdjustment


Accumulated
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312013-09-302013-06-302013-03-312012-12-312011-12-312010-12-31
Value-12.4-46.395-64.542-39.356-86.9-66.587-32.742-5.728-7.046-36.569-31.162-2.94-20.713-9.424
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax-2.5-21.936.1-33.375.9403.5-25.4-7.6-16.874.1-13.6-1.0-13.5-4.6
Percentage of Assets-0.0-0.1-0.2-0.1-0.3-0.3-0.1-0.0-0.0-0.2-0.2-0.0-0.1-0.1
Percentage of Assets us-gaap:AccumulatedTranslationAdjustment0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Treasury Stock Value

us-gaap:TreasuryStockValue

us-gaap:TreasuryStockValue


Treasury
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-31
Value30072694250024952494248924062403240123882382228022662084207720532051203920342031202820191941194019341727156213581104109610941093109110671025852852845845844823787549
Percentage of TreasuryStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets6.56.15.85.86.16.56.46.86.97.07.47.17.16.56.56.36.66.86.97.98.38.28.48.28.47.67.16.04.95.05.65.85.85.75.84.54.64.74.94.84.84.63.5

us-gaap:TreasuryStockValue us-gaap:ConsolidatedEntities

srt:ParentCompany


Treasury
Period End2020-12-312019-12-31
Value25032406
Percentage of TreasuryStockValue100.2100.0
Percentage of Assets5.86.4
Percentage of Assets srt:ParentCompany17.420.3

Minority Interest

us-gaap:MinorityInterest

us-gaap:MinorityInterest


Minority
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-31
Value9188768237576794927628548558387918768618548438608778688518347887547387747947897697827927930.00.00.00.00.0
Percentage of MinorityInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.00.00.0
Percentage of Assets2.02.01.91.81.61.32.02.42.52.52.52.72.72.72.62.62.82.92.93.33.23.13.23.33.43.53.53.53.53.60.00.00.00.00.0

us-gaap:MinorityInterest dei:LegalEntity

acgl:WatfordHoldingsLtd


Minority
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value918876823757679492762854855838791876861843
Percentage of MinorityInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets2.02.01.91.81.61.32.02.42.52.52.52.72.72.6
Percentage of Assets acgl:WatfordHoldingsLtd0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:MinorityInterest dei:LegalEntity, us-gaap:StatementEquityComponents

acgl:WatfordHoldingsLtd, us-gaap:NoncontrollingInterest


Minority
Period End2020-12-312019-12-312018-12-312017-12-312014-06-302014-03-312013-12-31
Value8237627918437927930.0
Percentage of MinorityInterest100.0100.0100.0100.0100.0100.00.0
Percentage of Assets1.92.02.52.63.53.60.0
Percentage of Assets acgl:WatfordHoldingsLtd us-gaap:NoncontrollingInterest0.00.00.00.00.00.00.0

Stock Issued During Period Value New Issues

us-gaap:StockIssuedDuringPeriodValueNewIssues us-gaap:StatementClassOfStock

us-gaap:StockIssuedDuringPeriodValueNewIssues

us-gaap:SeriesGPreferredStock


Stock
Period End2021-06-30
Value500
Percentage of StockIssuedDuringPeriodValueNewIssues100.0
Percentage of Assets0.0
Percentage of Assets us-gaap:SeriesGPreferredStock0.0

us-gaap:StockIssuedDuringPeriodValueNewIssues us-gaap:StatementEquityComponents

us-gaap:PreferredStock


Stock
Period End2021-06-302018-12-312018-09-302017-12-312017-09-302016-12-312015-12-312012-12-312012-09-302011-12-312011-09-30
Value5000.00.01002300.00.00.00.00.00.0
Percentage of StockIssuedDuringPeriodValueNewIssues100.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:PreferredStock0.00.00.00.00.00.00.00.00.00.00.0

Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value

us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue us-gaap:StatementEquityComponents

us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue

us-gaap:AdditionalPaidInCapital


Adjustments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value164014141328111213252715101021149.5211022139.6719.49121148.9328.83919117.64410167.4115.75.781135.6285.6156.074127.096
Percentage of AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Net Cash Provided By Used In Operating Activities

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetCashProvidedByUsedInOperatingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value8497625551009711610505830477235438223238182205189334252144109309221224144267205184
Percentage of NetCashProvidedByUsedInOperatingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues33.133.723.343.731.039.829.049.426.813.732.424.227.721.423.120.637.030.017.814.740.528.629.017.533.526.521.9

us-gaap:NetCashProvidedByUsedInOperatingActivities dei:LegalEntity, us-gaap:ConsolidatedEntities

acgl:WatfordHoldingsLtd, us-gaap:VariableInterestEntityPrimaryBeneficiary


Net
Period End2021-06-302021-03-312020-06-302020-03-312019-03-31
Value407.0622470
Percentage of NetCashProvidedByUsedInOperatingActivities4.70.98.84.029.9
Percentage of Revenues1.60.32.71.64.1
Percentage of Revenues acgl:WatfordHoldingsLtd us-gaap:VariableInterestEntityPrimaryBeneficiary0.00.00.00.00.0

us-gaap:NetCashProvidedByUsedInOperatingActivities dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities

acgl:WatfordHoldingsLtd, us-gaap:VariableInterestEntityPrimaryBeneficiary


Net
Period End2020-09-302019-09-30
Value4661
Percentage of NetCashProvidedByUsedInOperatingActivities4.67.4
Percentage of Revenues2.03.6
Percentage of Revenues acgl:WatfordHoldingsLtd us-gaap:VariableInterestEntityPrimaryBeneficiary0.00.0

Net Cash Provided By Used In Investing Activities

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:NetCashProvidedByUsedInInvestingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value-600.489-493.189-434.808-798.228-1531.694-278.496-556.007-503.532-452.151-294.793-163.937-821.841-179.96-95.28-210.43297-177.82-318.7023.381-106.363-232.919-131.125-68.013276-186.45527-100.479
Percentage of NetCashProvidedByUsedInInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-23.4-21.8-18.2-34.5-66.8-18.2-31.9-29.9-25.4-17.1-12.1-89.0-20.9-11.2-23.610.6-19.7-37.80.4-14.2-30.4-16.9-8.833.4-23.43.5-11.9

us-gaap:NetCashProvidedByUsedInInvestingActivities dei:LegalEntity, us-gaap:ConsolidatedEntities

acgl:WatfordHoldingsLtd, us-gaap:VariableInterestEntityPrimaryBeneficiary


Net
Period End2021-06-302021-03-312020-06-302020-03-312019-03-31
Value7421113-35.7-105.9
Percentage of NetCashProvidedByUsedInInvestingActivities-12.5-4.3-7.412.835.9
Percentage of Revenues2.90.95.0-2.3-6.1
Percentage of Revenues acgl:WatfordHoldingsLtd us-gaap:VariableInterestEntityPrimaryBeneficiary0.00.00.00.00.0

us-gaap:NetCashProvidedByUsedInInvestingActivities dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities

acgl:WatfordHoldingsLtd, us-gaap:VariableInterestEntityPrimaryBeneficiary


Net
Period End2020-09-302019-09-30
Value164-45.5
Percentage of NetCashProvidedByUsedInInvestingActivities-20.59.0
Percentage of Revenues7.1-2.7
Percentage of Revenues acgl:WatfordHoldingsLtd us-gaap:VariableInterestEntityPrimaryBeneficiary0.00.0

Net Cash Provided By Used In Financing Activities

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:NetCashProvidedByUsedInFinancingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value209-186.602-44.812-105.247805-134.496-34.166-37.411-50.60441-252.066595-5.375-63.063-3.065-339.567-94.7212.531-81.278-22.116-109.468-87.715-117.836-423.272-65.711-222.69-73.964
Percentage of NetCashProvidedByUsedInFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues8.1-8.2-1.9-4.535.2-8.8-2.0-2.2-2.82.4-18.664.5-0.6-7.4-0.3-36.9-10.50.3-10.0-3.0-14.3-11.3-15.2-51.3-8.2-28.7-8.8

us-gaap:NetCashProvidedByUsedInFinancingActivities dei:LegalEntity, us-gaap:ConsolidatedEntities

acgl:WatfordHoldingsLtd, us-gaap:VariableInterestEntityPrimaryBeneficiary


Net
Period End2021-06-302021-03-312020-06-302020-03-312019-03-31
Value-1.0-1.0-166.11228
Percentage of NetCashProvidedByUsedInFinancingActivities-0.50.5-20.6-9.167.7
Percentage of Revenues-0.0-0.0-7.20.81.6
Percentage of Revenues acgl:WatfordHoldingsLtd us-gaap:VariableInterestEntityPrimaryBeneficiary0.00.00.00.00.0

us-gaap:NetCashProvidedByUsedInFinancingActivities dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities

acgl:WatfordHoldingsLtd, us-gaap:VariableInterestEntityPrimaryBeneficiary


Net
Period End2020-09-302019-09-30
Value-125.9-3.4
Percentage of NetCashProvidedByUsedInFinancingActivities119.69.1
Percentage of Revenues-5.4-0.2
Percentage of Revenues acgl:WatfordHoldingsLtd us-gaap:VariableInterestEntityPrimaryBeneficiary0.00.0

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

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value45076103122-5.754166-58.777279-27.141-14.42714126-149.1474.972-253.338486-159.806
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues17.53.44.35.3-0.310.9-3.416.6-1.5-0.81.19.0-10.60.4-17.85.76.1-12.1

Increase Decrease In Other Operating Capital Net

us-gaap:IncreaseDecreaseInOtherOperatingCapitalNet

us-gaap:IncreaseDecreaseInOtherOperatingCapitalNet


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value13496-7.444-194.732-31.058223-83.146-22.24910937-63.331-54.64113-56.143165-97.707-25.5715133-38.49555-46.6643919-121.265702651-19.847-19.041-54.907-43.988-0.9673.179-26.089-64.86337-22.5730.217-2.109-32.075-42.701-19.741-54.5744.25233
Percentage of IncreaseDecreaseInOtherOperatingCapitalNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Net Cash Provided By Used In Operating Activities

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetCashProvidedByUsedInOperatingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value8497625551009711610505830477235438223238182205189334252144109309221224144267205184
Percentage of NetCashProvidedByUsedInOperatingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues33.133.723.343.731.039.829.049.426.813.732.424.227.721.423.120.637.030.017.814.740.528.629.017.533.526.521.9

us-gaap:NetCashProvidedByUsedInOperatingActivities dei:LegalEntity, us-gaap:ConsolidatedEntities

acgl:WatfordHoldingsLtd, us-gaap:VariableInterestEntityPrimaryBeneficiary


Net
Period End2021-06-302021-03-312020-06-302020-03-312019-03-31
Value407.0622470
Percentage of NetCashProvidedByUsedInOperatingActivities4.70.98.84.029.9
Percentage of Revenues1.60.32.71.64.1
Percentage of Revenues acgl:WatfordHoldingsLtd us-gaap:VariableInterestEntityPrimaryBeneficiary0.00.00.00.00.0

us-gaap:NetCashProvidedByUsedInOperatingActivities dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities

acgl:WatfordHoldingsLtd, us-gaap:VariableInterestEntityPrimaryBeneficiary


Net
Period End2020-09-302019-09-30
Value4661
Percentage of NetCashProvidedByUsedInOperatingActivities4.67.4
Percentage of Revenues2.03.6
Percentage of Revenues acgl:WatfordHoldingsLtd us-gaap:VariableInterestEntityPrimaryBeneficiary0.00.0

Net Income Loss

us-gaap:NetIncomeLoss

us-gaap:NetIncomeLoss


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value675438543419298144326392468448136227243150214-33.656185253742522111545880115283215228208182161114176256191892201641431689825234148243216
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues26.319.322.818.113.09.418.723.326.426.010.116.217.311.715.1-2.313.219.27.521.117.714.26.58.611.426.221.223.020.119.317.513.320.828.82.121.026.120.219.222.112.73.328.418.631.425.7

us-gaap:NetIncomeLoss us-gaap:ConsolidationItems

us-gaap:OperatingSegments


Net
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value433535409275177328392467443146225242149216-31.655184251712472061526282115280216229208182161114176256
Percentage of NetIncomeLoss99.098.697.792.0123.5100.6100.099.798.8107.799.199.699.1101.094.199.499.297.297.798.098.7107.4103.299.499.1100.7100.6100.1100.2100.0100.0100.0100.0
Percentage of Revenues19.222.517.712.011.618.823.326.325.710.916.117.211.615.3-2.113.119.07.320.617.414.17.08.911.325.921.423.220.119.317.513.320.828.8
Percentage of Revenues us-gaap:OperatingSegments0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NetIncomeLoss us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, us-gaap:AllOtherSegments


Net
Period End2021-06-302020-06-30
Value4.74423
Percentage of NetIncomeLoss0.78.0
Percentage of Revenues0.21.0
Percentage of Revenues us-gaap:OperatingSegments us-gaap:AllOtherSegments0.00.0

us-gaap:OperatingSegments, us-gaap:Corporate


Net
Period End2021-06-302020-06-30
Value670275
Percentage of NetIncomeLoss99.392.0
Percentage of Revenues26.112.0
Percentage of Revenues us-gaap:OperatingSegments us-gaap:Corporate0.00.0

us-gaap:NetIncomeLoss us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:StatementEquityComponents

us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value60-2.697577916712114385510-22.266-23.203-36.643-62.4612123175.044-52.948542232-11.635-12.278213018178.285210.77-20.7011338
Percentage of NetIncomeLoss9.0-0.610.619.056.084.14.59.911.82.3-16.3-10.2-15.0-41.510.1-71.09.32.0-71.521.710.520.8-19.9-15.318.310.98.47.64.011.60.5-18.07.915.1
Percentage of Revenues2.4-0.12.43.47.37.90.82.33.10.6-1.6-1.7-2.6-4.91.51.61.20.4-5.44.61.93.0-1.3-1.32.12.91.81.80.82.20.1-2.41.64.3
Percentage of Revenues us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NetIncomeLoss us-gaap:StatementBusinessSegments

us-gaap:CorporateAndOther


Net
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-30
Value4.197.7189.74423-33.834-2.1170.0151.5235.251-10.5012.0781.0071.407-2.158-2.0011.1592.0212.1045.7194.1762.01-4.355-2.5560.657
Percentage of NetIncomeLoss1.01.42.38.0-23.5-0.60.00.31.2-7.70.90.40.9-1.05.90.60.82.82.32.01.3-7.4-3.20.6
Percentage of Revenues0.20.30.41.0-2.2-0.10.00.10.3-0.80.10.10.1-0.2-0.10.10.20.20.50.40.2-0.5-0.30.1
Percentage of Revenues us-gaap:CorporateAndOther0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Profit Loss

us-gaap:ProfitLoss

us-gaap:ProfitLoss


Profit
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312011-03-312010-03-31
Value718475599488466-88.674326399485495136248256166214-45.21719927474303249175586412530820722321117916111417625625216
Percentage of ProfitLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues28.021.025.121.120.4-5.818.723.727.328.810.117.718.213.015.1-3.114.120.87.525.420.916.26.56.912.328.520.422.520.418.917.513.320.828.83.325.7

us-gaap:ProfitLoss us-gaap:ConsolidationItems

us-gaap:OperatingSegments


Profit
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value433536410275178328392467443146225242149216-31.655184251712472061526282115280216229208182161114176256
Percentage of ProfitLoss91.289.683.959.2-200.7100.698.396.289.5107.790.694.789.6101.070.092.491.697.281.483.087.0107.4129.091.590.9104.7103.098.4102.1100.0100.0100.0100.0
Percentage of Revenues19.122.517.712.011.618.823.326.325.710.916.117.211.615.3-2.113.119.07.320.617.414.17.08.911.325.921.423.220.119.317.513.320.828.8
Percentage of Revenues us-gaap:OperatingSegments0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:ProfitLoss us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, us-gaap:AllOtherSegments


Profit
Period End2021-06-302020-06-30
Value47190
Percentage of ProfitLoss6.640.8
Percentage of Revenues1.88.3
Percentage of Revenues us-gaap:OperatingSegments us-gaap:AllOtherSegments0.00.0

us-gaap:OperatingSegments, us-gaap:Corporate


Profit
Period End2021-06-302020-06-30
Value671275
Percentage of ProfitLoss93.459.2
Percentage of Revenues26.112.0
Percentage of Revenues us-gaap:OperatingSegments us-gaap:Corporate0.00.0

us-gaap:ProfitLoss us-gaap:StatementBusinessSegments

us-gaap:CorporateAndOther


Profit
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-30
Value416278190-266.682-15.7336.7511852-90.671231317-15.006-13.562152223564222-34.928-18.58910
Percentage of ProfitLoss8.810.416.140.8300.7-4.81.73.810.5-66.49.45.310.4-7.030.07.68.432.018.617.013.0-59.6-29.08.5
Percentage of Revenues1.82.63.48.3-17.4-0.90.41.03.0-6.71.71.01.4-1.1-0.91.11.72.44.73.62.1-3.9-2.01.0
Percentage of Revenues us-gaap:CorporateAndOther0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:ProfitLoss us-gaap:StatementEquityComponents

us-gaap:RetainedEarnings


Profit
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312011-03-312010-03-31
Value718475599488466-88.67431239948549556248256166201-45.21719927495303249175286412530820722321117916111417625625216
Percentage of ProfitLoss100.0100.0100.0100.0100.0100.095.8100.0100.0100.041.3100.0100.0100.094.0100.0100.0100.0129.1100.0100.0100.047.8100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues28.021.025.121.120.4-5.817.923.727.328.84.217.718.213.014.2-3.114.120.89.725.420.916.23.16.912.328.520.422.520.418.917.513.320.828.83.325.7
Percentage of Revenues us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Share Based Compensation

us-gaap:ShareBasedCompensation

us-gaap:ShareBasedCompensation


Share
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value164014141328111215259.971020149.49152715101021149.5211022139.6719.49121148.9328.83919117.64410167.4115.75.781135.6285.6156.074127.096
Percentage of ShareBasedCompensation100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Net Cash Provided By Used In Investing Activities

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:NetCashProvidedByUsedInInvestingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value-600.489-493.189-434.808-798.228-1531.694-278.496-556.007-503.532-452.151-294.793-163.937-821.841-179.96-95.28-210.43297-177.82-318.7023.381-106.363-232.919-131.125-68.013276-186.45527-100.479
Percentage of NetCashProvidedByUsedInInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-23.4-21.8-18.2-34.5-66.8-18.2-31.9-29.9-25.4-17.1-12.1-89.0-20.9-11.2-23.610.6-19.7-37.80.4-14.2-30.4-16.9-8.833.4-23.43.5-11.9

us-gaap:NetCashProvidedByUsedInInvestingActivities dei:LegalEntity, us-gaap:ConsolidatedEntities

acgl:WatfordHoldingsLtd, us-gaap:VariableInterestEntityPrimaryBeneficiary


Net
Period End2021-06-302021-03-312020-06-302020-03-312019-03-31
Value7421113-35.7-105.9
Percentage of NetCashProvidedByUsedInInvestingActivities-12.5-4.3-7.412.835.9
Percentage of Revenues2.90.95.0-2.3-6.1
Percentage of Revenues acgl:WatfordHoldingsLtd us-gaap:VariableInterestEntityPrimaryBeneficiary0.00.00.00.00.0

us-gaap:NetCashProvidedByUsedInInvestingActivities dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities

acgl:WatfordHoldingsLtd, us-gaap:VariableInterestEntityPrimaryBeneficiary


Net
Period End2020-09-302019-09-30
Value164-45.5
Percentage of NetCashProvidedByUsedInInvestingActivities-20.59.0
Percentage of Revenues7.1-2.7
Percentage of Revenues acgl:WatfordHoldingsLtd us-gaap:VariableInterestEntityPrimaryBeneficiary0.00.0

Payments To Acquire Productive Assets

us-gaap:PaymentsToAcquireProductiveAssets

us-gaap:PaymentsToAcquireProductiveAssets


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value1112139.039.2178.4710116.9369.423105.8089.0024.245.9795.7595.9095.1943.7383.2814.3323.9524.835-32.26410325.3084.2154.9785.3826.5463.8613.353.7424.6383.6863.716.4983.4613.1784.2668.0821.5532.2516.0571.803
Percentage of PaymentsToAcquireProductiveAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Net Cash Provided By Used In Financing Activities

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:NetCashProvidedByUsedInFinancingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value209-186.602-44.812-105.247805-134.496-34.166-37.411-50.60441-252.066595-5.375-63.063-3.065-339.567-94.7212.531-81.278-22.116-109.468-87.715-117.836-423.272-65.711-222.69-73.964
Percentage of NetCashProvidedByUsedInFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues8.1-8.2-1.9-4.535.2-8.8-2.0-2.2-2.82.4-18.664.5-0.6-7.4-0.3-36.9-10.50.3-10.0-3.0-14.3-11.3-15.2-51.3-8.2-28.7-8.8

us-gaap:NetCashProvidedByUsedInFinancingActivities dei:LegalEntity, us-gaap:ConsolidatedEntities

acgl:WatfordHoldingsLtd, us-gaap:VariableInterestEntityPrimaryBeneficiary


Net
Period End2021-06-302021-03-312020-06-302020-03-312019-03-31
Value-1.0-1.0-166.11228
Percentage of NetCashProvidedByUsedInFinancingActivities-0.50.5-20.6-9.167.7
Percentage of Revenues-0.0-0.0-7.20.81.6
Percentage of Revenues acgl:WatfordHoldingsLtd us-gaap:VariableInterestEntityPrimaryBeneficiary0.00.00.00.00.0

us-gaap:NetCashProvidedByUsedInFinancingActivities dei:LegalEntity, us-gaap:InvestmentsByConsolidatedAndNonconsolidatedEntities

acgl:WatfordHoldingsLtd, us-gaap:VariableInterestEntityPrimaryBeneficiary


Net
Period End2020-09-302019-09-30
Value-125.9-3.4
Percentage of NetCashProvidedByUsedInFinancingActivities119.69.1
Percentage of Revenues-5.4-0.2
Percentage of Revenues acgl:WatfordHoldingsLtd us-gaap:VariableInterestEntityPrimaryBeneficiary0.00.0

Payments For Repurchase Of Common Stock

us-gaap:PaymentsForRepurchaseOfCommonStock

us-gaap:PaymentsForRepurchaseOfCommonStock


Payments
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value3061790.00.0750.00.00.02.87198101703.2990.00.00.00.00.00.00.0750.03.5061981622022510.00.00.01.33315401720.00.00.00.003202923725853269181
Percentage of PaymentsForRepurchaseOfCommonStock100.0100.00.00.0100.00.00.00.0100.0100.0100.0100.0100.00.00.00.00.00.00.00.0100.00.0100.0100.0100.0100.0100.00.00.00.0100.0100.0100.0100.00.00.00.0100.0100.0100.0100.0100.0100.0100.0100.0

Effective Income Tax Rate Continuing Operations

us-gaap:EffectiveIncomeTaxRateContinuingOperations

us-gaap:EffectiveIncomeTaxRateContinuingOperations


Effective
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-30
Value-0.67.68.0750.585-0.460.001-0.0010.0850.008-0.0190.1160.0250.0230.094-0.01-0.0180.0850.01200.0430.0010.0070.020.0090.0030.0190.0280.0030.011-0.014-0.018-0.0220.0210.006
Percentage of EffectiveIncomeTaxRateContinuingOperations100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice us-gaap:AwardType

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice

us-gaap:EmployeeStockOption


Share
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-31
Value23.3220.9419.3751.6743.7438.0734.5228.8225.87
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice100.0100.0100.0100.0100.0100.0100.0100.0100.0

Deferred Tax Assets Net

us-gaap:DeferredTaxAssetsNet

us-gaap:DeferredTaxAssetsNet


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-31
Value211178173155252167175148150130
Percentage of DeferredTaxAssetsNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Unrecognized Tax Benefits

us-gaap:UnrecognizedTaxBenefits

us-gaap:UnrecognizedTaxBenefits


Unrecognized
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value2000000.02000000.02008000.02008000.02008000.02008000.000
Percentage of UnrecognizedTaxBenefits100.0100.0100.0100.0100.0100.00.00.0

Deferred Tax Assets Valuation Allowance

us-gaap:DeferredTaxAssetsValuationAllowance

us-gaap:DeferredTaxAssetsValuationAllowance


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-31
Value88484430171312154.309
Percentage of DeferredTaxAssetsValuationAllowance100.0100.0100.0100.0100.0100.0100.0100.0100.0

acgl:AcquisitionExpenseRatioPercentage

acgl:AcquisitionExpenseRatioPercentage


Acquisition
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value15.815.6-0.114.00.1530.14200.1470.1440.14500.1560.1520.1550.0030.1540.1530.16300.1710.1740.17900.1830.1860.1790.0020.1810.1740.1860.0040.1850.1730.16900.170.1760.1740.0030.1750.1710.17-0.0020.1760.171
Percentage of AcquisitionExpenseRatioPercentage100.0100.0100.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

acgl:AcquisitionExpenseRatioPercentage us-gaap:ConsolidationItems

us-gaap:OperatingSegments


Acquisition
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value15.3-0.213.80.1510.1410.0010.1430.1380.13800.1490.1430.1460.0050.1430.1430.15100.1590.160.164-0.0010.1710.1740.170.0020.1770.1720.1850.0030.1850.1730.169
Percentage of AcquisitionExpenseRatioPercentage98.1200.098.698.799.30.097.395.895.20.095.594.194.2166.792.993.592.60.093.092.091.60.093.493.595.0100.097.898.999.575.0100.0100.0100.0

acgl:AcquisitionExpenseRatioPercentage us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, acgl:InsuranceSegment


Acquisition
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value15.815.6-0.414.20.1570.1500.1510.1540.15-0.0010.1570.1660.1580.0010.1540.1520.14800.1490.1470.145-0.0030.1480.150.1480.0010.1570.150.160.0010.1730.1610.158
Percentage of AcquisitionExpenseRatioPercentage100.0100.0400.0101.4102.6105.60.0102.7106.9103.40.0100.6109.2101.933.3100.099.390.80.087.184.581.00.080.980.682.750.086.786.286.025.093.593.193.5

us-gaap:OperatingSegments, acgl:MortgageSegment


Acquisition
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value9.08.9-0.610.20.0930.1120.0010.10.0930.098-0.0010.1110.0950.095-0.0030.0790.10.118-0.0080.1010.1280.1360.0140.1910.1940.2070.0260.2260.2260.2360.0440.270.3270.317
Percentage of AcquisitionExpenseRatioPercentage57.057.1600.072.960.878.90.068.064.667.60.071.262.561.3-100.051.365.472.40.059.173.676.00.0104.4104.3115.61300.0124.9129.9126.91100.0145.9189.0187.6

us-gaap:OperatingSegments, acgl:ReinsuranceSegment


Acquisition
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value18.118.30.215.40.1890.1460.0020.1710.1550.1570.0050.1720.1470.1730.0190.1770.1630.1880.0010.1990.1920.21-0.0010.2130.2130.202-0.0010.2030.1970.2150.0030.2010.1850.179
Percentage of AcquisitionExpenseRatioPercentage114.6117.3-200.0110.0123.5102.80.0116.3107.6108.30.0110.396.7111.6633.3114.9106.5115.30.0116.4110.3117.30.0116.4114.5112.8-50.0112.2113.2115.675.0108.6106.9105.9

us-gaap:OperatingSegments, acgl:UnderwritingSegments


Acquisition
Period End2021-06-302020-06-30
Value15.515.1
Percentage of AcquisitionExpenseRatioPercentage98.19869.3

us-gaap:OperatingSegments, us-gaap:AllOtherSegments


Acquisition
Period End2021-06-302020-06-30
Value18.817.1
Percentage of AcquisitionExpenseRatioPercentage119.011176.5

acgl:AcquisitionExpenseRatioPercentage us-gaap:StatementBusinessSegments

us-gaap:CorporateAndOther


Acquisition
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-30
Value19.11.016.70.1710.156-0.0030.1830.1950.199-0.0030.2180.2150.229-0.0030.2490.230.2660.0020.260.2790.285-0.0010.2890.281
Percentage of AcquisitionExpenseRatioPercentage122.4-1000.0119.3111.8109.90.0124.5135.4137.20.0139.7141.4147.7-100.0161.7150.3163.20.0152.0160.3159.20.0157.9151.1

acgl:CombinedRatioPercentage

acgl:CombinedRatioPercentage


Combined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value82.090.7-2.094.91.0180.9150.0040.8420.8040.8170.0150.8230.8270.813-0.0171.1180.8460.8140.0040.880.9140.889-0.0020.9070.8970.8840.0030.890.8650.847-0.0010.860.8740.8460.0620.9020.8720.901-0.0280.9430.9961.10.0010.9040.9
Percentage of CombinedRatioPercentage100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

acgl:CombinedRatioPercentage us-gaap:ConsolidationItems

us-gaap:OperatingSegments


Combined
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value89.2-2.293.91.0120.90500.8220.7780.790.0130.8010.8020.788-0.0211.10.8220.7880.0030.8650.8990.871-0.0030.8970.8790.8750.0030.8850.8620.845-0.0020.8610.8740.846
Percentage of CombinedRatioPercentage98.3110.098.999.498.90.097.696.896.786.797.397.096.9123.598.497.296.875.098.398.498.0150.098.998.099.0100.099.499.799.8200.0100.1100.0100.0

acgl:CombinedRatioPercentage us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, acgl:InsuranceSegment


Combined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value94.397.7-1.0104.21.0831.0390.0041.040.9960.9990.0051.0480.990.986-0.0391.3871.0080.980.0080.9590.9940.943-0.0030.960.9540.9470.0030.9680.9330.931-0.0030.9690.9710.967
Percentage of CombinedRatioPercentage115.0107.750.0109.8106.4113.6100.0123.5123.9122.333.3127.3119.7121.3229.4124.1119.1120.4200.0109.0108.8106.1150.0105.8106.4107.1100.0108.8107.9109.9300.0112.7111.1114.3

us-gaap:OperatingSegments, acgl:MortgageSegment


Combined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value26.542.4-4.464.20.8090.441-0.0120.2460.280.256-0.0230.2460.3020.3880.0130.3340.3050.408-0.0130.5750.4950.675-0.0110.7520.7530.8850.0430.8660.850.813-0.0050.6110.6010.615
Percentage of CombinedRatioPercentage32.346.7220.067.779.548.2-300.029.234.831.3-153.329.936.547.7-76.529.936.150.1-325.065.354.275.9550.082.983.9100.11433.397.398.396.0500.071.068.872.7

us-gaap:OperatingSegments, acgl:ReinsuranceSegment


Combined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value87.1102.9-3.099.01.0681.02-0.0041.0030.9030.9520.0630.8990.9280.807-0.0161.2740.940.772-0.0010.760.8210.777-0.0040.8010.7610.74-0.0070.7430.7570.7300.70.7320.672
Percentage of CombinedRatioPercentage106.2113.5150.0104.3104.9111.5-100.0119.1112.3116.5420.0109.2112.299.394.1114.0111.194.8-25.086.489.887.4200.088.384.883.7-233.383.587.586.2-0.081.483.879.4

us-gaap:OperatingSegments, acgl:UnderwritingSegments


Combined
Period End2021-06-302020-06-30
Value79.8101.2
Percentage of CombinedRatioPercentage97.39941.1

us-gaap:OperatingSegments, us-gaap:AllOtherSegments


Combined
Period End2021-06-302020-06-30
Value105.0107.6
Percentage of CombinedRatioPercentage128.010569.7

acgl:CombinedRatioPercentage us-gaap:StatementBusinessSegments

us-gaap:CorporateAndOther


Combined
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-30
Value109.20.1106.01.0761.0440.0591.041.0341.0410.0371.0061.0061.010.0211.2741.0231.0250.0060.9971.0231.0160.0070.9941.038
Percentage of CombinedRatioPercentage120.4-5.0111.7105.7114.11475.0123.5128.6127.4246.7122.2121.6124.2-123.5114.0120.9125.9150.0113.3111.9114.3-350.0109.6115.7

acgl:ContractholderReceivablesCreditLossExpenseReversal

acgl:ContractholderReceivablesCreditLossExpenseReversal


Contractholder
Period End2021-06-302021-03-312020-12-312020-09-302020-06-30
Value-1382000.0-2785000.01213000.0389000.02748000.0
Percentage of ContractholderReceivablesCreditLossExpenseReversal100.0100.0100.0100.0100.0

acgl:DeconsolidationGainLossAmountNet dei:LegalEntity, us-gaap:ConsolidatedEntities, us-gaap:SubsequentEventType

acgl:DeconsolidationGainLossAmountNet

acgl:WatfordHoldingsLtd, us-gaap:VariableInterestEntityPrimaryBeneficiary, us-gaap:SubsequentEvent


Deconsolidation
Period End2021-07-01
Value65
Percentage of DeconsolidationGainLossAmountNet100.0

acgl:EquityInNetIncomeLossOfInvestmentFundsAccountedForUsingEquityMethodAndOtherIncomeLoss

acgl:EquityInNetIncomeLossOfInvestmentFundsAccountedForUsingEquityMethodAndOtherIncomeLoss


Equity
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-31
Value451357895-96.35-29.034-24.899-6.8081529-30.337-19.9-5.8419151611362.5133.004-7.918-3.2430.126-14.3328.3791.97-9.556-3.9199.694-9.559-17.191.859-14.441-23.0526.315196.11112
Percentage of EquityInNetIncomeLossOfInvestmentFundsAccountedForUsingEquityMethodAndOtherIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

acgl:IncomeLossFromOperatingAffiliatesEquityMethod

acgl:IncomeLossFromOperatingAffiliatesEquityMethod


Income
Period End2021-06-302021-03-312020-06-302020-03-31
Value2475-3.1738.516
Percentage of IncomeLossFromOperatingAffiliatesEquityMethod100.0100.0100.0100.0

acgl:IncomeLossFromOperatingAffiliatesEquityMethod us-gaap:ConsolidationItems

us-gaap:OperatingSegments


Income
Period End2021-03-312020-03-31
Value758.516
Percentage of IncomeLossFromOperatingAffiliatesEquityMethod100.0100.0

acgl:IncomeLossFromOperatingAffiliatesEquityMethod us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, us-gaap:Corporate


Income
Period End2021-06-302020-06-30
Value24-3.173
Percentage of IncomeLossFromOperatingAffiliatesEquityMethod100.0100.0

acgl:IncomeLossFromOperatingAffiliatesEquityMethod us-gaap:EquityMethodInvestmentNonconsolidatedInvestee

acgl:Coface


Income
Period End2021-06-302021-03-31
Value0.074
Percentage of IncomeLossFromOperatingAffiliatesEquityMethod0.098.7

acgl:IncreaseDecreaseInLossAndLossAdjustmentExpensesNetOfRecoverables

acgl:IncreaseDecreaseInLossAndLossAdjustmentExpensesNetOfRecoverables


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value388560445509652506112222160-6.005175146-164.218611422127539491741114247375461335010-5.0888.858-10.981-22.182215726839-59.998481301553.546497191
Percentage of IncreaseDecreaseInLossAndLossAdjustmentExpensesNetOfRecoverables100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

acgl:IncreaseDecreaseInUnearnedPremiumsNetOfPrepaidReinsurancePremiums

acgl:IncreaseDecreaseInUnearnedPremiumsNetOfPrepaidReinsurancePremiums


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value278560-53.031032.957392-60.429175-18.829156-67.68142-37.867177-113.74637.821159-96.545517169-108.536350.142156-27.6845564205-90.4454451200-166.3386.55695181-162.499.91963130-149.2429.0240.23696
Percentage of IncreaseDecreaseInUnearnedPremiumsNetOfPrepaidReinsurancePremiums100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

acgl:LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaimsPriorYearsPercentage us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

acgl:LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaimsPriorYearsPercentage

us-gaap:OperatingSegments, acgl:InsuranceSegment


Liability
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value0.50.500.30.0040.0020.0630.0070.0040.0080.0020.0110.0110.0040.0350.0060.0040.00400.0260.0090.012
Percentage of LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaimsPriorYearsPercentage100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0

us-gaap:OperatingSegments, acgl:MortgageSegment


Liability
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value12.93.20.41.30.0010.0180.0010.0960.0650.1130.0050.1280.080.046-0.0060.0780.1150.096-0.0050.0320.1660.044
Percentage of LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaimsPriorYearsPercentage2580.0640.00.0433.325.0900.01.61371.41625.01412.5250.01163.6727.31150.0-17.11300.02875.02400.00.0123.11844.4366.7

us-gaap:OperatingSegments, acgl:ReinsuranceSegment


Liability
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value2.84.20.37.60.0840.0210.0080.0420.035-0.005-0.0040.1170.0970.131-0.0060.1130.1260.234-0.0130.2360.240.181
Percentage of LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaimsPriorYearsPercentage560.0840.00.02533.32100.01050.012.7600.0875.0-62.5-200.01063.6881.83275.0-17.11883.33150.05850.00.0907.72666.71508.3

acgl:LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaimsRetroactiveReinsurance

acgl:LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaimsRetroactiveReinsurance


Liability
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302016-12-312016-09-30
Value0.0-183.893-242.8450.00.0-60.6350.00.00.02250.00.0-420.4040.00.802-0.8020.00.00.0
Percentage of LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaimsRetroactiveReinsurance0.0100.0100.00.00.0100.00.00.00.0100.00.00.0100.00.0100.0100.00.00.00.0

acgl:MinorityInterestOtherAdjustmentstoAdditionalPaidinCapital dei:LegalEntity

acgl:MinorityInterestOtherAdjustmentstoAdditionalPaidinCapital

acgl:WatfordHoldingsLtd


Minority
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value0.383210.2430.5950.1230.2052.0740.0
Percentage of MinorityInterestOtherAdjustmentstoAdditionalPaidinCapital100.0100.0100.0100.0100.0100.0100.00.0

acgl:NetRealizedGainsLosses

acgl:NetRealizedGainsLosses


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value218161366282557-362.9645264118145-162.793-47.315-75.447-101.99532663440-83.6051358343-127.981-82.798-27.089871425652211-6.6541459566136441229482278726249
Percentage of NetRealizedGainsLosses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

acgl:NoncontrollingInterestPeriodIncreaseDecreaseOther dei:LegalEntity

acgl:NoncontrollingInterestPeriodIncreaseDecreaseOther

acgl:WatfordHoldingsLtd


Noncontrolling
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-06-302019-03-31
Value-160000.0-901000.01826000.0587000.0-51000.000
Percentage of NoncontrollingInterestPeriodIncreaseDecreaseOther100.0100.0100.0100.0100.00.00.0

acgl:OtherOperatingExpenseRatioPercentage

acgl:OtherOperatingExpenseRatioPercentage


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value11.513.4-0.212.20.1260.134-0.0020.1370.1360.147-0.0030.1250.1320.142-0.0010.1350.1370.1560.0010.1620.1590.160.0030.1560.160.16300.1540.1560.1540.0010.1380.1490.1460.0030.1390.1460.1460.0020.1460.1540.1510.0070.1550.146
Percentage of OtherOperatingExpenseRatioPercentage100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

acgl:OtherOperatingExpenseRatioPercentage us-gaap:ConsolidationItems

us-gaap:OperatingSegments


Other
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value13.7-0.312.40.1270.138-0.0020.1410.140.155-0.0030.1310.1420.151-0.0010.1430.1480.16800.1750.1730.1760.0040.1710.1770.1750.0020.1580.1560.1530.0010.1390.1490.146
Percentage of OtherOperatingExpenseRatioPercentage102.2150.0101.6100.8103.0100.0102.9102.9105.4100.0104.8107.6106.3100.0105.9108.0107.70.0108.0108.8110.0133.3109.6110.6107.40.0102.6100.099.4100.0100.7100.0100.0

acgl:OtherOperatingExpenseRatioPercentage us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, acgl:InsuranceSegment


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value15.416.7-0.517.00.1730.181-0.0030.1910.1850.205-0.0020.1610.170.171-0.0040.170.1780.1740.0010.1690.1750.1670.0030.1620.1750.17300.160.1690.1700.1580.1750.172
Percentage of OtherOperatingExpenseRatioPercentage133.9124.6250.0139.3137.3135.1150.0139.4136.0139.566.7128.8128.8120.4400.0125.9129.9111.5100.0104.3110.1104.4100.0103.8109.4106.10.0103.9108.3110.40.0114.5117.4117.8

us-gaap:OperatingSegments, acgl:MortgageSegment


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value14.514.60.310.40.1030.133-0.0030.1080.1130.123-0.0050.1030.1330.138-0.0020.1270.1250.171-0.0080.330.3610.399-0.0030.3860.3750.4040.0090.3380.320.3580.0270.1830.1020.12
Percentage of OtherOperatingExpenseRatioPercentage126.1109.0-150.085.281.799.3150.078.883.183.7166.782.4100.897.2200.094.191.2109.6-800.0203.7227.0249.4-100.0247.4234.4247.90.0219.5205.1232.52700.0132.668.582.2

us-gaap:OperatingSegments, acgl:ReinsuranceSegment


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value6.19.4-0.27.50.0810.0830.0010.0890.0920.103-0.0050.1020.1050.1270.0030.1120.1170.15300.1410.1270.140.0050.1430.1420.1360.0030.1230.1120.1060.0020.1060.1110.109
Percentage of OtherOperatingExpenseRatioPercentage53.070.1100.061.564.361.9-50.065.067.670.1166.781.679.589.4-300.083.085.498.10.087.079.987.5166.791.788.883.40.079.971.868.8200.076.874.574.7

us-gaap:OperatingSegments, acgl:UnderwritingSegments


Other
Period End2021-06-302020-06-30
Value11.712.7
Percentage of OtherOperatingExpenseRatioPercentage101.710079.4

us-gaap:OperatingSegments, us-gaap:AllOtherSegments


Other
Period End2021-06-302020-06-30
Value10.110.8
Percentage of OtherOperatingExpenseRatioPercentage87.88571.4

acgl:OtherOperatingExpenseRatioPercentage us-gaap:StatementBusinessSegments

us-gaap:CorporateAndOther


Other
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-30
Value9.7-0.210.00.1080.09800.0920.1030.0830.0010.0730.0570.064-0.0010.0640.0590.0590.0010.0640.0510.0460.0050.0340.032
Percentage of OtherOperatingExpenseRatioPercentage72.4100.082.085.773.1-0.067.275.756.5-33.358.443.245.1100.047.443.137.8100.039.532.128.7166.721.820.0

acgl:OtherUnderwritingIncomeLoss

acgl:OtherUnderwritingIncomeLoss


Other
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-12-312019-09-30
Value5.5296.115.4136.6676.8526.7573.326
Percentage of OtherUnderwritingIncomeLoss100.0100.0100.0100.0100.0100.0100.0

acgl:OtherUnderwritingIncomeLoss us-gaap:ConsolidationItems

us-gaap:OperatingSegments


Other
Period End2021-03-312020-09-302020-03-312019-09-30
Value5.6994.8676.7192.747
Percentage of OtherUnderwritingIncomeLoss93.389.998.182.6

acgl:OtherUnderwritingIncomeLoss us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, acgl:InsuranceSegment


Other
Period End2020-09-30
Value-0.031
Percentage of OtherUnderwritingIncomeLoss-0.6

us-gaap:OperatingSegments, acgl:MortgageSegment


Other
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-30
Value4.1486.8974.66.454.5993.955
Percentage of OtherUnderwritingIncomeLoss75.0112.985.096.767.1118.9

us-gaap:OperatingSegments, acgl:ReinsuranceSegment


Other
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-30
Value1.053-1.1980.298-0.6512.12-1.208
Percentage of OtherUnderwritingIncomeLoss19.0-19.65.5-9.830.9-36.3

us-gaap:OperatingSegments, acgl:UnderwritingSegments


Other
Period End2021-06-302020-06-30
Value5.2015.799
Percentage of OtherUnderwritingIncomeLoss94.187.0

us-gaap:OperatingSegments, us-gaap:AllOtherSegments


Other
Period End2021-06-302020-06-30
Value0.3280.868
Percentage of OtherUnderwritingIncomeLoss5.913.0

acgl:OtherUnderwritingIncomeLoss us-gaap:StatementBusinessSegments

us-gaap:CorporateAndOther


Other
Period End2021-03-312020-09-302020-03-312019-09-30
Value0.4110.5460.1330.579
Percentage of OtherUnderwritingIncomeLoss6.710.11.917.4

acgl:ProceedsFromCommonSharesIssuedNet

acgl:ProceedsFromCommonSharesIssuedNet


Proceeds
Period End2021-06-302021-03-312020-09-302020-06-302020-03-31
Value10193000.0-10008000.05000.0-5134000.0-4527000.0
Percentage of ProceedsFromCommonSharesIssuedNet100.0100.0100.0100.0100.0

acgl:ProceedsFromPaymentsToNonredeemableNoncontrollingInterests

acgl:ProceedsFromPaymentsToNonredeemableNoncontrollingInterests


Proceeds
Period End2021-06-302021-03-312020-09-302020-06-302020-03-31
Value0.0150.00.0-2.867
Percentage of ProceedsFromPaymentsToNonredeemableNoncontrollingInterests0.0100.00.00.0100.0

acgl:RedeemableNoncontrollingInterestAccretionofIssuanceCosts dei:LegalEntity

acgl:RedeemableNoncontrollingInterestAccretionofIssuanceCosts

acgl:WatfordHoldingsLtd


Redeemable
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-30
Value23000.023000.023000.023000.023000.023000.092000.091000.094000.0
Percentage of RedeemableNoncontrollingInterestAccretionofIssuanceCosts100.0100.0100.0100.0100.0100.0100.0100.0100.0

acgl:SegmentOtherCostAndExpenseOperating

acgl:SegmentOtherCostAndExpenseOperating


Segment
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value1723171616181715161615131514131422121111179.3831210179.34511101413107.89414107.3469.049116.9796.7776.18117.0266.8815.79610
Percentage of SegmentOtherCostAndExpenseOperating100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

acgl:SegmentOtherCostAndExpenseOperating us-gaap:ConsolidationItems

us-gaap:OperatingSegments


Segment
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value23171616181715161615131514131422121111179.3831210179.34511101510107.8941410
Percentage of SegmentOtherCostAndExpenseOperating100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0102.380.1100.0100.0100.0100.0

acgl:SegmentOtherCostAndExpenseOperating us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, us-gaap:Corporate


Segment
Period End2021-06-302020-06-30
Value1716
Percentage of SegmentOtherCostAndExpenseOperating100.0100.0

acgl:StockGrantedDuringPeriodValueNetOfTaxWithholdingsSharebasedCompensation us-gaap:StatementEquityComponents

acgl:StockGrantedDuringPeriodValueNetOfTaxWithholdingsSharebasedCompensation

us-gaap:CommonStock


Stock
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-31
Value0.0020.0020.0010.00.00.0040.00.00.0020.0020.0010.00.0030.0190.0010.0010.0260.0010.00.0010.0020.0020.0010.00.0030.0010.0010.0010.0030.0020.00.0010.0030.00.0050.00.0040.0030.0050.0030.0060.001
Percentage of StockGrantedDuringPeriodValueNetOfTaxWithholdingsSharebasedCompensation100.0100.0100.00.00.0100.00.00.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.00.0100.0100.00.0100.00.0100.0100.0100.0100.0100.0100.0

acgl:TreasuryStockSharesAcquiredCumulativeSinceInception us-gaap:StatementClassOfStock

acgl:TreasuryStockSharesAcquiredCumulativeSinceInception

us-gaap:CommonStock


Treasury
Period End2021-06-302021-03-312020-12-31
Value7.83940.3
Percentage of TreasuryStockSharesAcquiredCumulativeSinceInception100.0100.0100.0

acgl:TreasuryStockValueAcquiredCumulativeSinceInception us-gaap:StatementClassOfStock

acgl:TreasuryStockValueAcquiredCumulativeSinceInception

us-gaap:CommonStock


Treasury
Period End2021-06-302021-03-312020-12-31
Value309423059
Percentage of TreasuryStockValueAcquiredCumulativeSinceInception100.0100.0100.0

acgl:UnderwritingIncomeLossSegment

acgl:UnderwritingIncomeLossSegment


Underwriting
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value38618522096-22.539154251231293260166234235236182-142.1721952121091221111101139410511611310112413212811096116-91.33473936769382.236-63.98486062
Percentage of UnderwritingIncomeLossSegment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

acgl:UnderwritingIncomeLossSegment us-gaap:ConsolidationItems

us-gaap:OperatingSegments


Underwriting
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value198229104-13.41160288235297265188234235237206-107.6171982141121211131111169310811411410112513312811096116
Percentage of UnderwritingIncomeLossSegment107.0103.9108.659.5103.9114.8101.9101.6102.1113.2100.1100.1100.2113.175.7101.4101.1103.098.9101.5100.9103.198.6103.198.5100.7100.1100.8100.8100.0100.0100.0100.0

acgl:UnderwritingIncomeLossSegment us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, acgl:InsuranceSegment


Underwriting
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value4918-12.644-31.159-56.722-28.175-13.881-24.1132.6530.562-15.644-26.7135.6347.8649.047-207.143-4.504102.581213.32929282123272216343318151314
Percentage of UnderwritingIncomeLossSegment12.89.9-5.7-32.3251.7-18.3-5.5-10.40.90.2-9.4-11.42.43.35.0145.7-2.34.72.417.63.026.424.822.722.523.420.116.527.725.014.513.714.112.8

us-gaap:OperatingSegments, acgl:MortgageSegment


Underwriting
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value2502001881307619727626225824424523020517417218618314842373723171716131.5428.0768.8078.0236.0664.9715.0634.479
Percentage of UnderwritingIncomeLossSegment64.7107.785.5135.1-339.1128.3110.0113.588.193.8147.298.387.473.894.6-131.194.070.238.730.533.821.615.618.015.811.61.48.07.16.14.74.55.33.8

us-gaap:OperatingSegments, acgl:ReinsuranceSegment


Underwriting
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value95-19.707535.506-33.125-9.39226-2.6583620-41.17430245424-86.8621855676272587154687389768192103907796
Percentage of UnderwritingIncomeLossSegment24.8-10.624.15.7147.0-6.110.4-1.112.58.0-24.713.210.423.113.561.19.726.161.950.864.852.962.857.964.863.579.275.666.069.880.781.880.683.3

us-gaap:OperatingSegments, acgl:UnderwritingSegments


Underwriting
Period End2021-06-302020-06-30
Value395-13.41
Percentage of UnderwritingIncomeLossSegment102.359.5

us-gaap:OperatingSegments, us-gaap:AllOtherSegments


Underwriting
Period End2021-06-302020-06-30
Value-8.866-9.129
Percentage of UnderwritingIncomeLossSegment-2.340.5

acgl:UnderwritingIncomeLossSegment us-gaap:StatementBusinessSegments

us-gaap:CorporateAndOther


Underwriting
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-30
Value-13.079-8.555-8.273-9.129-6.01-37.251-4.443-4.593-5.378-22.031-0.209-0.318-0.56-23.901-34.555-2.643-2.295-3.2661.379-1.724-0.944-3.5571.309-3.229
Percentage of UnderwritingIncomeLossSegment-7.0-3.9-8.640.5-3.9-14.8-1.9-1.6-2.1-13.2-0.1-0.1-0.2-13.124.3-1.4-1.1-3.01.1-1.5-0.9-3.11.4-3.1

acgl:UnderwritingRelatedAllowanceForCreditLossesCreditLossExpenseReversal

acgl:UnderwritingRelatedAllowanceForCreditLossesCreditLossExpenseReversal


Underwriting
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-06-302019-03-31
Value-1.381-5.2681.254-0.3515.8343.270.00.0
Percentage of UnderwritingRelatedAllowanceForCreditLossesCreditLossExpenseReversal100.0100.0100.0100.0100.0100.00.00.0

us-gaap:AdjustmentsToAdditionalPaidInCapitalOther us-gaap:StatementEquityComponents

us-gaap:AdjustmentsToAdditionalPaidInCapitalOther

us-gaap:AdditionalPaidInCapital


Adjustments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-31
Value11-3.626120.6060.8673.2022516282518142215-71.00316-0.3470.0-0.010.0851.3090.1170.1710.0831.3360.0780.0340.011.714-1.2431.3590.0182.2490.0780.0540.061.6710.016
Percentage of AdjustmentsToAdditionalPaidInCapitalOther100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts us-gaap:StatementEquityComponents

us-gaap:AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts

us-gaap:AdditionalPaidInCapital


Adjustments
Period End2021-06-302017-12-312016-12-312015-12-312012-12-312012-09-302011-12-312011-09-30
Value142.360.00.00.00.0010.00.0
Percentage of AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts100.0100.00.00.00.0100.00.00.0

us-gaap:BusinessCombinationAcquisitionRelatedCosts

us-gaap:BusinessCombinationAcquisitionRelatedCosts


Business
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value-1.2241.9168.251.6740.9772.5959.0811.9952.1781.19111.0916.9080.830.9012.992.67515347.142
Percentage of BusinessCombinationAcquisitionRelatedCosts100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:BusinessCombinationAcquisitionRelatedCosts us-gaap:ConsolidationItems

us-gaap:OperatingSegments


Business
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value1.2014.211.6740.9772.5959.0811.9952.1781.192.5571.0916.9080.830.9012.992.67515347.142
Percentage of BusinessCombinationAcquisitionRelatedCosts62.751.0100.0100.0100.0100.0100.0100.0100.022.1100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:BusinessCombinationAcquisitionRelatedCosts us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, us-gaap:AllOtherSegments


Business
Period End2021-06-30
Value0.22
Percentage of BusinessCombinationAcquisitionRelatedCosts-18.0

us-gaap:OperatingSegments, us-gaap:Corporate


Business
Period End2021-06-302020-06-30
Value-1.4440.977
Percentage of BusinessCombinationAcquisitionRelatedCosts118.0100.0

us-gaap:BusinessCombinationAcquisitionRelatedCosts us-gaap:StatementBusinessSegments

us-gaap:CorporateAndOther


Business
Period End2021-03-312020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value0.7150.00.00.00.00.00.09.00.00.00.00.00.00.00.00.00.0
Percentage of BusinessCombinationAcquisitionRelatedCosts37.30.00.00.00.00.00.077.90.00.00.00.00.00.00.00.00.0

us-gaap:BusinessCombinationStepAcquisitionEquityInterestInAcquireeFairValue1 us-gaap:BusinessAcquisition, us-gaap:SubsequentEventType

us-gaap:BusinessCombinationStepAcquisitionEquityInterestInAcquireeFairValue1

acgl:Coface, us-gaap:SubsequentEvent


Business
Period End2021-02-10
Value453
Percentage of BusinessCombinationStepAcquisitionEquityInterestInAcquireeFairValue1100.0

us-gaap:CededPremiumsWritten

us-gaap:CededPremiumsWritten


Ceded
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value886888498806649695486567492552393397397425341322360381283264306316231217255275218200299230206197230210
Percentage of CededPremiumsWritten100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CededPremiumsWritten us-gaap:ConsolidationItems

us-gaap:OperatingSegments


Ceded
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value948510830643747498585504600429440432488395385424474356357373413292311331369265278336262206197230210
Percentage of CededPremiumsWritten106.7102.4102.999.2107.5102.5103.2102.3108.7109.3110.8108.9114.8115.8119.4117.7124.2125.9135.3121.9130.7126.2143.4129.8134.3121.4139.1112.3114.0100.0100.0100.0100.0

us-gaap:CededPremiumsWritten us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, acgl:InsuranceSegment


Ceded
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value405421406382358378351302292320297259245247254222247234241217246248229209235224215187273185196180202184
Percentage of CededPremiumsWritten45.747.481.547.455.154.572.253.259.358.075.765.461.758.174.568.968.661.385.382.280.678.598.896.492.281.598.993.791.280.495.191.487.987.4

us-gaap:OperatingSegments, acgl:MortgageSegment


Ceded
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value55565747444455574248485750466257627345516.9694.7674.667.8326.9028.674.8977.9045.0794.6390.00.00.00.0
Percentage of CededPremiumsWritten6.36.311.65.96.86.411.310.28.78.812.414.412.810.818.317.917.319.416.019.42.31.52.03.62.73.22.23.91.72.00.00.00.00.0

us-gaap:OperatingSegments, acgl:ReinsuranceSegment


Ceded
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value4334714740024132593226169231841231361957910511516670891191606292891364583587312172827
Percentage of CededPremiumsWritten48.953.19.449.637.346.819.239.834.441.921.431.134.346.023.232.631.943.524.933.939.250.726.942.435.049.720.941.719.731.85.89.112.513.3

us-gaap:OperatingSegments, acgl:UnderwritingSegments


Ceded
Period End2021-06-302020-06-30
Value893643
Percentage of CededPremiumsWritten100.799.2

us-gaap:OperatingSegments, us-gaap:AllOtherSegments


Ceded
Period End2021-06-302020-06-30
Value6552
Percentage of CededPremiumsWritten7.48.0

us-gaap:CededPremiumsWritten us-gaap:StatementBusinessSegments

us-gaap:CorporateAndOther


Ceded
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-30
Value37405052484394424128333434111212106.0776.34.4574.4724.9616.1587.766
Percentage of CededPremiumsWritten4.28.16.28.06.99.016.68.67.57.38.48.78.13.53.93.42.72.12.41.51.42.12.83.0

us-gaap:ConcentrationRiskPercentage1 us-gaap:ConcentrationRiskByBenchmark, us-gaap:ConcentrationRiskByType

us-gaap:ConcentrationRiskPercentage1

us-gaap:StockholdersEquityTotal, us-gaap:ReinsurerConcentrationRisk


Concentration
Period End2021-03-312020-03-31
Value1.70.019
Percentage of ConcentrationRiskPercentage1100.0100.0

us-gaap:ConcentrationRiskPercentage1 us-gaap:CreditRatingAMBest, us-gaap:Collateral, us-gaap:ConcentrationRiskByBenchmark, us-gaap:ConcentrationRiskByType

acgl:NotRated, acgl:ReinsuranceTrustsOrLettersOfCredit, us-gaap:ReinsuranceRecoverable, us-gaap:CreditConcentrationRisk


Concentration
Period End2021-03-312020-03-31
Value92.00.9
Percentage of ConcentrationRiskPercentage15411.84736.8

us-gaap:ConcentrationRiskPercentage1 us-gaap:CreditRatingAMBest, us-gaap:ConcentrationRiskByBenchmark, us-gaap:ConcentrationRiskByType

acgl:AmBestAminusOrBetterRating, us-gaap:ReinsuranceRecoverable, us-gaap:CreditConcentrationRisk


Concentration
Period End2021-03-312020-03-31
Value64.50.608
Percentage of ConcentrationRiskPercentage13794.13200.0

acgl:NotRated, us-gaap:ReinsuranceRecoverable, us-gaap:CreditConcentrationRisk


Concentration
Period End2021-03-312020-03-31
Value35.50.384
Percentage of ConcentrationRiskPercentage12088.22021.1

us-gaap:DebtSecuritiesAvailableForSaleAllowanceForCreditLossNotPreviouslyRecorded

us-gaap:DebtSecuritiesAvailableForSaleAllowanceForCreditLossNotPreviouslyRecorded


Debt
Period End2020-12-312020-09-302020-06-302020-03-31
Value000634000.0
Percentage of DebtSecuritiesAvailableForSaleAllowanceForCreditLossNotPreviouslyRecorded0.00.00.0100.0

us-gaap:DebtSecuritiesAvailableForSaleAllowanceForCreditLossNotPreviouslyRecorded us-gaap:FinancialInstrument, us-gaap:InvestmentType

us-gaap:AssetBackedSecurities, us-gaap:FixedMaturities


Debt
Period End2020-12-312020-09-302020-06-302020-03-31
Value000517000.0
Percentage of DebtSecuritiesAvailableForSaleAllowanceForCreditLossNotPreviouslyRecorded0.00.00.081.5

us-gaap:CorporateBondSecurities, us-gaap:FixedMaturities


Debt
Period End2020-12-312020-09-302020-06-302020-03-31
Value000117000.0
Percentage of DebtSecuritiesAvailableForSaleAllowanceForCreditLossNotPreviouslyRecorded0.00.00.018.5

us-gaap:DebtSecuritiesAvailableForSaleAllowanceForCreditLossNotToSellBeforeRecoveryCreditLossPreviouslyRecordedExpenseReversal

us-gaap:DebtSecuritiesAvailableForSaleAllowanceForCreditLossNotToSellBeforeRecoveryCreditLossPreviouslyRecordedExpenseReversal


Debt
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-31
Value-791000.0-931000.0-1215000.0-1560000.0-4232000.0-23000.0
Percentage of DebtSecuritiesAvailableForSaleAllowanceForCreditLossNotToSellBeforeRecoveryCreditLossPreviouslyRecordedExpenseReversal100.0100.0100.0100.0100.0100.0

us-gaap:DebtSecuritiesAvailableForSaleAllowanceForCreditLossNotToSellBeforeRecoveryCreditLossPreviouslyRecordedExpenseReversal us-gaap:FinancialInstrument, us-gaap:InvestmentType

us-gaap:AssetBackedSecurities, us-gaap:FixedMaturities


Debt
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-31
Value-383000.0-382000.0-495000.0403000.0-1304000.0-2000.0
Percentage of DebtSecuritiesAvailableForSaleAllowanceForCreditLossNotToSellBeforeRecoveryCreditLossPreviouslyRecordedExpenseReversal48.441.040.7-25.830.88.7

us-gaap:CorporateBondSecurities, us-gaap:FixedMaturities


Debt
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-31
Value-412000.0-540000.0-718000.0-1996000.0-2903000.0-21000.0
Percentage of DebtSecuritiesAvailableForSaleAllowanceForCreditLossNotToSellBeforeRecoveryCreditLossPreviouslyRecordedExpenseReversal52.158.059.1127.968.691.3

us-gaap:MunicipalBonds, us-gaap:FixedMaturities


Debt
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-31
Value4000.0-9000.0-2000.033000.0-25000.00
Percentage of DebtSecuritiesAvailableForSaleAllowanceForCreditLossNotToSellBeforeRecoveryCreditLossPreviouslyRecordedExpenseReversal-0.51.00.2-2.10.6-0.0

us-gaap:DebtSecuritiesAvailableForSaleAllowanceForCreditLossSecuritiesSold

us-gaap:DebtSecuritiesAvailableForSaleAllowanceForCreditLossSecuritiesSold


Debt
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-31
Value974000.0239000.0396000.0605000.0837000.022000.0
Percentage of DebtSecuritiesAvailableForSaleAllowanceForCreditLossSecuritiesSold100.0100.0100.0100.0100.0100.0

us-gaap:DebtSecuritiesAvailableForSaleAllowanceForCreditLossSecuritiesSold us-gaap:FinancialInstrument, us-gaap:InvestmentType

us-gaap:AssetBackedSecurities, us-gaap:FixedMaturities


Debt
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-31
Value117000.083000.0217000.028000.0319000.07000.0
Percentage of DebtSecuritiesAvailableForSaleAllowanceForCreditLossSecuritiesSold12.034.754.84.638.131.8

us-gaap:CorporateBondSecurities, us-gaap:FixedMaturities


Debt
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-31
Value857000.0156000.0131000.0577000.0504000.015000.0
Percentage of DebtSecuritiesAvailableForSaleAllowanceForCreditLossSecuritiesSold88.065.333.195.460.268.2

us-gaap:MunicipalBonds, us-gaap:FixedMaturities


Debt
Period End2020-12-312020-09-302020-06-302020-03-31
Value48000.0014000.00
Percentage of DebtSecuritiesAvailableForSaleAllowanceForCreditLossSecuritiesSold12.10.01.70.0

us-gaap:DebtSecuritiesAvailableForSaleChangeInPresentValueExpenseReversal

us-gaap:DebtSecuritiesAvailableForSaleChangeInPresentValueExpenseReversal


Debt
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-31
Value0.0592.603-6.9810.2291.09.349
Percentage of DebtSecuritiesAvailableForSaleChangeInPresentValueExpenseReversal100.0100.0100.0100.0100.0100.0

us-gaap:DebtSecuritiesAvailableForSaleChangeInPresentValueExpenseReversal us-gaap:FinancialInstrument, us-gaap:InvestmentType

us-gaap:AssetBackedSecurities, us-gaap:FixedMaturities


Debt
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-31
Value0.0520.1820.0740.0270.6952.146
Percentage of DebtSecuritiesAvailableForSaleChangeInPresentValueExpenseReversal88.17.0-1.111.869.523.0

us-gaap:CorporateBondSecurities, us-gaap:FixedMaturities


Debt
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-31
Value0.0072.4210.0010.2020.297.151
Percentage of DebtSecuritiesAvailableForSaleChangeInPresentValueExpenseReversal11.993.0-0.088.229.076.5

us-gaap:MunicipalBonds, us-gaap:FixedMaturities


Debt
Period End2020-12-312020-09-302020-06-302020-03-31
Value0.00.00.0440.023
Percentage of DebtSecuritiesAvailableForSaleChangeInPresentValueExpenseReversal-0.00.04.40.2

us-gaap:DebtSecuritiesAvailableForSaleChangeInPresentValueExpenseReversal us-gaap:InvestmentType

us-gaap:FixedMaturities


Debt
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-06-302019-03-31
Value-0.8961.6485.89-1.332-3.2259.320.00.0
Percentage of DebtSecuritiesAvailableForSaleChangeInPresentValueExpenseReversal-1518.663.3-84.4-581.7-322.599.70.00.0

us-gaap:DebtSecuritiesAvailableForSaleChangeInPresentValueExpenseReversal us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:StatementEquityComponents

us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss


Debt
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-31
Value-0.8961.647-1.165-1.333-3.2259.32
Percentage of DebtSecuritiesAvailableForSaleChangeInPresentValueExpenseReversal-1518.663.316.7-582.1-322.599.7

us-gaap:DebtSecuritiesAvailableForSaleRealizedGain

us-gaap:DebtSecuritiesAvailableForSaleRealizedGain


Debt
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-30
Value115651042321787375
Percentage of DebtSecuritiesAvailableForSaleRealizedGain100.0100.0100.0100.0100.0100.0100.0

us-gaap:DebtSecuritiesAvailableForSaleRealizedLoss

us-gaap:DebtSecuritiesAvailableForSaleRealizedLoss


Debt
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-30
Value50621649313015
Percentage of DebtSecuritiesAvailableForSaleRealizedLoss100.0100.0100.0100.0100.0100.0100.0

us-gaap:DerivativeGainLossOnDerivativeNet

us-gaap:DerivativeGainLossOnDerivativeNet


Derivative
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value-51.109363220-0.836127-22.98942633539-17.556-2.146-3.9632.2974.298-4.77-9.181-46.714-16.9642020-38.18335-41.49636367.44912-12.7684.071.57415-0.3782.7690.2970.277-4.669-8.184363.176-11.3213-7.0328
Percentage of DerivativeGainLossOnDerivativeNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DerivativeGainLossOnDerivativeNet us-gaap:DerivativeInstrumentRisk, us-gaap:HedgingDesignation

acgl:Tba, us-gaap:Nondesignated


Derivative
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value0.00.120.2640.745-0.0440.2690.0480.19-0.033-0.0030.0-0.097-0.1340.1220.086-0.0650.266-0.0230.0370.297
Percentage of DerivativeGainLossOnDerivativeNet0.00.6-31.60.60.20.60.10.5-0.10.0-0.02.4-5.82.8-1.80.7-0.60.10.21.4

us-gaap:ForeignExchangeForward, us-gaap:Nondesignated


Derivative
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value1.295-22.07146103.523-10.877.5312.044-5.365-13.709-8.696-5.458-1.692-5.924-2.229-0.228-0.272-11.7664.3634.583-13.782-4.752
Percentage of DerivativeGainLossOnDerivativeNet-2.5-61.1141.153.1-421.4-8.5-32.84.8-8.4-38.2-22.131.178.8149.5-97.0-5.35.7128.2-9.3-27.0-67.8-22.9

us-gaap:Future, us-gaap:Nondesignated


Derivative
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value-54.759479.70510-1.60795-26.3846662759-15.399-0.245.032.0094.899-5.317.72-51.428-15.3683426
Percentage of DerivativeGainLossOnDerivativeNet107.1131.329.553.7192.275.4114.8107.7104.776.2150.387.711.2-126.987.5114.0111.3-84.1110.190.6171.5127.6

us-gaap:OtherContract, us-gaap:Nondesignated


Derivative
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value2.35510-23.26-1.509-3.01641-4.096-5.6142.3122-11.0223.304-0.214-2.9722.651-0.4950.726-5.070.085-6.156-0.792-1.264
Percentage of DerivativeGainLossOnDerivativeNet-4.629.8-70.6-7.4360.832.517.8-13.13.661.5-28.0-18.810.075.0115.4-11.5-15.255.2-0.236.3-3.9-6.1

us-gaap:DerivativeGainLossOnDerivativeNet us-gaap:HedgingDesignation

us-gaap:Nondesignated


Derivative
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-30
Value-51.109363220-0.836127-22.98942633539-17.556-2.146-3.9632.2974.298-4.77-9.181-46.714-16.9642020-38.18335-41.49636367.44912-12.7684.071.57415-0.3782.7690.2970.277
Percentage of DerivativeGainLossOnDerivativeNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DividendsPreferredStock

us-gaap:DividendsPreferredStock


Dividends
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value11101010101010101010101211115.4845.4855.4845.4855.4845.4855.4845.4855.4845.4855.4845.4855.4845.4855.4845.4855.4847.6496.4616.4616.4616.4616.4616.4616.4616.4616.461
Percentage of DividendsPreferredStock100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DividendsPreferredStock us-gaap:ConsolidationItems

us-gaap:OperatingSegments


Dividends
Period End2021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value101010101010101010101211115.4845.4855.4845.4855.4845.4855.4845.4855.4845.4855.4845.4855.4845.4855.484
Percentage of DividendsPreferredStock100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DividendsPreferredStock us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, us-gaap:Corporate


Dividends
Period End2021-06-302020-06-30
Value1110
Percentage of DividendsPreferredStock100.0100.0

us-gaap:DividendsPreferredStock us-gaap:StatementEquityComponents

us-gaap:RetainedEarnings


Dividends
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value11101010101010101010101211115.4845.4855.4845.4855.4845.4855.4845.4855.4845.4855.4845.4855.4845.4855.4845.4855.4847.6496.46145-6.461-6.461-6.461-6.461-6.461-6.461-6.461
Percentage of DividendsPreferredStock100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0700.0-100.0-100.0-100.0-100.0-100.0-100.0-100.0

us-gaap:EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

us-gaap:EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents


Effect
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-7.306-6.08428158.981-30.72326-10.272-1.5123.449-7.508-1.194-12.0421.6110.2368.2726.9982.618
Percentage of EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:EquitySecuritiesFvNiRealizedGainLoss

us-gaap:EquitySecuritiesFvNiRealizedGainLoss


Equity
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value33371926-18.25-0.5391.815.217-6.64410-26.819-2.012-5.918-5.3680.00.0
Percentage of EquitySecuritiesFvNiRealizedGainLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.0

us-gaap:EquitySecuritiesFvNiUnrealizedGainLoss

us-gaap:EquitySecuritiesFvNiUnrealizedGainLoss


Equity
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value65199833145-175.56639-1.2062237-18.76510-7.278-7.5830.00.0
Percentage of EquitySecuritiesFvNiUnrealizedGainLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.0

us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1 us-gaap:FairValueByAssetClass, us-gaap:FairValueByMeasurementFrequency, us-gaap:InvestmentType

us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1

acgl:EquitySecuritiesFairValueOption, us-gaap:FairValueMeasurementsRecurring, acgl:FairValueOption


Fair
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-30
Value2.5022.1882.0761.4321.9210.1270.00.00.00.0
Percentage of FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1100.0100.0100.0100.0100.0100.00.00.00.00.0

us-gaap:AssetBackedSecurities, us-gaap:FairValueMeasurementsRecurring, us-gaap:AvailableforsaleSecurities


Fair
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-30
Value0.012-0.068-0.075-0.0640.0090.00.01.7570.00.003
Percentage of FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings10.5-3.1-3.6-4.50.50.00.00.00.00.0

us-gaap:CorporateDebtSecurities, us-gaap:FairValueMeasurementsRecurring, acgl:FairValueOption


Fair
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-30
Value0.0090.004-0.0340.00.0-1.227-0.049-0.29-0.503-0.537
Percentage of FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings10.40.2-1.60.00.0-966.10.00.00.00.0

us-gaap:CorporateDebtSecurities, us-gaap:FairValueMeasurementsRecurring, us-gaap:AvailableforsaleSecurities


Fair
Period End2020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-30
Value-5.8720.00.0070.00.00.0-0.0010.0
Percentage of FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1-282.90.00.40.00.00.00.00.0

us-gaap:OtherInvestments, us-gaap:FairValueMeasurementsRecurring, acgl:FairValueOption


Fair
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-30
Value0.6330.2480.885-0.987-0.027-0.411-11.6140.298-1.4590.336
Percentage of FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings125.311.342.6-68.9-1.4-323.60.00.00.00.0

us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1 us-gaap:FairValueByMeasurementFrequency, us-gaap:InvestmentType

us-gaap:FairValueMeasurementsRecurring, us-gaap:EquitySecurities


Fair
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-30
Value0.9220.904-0.94611-3.721-0.0260.00.00.00.0
Percentage of FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings136.941.3-45.6824.0-193.7-20.50.00.00.00.0

us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeLoss us-gaap:FairValueByAssetClass, us-gaap:FairValueByMeasurementFrequency, us-gaap:InvestmentType

us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeLoss

us-gaap:AssetBackedSecurities, us-gaap:FairValueMeasurementsRecurring, us-gaap:AvailableforsaleSecurities


Fair
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-30
Value-57000.0114000.0191000.0-287000.0-22000.001000.04000.02000.0-4000.0
Percentage of FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeLoss100.0100.0100.0100.0100.00.0100.0100.0100.0100.0

us-gaap:CorporateDebtSecurities, us-gaap:FairValueMeasurementsRecurring, us-gaap:AvailableforsaleSecurities


Fair
Period End2020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-30
Value6936000.0-1123000.0-5416000.0-301000.0102000.0-118000.0-32000.0-316000.0
Percentage of FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeLoss3631.4391.324618.20.010200.0-2950.0-1600.07900.0

us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases us-gaap:FairValueByAssetClass, us-gaap:FairValueByMeasurementFrequency, us-gaap:InvestmentType

us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases

us-gaap:CorporateDebtSecurities, us-gaap:FairValueMeasurementsRecurring, acgl:FairValueOption


Fair
Period End2020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-30
Value0.00.0330.0330.00.00.00.00.0
Percentage of FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases0.0100.0100.00.00.00.00.00.0

us-gaap:OtherInvestments, us-gaap:FairValueMeasurementsRecurring, acgl:FairValueOption


Fair
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-30
Value5.6387.365220.0030.0213.7130.00.06.250.0
Percentage of FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases0.00.00.09.163.60.00.00.00.00.0

us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases us-gaap:FairValueByMeasurementFrequency, us-gaap:InvestmentType

us-gaap:FairValueMeasurementsRecurring, us-gaap:EquitySecurities


Fair
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-30
Value5.1020.1930.00.03.464120.00.00.00.0
Percentage of FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases0.00.00.00.010497.00.00.00.00.00.0

us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales us-gaap:FairValueByAssetClass, us-gaap:FairValueByMeasurementFrequency, us-gaap:InvestmentType

us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales

us-gaap:OtherInvestments, us-gaap:FairValueMeasurementsRecurring, acgl:FairValueOption


Fair
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-30
Value0.3016.7863.5887.183170.080.0740.0740.0740.074
Percentage of FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales us-gaap:FairValueByMeasurementFrequency, us-gaap:InvestmentType

us-gaap:FairValueMeasurementsRecurring, us-gaap:EquitySecurities


Fair
Period End2020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-30
Value8.349150.0270.00.00.00.0
Percentage of FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales232.7215.10.034977.50.00.00.00.0

us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSettlements us-gaap:FairValueByAssetClass, us-gaap:FairValueByMeasurementFrequency, us-gaap:InvestmentType

us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSettlements

us-gaap:AssetBackedSecurities, us-gaap:FairValueMeasurementsRecurring, us-gaap:AvailableforsaleSecurities


Fair
Period End2021-06-302020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-30
Value0.0030.0110.0451.3570.0180.0130.0150.0330.033
Percentage of FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSettlements100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CorporateDebtSecurities, us-gaap:FairValueMeasurementsRecurring, us-gaap:AvailableforsaleSecurities


Fair
Period End2020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-30
Value0.00.01.4620.4560.4560.4560.4560.456
Percentage of FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSettlements0.00.0107.72533.33507.73040.01381.81381.8

us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersNet us-gaap:FairValueByAssetClass, us-gaap:FairValueByMeasurementFrequency, us-gaap:InvestmentType

us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersNet

us-gaap:CorporateDebtSecurities, us-gaap:FairValueMeasurementsRecurring, us-gaap:AvailableforsaleSecurities


Fair
Period End2020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-30
Value-1.9080.00.01.860.00.00.00.0
Percentage of FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersNet100.00.00.0100.00.00.00.00.0

us-gaap:OtherInvestments, us-gaap:FairValueMeasurementsRecurring, acgl:FairValueOption


Fair
Period End2020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-30
Value0.00.02.984-13.052440.00.00.0
Percentage of FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersNet-0.00.00.0-701.70.00.00.00.0

us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings us-gaap:FairValueByLiabilityClass, us-gaap:FairValueByMeasurementFrequency

us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings

acgl:ContingentConsiderationClassifiedasaLiability, us-gaap:FairValueMeasurementsRecurring


Fair
Period End2020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-30
Value0.00.0180.0540.0790.4230.9081.7111.481
Percentage of FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings0.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements us-gaap:FairValueByLiabilityClass, us-gaap:FairValueByMeasurementFrequency

us-gaap:FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements

acgl:ContingentConsiderationClassifiedasaLiability, us-gaap:FairValueMeasurementsRecurring


Fair
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-30
Value-0.001-0.0040.626.7350.0850.56600.00.00.0
Percentage of FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements100.0100.0100.0100.0100.0100.0100.00.00.00.0

us-gaap:FairValueOptionChangesInFairValueGainLoss1 us-gaap:InvestmentType

us-gaap:FairValueOptionChangesInFairValueGainLoss1

acgl:OtherInvestmentsFairValueOption


Fair
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value604661178-307.8-21.778-33.7818
Percentage of FairValueOptionChangesInFairValueGainLoss1100.0100.0100.0100.0100.0100.0100.0100.0

acgl:ShortTermInvestmentsFairValueOption


Fair
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value-0.1040.7363.3773.368-8.681-1.941-1.3920.72
Percentage of FairValueOptionChangesInFairValueGainLoss1-0.21.65.51.92.88.94.14.0

us-gaap:EquitySecurities


Fair
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value5.4922.0654.0486.664-4.909-1.2316.4144.266
Percentage of FairValueOptionChangesInFairValueGainLoss19.04.46.63.71.65.7-19.023.4

us-gaap:FixedMaturities


Fair
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value10163468-127.666-3.8951131
Percentage of FairValueOptionChangesInFairValueGainLoss117.935.355.438.241.517.9-33.8171.2

us-gaap:ForeignCurrencyTransactionGainLossBeforeTax

us-gaap:ForeignCurrencyTransactionGainLossBeforeTax


Foreign
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value-17.77520-72.209-44.885-39.21172-52.30633-4.9523.525241053-19.721-28.807-28.028-39.543-19.40438-2.62124-23.5664.5214-19.583663656-2.294-6.563-9.848-40.5621324-22.997-16.95931-20.6881260-18.375-36.9126.039-65.1574838
Percentage of ForeignCurrencyTransactionGainLossBeforeTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ForeignCurrencyTransactionGainLossBeforeTax us-gaap:ConsolidationItems

us-gaap:OperatingSegments


Foreign
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value21-62.349-38.681-42.43863-38.03129-6.195.175207.1346-15.039-27.894-27.785-37.821-19.84535-4.23222-22.0412.28616-22.571663457-2.764-6.656-9.848-40.5621324
Percentage of ForeignCurrencyTransactionGainLossBeforeTax107.286.386.2108.287.172.789.9125.0146.883.065.886.076.396.899.195.6102.392.3161.591.193.550.6109.4115.3100.594.2102.8120.5101.4100.0100.0100.0100.0

us-gaap:ForeignCurrencyTransactionGainLossBeforeTax us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, us-gaap:AllOtherSegments


Foreign
Period End2021-06-302020-06-30
Value0.1173.227
Percentage of ForeignCurrencyTransactionGainLossBeforeTax-0.7-8.2

us-gaap:OperatingSegments, us-gaap:Corporate


Foreign
Period End2021-06-302020-06-30
Value-17.892-42.438
Percentage of ForeignCurrencyTransactionGainLossBeforeTax100.7108.2

us-gaap:ForeignCurrencyTransactionGainLossBeforeTax us-gaap:StatementBusinessSegments

us-gaap:CorporateAndOther


Foreign
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-30
Value-1.442-9.86-6.2043.2279.364-14.2753.331.238-1.654.173.7087.495-4.682-0.913-0.243-1.7220.4412.9551.6112.201-1.5252.234-1.3762.988
Percentage of ForeignCurrencyTransactionGainLossBeforeTax-7.213.713.8-8.212.927.310.1-25.0-46.817.034.214.023.73.20.94.4-2.37.7-61.58.96.549.4-9.4-15.3

us-gaap:GainLossOnInvestmentsExcludingOtherThanTemporaryImpairments us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:StatementEquityComponents

us-gaap:GainLossOnInvestmentsExcludingOtherThanTemporaryImpairments

us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss


Gain
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value642.004628718214616435911-23.413-23.888-38.935-67.5862327247.813-42.107613144-0.854-2.0192342242723262.132-21.8251444
Percentage of GainLossOnInvestmentsExcludingOtherThanTemporaryImpairments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:GainLossOnSaleOfOtherInvestments

us-gaap:GainLossOnSaleOfOtherInvestments


Gain
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value10-23.0454.8847.303-6.515-2.097-10.6451.335-1.628-8.410.021-6.773-0.248-9.09-4.944-0.782-14.056-5.817-10.534-10.858-15.066-5.829-15.762-7.142-8.638-4.588-3.927-7.179-10.962-2.706-2.0870.407-0.8651.046-0.721-0.112-0.9961.0621.685-6.32-1.5132.892-0.4761.116-2.253
Percentage of GainLossOnSaleOfOtherInvestments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ImpairmentOfInvestments

us-gaap:ImpairmentOfInvestments


Impairment
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value0.00.00.00.5330.6441.1630.0491.3091.7050.4920.470.1621.7231.878
Percentage of ImpairmentOfInvestments0.00.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ImpairmentOfInvestments us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:StatementEquityComponents

us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss


Impairment
Period End2020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-30
Value0.00.00.5331.1630.0491.3090.4920.470.1621.878
Percentage of ImpairmentOfInvestments0.00.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncomeLossFromEquityMethodInvestments

us-gaap:IncomeLossFromEquityMethodInvestments


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value1227189126-65.119-4.20927173246-6.882158.472283031324816168.7376.6555.517-2.118165.8892.4244.9669.243.2535.2725.665101316247.78724-14.702-30.5495.97329229.708-0.34829
Percentage of IncomeLossFromEquityMethodInvestments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncomeLossFromEquityMethodInvestments us-gaap:ConsolidationItems

us-gaap:OperatingSegments


Income
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value7189126-65.119-4.20927173246-6.882158.472283031324816168.7376.6555.517-2.118165.8892.4244.9669.243.2535.2725.6651013
Percentage of IncomeLossFromEquityMethodInvestments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncomeLossFromEquityMethodInvestments us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, us-gaap:Corporate


Income
Period End2021-06-302020-06-30
Value122-65.119
Percentage of IncomeLossFromEquityMethodInvestments100.0100.0

us-gaap:IncreaseDecreaseInCashCollateralForBorrowedSecurities

us-gaap:IncreaseDecreaseInCashCollateralForBorrowedSecurities


Increase
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value0.0-26.6140.405-55.001690.6-37.20829-43.8139-14.737-161.567136275.253-180.9461279.22-24.4034335-47.014125.529-60.20721-14.032-4.669580.713-44.244116-40.67724-6.322-16.15-80.376-48.853125-131.389-10.38530-30.092
Percentage of IncreaseDecreaseInCashCollateralForBorrowedSecurities0.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInCashCollateralForLoanedSecurities

us-gaap:IncreaseDecreaseInCashCollateralForLoanedSecurities


Increase
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value0.0-26.6140.405-55.001690.6-37.20829-43.8139-14.737-161.567136275.253-180.9461279.22-24.4034335-47.014125.529-60.20721-14.032-4.669580.713-44.244116-40.67724-6.322-16.15-80.376-48.853125-131.389-10.38530-30.092
Percentage of IncreaseDecreaseInCashCollateralForLoanedSecurities0.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInDeferredPolicyAcquisitionCosts

us-gaap:IncreaseDecreaseInDeferredPolicyAcquisitionCosts


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value88126361417758.654131.622231.7730.9634.764304.747201141-2.3097.4563.430-12.7142.7132.705369.4641613412.155216.81245-16.8515.8321332-27.245-1.1157.74322-18.91-0.047-2.03819
Percentage of IncreaseDecreaseInDeferredPolicyAcquisitionCosts100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInPremiumsReceivable

us-gaap:IncreaseDecreaseInPremiumsReceivable


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value173608-143.123-1.87245418-91.01326162858.049-33.7033.178233-135.738-55.35546176-127.296-79.90561217-81.958-97.90114192-62.731-46.18783242-99.867-44.9536.23198-84.474-68.88183190-106.818-82.277118-157.034-63.19720116
Percentage of IncreaseDecreaseInPremiumsReceivable100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInReinsurancePayables

us-gaap:IncreaseDecreaseInReinsurancePayables


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value91240-139.67735279-32.77757662-10.258-5.2653553-28.999-12.5842920-17.656-24.5142151-10.127-15.41535-16.022-22.922-16.182605.4284.257-21.6946.9021723-17.95840-3.1818.896-19.36823-7.1223.277-4.85319-36.669
Percentage of IncreaseDecreaseInReinsurancePayables100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInUnearnedPremiumsNet

us-gaap:IncreaseDecreaseInUnearnedPremiumsNet


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-31
Value-278.615-560.03553-103.052-2.957-392.80260-175.43418-156.39367-42.67537-177.645113-63.517-7.821-159.24396-55.875-17.578-169.656108-35.289-0.142-156.73127-55.888-64.776-205.21-44.135-51.719-200.006
Percentage of IncreaseDecreaseInUnearnedPremiumsNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInUnearnedPremiumsNet us-gaap:ConsolidationItems

us-gaap:OperatingSegments


Increase
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-31
Value-528.4558.001-101.767-28.636-346.14139-145.514-13.119-157.153-26.62118-134.84198-38.42-18.172-137.55482-8.875-33.317-141.03985-9.44212-104.419649.157-25.954-175.182-44.135-51.719-200.006
Percentage of IncreaseDecreaseInUnearnedPremiumsNet94.415.198.8968.488.165.182.9-69.7100.578.462.450.075.986.860.5232.386.485.415.9189.583.178.826.8-9054.266.6234.0-16.440.185.4100.0100.0100.0

us-gaap:IncreaseDecreaseInUnearnedPremiumsNet us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, acgl:InsuranceSegment


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-31
Value-98.128-175.365-89.299-105.00715-112.829-42.927-98.504-35.388-67.82724-15.79422-37.46141-29.76621-42.5448-22.4112-36.67552-20.4510.758-34.08929-19.607-71.17-68.101-22.842-42.912-59.585
Percentage of IncreaseDecreaseInUnearnedPremiumsNet35.231.3-168.4101.9-529.228.7-71.056.1-187.943.436.137.059.021.136.746.9-270.026.750.040.1-71.021.648.858.0-533.821.8106.935.1109.933.251.883.029.8

us-gaap:OperatingSegments, acgl:MortgageSegment


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-31
Value-1.6251.1224.12524020322531155.2147.591105.2017.6-15.533-16.068-30.175-11.467-3.582-44.953-44.748-30.391-12.277-9.211-1.504-1.658-5.5390.436-4.503-11.86-6.076-14.106
Percentage of IncreaseDecreaseInUnearnedPremiumsNet0.6-0.27.8-51.4-1373.5-5.253.2-14.6165.6-10.07.7-17.827.3-2.96.724.5205.418.9-11.96.4255.726.4-28.034.86486.61.0-6.09.9-0.72.226.911.77.1

us-gaap:OperatingSegments, acgl:ReinsuranceSegment


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-31
Value-187.708-354.21293-49.704-84.897-253.7250-72.621-8.906-104.92323-18.418-13.762-102.581496.879-23.222-64.8394517-0.846-59.616622321-68.826363444-102.578-9.433-2.731-126.315
Percentage of IncreaseDecreaseInUnearnedPremiumsNet67.463.2175.748.22871.164.682.941.4-47.367.134.643.2-36.357.743.4-10.8296.940.747.4-30.64.835.158.0-66.0-15007.043.9133.0-61.4-69.150.021.45.363.2

us-gaap:OperatingSegments, acgl:UnderwritingSegments


Increase
Period End2021-06-302020-06-30
Value-287.461-28.636
Percentage of IncreaseDecreaseInUnearnedPremiumsNet103.2968.4

us-gaap:OperatingSegments, us-gaap:AllOtherSegments


Increase
Period End2021-06-302020-06-30
Value8.84625
Percentage of IncreaseDecreaseInUnearnedPremiumsNet-3.2-868.4

us-gaap:IncreaseDecreaseInUnearnedPremiumsNet us-gaap:StatementBusinessSegments

us-gaap:CorporateAndOther


Increase
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-30
Value-31.5845-1.28525-46.66121-29.92310.70714-16.05418-42.80415-25.09710-21.68914-47.015-28.61723-25.847-12.999
Percentage of IncreaseDecreaseInUnearnedPremiumsNet5.684.91.2-868.411.934.917.1169.7-0.521.637.650.024.113.239.5-132.313.614.684.1-89.516.921.273.29154.2

us-gaap:InvestmentIncomeInterestAndDividend

us-gaap:InvestmentIncomeInterestAndDividend


Investment
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value1351251371501511681751811761821731671621521501391341381121131091111081011029895918576757476748079808086899394959595
Percentage of InvestmentIncomeInterestAndDividend100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:InvestmentIncomeInterestAndDividend us-gaap:InvestmentType

acgl:OtherInvestmentIncome


Investment
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-30
Value1914142216191822182138393837423714189.4088.8368.26138.2941010127.1367.9149.0994.7184.9243.7534.7346.2994.2283.7952.98
Percentage of InvestmentIncomeInterestAndDividend14.811.410.514.610.811.510.412.510.511.622.123.423.524.528.327.111.213.38.47.87.612.37.710.110.212.97.48.610.76.26.55.16.28.55.34.83.7

acgl:TermLoanInvestments


Investment
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-30
Value16141822202325242424252120191921252818202116181413146.9085.6695.0695.2966.0264.2174.5514.8763.557
Percentage of InvestmentIncomeInterestAndDividend12.511.713.114.913.513.814.413.314.013.514.713.112.812.914.315.322.525.117.018.019.816.717.614.913.915.38.17.46.77.17.95.75.76.14.4

us-gaap:EquitySecurities


Investment
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-30
Value8.5845.65106.6596.2196.0074.5093.9924.3682.9882.6443.1654.7772.5682.5682.8873.6542.6432.1273.3113.6633.4354.7913.4862.5782.6794.0342.7793.2712.9212.0912.2413.1641.4231.8652.0092.425
Percentage of InvestmentIncomeInterestAndDividend6.44.57.34.44.13.62.62.22.51.61.51.92.91.71.72.12.71.91.92.93.43.14.43.42.52.74.23.03.83.82.83.04.11.92.32.53.0

us-gaap:FixedMaturities


Investment
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-30
Value8890939810511412312612512912712011510710196949472717773737071687066656263626262696870
Percentage of InvestmentIncomeInterestAndDividend65.671.968.265.269.468.270.469.970.871.073.572.070.970.767.268.770.368.264.562.771.366.268.069.669.569.374.072.077.382.083.984.281.383.486.385.987.8

us-gaap:ShortTermInvestments


Investment
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-30
Value1.1380.6071.2291.3323.3834.8963.9483.8343.8594.1794.9944.5474.3924.864.2322.9572.0161.7593.0561.7030.8160.4960.1210.1270.2250.1960.4710.9050.1070.4060.0860.4170.3640.3920.3630.4850.76
Percentage of InvestmentIncomeInterestAndDividend0.80.50.90.92.22.92.22.12.22.32.92.72.73.22.82.11.51.32.71.50.70.40.10.10.20.20.51.00.10.50.10.60.50.50.50.60.9

us-gaap:InvestmentIncomeInvestmentExpense

us-gaap:InvestmentIncomeInvestmentExpense


Investment
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value23272322202321202125162326252523222021202117121515191311129.1698.4518.0717.9238.6656.4366.1466.4046.6815.8396.4236.4056.1164.9485.2084.826
Percentage of InvestmentIncomeInvestmentExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.010