STFC


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

Table of contents



us-gaap:CommonStockValue
us-gaap:ConsolidatedEntities
us-gaap:StatementEquityComponents
us-gaap:SharesOutstanding

us-gaap:CommonStockSharesIssued

us-gaap:CommonStockSharesAuthorized
us-gaap:StatementClassOfStock
us-gaap:PreferredStockSharesAuthorized

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic

us-gaap:EarningsPerShareBasic

us-gaap:EarningsPerShareDiluted

us-gaap:ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest

us-gaap:CostsAndExpenses

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

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments, us-gaap:Subsegments

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

us-gaap:InterestExpenseDebt
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

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

us-gaap:NetIncomeLossAvailableToCommonStockholdersDiluted

us-gaap:NetInvestmentIncome
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OtherComprehensiveIncomeLossNetOfTax
us-gaap:StatementEquityComponents

us-gaap:OtherIncome

us-gaap:ProfitLoss
us-gaap:StatementEquityComponents

us-gaap:RealizedInvestmentGainsLosses
us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:StatementEquityComponents

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax

us-gaap:Revenues
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:Assets
us-gaap:ConsolidatedEntities
us-gaap:ConsolidationItems

us-gaap:Liabilities
us-gaap:ConsolidatedEntities

us-gaap:LiabilitiesAndStockholdersEquity
us-gaap:ConsolidatedEntities

us-gaap:StockholdersEquity
us-gaap:ConsolidatedEntities
us-gaap:StatementEquityComponents

us-gaap:CashAndCashEquivalentsAtCarryingValue
us-gaap:ConsolidatedEntities

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment

us-gaap:PropertyPlantAndEquipmentNet

us-gaap:DeferredTaxAssetsLiabilitiesNet

us-gaap:EquitySecuritiesFvNi
us-gaap:FairValueByFairValueHierarchyLevel
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FinancialInstrument
us-gaap:FinancialInstrument

us-gaap:StockholdersEquity
us-gaap:ConsolidatedEntities
us-gaap:StatementEquityComponents

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:StatementEquityComponents
us-gaap:StockIssuedDuringPeriodValueNewIssues

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:DeferredIncomeTaxExpenseBenefit

us-gaap:IncreaseDecreaseInOtherOperatingCapitalNet

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

us-gaap:ProfitLoss
us-gaap:StatementEquityComponents

us-gaap:ShareBasedCompensation

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:PaymentsOfDividendsCommonStock
us-gaap:LongtermDebtType
us-gaap:DebtInstrumentInterestRateStatedPercentage

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
us-gaap:ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRange

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice
us-gaap:ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRange

us-gaap:DeferredTaxAssetsValuationAllowance

stfc:AcquisitionAndOperatingExpenses
us-gaap:StatementEquityComponents
stfc:AdjustmentsToAdditionalPaidInCapitalStockOptionsGranted

stfc:AssumedPremiumsUnderPoolingArrangement
us-gaap:StatementEquityComponents
stfc:CashDividendsPaidToAffiliates
us-gaap:ConsolidationItems
stfc:CorporateExpenses
us-gaap:ConsolidationItems
stfc:GaapExpenseAdjustments
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

stfc:IncomeTaxReconciliationTaxExemptIncomeAndDividendDeduction

stfc:IncomeTaxReconciliationTaxExemptIncomeAndDividendDeductionsTaxRate

stfc:IncreaseDecreaseInAccruedInvestmentIncomeAndOtherAssets

stfc:IncreaseDecreaseInReinsuranceRecoverableAndPrepaidReinsurancePremiums

stfc:IncurredClaimPropertyCasualtyAndLiabilityToAffiliates

stfc:InterestExpenseDebtToAffiliates

stfc:LossesAndLossExpensesAssumedFromExternalInsurersAndReinsurers

stfc:LossesAndLossExpensesAssumedUnderPoolingArrangement

stfc:LossesAndLossExpensesCededToExternalInsurersAndReinsurers

stfc:LossesAndLossExpensesCededUnderPoolingArrangement

stfc:NetAcquisitionandOperatingExpenses

stfc:NetAssumedLossesAndLossExpensesIncurred

stfc:NetInvestmentIncomeFromAffiliates

stfc:OtherComprehensiveIncomeReclassificationOfDefinedBenefitPlanNetActuarialLossBeforeTax

stfc:PaymentsToAcquireTreasuryStock

stfc:PremiumsCededUnderPoolingArrangement

stfc:PremiumsEarnedNetPropertyAndCasualtyToAffiliates

us-gaap:AssumedPremiumsEarned

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect

us-gaap:CededPremiumsEarned

us-gaap:CommonStockDividendsPerShareCashPaid

us-gaap:CurrentIncomeTaxExpenseBenefit

us-gaap:DebtSecuritiesAvailableForSaleRealizedGain

us-gaap:DebtSecuritiesAvailableForSaleRealizedGainLoss

us-gaap:DebtSecuritiesAvailableForSaleRealizedLoss

us-gaap:DeferredPolicyAcquisitionCostsAdditions

us-gaap:DeferredPolicyAcquisitionCostsDisposition
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAmortizationOfGainsLosses
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAmortizationOfPriorServiceCostCredit

us-gaap:DefinedBenefitPlanContributionsByEmployer
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedReturnOnPlanAssets
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanInterestCost
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanNetPeriodicBenefitCost
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanServiceCost

us-gaap:DepreciationAmortizationAndAccretionNet
us-gaap:StatementEquityComponents
us-gaap:DividendsCommonStockCash

us-gaap:EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate

us-gaap:EffectiveIncomeTaxRateReconciliationDeductions

us-gaap:EffectiveIncomeTaxRateReconciliationOtherAdjustments
us-gaap:FinancialInstrument
us-gaap:EquitySecuritiesFvNiGainLoss
us-gaap:FinancialInstrument
us-gaap:EquitySecuritiesFvNiRealizedGainLoss

us-gaap:EquitySecuritiesFvNiUnrealizedGain
us-gaap:FinancialInstrument

us-gaap:EquitySecuritiesFvNiUnrealizedGainLoss
us-gaap:FinancialInstrument

us-gaap:EquitySecuritiesFvNiUnrealizedLoss
us-gaap:FinancialInstrument

us-gaap:ExcessTaxBenefitFromShareBasedCompensationOperatingActivities
us-gaap:FederalHomeLoanBankAdvancesBranchOfFHLBBank
us-gaap:FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresRepaymentAndPenalties

us-gaap:FederalIncomeTaxExpenseBenefitContinuingOperations

us-gaap:GainLossOnSaleOfInvestments

us-gaap:ImpairmentOfLongLivedAssetsToBeDisposedOf

us-gaap:IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate

us-gaap:IncomeTaxReconciliationOtherAdjustments

us-gaap:IncreaseDecreaseInAccruedIncomeTaxesPayable

us-gaap:IncreaseDecreaseInDeferredPolicyAcquisitionCosts

us-gaap:IncreaseDecreaseInPensionAndPostretirementObligations

us-gaap:IncreaseDecreaseInPremiumsReceivable

us-gaap:IncreaseDecreaseInPropertyAndCasualtyInsuranceLiabilities

us-gaap:IncreaseDecreaseInUnearnedPremiums

us-gaap:IncrementalCommonSharesAttributableToShareBasedPaymentArrangements

us-gaap:IncurredClaimsPropertyCasualtyAndLiability

us-gaap:InvestmentIncomeInterest
us-gaap:FinancialInstrument

us-gaap:InvestmentIncomeInvestmentExpense

us-gaap:LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidCurrentYear1

us-gaap:LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidPriorYears1
us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:StatementEquityComponents
us-gaap:OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax

us-gaap:OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeTax

us-gaap:OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax
us-gaap:StatementEquityComponents

us-gaap:OtherComprehensiveIncomeLossAvailableForSaleSecuritiesTax

us-gaap:OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax
us-gaap:StatementEquityComponents

us-gaap:OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax
us-gaap:StatementEquityComponents

us-gaap:OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax

us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax
us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:StatementEquityComponents
us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax

us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetTransitionAssetObligationBeforeTax

us-gaap:OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax

us-gaap:OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax

us-gaap:OtherExpenses

us-gaap:PaymentsForLossesAndLossAdjustmentExpense

us-gaap:PaymentsToAcquireAvailableForSaleSecuritiesDebt

us-gaap:PaymentsToAcquireAvailableForSaleSecuritiesEquity

us-gaap:PaymentsToAcquireOtherInvestments

us-gaap:PremiumsEarnedNetOtherInsurance

us-gaap:PremiumsEarnedNetPropertyAndCasualty

us-gaap:PremiumsReceivableAllowanceForDoubtfulAccountsPeriodIncreaseDecrease

us-gaap:PremiumsReceivableAllowanceForDoubtfulAccountsWriteOffsAgainstAllowance

us-gaap:ProceedsFromIssuanceOfCommonStock

us-gaap:ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities

us-gaap:ProceedsFromSaleOfAvailableForSaleSecurities

us-gaap:ProceedsFromSaleOfAvailableForSaleSecuritiesDebt

us-gaap:ProceedsFromSaleOfAvailableForSaleSecuritiesEquity

us-gaap:ProceedsFromSaleOfOtherInvestments

us-gaap:ProceedsFromSaleOfPropertyPlantAndEquipment

us-gaap:ProceedsFromShortTermDebt

us-gaap:ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax
us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome
us-gaap:StatementEquityComponents

us-gaap:RepaymentsOfShortTermDebt
us-gaap:StatementEquityComponents
us-gaap:StockIssuedDuringPeriodSharesNewIssues
us-gaap:StatementEquityComponents
us-gaap:StockIssuedDuringPeriodValueStockOptionsExercised
us-gaap:CumulativeEffectPeriodOfAdoption, us-gaap:AdjustmentsForNewAccountingPronouncements, us-gaap:StatementEquityComponents
us-gaap:StockholdersEquityPeriodIncreaseDecrease

us-gaap:SupplementalInformationForPropertyCasualtyInsuranceUnderwritersCurrentYearClaimsAndClaimsAdjustmentExpense

us-gaap:SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense
us-gaap:LiabilityForCatastropheClaimsByCatastrophicEvent
us-gaap:NoncatastrophicEvent

dei:EntityCommonStockSharesOutstanding

stfc:AvailableForSaleDebtSecuritiesWithInsuranceRegulators
us-gaap:RelatedPartyTransactionsByRelatedParty
stfc:DeferredPolicyAcquisitionCostsAssumed
us-gaap:RelatedPartyTransactionsByRelatedParty
stfc:DeferredPolicyAcquisitionCostsCeded

stfc:DeferredPolicyAcquisitionsCostsfromAffiliates
us-gaap:RelatedPartyTransactionsByRelatedParty

stfc:DeferredTaxAssetOtherLiability

stfc:DeferredTaxAssetsLossesAndLossExpensesPayableDiscounting

stfc:DeferredTaxLiabilitiesDeferralOfPolicyAcquisitionCosts

stfc:InvestableAssets

stfc:LossesAndLossExpensesPayableFromAffiliate

stfc:LossesAndLossExpensesPayableFromAffiliates
us-gaap:RelatedPartyTransactionsByRelatedParty

stfc:MortgageBackedSecuritiesAmortizedCost

stfc:MortgageBackedSecuritiesFairValue

stfc:NetOtherLiabilitiesfromAffiliates
us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:AwardType
stfc:NumberOfSecuritiesAvailableForIssuanceUnderEquityCompensationPlans
stfc:InternationalFundName, us-gaap:DefinedBenefitPlanByPlanAssetCategories, us-gaap:RetirementPlanType
stfc:OtherInvestedAssetsFairValueDisclosure
us-gaap:RelatedPartyTransactionsByRelatedParty
stfc:OtherLiabilitiesAssumed
us-gaap:RelatedPartyTransactionsByRelatedParty
stfc:OtherLiabilitiesCeded

stfc:PostretirementPlanEstimatedFutureSubsidy

stfc:SegmentAssets
us-gaap:StatementBusinessSegments

stfc:StatutoryAccountingPoliciesStatutoryPercentAvailableforDividendPaymentswithoutRegulatoryApproval
us-gaap:RetirementPlanType
stfc:SupplementalExecutiveRetirementPlanCurrent
us-gaap:InvestmentsInAndAdvancesToAffiliatesCategorization
stfc:UnearnedPremiumsAssumed
us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:InvestmentsInAndAdvancesToAffiliatesCategorization
stfc:UnearnedPremiumsCeded
us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:InvestmentsInAndAdvancesToAffiliatesCategorization
stfc:UnearnedPremiumsDirect

stfc:UnearnedPremiumsFromAffiliates
us-gaap:InvestmentsInAndAdvancesToAffiliatesCategorization
us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:InvestmentsInAndAdvancesToAffiliatesCategorization
stfc:UnpaidLossesAndLossAdjustmentExpenseDirect

us-gaap:AccruedInvestmentIncomeReceivable
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FinancialInstrument
us-gaap:AlternativeInvestment
us-gaap:FinancialInstrument
us-gaap:InvestmentsInAndAdvancesToAffiliatesCategorization
us-gaap:AssumedLiabilityForUnpaidClaimsAndClaimsAdjustmentExpense
us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
us-gaap:FinancialInstrument

us-gaap:AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
us-gaap:FinancialInstrument

us-gaap:AvailableForSaleDebtSecuritiesAmortizedCostBasis
us-gaap:FinancialInstrument

us-gaap:AvailableForSaleSecurities

us-gaap:AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
us-gaap:FinancialInstrument

us-gaap:AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
us-gaap:FinancialInstrument

us-gaap:AvailableForSaleSecuritiesAmortizedCost
us-gaap:FinancialInstrument

us-gaap:AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss
us-gaap:FinancialInstrument

us-gaap:AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLoss
us-gaap:FinancialInstrument

us-gaap:AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue
us-gaap:FinancialInstrument

us-gaap:AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss
us-gaap:FinancialInstrument

us-gaap:AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
us-gaap:FinancialInstrument

us-gaap:AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
us-gaap:FinancialInstrument

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue

us-gaap:AvailableForSaleSecuritiesDebtSecurities
us-gaap:FairValueByFairValueHierarchyLevel
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FinancialInstrument
us-gaap:FinancialInstrument

us-gaap:AvailableForSaleSecuritiesEquitySecurities
us-gaap:InvestmentsInAndAdvancesToAffiliatesCategorization
us-gaap:CededPremiumsPayable
us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger
us-gaap:FinancialInstrument

us-gaap:DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss
us-gaap:FinancialInstrument

us-gaap:DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months
us-gaap:FinancialInstrument

us-gaap:DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss
us-gaap:FinancialInstrument

us-gaap:DebtSecuritiesAvailableForSaleUnrealizedLossPosition
us-gaap:FinancialInstrument

us-gaap:DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss
us-gaap:FinancialInstrument

us-gaap:DeferredIncomeTaxAssetsNet
us-gaap:ConsolidatedEntities

us-gaap:DeferredIncomeTaxLiabilities

us-gaap:DeferredPolicyAcquisitionCosts

us-gaap:DeferredTaxAssetsCapitalLossCarryforwards

us-gaap:DeferredTaxAssetsGross

us-gaap:DeferredTaxAssetsOperatingLossCarryforwards

us-gaap:DeferredTaxAssetsOther

us-gaap:DeferredTaxAssetsTaxCreditCarryforwards

us-gaap:DeferredTaxAssetsTaxCreditCarryforwardsForeign

us-gaap:DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPostretirementBenefits

us-gaap:DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsUnearnedPremiumsReserve

us-gaap:DeferredTaxLiabilitiesInvestments
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAccumulatedBenefitObligation
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfCompensationIncrease
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanBenefitObligation

us-gaap:DefinedBenefitPlanExpectedAmortizationNextFiscalYear

us-gaap:DefinedBenefitPlanExpectedAmortizationOfGainLossNextFiscalYear

us-gaap:DefinedBenefitPlanExpectedAmortizationOfPriorServiceCostCreditNextFiscalYear
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths
us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsRemainderOfFiscalYear
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo
us-gaap:DefinedBenefitPlanByPlanAssetCategories, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanFairValueOfPlanAssets
us-gaap:DefinedBenefitPlanByPlanAssetCategories, us-gaap:RetirementPlanType
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:RetirementPlanType
us-gaap:RetirementPlanType
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanFundedStatusOfPlan

us-gaap:DueFromAffiliateCurrent

us-gaap:DueFromAffiliates
us-gaap:ConsolidatedEntities

us-gaap:DueToAffiliateCurrentAndNoncurrent

us-gaap:DueToRelatedPartiesCurrentAndNoncurrent

us-gaap:EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized
us-gaap:AwardType
us-gaap:ConsolidatedEntities
us-gaap:EquityMethodInvestments

us-gaap:ExcessTierOneRiskBasedCapitalToRiskWeightedAssets
us-gaap:FederalHomeLoanBankAdvancesBranchOfFHLBBank
us-gaap:FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresAmountOfAvailableUnusedFunds

us-gaap:FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresCollateralPledged1
us-gaap:FairValueByFairValueHierarchyLevel
us-gaap:FederalHomeLoanBankStock

us-gaap:FinancialInstrumentsOwnedAndPledgedAsCollateralAtFairValue

us-gaap:IncomeTaxesReceivable

us-gaap:Investments

us-gaap:InvestmentsFairValueDisclosure
us-gaap:FairValueByFairValueHierarchyLevel
us-gaap:FinancialInstrument
us-gaap:InvestmentsInAndAdvancesToAffiliatesCategorization
us-gaap:LiabilityForClaimsAndClaimsAdjustmentExpense

us-gaap:LiabilityForClaimsAndClaimsAdjustmentExpensePropertyCasualtyLiability

us-gaap:LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet

us-gaap:NotesPayable
us-gaap:ConsolidatedEntities
us-gaap:FairValueByMeasurementBasis
us-gaap:NotesPayableFairValueDisclosure
us-gaap:FairValueByMeasurementBasis, us-gaap:LongtermDebtType
us-gaap:LongtermDebtType
us-gaap:LongtermDebtType, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:AccountsNotesLoansAndFinancingReceivableByReceivableType, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementBasis, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:NotesReceivableFairValueDisclosure

us-gaap:OtherInvestments
us-gaap:FinancialInstrument

us-gaap:OtherInvestmentsAndSecuritiesAtCost
us-gaap:ConsolidatedEntities

us-gaap:OtherLiabilities
us-gaap:ConsolidatedEntities

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesCurrentAndNoncurrent

us-gaap:PremiumsReceivableAllowanceForDoubtfulAccounts

us-gaap:PremiumsReceivableGross

us-gaap:PrepaidReinsurancePremiums

us-gaap:ReinsuranceRecoverables

us-gaap:ReinsuranceRecoverablesAllowance

us-gaap:ReinsuranceRecoverablesGross
us-gaap:CreditRatingAMBest

us-gaap:ReinsuranceRecoverablesOnPaidAndUnpaidLosses
us-gaap:SubsequentEventType
us-gaap:SaleOfStockPricePerShare

us-gaap:SalvageAndSubrogationRecoveriesValue
us-gaap:AwardType
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber
us-gaap:ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRange

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice
us-gaap:ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRange

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber

us-gaap:SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1
stfc:Tail, us-gaap:ShortdurationInsuranceContractsAccidentYear, us-gaap:StatementBusinessSegments
us-gaap:ShortdurationInsuranceContractsCumulativePaidClaimsAndAllocatedClaimAdjustmentExpenseNet
stfc:Tail, us-gaap:StatementBusinessSegments
stfc:Tail, us-gaap:StatementBusinessSegments
us-gaap:ShortdurationInsuranceContractsHistoricalClaimsDurationYearEight
stfc:Tail, us-gaap:StatementBusinessSegments
us-gaap:ShortdurationInsuranceContractsHistoricalClaimsDurationYearFive
stfc:Tail, us-gaap:StatementBusinessSegments
us-gaap:ShortdurationInsuranceContractsHistoricalClaimsDurationYearFour
stfc:Tail, us-gaap:StatementBusinessSegments
us-gaap:ShortdurationInsuranceContractsHistoricalClaimsDurationYearNine
stfc:Tail, us-gaap:StatementBusinessSegments
us-gaap:ShortdurationInsuranceContractsHistoricalClaimsDurationYearOne
stfc:Tail, us-gaap:StatementBusinessSegments
us-gaap:ShortdurationInsuranceContractsHistoricalClaimsDurationYearSeven
stfc:Tail, us-gaap:StatementBusinessSegments
us-gaap:ShortdurationInsuranceContractsHistoricalClaimsDurationYearSix
stfc:Tail, us-gaap:StatementBusinessSegments
us-gaap:ShortdurationInsuranceContractsHistoricalClaimsDurationYearTen
stfc:Tail, us-gaap:StatementBusinessSegments
us-gaap:ShortdurationInsuranceContractsHistoricalClaimsDurationYearThree
stfc:Tail, us-gaap:StatementBusinessSegments
us-gaap:ShortdurationInsuranceContractsHistoricalClaimsDurationYearTwo
stfc:Tail, us-gaap:ShortdurationInsuranceContractsAccidentYear, us-gaap:StatementBusinessSegments
us-gaap:ShortdurationInsuranceContractsIncurredButNotReportedIbnrClaimsLiabilityNet
stfc:Tail, us-gaap:ShortdurationInsuranceContractsAccidentYear, us-gaap:StatementBusinessSegments
us-gaap:ShortdurationInsuranceContractsIncurredClaimsAndAllocatedClaimAdjustmentExpenseNet
stfc:Tail, us-gaap:StatementBusinessSegments

us-gaap:ShortdurationInsuranceContractsLiabilityForUnpaidClaimsAndAllocatedClaimAdjustmentExpenseNet
stfc:Tail, us-gaap:StatementBusinessSegments
stfc:Tail, us-gaap:StatementBusinessSegments
us-gaap:ShortdurationInsuranceContractsLiabilityForUnpaidClaimsAndAllocatedClaimAdjustmentExpenseNetNotSeparatelyPresented
us-gaap:StatementBusinessSegments
us-gaap:ShortdurationInsuranceContractsLiabilityForUnpaidClaimsAndClaimAdjustmentExpenseOtherReconcilingItem

us-gaap:ShortdurationInsuranceContractsLiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseAccumulatedUnallocatedClaimAdjustmentExpense

us-gaap:StatutoryAccountingPracticesStatutoryAmountAvailableForDividendPaymentsWithoutRegulatoryApproval

us-gaap:StatutoryAccountingPracticesStatutoryCapitalAndSurplusBalance
us-gaap:InvestmentType
us-gaap:SummaryOfInvestmentsOtherThanInvestmentsInRelatedPartiesCarryingAmount

us-gaap:SupplementaryInsuranceInformationDeferredPolicyAcquisitionCosts
us-gaap:StatementBusinessSegments

us-gaap:SupplementaryInsuranceInformationLiabilityForFuturePolicyBenefitsLossesClaimsAndLossExpenseReserves
us-gaap:StatementBusinessSegments

us-gaap:SupplementaryInsuranceInformationUnearnedPremiums
us-gaap:StatementBusinessSegments

us-gaap:TierOneRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssets

us-gaap:TreasuryStockShares

us-gaap:UnearnedPremiums

Plots across concepts


IncomeStatement
Profit Loss
Expenses
Interest Expense Debt
Balance Sheet
Cash And Cash Equivalents At Carrying Value
Assets
Property Plant And Equipment Net
Current Assets
Cash And Cash Equivalents At Carrying Value
NonCurrent Assets
Property Plant And Equipment Net
PropertyPlantAndEquipmentNet
Accumulated Depreciation Depletion And Amortization Property Plant And Equipment
Liabilities
Other Liabilities
Stockholders Equity
Accumulated Other Comprehensive Income Loss Net Of Tax
Per Share
Earnings Per Share Diluted
CashFlow
Net Cash Provided By Used In Operating Activities
NetCashProvidedByUsedInOperatingActivities
Share Based Compensation
NetCashProvidedByUsedInFinancingActivities
Net Cash Provided By Used In Financing Activities
Shares
Treasury Stock Shares

Tables

  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
us-gaap:CommonStockValue ███▇▇▇▇▇▇▆▆▆▆▅▅▄▄▄▄▃▃▃▃▃▃▂▂▂▂▂▂▂▂▁▁▁▁▁▁▁▁127.5127.4126.8126.7126.7126.5125.9125.8125.7125.3125.0124.5124.1123.8123.0122.5122.2121.9121.6121.1120.9120.6120.4119.9119.8119.5119.3119.2119.2119.0118.8118.6118.5118.2118.1118.0118.0117.8117.8117.6117.6NA117.3NANA
 us-gaap:SharesOutstanding us-gaap:StatementEquityComponents us-gaap:CommonStock██▇▇▇▆▆▅▅▄▄▃▃▂▁51.050.950.750.750.750.650.450.350.350.150.049.849.749.549.2NANANA48.6NANANA48.1NANANA47.7NANANA47.5NANANA47.3NANANA47.1NANANA46.9NANA
 us-gaap:SharesOutstanding us-gaap:StatementEquityComponents us-gaap:TreasuryStock███████▁▁▁▁▁▁▁▁6.96.96.96.96.96.96.96.86.86.86.86.86.86.86.8NANANA6.8NANANA6.8NANANA6.8NANANA6.8NANANA-6.8NANANA-6.8NANANA-6.8NANA
us-gaap:CommonStockSharesIssued █████████████████████████████████▇▇▇▁▇▇▇▇51.050.950.750.750.750.650.450.350.350.150.049.849.749.549.249.048.948.848.648.448.448.248.147.947.947.847.747.747.747.647.547.447.447.347.347.24.72e-0547.147.147.047.0NA46.9NANA
us-gaap:CommonStockSharesAuthorized ████████████████████████████████████▁████100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0001100.0100.0100.0100.0NA100.0NANA
 us-gaap:PreferredStockSharesAuthorized us-gaap:StatementClassOfStock us-gaap:PreferredClassA████████████████████████████████████▁2.52.52.52.52.52.52.52.52.52.52.52.52.52.52.52.52.52.52.52.52.52.52.52.52.52.52.52.52.52.52.52.52.52.52.52.52.5e-06NA2.5e-06NANANANANANA
 us-gaap:PreferredStockSharesAuthorized us-gaap:StatementClassOfStock us-gaap:PreferredClassB██████▁█████████████████████████████▁2.52.52.52.52.52.50.02.52.52.52.52.52.52.52.52.52.52.52.52.52.52.52.52.52.52.52.52.52.52.52.52.52.52.52.52.52.5e-06NA2.5e-06NANANANANANA
us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding █▁44.844.6NA44.344.143.7NA44.043.443.9NA43.643.442.6NA42.242.541.9NA42.141.541.8NA41.941.541.4NA41.541.241.3NA40.940.840.7NA40.440.340.3NA40.340.2NANANANA
us-gaap:WeightedAverageNumberOfSharesOutstandingBasic █▁44.043.9NA43.843.843.7NA43.543.443.3NA43.042.842.6NA42.242.141.9NA41.641.541.4NA41.141.041.0NA40.940.840.8NA40.640.540.5NA40.340.340.3NA40.340.2NANANANA
us-gaap:EarningsPerShareBasic ▆▆▇▆▆▃▆▆▆▇▅▆▆▆▆▅▆▆▆▆▅▆▆▆▆▆▇▆▆▆▆▆▆▆▆▆▆▆█▄▁▆▇▆▅0.010.081.870.260.78-2.620.750.26-0.141.14-0.570.780.14-0.05-0.14-0.230.21-0.10.780.24-0.590.070.080.50.060.61.60.290.070.670.40.460.150.490.52-0.14-0.07-0.052.47-1.46-5.010.320.940.01-0.66
us-gaap:EarningsPerShareDiluted ▆▆▇▆▆▃▆▆▆▇▅▆▆▆▆▅▆▆▆▆▅▆▆▆▆▆▇▆▆▆▆▆▆▆▆▆▆▆█▄▁▆▇▆▅0.010.081.870.260.74-2.620.720.25-0.141.12-0.570.760.14-0.05-0.14-0.230.21-0.10.770.24-0.590.070.070.50.060.61.580.280.070.660.40.450.150.490.51-0.14-0.07-0.052.46-1.46-5.010.320.950.0-0.66
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
 EBT Margin us-gaap:ConsolidationItems us-gaap:OperatingSegments█▁414.7412.2NA391.6434.8214.8NA334.5340.1367.6NA346.0341.7323.7NA358.4355.7344.3NA352.8348.5339.2NA349.7337.4334.9NA291.3294.4291.3NA292.7285.3285.3NA286.4286.7NANANANANANANANA
 EBT Margin us-gaap:ConsolidationItems,us-gaap:StatementBusinessSegments us-gaap:OperatingSegments,stfc:InsuranceSegments█▁369.9355.9NA353.2340.7330.5NA319.6307.7302.7NA306.8307.5314.9NA319.0320.1317.3NA325.8322.4319.9NA319.7311.5315.3NA270.2268.3262.5NA266.0263.5261.3NA261.4258.4NANANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
us-gaap:ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest ▅▄▆▅▆▃▅▅▅▆▄▅▅▄▄▄▅▅▄▅▅▅▅▅▄▅▆▅▅▅▆▅▄▅▅▅▅▅█▃▁▅17.4-40.461.417.065.9-90.419.029.020.777.2-12.622.5-2.5-30.8-17.0-15.014.211.3-16.79.1-3.326.89.3-1.3-24.934.040.9-6.328.335.452.725.4-54.333.60.824.7-8.113.7174.0-68.3-198.918.1NANANA
us-gaap:CostsAndExpenses █▁410.5406.6NA376.8393.2358.8NA321.8347.7306.0NA305.0334.0327.0NA369.6343.8349.5NA345.4373.6335.4NANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:GainLossOnInvestments ▆▇█▆█▁▆▅▆▇▃▆26.738.266.620.075.9-135.224.0-5.010.344.9-67.917.8NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments ▅▅█▆▆▁▆▅▅▇▄▆▅▅▆▅▅▅▆▅▄▅▅▆▅▆▅▅▅▆▆▆▅▆▆▅▅▅▇▄▁▆▆▅▄4.25.6102.014.841.6-144.040.312.7-7.661.6-32.541.07.7-3.337.9-11.211.9-5.233.17.4-25.13.80.829.93.433.2-17.113.13.127.716.318.76.320.020.9-5.6-2.7-2.064.9-52.0-137.615.634.1-0.2-30.0
us-gaap:IncomeTaxExpenseBenefit ▆▆▇▆▆▄▆▆▅▆▅▆▆▆█▅▆▆▆▅▆▆▅▆▆▆▁▆▆▆▆▆▆▆▆▆3.62.020.23.27.3-29.47.61.2-1.412.2-8.07.61.7-1.243.7-1.73.2-1.10.6-2.7-0.50.8-2.39.20.78.5-82.51.20.10.6-0.10.20.10.30.0-0.1NANA-35.76.763.8NANA-0.4-3.8
us-gaap:InterestExpenseDebt ▁▁▁▁▂▁▁▁▂▁▁▁▃▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂█▃▃▃▃▃▃▃▃▃▃▃▃1.11.11.11.11.31.21.21.21.31.21.21.21.71.61.51.51.51.41.41.41.41.31.41.31.41.31.41.41.31.31.41.63.81.71.71.81.71.81.71.91.71.81.81.71.8
us-gaap:InterestPaidNet ▄▄▅▅▄▅▅▅▁█▅1.11.11.21.21.11.21.31.20.61.71.2NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:NetIncomeLossAvailableToCommonStockholdersDiluted 0.6NANANA32.7NANANA-6.2NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:NetInvestmentIncome ▃▃▃▃▃▃▄▄▆▄▆▅▅▄▆▃▄▃▅▃▄▂▃▃▄▁▃▃▅▃▂▃▄▂▄▂▅▂▃▅█▅▄▄▅17.717.617.617.917.718.920.019.321.719.422.720.821.519.922.318.719.118.720.617.619.117.417.818.719.815.417.718.920.517.617.418.819.716.920.217.220.517.518.920.325.221.020.219.320.8
us-gaap:OtherComprehensiveIncomeLossNetOfTax ▅▂▃▅▆▆▄▆▆▆▅▄▄▃▄▄▅▅▂▄▆▆▅▃▃▅▃▃▆▅▇▅▁▅▃▆▄▅█▄▅16.8-44.0-20.45.431.624.2-13.717.526.927.811.9-11.0-8.5-28.7-11.2-5.55.515.4-49.2-1.021.323.86.2-22.0-27.69.3-24.5-18.225.38.336.36.9-60.513.9-20.130.2-5.415.760.8-9.615.2NANANANA
us-gaap:OtherIncome ▁▂▂▂▂▂▃▂▁▂▃▂▂▂▂▂▃▂▂▂▂▂▂▂▃▁█▂▁▂▂▁▂▁▄▃▅▃▃▃▁▃▃▁▃0.40.50.50.50.50.60.80.60.40.60.80.60.60.60.60.50.70.50.60.60.50.60.50.50.70.41.80.60.30.50.60.40.60.40.90.81.10.80.70.70.30.80.80.30.7
us-gaap:ProfitLoss ▆▆█▆▆▃▆▆▆▇▅▆▆▆▆▅▆▆▆▆▅▆▆▆▆▆▇▆▆▆▆▆▆▆▆▆▆▆█▄▁▆▇▆▅0.63.681.811.634.3-114.632.711.5-6.249.4-24.533.46.0-2.1-5.8-9.58.7-4.132.510.1-24.63.03.120.72.724.765.411.93.027.116.418.56.219.720.9-5.5-2.7-2.099.3-58.7-201.412.837.60.2-26.2
us-gaap:RealizedInvestmentGainsLosses ▆▇█▆█▁▆▅▆▇▃▆▆▅▆▆▆▆▆▆▆▆▆▆▆▆▆▆▆▆▆▆▆▆▆▆▆▆▆▆▆▆▆▆▅26.738.266.620.075.9-135.224.0-5.010.344.9-67.917.812.1-11.721.320.215.87.819.98.86.51.34.310.85.43.83.11.65.310.77.57.51.56.78.27.06.77.112.110.26.58.28.62.80.3
us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax ██▁██▇████▇██▇████████████▇▇▇▇▇▇▇▇▇▇▇▇███████414.7412.2-1039.2391.6434.8214.8367.8334.5340.1367.6264.4346.0341.7323.7362.9358.4355.7344.3364.9352.8348.5339.2346.6349.7337.4334.9295.7291.3294.4291.3289.7292.7285.3285.3296.7286.4286.7280.3401.1388.0384.4380.2356.9340.7331.1
us-gaap:Revenues ▇▇█▆█▁▆▅▅▆▃▅▅▄▆▅▅▅▆▅▅▅▅▅▅▅▄▃▃▃▃▃▃▃▄▃▃▃▇▆▆▆▅▅▅414.7412.2441.2391.6434.8214.8367.8334.5340.1367.6264.4346.0341.7323.7362.9358.4355.7344.3364.9352.8348.5339.2346.6349.7337.4334.9295.7291.3294.4291.3289.7292.7285.3285.3296.7286.4286.7280.3401.1388.0384.4380.2356.9340.7331.1
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
us-gaap:Assets █████▆▇▇▆▆▆▆▆▆▇▇▇▇▆▇▆▅▅▅▅▄▄▂▂▂▁▁▁▁▁▁▁▁▅▅▅3094.03065.53102.53068.53080.22960.12985.42979.82961.22924.12895.92939.22946.82957.33014.33056.43032.52978.92959.42970.02933.52868.52828.52807.72800.52777.12766.92586.12578.12516.92496.42482.12470.72501.92477.82479.52486.92462.82790.82811.82824.2NA2722.0NANA
us-gaap:Liabilities ▇▆▆▇▇▆▅▆▆▆▆▆▆▇▇▇▇▆▆▆▆▅▄▄▄▃▄▂▁▁▁▂▂▁▂▂▂▁▆█▇2115.72093.52092.52124.42149.72093.42025.52036.12045.02028.82077.42069.82099.82108.22133.42159.22118.12077.82068.12062.22032.11959.61943.91932.41923.01872.91894.01751.61734.41699.41711.41748.11759.41734.41740.61740.41767.21730.52032.52210.62149.5NA1870.2NANA
us-gaap:LiabilitiesAndStockholdersEquity █████▆▇▇▆▆▆▆▆▆▇▇▇▇▆▇▆▅▅▅▅▄▄▂▂▂▁▁▁▁▁▁▁▁▅▅▅3094.03065.53102.53068.53080.22960.12985.42979.82961.22924.12895.92939.22946.82957.33014.33056.43032.52978.92959.42970.02933.52868.52828.52807.72800.52777.12766.92586.12578.12516.92496.42482.12470.72501.92477.82479.52486.92462.82790.82811.82824.2NA2722.0NANA
us-gaap:StockholdersEquity ▇▇█▇▇▆▇▇▆▆▅▆▅▅▆▆▆▆▆▆▆▆▆▆▆▆▆▅▅▅▄▃▃▄▃▃▃▃▄▁▂978.3972.01010.0944.1930.5866.7959.9943.7916.2895.3818.5869.4847.0849.1880.9897.2914.4901.1891.3907.8901.4908.9884.6875.3877.5904.2872.9834.5843.7817.5785.0734.0711.3767.5737.2739.1719.7732.3758.3601.2674.7NA851.8NANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
us-gaap:CashAndCashEquivalentsAtCarryingValue ▃▁▂▃▄▃▂▁▁▂▁▁▁▁▂▃▁▁▁▂▁▁▁▁▁▂▂▂▂▂▂▁▂▂▁▂▁▂█▄▂▂▂▂▂108.759.190.7131.4174.6126.678.038.344.872.359.849.540.860.991.5111.148.844.851.169.553.047.758.150.950.668.486.382.271.578.380.354.368.564.359.064.255.463.0356.0186.793.482.488.398.366.0
us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents NANA90.7NANANA78.0NANANA59.8NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment ▄▄▄3.53.53.5NANA3.55.9NANANA7.5NANANA6.8NANANA6.6NANANA6.3NANANA6.1NANANA6.8NANANA5.6NANANA7.5NANANA7.2NANA
us-gaap:PropertyPlantAndEquipmentNet ▁▁▁▁▁▁▁▁▁▃▄▄▄▅▅▅▅▅▅▅▅▅▅▅▅▅▅▆▆▆▆▆▆▆▆██████3.84.24.24.24.24.24.24.24.26.07.17.17.17.27.37.37.27.37.47.47.57.57.67.77.77.68.18.28.28.38.48.48.48.58.810.410.510.310.410.410.5NA11.6NANA
us-gaap:DeferredTaxAssetsLiabilitiesNet NANA27.3NANANA42.2NANANA77.8NANANA57.2NANANA102.1NANANA102.5NANANA97.43.74.27.711.910.08.61.41.00.40.8NA0.5NANANANANANA
us-gaap:EquitySecuritiesFvNi NANA389.7NANANA395.2NANANA315.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:EquitySecuritiesFvNi us-gaap:FairValueByFairValueHierarchyLevel us-gaap:FairValueInputsLevel1NANA389.7NANANA395.2NANANA315.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:EquitySecuritiesFvNi us-gaap:FairValueByFairValueHierarchyLevel,us-gaap:FinancialInstrument us-gaap:FairValueInputsLevel1,stfc:LargeCapSecuritiesNANA134.2NANANA104.4NANANA77.2NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:EquitySecuritiesFvNi us-gaap:FairValueByFairValueHierarchyLevel,us-gaap:FinancialInstrument us-gaap:FairValueInputsLevel1,stfc:MutualandexchangetradedfundsDomainNANA255.5NANANA290.8NANANA237.8NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:EquitySecuritiesFvNi us-gaap:FinancialInstrument stfc:LargeCapSecuritiesNANA134.2NANANA104.4NANANA77.2NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:EquitySecuritiesFvNi us-gaap:FinancialInstrument stfc:MutualandexchangetradedfundsDomainNANA255.5NANANA290.8NANANA237.8NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
us-gaap:StockholdersEquity ▇▇█▇▇▆▇▇▆▆▅▆▅▅▆▆▆▆▆▆▆▆▆▆▆▆▆▅▅▅▄▃▃▄▃▃▃▃▄▁▂978.3972.01010.0944.1930.5866.7959.9943.7916.2895.3818.5869.4847.0849.1880.9897.2914.4901.1891.3907.8901.4908.9884.6875.3877.5904.2872.9834.5843.7817.5785.0734.0711.3767.5737.2739.1719.7732.3758.3601.2674.7NA851.8NANA
us-gaap:CommonStockValue ███▇▇▇▇▇▇▆▆▆▆▅▅▄▄▄▄▃▃▃▃▃▃▂▂▂▂▂▂▂▂▁▁▁▁▁▁▁▁127.5127.4126.8126.7126.7126.5125.9125.8125.7125.3125.0124.5124.1123.8123.0122.5122.2121.9121.6121.1120.9120.6120.4119.9119.8119.5119.3119.2119.2119.0118.8118.6118.5118.2118.1118.0118.0117.8117.8117.6117.6NA117.3NANA
us-gaap:AdditionalPaidInCapitalCommonStock ▇█▇▇▇▇▇▇▇▆▆▆▅▅▄▄▄▄▄▃▃▃▃▃▃▂▂▂▂▂▂▂▂▂▁▁▁▁▁▁▁213.1220.1213.3212.1211.1209.1206.7205.2202.5198.4194.2188.6184.8180.3171.8167.3165.6162.6159.9156.0154.8155.1153.5149.8146.7144.5143.2141.6140.5138.7137.5135.4134.2132.3131.6130.2129.5128.1127.3125.7125.0NA122.1NANA
us-gaap:RetainedEarningsAccumulatedDeficit ███▆▆▅█▇▇▇▆▇▆▆▅▆▆▆▆▅▅▆▆▆▆▆▅▄▄▄▃▃▂▂▂▂▂▂▃▁▂769.8773.5774.4700.4693.2663.2782.7754.4747.2757.7712.7741.6712.3710.7666.2676.2689.9685.4693.8665.5659.5688.3689.4690.5673.8675.3654.7593.5585.6586.7563.8551.4536.9534.8519.1502.4513.9522.7565.2470.7535.3NA736.1NANA
us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax ▄▃▅▅▅▄▃▃▃▂▁▂▂▃▅▆▆▆▅▇▇▆▅▅▆▇▇▇█▇▇▆▅▇▇█▇▇▆▄▅-13.3-30.113.923.317.9-13.7-37.9-24.2-41.7-68.6-96.4-68.3-57.3-48.836.747.953.447.932.581.782.761.437.631.453.481.071.796.2114.489.180.844.537.698.184.2104.374.179.563.83.012.6NA-7.9NANA
 us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax us-gaap:ConsolidatedEntities srt:ParentCompanyNANA13.9NANANA-37.9NANANA-96.4NANANA3.8NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax us-gaap:StatementEquityComponents us-gaap:AccumulatedDefinedBenefitPlansAdjustment▁▁▁▂▂▂▁▂▂▂▂▅▅▅▆▆▆▆▆▆▆▆▆▅▅▅▅████▅▅▅▅▅▅▅▅-79.1-81.3-83.6-73.4-75.1-76.7-78.3-74.3-74.9-75.6-76.2-36.4-37.0-37.6-29.3-29.1-29.6-29.9-30.3-28.9-29.6-30.3-30.9-35.4-36.3-37.3-38.3-4.1-4.4-3.6-3.8-37.2-38.1-39.0-39.9-33.0-33.8-34.4-35.1NANANA-79.5NANA
 us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax us-gaap:StatementEquityComponents us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss▅▄▆▆▆▅▄▄▄▃▁▁▁▂▅▆▆▆▅▇▇▆▅▅▆▇▇▆▇▆▆▆▅█▇█▇▇▆65.851.297.596.793.063.040.450.133.27.0-20.2-31.9-20.3-11.266.077.083.077.862.8110.6112.391.768.566.889.7118.3110.0100.3118.892.784.681.775.7137.0124.0137.2107.8113.798.7NANANA71.3NANA
us-gaap:TreasuryStockValue ██▇▇▇▇▅▅▅▅▄▄▃▃▃▃▃▃▃▃▃▃▂▂▂▂▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁118.8118.9118.4118.4118.4118.4117.5117.5117.5117.5117.0117.0116.9116.9116.8116.7116.7116.7116.5116.5116.5116.5116.3116.3116.2116.1116.0116.0116.0116.0115.9115.9115.9115.9115.8115.8115.8115.8115.8115.8115.8NA115.8NANA
 us-gaap:StockIssuedDuringPeriodValueNewIssues us-gaap:StatementEquityComponents us-gaap:AdditionalPaidInCapital▂▂▂▁▂▃▂▂▄▂▅▃▃█0.80.61.0-0.20.91.31.10.72.60.73.22.01.96.2NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:StockIssuedDuringPeriodValueNewIssues us-gaap:StatementEquityComponents us-gaap:CommonStock▂▆▂▁▃▆▂▂▄▄▅▄▄█0.10.60.10.00.20.60.10.10.40.30.50.40.30.8NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
us-gaap:NetCashProvidedByUsedInOperatingActivities ▇▆▇█▇▆▇▇▆▆▇▇▇▇▇▇▇▇█▇▇▇▇█▇█▇▇▇▇▇▇▇▇▇▇▇▁▇▇▆█▇█-6.8-18.927.254.0-4.2-28.00.022.5-36.0-30.416.9-8.1-11.5-10.77.239.317.73.751.517.520.024.541.346.27.754.634.036.82.52.334.426.13.68.022.915.719.3-343.58.6-7.4-32.674.434.054.5NA
us-gaap:NetCashProvidedByUsedInInvestingActivities ▅▃▁▂▅▄▄▂▃▅▃▄▃▂▂▄▃▃▁▃▃▂▂▂▃▁▂▃▃▃▃▃▃▃▂▃▃▅█▆▅▁▂▃59.8-9.0-64.6-32.655.320.143.0-25.59.846.8-6.023.6-8.8-24.8-26.725.3-12.1-7.0-63.8-19.1-13.3-31.4-33.5-42.3-22.9-69.0-26.8-22.4-6.7-0.6-6.0-21.53.21.3-24.7-0.9-21.656.5165.8106.748.4-74.7-39.0-16.1NA
us-gaap:NetCashProvidedByUsedInFinancingActivities ▅▅▅▁▅█▅▅▅▅▅▄▅▅▅▅▅▅▄▆▅▅▅▅▅▅▅▅▅▅▅▄▅▅▅▄▄▄▄▄▄▄▄▄-3.4-3.7-3.3-64.6-3.156.5-3.3-3.5-1.3-3.9-0.6-6.80.24.9-0.1-2.3-1.6-3.0-6.118.1-1.4-3.5-0.6-3.6-2.6-3.5-3.1-3.7-2.6-3.7-2.4-18.8-2.6-4.0-3.4-6.0-5.3-6.0-5.1-6.0-4.8-5.6-5.0-6.1NA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
us-gaap:DeferredIncomeTaxExpenseBenefit ▆▆▇▆▆▄▆▆▅▆▅▆▆▆█▅▆▅▆▅▆▆▅▆▆▆▁▆▆3.62.020.13.27.7-29.47.61.2-1.412.6-8.07.71.7-0.243.3-1.63.0-1.00.8-1.2-0.50.8-1.96.50.58.1-80.70.00.0NANANANANANANANANANANANANANANANA
us-gaap:IncreaseDecreaseInOtherOperatingCapitalNet ▁█6.39.5NA-50.517.224.8NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:NetCashProvidedByUsedInOperatingActivities ▇▆▇█▇▆▇▇▆▆▇▇▇▇▇▇▇▇█▇▇▇▇█▇█▇▇▇▇▇▇▇▇▇▇▇▁▇▇▆█▇█-6.8-18.927.254.0-4.2-28.00.022.5-36.0-30.416.9-8.1-11.5-10.77.239.317.73.751.517.520.024.541.346.27.754.634.036.82.52.334.426.13.68.022.915.719.3-343.58.6-7.4-32.674.434.054.5NA
us-gaap:ProfitLoss ▆▆█▆▆▃▆▆▆▇▅▆▆▆▆▅▆▆▆▆▅▆▆▆▆▆▇▆▆▆▆▆▆▆▆▆▆▆█▄▁▆▇▆▅0.63.681.811.634.3-114.632.711.5-6.249.4-24.533.46.0-2.1-5.8-9.58.7-4.132.510.1-24.63.03.120.72.724.765.411.93.027.116.418.56.219.720.9-5.5-2.7-2.099.3-58.7-201.412.837.60.2-26.2
us-gaap:ShareBasedCompensation ▁█-8.26.7NANA-1.00.5-0.92.60.63.84.46.70.00.01.20.21.11.70.51.00.81.4-0.62.71.41.00.90.31.41.00.51.11.31.20.80.81.10.81.00.31.10.80.80.9NA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
us-gaap:NetCashProvidedByUsedInInvestingActivities ▅▃▁▂▅▄▄▂▃▅▃▄▃▂▂▄▃▃▁▃▃▂▂▂▃▁▂▃▃▃▃▃▃▃▂▃▃▅█▆▅▁▂▃59.8-9.0-64.6-32.655.320.143.0-25.59.846.8-6.023.6-8.8-24.8-26.725.3-12.1-7.0-63.8-19.1-13.3-31.4-33.5-42.3-22.9-69.0-26.8-22.4-6.7-0.6-6.0-21.53.21.3-24.7-0.9-21.656.5165.8106.748.4-74.7-39.0-16.1NA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
us-gaap:NetCashProvidedByUsedInFinancingActivities ▅▅▅▁▅█▅▅▅▅▅▄▅▅▅▅▅▅▄▆▅▅▅▅▅▅▅▅▅▅▅▄▅▅▅▄▄▄▄▄▄▄▄▄-3.4-3.7-3.3-64.6-3.156.5-3.3-3.5-1.3-3.9-0.6-6.80.24.9-0.1-2.3-1.6-3.0-6.118.1-1.4-3.5-0.6-3.6-2.6-3.5-3.1-3.7-2.6-3.7-2.4-18.8-2.6-4.0-3.4-6.0-5.3-6.0-5.1-6.0-4.8-5.6-5.0-6.1NA
us-gaap:PaymentsOfDividendsCommonStock ▂▃▂▂▂▂▂▂▂▂▂▁▂▂▂▂▂▂▂▁▂▁▂▁▂▁▂▁▁▂▁▁▁▁▂████▇████4.34.54.44.44.34.44.44.34.34.44.34.14.44.34.24.24.24.34.24.14.24.14.24.04.24.14.24.04.14.24.04.04.14.04.26.06.16.06.15.96.16.06.06.0NA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
 us-gaap:DebtInstrumentInterestRateStatedPercentage us-gaap:LongtermDebtType us-gaap:NotesPayableToBanksNANA3.96e-06NA3.9600000000000004e-083.9600000000000004e-083.9600000000000004e-083.9600000000000004e-083.9600000000000004e-083.9600000000000004e-083.9600000000000004e-083.9600000000000004e-083.9600000000000004e-08NA0.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:DebtInstrumentInterestRateStatedPercentage us-gaap:LongtermDebtType us-gaap:SubordinatedDebtNANA4.43e-06NA4.55e-085.7799999999999995e-086.11e-086.329999999999999e-086.719999999999999e-086.82613e-086.94e-086.519999999999999e-086.5e-086.210000000000001e-085.6800000000000006e-085.52e-085.4e-085.25e-085.1299999999999996e-085.04e-084.87e-084.61e-084.61e-084.53e-084.48e-084.46e-084.44e-084.43e-084.43e-084.44e-084.44e-084.46e-084.4699999999999997e-084.4900000000000005e-084.51e-084.62e-084.67e-08NA4.73e-08NANANANANANA

Common Stock Value

us-gaap:CommonStockValue

us-gaap:CommonStockValue


Common
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value127127126126126126125125125125125124124123123122122121121121120120120119119119119119119119118118118118118118118117117117117117
Percentage of CommonStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets4.14.24.14.14.14.34.24.24.24.34.34.24.24.24.14.04.04.14.14.14.14.24.34.34.34.34.34.64.64.74.84.84.84.74.84.84.74.84.24.24.24.3

us-gaap:CommonStockValue us-gaap:ConsolidatedEntities

srt:ParentCompany


Common
Period End2020-12-312019-12-312018-12-312017-12-31
Value126125125123
Percentage of CommonStockValue100.0100.0100.0100.0
Percentage of Assets4.14.24.34.1
Percentage of Assets srt:ParentCompany11.211.613.212.8

Shares Outstanding

us-gaap:SharesOutstanding us-gaap:StatementEquityComponents

us-gaap:SharesOutstanding

us-gaap:CommonStock


Shares
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-31
Value515050505050505050505049494949484847474747464646
Percentage of SharesOutstanding100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:TreasuryStock


Shares
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-31
Value6.96.96.96.96.96.96.96.86.86.86.86.86.86.86.86.86.86.86.8-6.8-6.8-6.8-6.8-6.8
Percentage of SharesOutstanding13.513.613.613.613.613.613.713.513.513.613.613.713.713.713.814.014.114.314.3-14.4-14.4-14.5-14.6-14.7

Common Stock Shares Issued

us-gaap:CommonStockSharesIssued

us-gaap:CommonStockSharesIssued


Common
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value5150505050505050505050494949494948484848484848474747474747474747474747474.72e-054747474746
Percentage of CommonStockSharesIssued100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Common Stock Shares Authorized

us-gaap:CommonStockSharesAuthorized

us-gaap:CommonStockSharesAuthorized


Common
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value1001001001001001001001001001001001001001001001001001001001001001001001001001001001001001001001001001001001000.0001100100100100100
Percentage of CommonStockSharesAuthorized100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Preferred Stock Shares Authorized

us-gaap:PreferredStockSharesAuthorized us-gaap:StatementClassOfStock

us-gaap:PreferredStockSharesAuthorized

us-gaap:PreferredClassA


Preferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302011-12-31
Value2500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02.52.5
Percentage of PreferredStockSharesAuthorized100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PreferredClassB


Preferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302011-12-31
Value2500000.02500000.02500000.02500000.02500000.02500000.002500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02500000.02.52.5
Percentage of PreferredStockSharesAuthorized100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Weighted Average Number Of Diluted Shares Outstanding

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding


Weighted
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-30
Value44444444434443434343424242414241414141414141414040404040404040
Percentage of WeightedAverageNumberOfDilutedSharesOutstanding100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Weighted Average Number Of Shares Outstanding Basic

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic


Weighted
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-30
Value44434343434343434342424242414141414141414040404040404040404040
Percentage of WeightedAverageNumberOfSharesOutstandingBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Earnings Per Share Basic

us-gaap:EarningsPerShareBasic

us-gaap:EarningsPerShareBasic


Earnings
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value0.010.081.870.260.78-2.620.750.26-0.141.14-0.570.780.14-0.05-0.14-0.230.21-0.10.780.24-0.590.070.080.50.060.61.60.290.070.670.40.460.150.490.52-0.14-0.07-0.052.47-1.46-5.010.320.940.01-0.66
Percentage of EarningsPerShareBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Earnings Per Share Diluted

us-gaap:EarningsPerShareDiluted

us-gaap:EarningsPerShareDiluted


Earnings
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value0.010.081.870.260.74-2.620.720.25-0.141.12-0.570.760.14-0.05-0.14-0.230.21-0.10.770.24-0.590.070.070.50.060.61.580.280.070.660.40.450.150.490.51-0.14-0.07-0.052.46-1.46-5.010.320.950-0.66
Percentage of EarningsPerShareDiluted100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0

Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest

us-gaap:ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest

us-gaap:ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest


Comprehensive
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-31
Value17-40.4611765-90.419292077-12.622-2.5-30.8-17.0-15.01411-16.79.1-3.3269.3-1.3-24.93440-6.328355225-54.3330.824-8.113174-68.3-198.918
Percentage of ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax4.2-9.80.04.315.2-42.15.28.76.121.0-4.86.5-0.7-9.5-4.7-4.24.03.3-4.62.6-0.97.92.7-0.4-7.410.213.8-2.29.612.218.28.7-19.011.80.38.6-2.84.943.4-17.6-51.74.8

Costs And Expenses

us-gaap:CostsAndExpenses

us-gaap:CostsAndExpenses


Costs
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-31
Value410406376393358321347306305334327369343349345373335
Percentage of CostsAndExpenses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax99.098.696.290.4167.096.2102.283.288.297.7101.0103.196.7101.597.9107.298.9

Gain Loss On Investments

us-gaap:GainLossOnInvestments

us-gaap:GainLossOnInvestments


Gain
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value2638662075-135.224-5.01044-67.917
Percentage of GainLossOnInvestments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax6.49.30.05.117.5-62.96.5-1.53.012.2-25.75.1

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

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

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest

us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:AccumulatedDefinedBenefitPlansAdjustment


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-30
Value-2.8-2.9-1.2-2.1-2.0-2.1-0.9-0.8-0.8-0.8-4.6-0.8-0.7-0.8-0.5-0.8-0.5-0.7-0.9-1.1-0.9-1.0-1.6-1.5-1.5-1.5-0.1-0.3-0.8-0.2-0.9-0.9-0.9-0.9-0.5-0.8-0.6
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-0.7-0.70.0-0.5-0.5-1.0-0.2-0.2-0.2-0.2-1.7-0.2-0.2-0.2-0.1-0.2-0.1-0.2-0.2-0.3-0.3-0.3-0.5-0.4-0.4-0.4-0.0-0.1-0.3-0.1-0.3-0.3-0.3-0.3-0.2-0.3-0.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome us-gaap:AccumulatedDefinedBenefitPlansAdjustment0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-30
Value-0.81.5-3.5-0.21.02.40.71.21.50.10.30.01.30.42120157.8198.86.51.34.3105.44.23.11.65.3107.57.51.56.78.07.06.7
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest28.6-51.7291.79.5-50.0-114.3-77.8-150.0-187.5-12.5-6.5-0.0-185.7-50.0-4260.0-2525.0-3160.0-1114.3-2211.1-800.0-722.2-130.0-268.8-720.0-360.0-280.0-3100.0-533.3-662.5-5350.0-833.3-833.3-166.7-744.4-1600.0-875.0-1116.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-0.20.40.0-0.10.21.10.20.40.40.00.10.00.40.15.95.64.42.35.52.51.90.41.23.11.61.31.00.51.83.72.62.60.52.32.72.42.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments


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
Value4.25.61021441-144.04012-7.661-32.5417.7-3.337-11.211-5.2337.4-25.13.80.8293.433-17.1133.12716186.32020-5.6-2.7-2.064-52.0-137.61534-0.2-30.0
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax1.01.40.03.89.6-67.011.03.8-2.216.8-12.311.82.3-1.010.4-3.13.3-1.59.12.1-7.21.10.28.61.09.9-5.84.51.19.55.66.42.27.07.0-2.0-0.9-0.716.2-13.4-35.84.10.0-0.1-9.1

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments us-gaap:ConsolidationItems

us-gaap:MaterialReconcilingItems


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-30
Value2.6-5.4-4.13.67.12.3-3.64.11.90.3-5.1-1.3-5.0-6.6-6.4-5.0-1.2-7.7-6.6-0.12.2-3.3-5.8-1.04.1-1.2252.86.13.2-3.61.91.7-0.5-3.0
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments61.9-96.4-4.024.317.1-1.6-8.932.3-25.00.515.7-3.2-64.9200.0-16.944.6-10.1148.1-19.9-1.4-8.8-86.8-725.0-3.3120.6-3.6-146.821.4196.811.6-19.330.28.58.9111.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.6-1.30.00.91.61.1-1.01.20.60.1-1.9-0.4-1.5-2.0-1.8-1.4-0.3-2.2-1.8-0.00.6-1.0-1.7-0.31.2-0.48.51.02.11.1-1.20.70.6-0.2-1.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:MaterialReconcilingItems0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments


Income
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-30
Value1.6111134-146.38.6-9.56142123.3-6.2132.57.5-27.37.130-0.73410-3.024224.418-5.10.3
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments38.1196.475.782.9101.667.7125.099.5103.2164.9-100.055.4110.1-48.1101.4108.8186.8103.3-20.6103.678.6-96.888.4119.369.891.591.1-11.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.42.72.97.9-68.12.6-2.816.712.23.71.0-1.73.70.72.1-7.82.18.8-0.210.33.5-1.08.47.61.56.4-1.80.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, stfc:BusinessInsurance


Income
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value2.83.014-12.4-30.01.2-12.4-5.9-5.2-8.8-8.31.30.8-4.9-17.5-11.6-7.7-13.7-6.8-14.8-1.410-3.3-5.9-8.50.8-1.1-4.5-5.3
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments66.753.697.3-29.820.89.4163.2-9.6-12.7-114.3251.5-11.66.794.2-236.546.2-202.6-1712.5-22.7-435.3-4.2-59.1-25.2-190.3-30.74.9-5.9-71.4-26.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.70.73.7-2.9-14.00.4-3.6-1.6-1.5-2.6-2.60.40.2-1.4-5.0-3.3-2.3-4.0-1.9-4.4-0.43.4-1.1-2.0-2.90.3-0.4-1.6-1.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments stfc:BusinessInsurance0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, stfc:InsuranceSegments


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-30
Value-42.8-44.822-26.7-59.1-30.1-0.2-5.7-41.6-3.1173.6-21.0-5.00.3-45.2-21.9-24.1-0.9-19.0-53.0-11.7-15.61.3-26.015-63.0-10.2-28.7-3.9-6.9-4.0-17.3-5.7-5.0-29.6-27.5
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments-1019.0-800.021.7-180.4-142.120.9-0.5-44.9547.4-5.0-54.58.8-272.7151.50.8403.6-184.0463.5-2.7-256.8211.2-307.9-1950.04.3-764.745.8368.4-77.9-925.8-14.1-42.3-21.4-274.6-28.5-23.9528.61018.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-10.3-10.90.0-6.8-13.6-14.0-0.1-1.7-12.2-0.86.71.0-6.1-1.50.1-12.6-6.2-7.0-0.2-5.4-15.2-3.4-4.50.4-7.74.5-21.3-3.5-9.7-1.3-2.4-1.4-6.1-2.0-1.7-10.3-9.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments stfc:InsuranceSegments0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, stfc:InvestmentOperationsSegment


Income
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-30
Value44553793-116.314326438338.23834262625182925192025282621232427
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments1057.1996.4256.1225.080.8112.6-421.1104.494.1436.4-248.5-347.3293.3-509.6356.8-102.0492.198.7741.259.0156.5832.3102.2140.6336.5118.0-432.1-1007.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax10.713.59.721.5-54.14.39.417.511.29.82.510.99.87.77.57.35.58.47.55.97.08.89.79.07.48.38.49.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments stfc:InvestmentOperationsSegment0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, stfc:PersonalInsurance


Income
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value-44.2-49.4-30.7-40.40.3-6.3-29.94.26.9-13.21.7-7.4-17.9-10.62.6-25.13.93.46.9-10.217-11.64.5-10.75.1-1.1-6.0-6.81.3
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments-1052.4-882.1-207.4-97.1-0.2-49.6393.46.816.8-171.4-51.566.1-150.4203.835.1100.0102.6425.023.1-300.052.467.834.4-345.218.4-6.7-32.1-107.96.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-10.7-12.0-7.8-9.30.1-1.9-8.81.12.0-3.90.5-2.1-5.0-3.10.7-7.21.11.02.0-3.05.2-3.91.5-3.61.8-0.4-2.0-2.40.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments stfc:PersonalInsurance0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, stfc:SpecialtyInsurance


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
Value-1.41.6-0.5-10.4-6.3-0.4-9.4-0.60.7-1.4-4.11.91.01.6-4.5-39.1-4.8-8.6-14.4-4.1-16.3-7.9-5.31.2-1.0-0.8-61.5-11.4-12.1-0.5-6.63.1-6.0-1.7
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments-33.328.6-0.5-70.3-15.10.3-23.3-4.7-9.2-2.312.64.613.0-48.5-11.9349.1-40.3165.4-43.5-55.464.9-207.9-662.54.0-29.4-2.4359.6-87.0-390.3-1.8-40.516.6-95.2-8.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-0.30.40.0-2.7-1.4-0.2-2.6-0.20.2-0.4-1.60.50.30.5-1.2-10.9-1.3-2.5-3.9-1.2-4.7-2.3-1.50.3-0.3-0.2-20.8-3.9-4.1-0.2-2.31.1-2.1-0.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments stfc:SpecialtyInsurance0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, us-gaap:AllOtherSegments


Income
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-30
Value-0.20.00.00.10.10.00.10.10.10.10.10.10.40.10.10.10.10.10.10.10.10.10.1-0.40.00.0-0.10.10.10.00.50.40.60.30.6
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments-0.20.00.0-0.10.20.0-1.30.2-0.30.21.3-3.01.1-0.90.8-1.90.31.4-0.42.612.50.32.9-1.2-0.00.0-3.20.40.60.07.92.02.9-5.4-22.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.00.00.00.00.00.00.00.00.00.00.00.00.10.00.00.00.00.00.00.00.00.00.0-0.10.00.0-0.00.00.00.00.20.10.20.10.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments us-gaap:AllOtherSegments0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments, us-gaap:Subsegments

us-gaap:OperatingSegments, stfc:InvestmentOperationsSegment, stfc:NetRealizedCapitalGains


Income
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-30
Value26382075-135.2-5.010441712-11.720157.88.86.51.3105.44.21.65.3107.51.56.77.06.7
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments635.7682.1135.1182.593.9-39.4-135.572.943.4157.1354.5-180.4132.8-150.0118.9-25.934.236.1158.812.712.2171.038.640.123.833.5-125.0-248.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax6.49.35.117.5-62.9-1.53.012.25.13.5-3.65.64.42.32.51.90.43.11.61.30.51.83.72.60.52.32.42.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments stfc:InvestmentOperationsSegment stfc:NetRealizedCapitalGains0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Income Tax Expense Benefit

us-gaap:IncomeTaxExpenseBenefit

us-gaap:IncomeTaxExpenseBenefit


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302011-12-312011-09-302011-06-302010-09-302010-06-30
Value3.62.0203.27.3-29.47.61.2-1.412-8.07.61.7-1.243-1.73.2-1.10.6-2.7-0.50.8-2.39.20.78.5-82.51.20.10.6-0.10.20.10.30.0-0.1-35.76.763-0.4-3.8
Percentage of IncomeTaxExpenseBenefit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.90.50.00.81.7-13.72.10.4-0.43.3-3.02.20.5-0.412.0-0.50.9-0.30.2-0.8-0.10.2-0.72.60.22.5-27.90.40.00.2-0.00.10.00.10.0-0.0-8.91.716.6-0.1-1.1

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

us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:AccumulatedDefinedBenefitPlansAdjustment


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-30
Value-0.6-0.65.4-0.4-0.4-0.51.0-0.2-0.1-0.2-0.1-0.2-0.1-0.20.3-0.3-0.2-0.30.7-0.4-0.2-0.4-2.4-0.6-0.5-0.5180.00.00.00.00.00.00.00.00.0
Percentage of IncomeTaxExpenseBenefit-16.7-30.026.7-12.5-5.51.713.2-16.77.1-1.61.2-2.6-5.916.70.717.6-6.227.3116.714.840.0-50.0104.3-6.5-71.4-5.9-22.40.00.00.0-0.00.00.00.00.0-0.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-0.1-0.10.0-0.1-0.1-0.20.3-0.1-0.0-0.1-0.0-0.1-0.0-0.10.1-0.1-0.1-0.10.2-0.1-0.1-0.1-0.7-0.2-0.1-0.16.30.00.00.00.00.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome us-gaap:AccumulatedDefinedBenefitPlansAdjustment0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss


Income
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-30
Value-0.20.30.00.20.50.10.30.30.00.00.00.30.17.57.05.62.77.03.12.20.51.53.71.91.57.20.00.00.00.0-0.10.00.00.00.0
Percentage of IncomeTaxExpenseBenefit-5.615.00.02.7-1.71.325.0-21.40.0-0.00.017.6-8.317.2-411.8175.0-245.51166.7-114.8-440.062.5-65.240.2271.417.6-8.70.00.00.0-0.0-50.00.00.00.0-0.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-0.00.10.00.00.20.00.10.10.00.00.00.10.02.12.01.60.81.90.90.60.10.41.10.60.42.40.00.00.00.0-0.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Interest Expense Debt

us-gaap:InterestExpenseDebt

us-gaap:InterestExpenseDebt


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value1100000.01100000.01100000.01100000.01300000.01200000.01200000.01200000.01300000.01200000.01200000.01200000.01700000.01600000.01500000.01500000.01500000.01400000.01400000.01400000.01400000.01300000.01400000.01300000.01400000.01300000.01400000.01400000.01300000.01300000.01400000.01600000.03800000.01700000.01700000.01800000.01700000.01800000.01700000.01900000.01700000.01800000.01800000.01700000.01800000.0
Percentage of InterestExpenseDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.30.30.00.30.30.60.30.40.40.30.50.30.50.50.40.40.40.40.40.40.40.40.40.40.40.40.50.50.40.40.50.51.30.60.60.60.60.60.40.50.40.50.00.50.5

us-gaap:InterestExpenseDebt us-gaap:ConsolidationItems

us-gaap:MaterialReconcilingItems


Interest
Period End2021-06-302020-06-302013-09-302013-06-302012-09-302012-06-30
Value-1100000.0-1300000.01600000.03800000.01800000.01700000.0
Percentage of InterestExpenseDebt-100.0-100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-0.3-0.30.51.30.60.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:MaterialReconcilingItems0.00.00.00.00.00.0

us-gaap:InterestExpenseDebt us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:MaterialReconcilingItems, us-gaap:MaterialReconcilingItems


Interest
Period End2021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-30
Value-1100000.0-1100000.0-1300000.0-1200000.0-1200000.0-1300000.01200000.0-1200000.0-1700000.0-1600000.0-1500000.0-1500000.0-1400000.0-1400000.0-1400000.0-1300000.0-1300000.0-1400000.0
Percentage of InterestExpenseDebt-100.0-100.0-100.0-100.0-100.0-100.0100.0-100.0-100.0-100.0-100.0-100.0-100.0-100.0-100.0-100.0-100.0-100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-0.3-0.3-0.3-0.6-0.4-0.40.3-0.3-0.5-0.5-0.4-0.4-0.4-0.4-0.4-0.4-0.4-0.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:MaterialReconcilingItems us-gaap:MaterialReconcilingItems0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Interest Paid Net

us-gaap:InterestPaidNet

us-gaap:InterestPaidNet


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value1100000.01100000.01200000.01200000.01100000.01200000.01300000.01200000.0600000.01700000.01200000.0
Percentage of InterestPaidNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.30.30.00.30.30.60.40.40.20.50.5

Net Income Loss

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

us-gaap:NetIncomeLoss

us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:AccumulatedDefinedBenefitPlansAdjustment


Net
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-30
Value-2.2-2.3-1.7-1.6-1.6-0.6-0.7-0.6-0.6-0.6-0.6-0.5-0.3-0.4-0.7-0.7-0.6-0.9-1.0-1.0-0.3-0.8-0.2-0.9-0.9-0.9-0.9-0.5-0.8-0.6
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-0.5-0.6-0.4-0.4-0.7-0.2-0.2-0.2-0.2-0.2-0.2-0.1-0.1-0.1-0.2-0.2-0.2-0.3-0.3-0.3-0.1-0.3-0.1-0.3-0.3-0.3-0.3-0.2-0.3-0.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome us-gaap:AccumulatedDefinedBenefitPlansAdjustment0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss


Net
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-30
Value-0.61.2-0.20.81.90.91.20.10.01.00.313105.15.74.30.87.13.52.71.65.3107.57.61.56.78.07.06.7
Percentage of NetIncomeLoss27.3-52.211.8-50.0-118.8-150.0-171.4-16.7-0.0-166.7-50.0-2640.0-3400.0-1275.0-814.3-614.3-133.3-788.9-350.0-270.0-533.3-662.5-5350.0-833.3-844.4-166.7-744.4-1600.0-875.0-1116.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-0.10.3-0.10.20.90.30.40.00.00.30.13.72.91.51.61.20.22.01.00.80.51.83.72.62.60.52.32.72.42.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Net Income Loss Available To Common Stockholders Diluted

us-gaap:NetIncomeLossAvailableToCommonStockholdersDiluted

us-gaap:NetIncomeLossAvailableToCommonStockholdersDiluted


Net
Period End2021-06-302020-06-302019-06-30
Value0.632-6.2
Percentage of NetIncomeLossAvailableToCommonStockholdersDiluted100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.17.5-1.8

Net Investment Income

us-gaap:NetInvestmentIncome

us-gaap:NetInvestmentIncome


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value171717171718201921192220211922181918201719171718191517182017171819162017201718202521201920
Percentage of NetInvestmentIncome100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax4.34.30.04.64.18.85.45.86.45.38.66.06.36.16.15.25.45.45.65.05.55.15.15.35.94.66.06.57.06.06.06.46.95.96.86.07.26.24.75.26.65.50.05.76.3

us-gaap:NetInvestmentIncome us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, stfc:NetInvestmentIncome


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
Value17171717171820192119222021192218191820171917171819151718201717181916
Percentage of NetInvestmentIncome100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax4.34.30.04.64.18.85.45.86.45.38.66.06.36.16.15.25.45.45.65.05.55.15.15.35.94.66.06.57.06.06.06.46.95.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments stfc:NetInvestmentIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Other Comprehensive Income Loss Net Of Tax

us-gaap:OtherComprehensiveIncomeLossNetOfTax

us-gaap:OtherComprehensiveIncomeLossNetOfTax


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-30
Value16-44.0-20.45.43124-13.717262711-11.0-8.5-28.7-11.2-5.55.515-49.2-1.021236.2-22.0-27.69.3-24.5-18.2258.3366.9-60.513-20.130-5.41560-9.615
Percentage of OtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax4.1-10.70.01.47.311.3-3.75.27.97.64.5-3.2-2.5-8.9-3.1-1.51.54.5-13.5-0.36.17.01.8-6.3-8.22.8-8.3-6.28.62.812.52.4-21.24.9-6.810.5-1.95.615.2-2.54.0

us-gaap:OtherComprehensiveIncomeLossNetOfTax us-gaap:StatementEquityComponents

us-gaap:AccumulatedDefinedBenefitPlansAdjustment


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-30
Value2.22.3-20.81.71.61.6-4.00.60.70.60.20.60.60.6-0.20.50.30.4-1.40.70.70.64.50.91.01.0-34.20.3-0.80.2330.90.90.9-6.90.80.6
Percentage of OtherComprehensiveIncomeLossNetOfTax13.1-5.2102.031.55.16.629.23.42.62.21.7-5.5-7.1-2.11.8-9.15.52.62.8-70.03.32.572.6-4.1-3.610.8139.6-1.6-3.22.492.013.0-1.56.534.32.6-11.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.50.60.00.40.40.7-1.10.20.20.20.10.20.20.2-0.10.10.10.1-0.40.20.20.21.30.30.30.3-11.60.1-0.30.111.50.30.30.3-2.30.30.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:AccumulatedDefinedBenefitPlansAdjustment0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-30
Value14-46.30.43.73022-9.716262711-11.6-9.1-29.3-11.0-6.05.215-47.8-1.720231.7-22.9-28.68.39.7-18.5268.12.96.0-61.313-13.229-5.9
Percentage of OtherComprehensiveIncomeLossNetOfTax86.9105.2-2.068.594.993.470.896.697.497.898.3105.5107.1102.198.2109.194.597.497.2170.096.797.527.4104.1103.689.2-39.6101.6103.297.68.087.0101.393.565.797.4109.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax3.5-11.20.00.96.910.5-2.65.17.77.44.4-3.4-2.7-9.1-3.0-1.71.54.4-13.1-0.55.96.80.5-6.5-8.52.53.3-6.48.92.81.02.0-21.54.6-4.410.3-2.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Other Income

us-gaap:OtherIncome

us-gaap:OtherIncome


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
Value400000.0500000.0500000.0500000.0500000.0600000.0800000.0600000.0400000.0600000.0800000.0600000.0600000.0600000.0600000.0500000.0700000.0500000.0600000.0600000.0500000.0600000.0500000.0500000.0700000.0400000.01800000.0600000.0300000.0500000.0600000.0400000.0600000.0400000.0900000.0800000.01100000.0800000.0700000.0700000.0300000.0800000.0800000.0300000.0700000.0
Percentage of OtherIncome100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.10.10.00.10.10.30.20.20.10.20.30.20.20.20.20.10.20.10.20.20.10.20.10.10.20.10.60.20.10.20.20.10.20.10.30.30.40.30.20.20.10.20.00.10.2

Profit Loss

us-gaap:ProfitLoss

us-gaap:ProfitLoss


Profit
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value0.63.6811134-114.63211-6.249-24.5336.0-2.1-5.8-9.58.7-4.13210-24.63.03.1202.72465113.02716186.21920-5.5-2.7-2.099-58.7-201.412370.2-26.2
Percentage of ProfitLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.10.90.03.07.9-53.48.93.4-1.813.4-9.39.71.8-0.6-1.6-2.72.4-1.28.92.9-7.10.90.95.90.87.422.14.11.09.35.76.32.26.97.0-1.9-0.9-0.724.8-15.1-52.43.40.00.1-7.9

us-gaap:ProfitLoss us-gaap:StatementEquityComponents

us-gaap:RetainedEarnings


Profit
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.63.6811134-114.63211-6.249-24.5336.0-2.1
Percentage of ProfitLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.10.90.03.07.9-53.48.93.4-1.813.4-9.39.71.8-0.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Realized Investment Gains Losses

us-gaap:RealizedInvestmentGainsLosses

us-gaap:RealizedInvestmentGainsLosses


Realized
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
Value2638662075-135.224-5.01044-67.91712-11.72120157.8198.86.51.34.3105.43.83.11.65.3107.57.51.56.78.27.06.77.112106.58.28.62.80.3
Percentage of RealizedInvestmentGainsLosses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax6.49.30.05.117.5-62.96.5-1.53.012.2-25.75.13.5-3.65.95.64.42.35.52.51.90.41.23.11.61.11.00.51.83.72.62.60.52.32.82.42.32.53.02.61.72.20.00.80.1

us-gaap:RealizedInvestmentGainsLosses us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:StatementEquityComponents

us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss


Realized
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-0.81.5-3.5-0.21.02.40.71.21.50.10.30.01.30.42120157.8198.86.51.34.3105.44.23.11.65.3107.57.51.56.78.07.06.7
Percentage of RealizedInvestmentGainsLosses-3.03.9-5.3-1.01.3-1.82.9-24.014.60.2-0.40.010.7-3.4100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0110.5100.0100.0100.0100.0100.0100.0100.0100.097.6100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-0.20.40.0-0.10.21.10.20.40.40.00.10.00.40.15.95.64.42.35.52.51.90.41.23.11.61.31.00.51.83.72.62.60.52.32.72.42.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Revenue From Contract With Customer Excluding Assessed Tax

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax


Revenue
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
Value414412-1039.2391434214367334340367264346341323362358355344364352348339346349337334295291294291289292285285296286286280401388384380356340331
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Revenues

us-gaap:Revenues

us-gaap:Revenues


Revenues
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value414412441391434214367334340367264346341323362358355344364352348339346349337334295291294291289292285285296286286280401388384380356340331
Percentage of Revenues100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax100.0100.0-42.5100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:Revenues us-gaap:ConsolidationItems

stfc:CorporateAndReconcilingItems


Revenuesus-gaap:
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-30
Value416413393436216336341369347343325360357345354350340351338
Percentage of Revenues100.4100.4100.4100.3100.7100.5100.5100.4100.5100.5100.5100.4100.4100.4100.4100.4100.4100.4100.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax100.4100.4100.4100.3100.7100.5100.5100.4100.5100.5100.5100.4100.4100.4100.4100.4100.4100.4100.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax stfc:CorporateAndReconcilingItems0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:IntersegmentElimination


Revenuesus-gaap:
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-30
Value1.61.61.51.51.61.71.61.61.61.81.61.61.61.51.51.5-1.4-1.4-1.4-1.4-1.3-1.3-1.3-1.41.3-1.3-5.6-2.3
Percentage of Revenues0.40.40.40.30.70.50.50.40.50.50.50.40.40.40.40.4-0.4-0.4-0.4-0.4-0.4-0.4-0.4-0.50.5-0.5-2.0-0.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.40.40.40.30.70.50.50.40.50.50.50.40.40.40.40.4-0.4-0.4-0.4-0.4-0.4-0.4-0.4-0.50.5-0.5-2.0-0.8
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:IntersegmentElimination0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:MaterialReconcilingItems


Revenuesus-gaap:
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
Value-1.6-1.610-1.5-1.5-1.611-1.7-1.6-1.611-1.6-1.8-1.69.0-1.6-1.6-1.510-1.5-1.5-1.49.8-1.4-1.4
Percentage of Revenues-0.4-0.42.4-0.4-0.3-0.73.1-0.5-0.5-0.44.3-0.5-0.5-0.52.5-0.4-0.4-0.42.8-0.4-0.4-0.42.8-0.4-0.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-0.4-0.4-1.0-0.4-0.3-0.73.1-0.5-0.5-0.44.3-0.5-0.5-0.52.5-0.4-0.4-0.42.8-0.4-0.4-0.42.8-0.4-0.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:MaterialReconcilingItems0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments


Revenuesus-gaap:
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-30
Value414412391434214334340367261346341323360358355344362352348339344349337334292291294291292285285286286
Percentage of Revenues100.0100.0100.0100.0100.0100.0100.0100.099.0100.0100.0100.099.4100.0100.0100.099.4100.0100.0100.099.5100.0100.0100.098.9100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax100.0100.0100.0100.0100.0100.0100.0100.099.0100.0100.0100.099.4100.0100.0100.099.4100.0100.0100.099.5100.0100.0100.098.9100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax 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:Revenues us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, stfc:BusinessInsuranceSegments


Revenuesus-gaap:
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-31
Value157148144137132127118116115115114114104103115119119969696969593928988
Percentage of Revenues38.036.136.931.761.638.034.731.733.333.835.531.929.530.132.634.335.227.728.628.733.032.632.131.731.431.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax38.036.136.931.761.638.034.731.733.333.835.531.929.530.132.634.335.227.728.628.733.032.632.131.731.431.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments stfc:BusinessInsuranceSegments0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, stfc:InsuranceSegments


Revenuesus-gaap:
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-30
Value369355353340330319307302306307314319320317325322319319311315270268262266263261261258
Percentage of Revenues89.286.390.278.4153.995.590.582.388.790.097.389.090.092.292.392.594.391.492.394.192.891.190.190.992.491.691.390.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax89.286.390.278.4153.995.590.582.388.790.097.389.090.092.292.392.594.391.492.394.192.891.190.190.992.491.691.390.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments stfc:InsuranceSegments0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, stfc:InvestmentOperationsSegment


Revenuesus-gaap:
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-30
Value44553793-116.314326438338.23834262625182925192025282621232427
Percentage of Revenues10.713.59.721.5-54.14.39.417.511.29.82.510.99.87.77.57.35.58.47.55.97.08.89.79.07.48.38.49.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax10.713.59.721.5-54.14.39.417.511.29.82.510.99.87.77.57.35.58.47.55.97.08.89.79.07.48.38.49.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments stfc:InvestmentOperationsSegment0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, stfc:PersonalInsuranceSegments


Revenuesus-gaap:
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-31
Value213207208202198192188181173164156144152152145145145147148150112113114116117114
Percentage of Revenues51.450.453.346.692.257.655.449.450.048.348.340.242.944.441.241.742.942.143.944.838.638.639.239.841.140.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax51.450.453.346.692.257.655.449.450.048.348.340.242.944.441.241.742.942.143.944.838.638.639.239.841.140.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments stfc:PersonalInsuranceSegments0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, stfc:SpecialtyInsuranceSegment


Revenuesus-gaap:
Period End2021-06-302021-03-312020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-31
Value-0.8-0.60.00.0-0.11.44.8182743606261655755756669615854565658
Percentage of Revenues-0.2-0.10.00.0-0.00.41.35.47.913.516.917.617.718.516.616.221.619.820.721.219.918.819.419.920.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-0.2-0.10.00.0-0.00.41.35.47.913.516.917.617.718.516.616.221.619.820.721.219.918.819.419.920.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:OperatingSegments stfc:SpecialtyInsuranceSegment0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Assets

us-gaap:Assets

us-gaap:Assets


Assets
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value309430653102306830802960298529792961292428952939294629573014305630322978295929702933286828282807280027772766258625782516249624822470250124772479248624622790281128242722
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:Assets us-gaap:ConsolidatedEntities

srt:ParentCompany


Assetsus-gaap:
Period End2020-12-312019-12-312018-12-312017-12-31
Value11361089948962
Percentage of Assets36.636.532.731.9
Percentage of Assets36.636.532.731.9
Percentage of Assets srt:ParentCompany100.0100.0100.0100.0

us-gaap:Assets us-gaap:ConsolidationItems

us-gaap:CorporateNonSegment


Assetsus-gaap:
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value231238237233295298
Percentage of Assets7.58.08.27.710.010.5
Percentage of Assets7.58.08.27.710.010.5
Percentage of Assets us-gaap:CorporateNonSegment100.0100.0100.0100.0100.0100.0

Liabilities

us-gaap:Liabilities

us-gaap:Liabilities


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value211520932092212421492093202520362045202820772069209921082133215921182077206820622032195919431932192318721894175117341699171117481759173417401740176717302032221021491870
Percentage of Liabilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets68.468.367.469.269.870.767.868.369.169.471.770.471.371.370.870.669.869.869.969.469.368.368.768.868.767.468.567.767.367.568.670.471.269.370.270.271.170.372.878.676.168.7

us-gaap:Liabilities us-gaap:ConsolidatedEntities

srt:ParentCompany


Liabilitiesus-gaap:
Period End2020-12-312019-12-312018-12-312017-12-31
Value126129129127
Percentage of Liabilities6.06.46.26.0
Percentage of Assets4.14.34.54.2
Percentage of Assets srt:ParentCompany11.111.913.713.2

Liabilities And Stockholders Equity

us-gaap:LiabilitiesAndStockholdersEquity

us-gaap:LiabilitiesAndStockholdersEquity


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value309430653102306830802960298529792961292428952939294629573014305630322978295929702933286828282807280027772766258625782516249624822470250124772479248624622790281128242722
Percentage of LiabilitiesAndStockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:LiabilitiesAndStockholdersEquity us-gaap:ConsolidatedEntities

srt:ParentCompany


Liabilities
Period End2020-12-312019-12-312018-12-312017-12-31
Value11361089948962
Percentage of LiabilitiesAndStockholdersEquity36.636.532.731.9
Percentage of Assets36.636.532.731.9
Percentage of Assets srt:ParentCompany100.0100.0100.0100.0

Stockholders Equity

us-gaap:StockholdersEquity

us-gaap:StockholdersEquity


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-312009-12-31
Value9789721010944930866959943916895818869847849880897914901891907901908884875877904872834843817785734711767737739719732758601674851849
Percentage of StockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets31.631.732.630.830.229.332.231.730.930.628.329.628.728.729.229.430.230.230.130.630.731.731.331.231.332.631.532.332.732.531.429.628.830.729.829.828.929.727.221.423.931.30.0

us-gaap:StockholdersEquity us-gaap:ConsolidatedEntities

srt:ParentCompany


Stockholders
Period End2020-12-312019-12-312018-12-312017-12-31
Value1010959818835
Percentage of StockholdersEquity100.0100.0100.094.8
Percentage of Assets32.632.228.327.7
Percentage of Assets srt:ParentCompany88.988.186.386.8

us-gaap:StockholdersEquity us-gaap:StatementEquityComponents

us-gaap:AccumulatedOtherComprehensiveIncome


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-31
Value-13.3-30.1132317-13.7-37.9-24.2-41.7-68.6-96.4-106.1-95.8-88.136323771808463-7.9-2.9-97.6
Percentage of StockholdersEquity-1.4-3.11.42.51.9-1.6-3.9-2.6-4.6-7.7-11.8-12.2-11.3-10.44.23.64.38.210.311.48.4-0.9-0.30.0
Percentage of Assets-0.4-1.00.40.80.6-0.5-1.3-0.8-1.4-2.3-3.3-3.6-3.3-3.01.21.11.32.63.23.42.3-0.30.00.0
Percentage of Assets us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AdditionalPaidInCapital


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-31
Value213220213212211209206205202198194188184180171159153143137131127122115109
Percentage of StockholdersEquity21.822.621.122.522.724.121.521.722.122.223.721.721.821.219.517.917.416.417.517.916.814.313.60.0
Percentage of Assets6.97.26.96.96.97.16.96.96.86.86.76.46.36.15.75.45.45.25.55.34.64.50.00.0
Percentage of Assets us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CommonStock


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-31
Value127127126126126126125125125125125124124123123121120119118118117117116115
Percentage of StockholdersEquity13.013.112.613.413.614.613.113.313.714.015.314.314.714.614.013.613.613.715.116.015.513.813.70.0
Percentage of Assets4.14.24.14.14.14.34.24.24.24.34.34.24.24.24.14.14.34.34.84.84.24.30.00.0
Percentage of Assets us-gaap:CommonStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:RetainedEarnings


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-31
Value769773774700693663782754747757712741712710666693689654563519565736735749
Percentage of StockholdersEquity78.779.676.774.274.576.581.579.981.684.687.185.384.183.775.677.877.975.071.870.474.586.486.60.0
Percentage of Assets24.925.225.022.822.522.426.225.325.225.924.625.224.224.022.123.424.423.722.621.020.327.00.00.0
Percentage of Assets us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:TreasuryStock


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-31
Value118118118118118118-117.5117-117.5-117.5-117.0117-116.9-116.9-116.8-116.5-116.3-116.0-115.9-115.8-115.8-115.8-115.7-115.5
Percentage of StockholdersEquity12.112.211.712.512.713.7-12.212.5-12.8-13.1-14.313.5-13.8-13.8-13.3-13.1-13.1-13.3-14.8-15.7-15.3-13.6-13.60.0
Percentage of Assets3.83.93.83.93.84.0-3.93.9-4.0-4.0-4.04.0-4.0-4.0-3.9-3.9-4.1-4.2-4.6-4.7-4.1-4.30.00.0
Percentage of Assets us-gaap:TreasuryStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Cash And Cash Equivalents At Carrying Value

us-gaap:CashAndCashEquivalentsAtCarryingValue

us-gaap:CashAndCashEquivalentsAtCarryingValue


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302009-12-312008-12-31
Value108599013117412678384472594940609111148445169534758505068868271788054686459645563356186938288986690150
Percentage of CashAndCashEquivalentsAtCarryingValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets3.51.92.94.35.74.32.61.31.52.52.11.71.42.13.03.61.61.51.72.31.81.72.11.81.82.53.13.22.83.13.22.22.82.62.42.62.22.612.86.63.30.03.20.00.00.00.0

us-gaap:CashAndCashEquivalentsAtCarryingValue us-gaap:ConsolidatedEntities

srt:ParentCompany


Cash
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value7.38.8148.88.110
Percentage of CashAndCashEquivalentsAtCarryingValue8.011.324.79.615.918.1
Percentage of Assets0.20.30.50.30.30.4
Percentage of Assets srt:ParentCompany0.60.81.60.90.00.0

Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents


Cash
Period End2020-12-312019-12-312018-12-31
Value907859
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents100.0100.0100.0
Percentage of Assets2.92.62.1

Accumulated Depreciation Depletion And Amortization Property Plant And Equipment

us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment

us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment


Accumulated
Period End2021-06-302021-03-312020-12-312020-03-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-31
Value3500000.03500000.03500000.03500000.05900000.07500000.06800000.06600000.06300000.06100000.06800000.05600000.07500000.07200000.0
Percentage of AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.10.10.10.10.20.30.20.20.20.20.30.20.30.3

Property Plant And Equipment Net

us-gaap:PropertyPlantAndEquipmentNet

us-gaap:PropertyPlantAndEquipmentNet


Property
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value3.84.24.24.24.24.24.24.24.26.07.17.17.17.27.37.37.27.37.47.47.57.57.67.77.77.68.18.28.28.38.48.48.48.58.810101010101011
Percentage of PropertyPlantAndEquipmentNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.10.10.10.10.10.10.10.10.10.20.20.20.20.20.20.20.20.20.30.20.30.30.30.30.30.30.30.30.30.30.30.30.30.30.40.40.40.40.40.40.40.4

Deferred Tax Assets Liabilities Net

us-gaap:DeferredTaxAssetsLiabilitiesNet

us-gaap:DeferredTaxAssetsLiabilitiesNet


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302011-12-31
Value27427757102102973.74.27.71110.08.61.41.00.40.80.5
Percentage of DeferredTaxAssetsLiabilitiesNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.91.42.71.93.53.63.50.10.20.30.50.40.30.10.00.00.00.0

Equity Securities Fv Ni

us-gaap:EquitySecuritiesFvNi

us-gaap:EquitySecuritiesFvNi


Equity
Period End2020-12-312019-12-312018-12-31
Value389395315
Percentage of EquitySecuritiesFvNi100.0100.0100.0
Percentage of Assets12.613.210.9

us-gaap:EquitySecuritiesFvNi us-gaap:FairValueByFairValueHierarchyLevel

us-gaap:FairValueInputsLevel1


Equity
Period End2020-12-312019-12-312018-12-31
Value389395315
Percentage of EquitySecuritiesFvNi100.0100.0100.0
Percentage of Assets12.613.210.9
Percentage of Assets us-gaap:FairValueInputsLevel10.00.00.0

us-gaap:EquitySecuritiesFvNi us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FinancialInstrument

us-gaap:FairValueInputsLevel1, stfc:LargeCapSecurities


Equity
Period End2020-12-312019-12-312018-12-31
Value13410477
Percentage of EquitySecuritiesFvNi34.426.424.5
Percentage of Assets4.33.52.7
Percentage of Assets us-gaap:FairValueInputsLevel1 stfc:LargeCapSecurities0.00.00.0

us-gaap:FairValueInputsLevel1, stfc:MutualandexchangetradedfundsDomain


Equity
Period End2020-12-312019-12-312018-12-31
Value255290237
Percentage of EquitySecuritiesFvNi65.673.675.5
Percentage of Assets8.29.78.2
Percentage of Assets us-gaap:FairValueInputsLevel1 stfc:MutualandexchangetradedfundsDomain0.00.00.0

us-gaap:EquitySecuritiesFvNi us-gaap:FinancialInstrument

stfc:LargeCapSecurities


Equity
Period End2020-12-312019-12-312018-12-31
Value13410477
Percentage of EquitySecuritiesFvNi34.426.424.5
Percentage of Assets4.33.52.7
Percentage of Assets stfc:LargeCapSecurities0.00.00.0

stfc:MutualandexchangetradedfundsDomain


Equity
Period End2020-12-312019-12-312018-12-31
Value255290237
Percentage of EquitySecuritiesFvNi65.673.675.5
Percentage of Assets8.29.78.2
Percentage of Assets stfc:MutualandexchangetradedfundsDomain0.00.00.0

Stockholders Equity

us-gaap:StockholdersEquity

us-gaap:StockholdersEquity


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-312009-12-31
Value9789721010944930866959943916895818869847849880897914901891907901908884875877904872834843817785734711767737739719732758601674851849
Percentage of StockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets31.631.732.630.830.229.332.231.730.930.628.329.628.728.729.229.430.230.230.130.630.731.731.331.231.332.631.532.332.732.531.429.628.830.729.829.828.929.727.221.423.931.30.0

us-gaap:StockholdersEquity us-gaap:ConsolidatedEntities

srt:ParentCompany


Stockholders
Period End2020-12-312019-12-312018-12-312017-12-31
Value1010959818835
Percentage of StockholdersEquity100.0100.0100.094.8
Percentage of Assets32.632.228.327.7
Percentage of Assets srt:ParentCompany88.988.186.386.8

us-gaap:StockholdersEquity us-gaap:StatementEquityComponents

us-gaap:AccumulatedOtherComprehensiveIncome


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-31
Value-13.3-30.1132317-13.7-37.9-24.2-41.7-68.6-96.4-106.1-95.8-88.136323771808463-7.9-2.9-97.6
Percentage of StockholdersEquity-1.4-3.11.42.51.9-1.6-3.9-2.6-4.6-7.7-11.8-12.2-11.3-10.44.23.64.38.210.311.48.4-0.9-0.30.0
Percentage of Assets-0.4-1.00.40.80.6-0.5-1.3-0.8-1.4-2.3-3.3-3.6-3.3-3.01.21.11.32.63.23.42.3-0.30.00.0
Percentage of Assets us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AdditionalPaidInCapital


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-31
Value213220213212211209206205202198194188184180171159153143137131127122115109
Percentage of StockholdersEquity21.822.621.122.522.724.121.521.722.122.223.721.721.821.219.517.917.416.417.517.916.814.313.60.0
Percentage of Assets6.97.26.96.96.97.16.96.96.86.86.76.46.36.15.75.45.45.25.55.34.64.50.00.0
Percentage of Assets us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CommonStock


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-31
Value127127126126126126125125125125125124124123123121120119118118117117116115
Percentage of StockholdersEquity13.013.112.613.413.614.613.113.313.714.015.314.314.714.614.013.613.613.715.116.015.513.813.70.0
Percentage of Assets4.14.24.14.14.14.34.24.24.24.34.34.24.24.24.14.14.34.34.84.84.24.30.00.0
Percentage of Assets us-gaap:CommonStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:RetainedEarnings


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-31
Value769773774700693663782754747757712741712710666693689654563519565736735749
Percentage of StockholdersEquity78.779.676.774.274.576.581.579.981.684.687.185.384.183.775.677.877.975.071.870.474.586.486.60.0
Percentage of Assets24.925.225.022.822.522.426.225.325.225.924.625.224.224.022.123.424.423.722.621.020.327.00.00.0
Percentage of Assets us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:TreasuryStock


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-31
Value118118118118118118-117.5117-117.5-117.5-117.0117-116.9-116.9-116.8-116.5-116.3-116.0-115.9-115.8-115.8-115.8-115.7-115.5
Percentage of StockholdersEquity12.112.211.712.512.713.7-12.212.5-12.8-13.1-14.313.5-13.8-13.8-13.3-13.1-13.1-13.3-14.8-15.7-15.3-13.6-13.60.0
Percentage of Assets3.83.93.83.93.84.0-3.93.9-4.0-4.0-4.04.0-4.0-4.0-3.9-3.9-4.1-4.2-4.6-4.7-4.1-4.30.00.0
Percentage of Assets us-gaap:TreasuryStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Common Stock Value

us-gaap:CommonStockValue

us-gaap:CommonStockValue


Common
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value127127126126126126125125125125125124124123123122122121121121120120120119119119119119119119118118118118118118118117117117117117
Percentage of CommonStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets4.14.24.14.14.14.34.24.24.24.34.34.24.24.24.14.04.04.14.14.14.14.24.34.34.34.34.34.64.64.74.84.84.84.74.84.84.74.84.24.24.24.3

us-gaap:CommonStockValue us-gaap:ConsolidatedEntities

srt:ParentCompany


Common
Period End2020-12-312019-12-312018-12-312017-12-31
Value126125125123
Percentage of CommonStockValue100.0100.0100.0100.0
Percentage of Assets4.14.24.34.1
Percentage of Assets srt:ParentCompany11.211.613.212.8

Additional Paid In Capital Common Stock

us-gaap:AdditionalPaidInCapitalCommonStock

us-gaap:AdditionalPaidInCapitalCommonStock


Additional
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value213220213212211209206205202198194188184180171167165162159156154155153149146144143141140138137135134132131130129128127125125122
Percentage of AdditionalPaidInCapitalCommonStock100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets6.97.26.96.96.97.16.96.96.86.86.76.46.36.15.75.55.55.55.45.35.35.45.45.35.25.25.25.55.45.55.55.55.45.35.35.35.25.24.64.54.44.5

us-gaap:AdditionalPaidInCapitalCommonStock us-gaap:ConsolidatedEntities

srt:ParentCompany


Additional
Period End2020-12-312019-12-312018-12-312017-12-31
Value213206194171
Percentage of AdditionalPaidInCapitalCommonStock100.0100.0100.0100.0
Percentage of Assets6.96.96.75.7
Percentage of Assets srt:ParentCompany18.819.020.517.8

Retained Earnings Accumulated Deficit

us-gaap:RetainedEarningsAccumulatedDeficit

us-gaap:RetainedEarningsAccumulatedDeficit


Retained
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-312009-12-31
Value769773774700693663782754747757712741712710666676689685693665659688689690673675654593585586563551536534519502513522565470535736715
Percentage of RetainedEarningsAccumulatedDeficit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets24.925.225.022.822.522.426.225.325.225.924.625.224.224.022.122.122.823.023.422.422.524.024.424.624.124.323.722.922.723.322.622.221.721.421.020.320.721.220.316.719.027.00.0

us-gaap:RetainedEarningsAccumulatedDeficit us-gaap:ConsolidatedEntities

srt:ParentCompany


Retained
Period End2020-12-312019-12-312018-12-312017-12-31
Value774782712653
Percentage of RetainedEarningsAccumulatedDeficit100.0100.0100.098.0
Percentage of Assets25.026.224.621.7
Percentage of Assets srt:ParentCompany68.271.975.267.9

Accumulated Other Comprehensive Income Loss Net Of Tax

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax


Accumulated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312018-01-012017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value-13.3-30.1132317-13.7-37.9-24.2-41.7-68.6-96.4-68.3-57.3-48.8-20.136475347328182613731538171961148980443798841047479633.012-7.9
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets-0.4-1.00.40.80.6-0.5-1.3-0.8-1.4-2.3-3.3-2.3-1.9-1.70.01.21.61.81.61.12.82.82.11.31.11.92.92.63.74.43.53.21.81.53.93.44.23.03.22.30.10.4-0.3

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax us-gaap:ConsolidatedEntities

srt:ParentCompany


Accumulated
Period End2020-12-312019-12-312018-12-312017-12-31
Value13-37.9-96.43.8
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax100.0100.0100.010.4
Percentage of Assets0.4-1.3-3.30.1
Percentage of Assets srt:ParentCompany1.2-3.5-10.20.4

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax us-gaap:StatementEquityComponents

us-gaap:AccumulatedDefinedBenefitPlansAdjustment


Accumulated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312018-01-012017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312010-12-31
Value-79.1-81.3-83.6-73.4-75.1-76.7-78.3-74.3-74.9-75.6-76.2-36.4-37.0-37.6-38.2-29.3-29.1-29.6-29.9-30.3-28.9-29.6-30.3-30.9-35.4-36.3-37.3-38.3-4.1-4.4-3.6-3.8-37.2-38.1-39.0-39.9-33.0-33.8-34.4-35.1-79.5
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax594.7270.1-601.4-315.0-419.6559.9206.6307.0179.6110.279.053.364.677.0190.0-79.8-60.8-55.4-62.4-93.2-35.4-35.8-49.3-82.2-112.7-68.0-46.0-53.4-4.3-3.8-4.0-4.7-83.6-101.3-39.8-47.4-31.6-45.6-43.3-55.01006.3
Percentage of Assets-2.6-2.7-2.7-2.4-2.4-2.6-2.6-2.5-2.5-2.6-2.6-1.2-1.3-1.30.0-1.0-1.0-1.0-1.0-1.0-1.0-1.0-1.1-1.1-1.3-1.3-1.3-1.4-0.2-0.2-0.1-0.2-1.5-1.5-1.6-1.6-1.3-1.4-1.4-1.3-2.9
Percentage of Assets us-gaap:AccumulatedDefinedBenefitPlansAdjustment0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss


Accumulated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312018-01-012017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312010-12-31
Value6551979693634050337.0-20.2-31.9-20.3-11.218667783776211011291686689118110100118928481751371241371071139871
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax-494.7-170.1701.4415.0519.6-459.9-106.6-207.0-79.6-10.221.046.735.423.0-90.0179.8160.8155.4162.4193.2135.4135.8149.3182.2212.7168.0146.0153.4104.3103.8104.0104.7183.6201.3139.7147.3131.5145.5143.0154.7-902.5
Percentage of Assets2.11.73.13.23.02.11.41.71.10.2-0.7-1.1-0.7-0.40.02.22.52.72.62.13.73.83.22.42.43.24.34.03.94.63.73.43.33.15.55.05.54.34.63.52.6
Percentage of Assets us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Treasury Stock Value

us-gaap:TreasuryStockValue

us-gaap:TreasuryStockValue


Treasury
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value118118118118118118117117117117117117116116116116116116116116116116116116116116116116116116115115115115115115115115115115115115
Percentage of TreasuryStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets3.83.93.83.93.84.03.93.94.04.04.04.04.04.03.93.83.83.93.93.94.04.14.14.14.14.24.24.54.54.64.64.74.74.64.74.74.74.74.14.14.14.3

us-gaap:TreasuryStockValue us-gaap:ConsolidatedEntities

srt:ParentCompany


Treasury
Period End2020-12-312019-12-312018-12-312017-12-31
Value118117117116
Percentage of TreasuryStockValue100.0100.0100.0100.0
Percentage of Assets3.83.94.03.9
Percentage of Assets srt:ParentCompany10.410.812.312.1

Stock Issued During Period Value New Issues

us-gaap:StockIssuedDuringPeriodValueNewIssues us-gaap:StatementEquityComponents

us-gaap:StockIssuedDuringPeriodValueNewIssues

us-gaap:AdditionalPaidInCapital


Stock
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.80.61.0-0.20.91.31.10.72.60.73.22.01.96.2
Percentage of StockIssuedDuringPeriodValueNewIssues100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CommonStock


Stock
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.10.60.10.00.20.60.10.10.40.30.50.40.30.8
Percentage of StockIssuedDuringPeriodValueNewIssues12.5100.010.0-0.022.246.29.114.315.442.915.620.015.812.9
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:CommonStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Net Cash Provided By Used In Operating Activities

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetCashProvidedByUsedInOperatingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value-6.8-18.92754-4.2-28.00.022-36.0-30.416-8.1-11.5-10.77.239173.75117202441467.75434362.52.334263.68.0221519-343.58.6-7.4-32.6743454
Percentage of NetCashProvidedByUsedInOperatingActivities100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-1.6-4.6-2.613.8-1.0-13.00.06.7-10.6-8.36.4-2.3-3.4-3.32.011.05.01.114.15.05.77.211.913.22.316.311.512.60.80.811.98.91.32.87.75.56.7-122.52.1-1.9-8.519.69.516.0

Net Cash Provided By Used In Investing Activities

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:NetCashProvidedByUsedInInvestingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value59-9.0-64.6-32.6552043-25.59.846-6.023-8.8-24.8-26.725-12.1-7.0-63.8-19.1-13.3-31.4-33.5-42.3-22.9-69.0-26.8-22.4-6.7-0.6-6.0-21.53.21.3-24.7-0.9-21.65616510648-74.7-39.0-16.1
Percentage of NetCashProvidedByUsedInInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax14.4-2.26.2-8.312.79.411.7-7.62.912.7-2.36.8-2.6-7.7-7.47.1-3.4-2.0-17.5-5.4-3.8-9.3-9.7-12.1-6.8-20.6-9.1-7.7-2.3-0.2-2.1-7.31.10.5-8.3-0.3-7.520.241.327.512.6-19.6-10.9-4.7

Net Cash Provided By Used In Financing Activities

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:NetCashProvidedByUsedInFinancingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value-3.4-3.7-3.3-64.6-3.156-3.3-3.5-1.3-3.9-0.6-6.80.24.9-0.1-2.3-1.6-3.0-6.118-1.4-3.5-0.6-3.6-2.6-3.5-3.1-3.7-2.6-3.7-2.4-18.8-2.6-4.0-3.4-6.0-5.3-6.0-5.1-6.0-4.8-5.6-5.0-6.1
Percentage of NetCashProvidedByUsedInFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-0.8-0.90.3-16.5-0.726.3-0.9-1.0-0.4-1.1-0.2-2.00.11.5-0.0-0.6-0.4-0.9-1.75.1-0.4-1.0-0.2-1.0-0.8-1.0-1.0-1.3-0.9-1.3-0.8-6.4-0.9-1.4-1.1-2.1-1.8-2.1-1.3-1.5-1.2-1.5-1.4-1.8

Deferred Income Tax Expense Benefit

us-gaap:DeferredIncomeTaxExpenseBenefit

us-gaap:DeferredIncomeTaxExpenseBenefit


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-30
Value3.62.0203.27.7-29.47.61.2-1.412-8.07.71.7-0.243-1.63.0-1.00.8-1.2-0.50.8-1.96.50.58.1-80.70.00.0
Percentage of DeferredIncomeTaxExpenseBenefit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.0

Increase Decrease In Other Operating Capital Net

us-gaap:IncreaseDecreaseInOtherOperatingCapitalNet

us-gaap:IncreaseDecreaseInOtherOperatingCapitalNet


Increase
Period End2021-06-302021-03-312020-09-302020-06-302020-03-31
Value6.39.5-50.51724
Percentage of IncreaseDecreaseInOtherOperatingCapitalNet100.0100.0100.0100.0100.0

Net Cash Provided By Used In Operating Activities

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetCashProvidedByUsedInOperatingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value-6.8-18.92754-4.2-28.00.022-36.0-30.416-8.1-11.5-10.77.239173.75117202441467.75434362.52.334263.68.0221519-343.58.6-7.4-32.6743454
Percentage of NetCashProvidedByUsedInOperatingActivities100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-1.6-4.6-2.613.8-1.0-13.00.06.7-10.6-8.36.4-2.3-3.4-3.32.011.05.01.114.15.05.77.211.913.22.316.311.512.60.80.811.98.91.32.87.75.56.7-122.52.1-1.9-8.519.69.516.0

Net Income Loss

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

us-gaap:NetIncomeLoss

us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:AccumulatedDefinedBenefitPlansAdjustment


Net
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-30
Value-2.2-2.3-1.7-1.6-1.6-0.6-0.7-0.6-0.6-0.6-0.6-0.5-0.3-0.4-0.7-0.7-0.6-0.9-1.0-1.0-0.3-0.8-0.2-0.9-0.9-0.9-0.9-0.5-0.8-0.6
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-0.5-0.6-0.4-0.4-0.7-0.2-0.2-0.2-0.2-0.2-0.2-0.1-0.1-0.1-0.2-0.2-0.2-0.3-0.3-0.3-0.1-0.3-0.1-0.3-0.3-0.3-0.3-0.2-0.3-0.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome us-gaap:AccumulatedDefinedBenefitPlansAdjustment0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss


Net
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-30
Value-0.61.2-0.20.81.90.91.20.10.01.00.313105.15.74.30.87.13.52.71.65.3107.57.61.56.78.07.06.7
Percentage of NetIncomeLoss27.3-52.211.8-50.0-118.8-150.0-171.4-16.7-0.0-166.7-50.0-2640.0-3400.0-1275.0-814.3-614.3-133.3-788.9-350.0-270.0-533.3-662.5-5350.0-833.3-844.4-166.7-744.4-1600.0-875.0-1116.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-0.10.3-0.10.20.90.30.40.00.00.30.13.72.91.51.61.20.22.01.00.80.51.83.72.62.60.52.32.72.42.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Profit Loss

us-gaap:ProfitLoss

us-gaap:ProfitLoss


Profit
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value0.63.6811134-114.63211-6.249-24.5336.0-2.1-5.8-9.58.7-4.13210-24.63.03.1202.72465113.02716186.21920-5.5-2.7-2.099-58.7-201.412370.2-26.2
Percentage of ProfitLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.10.9-7.93.07.9-53.48.93.4-1.813.4-9.39.71.8-0.6-1.6-2.72.4-1.28.92.9-7.10.90.95.90.87.422.14.11.09.35.76.32.26.97.0-1.9-0.9-0.724.8-15.1-52.43.410.50.1-7.9

us-gaap:ProfitLoss us-gaap:StatementEquityComponents

us-gaap:RetainedEarnings


Profit
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.63.6811134-114.63211-6.249-24.5336.0-2.1
Percentage of ProfitLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.10.9-7.93.07.9-53.48.93.4-1.813.4-9.39.71.8-0.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Share Based Compensation

us-gaap:ShareBasedCompensation

us-gaap:ShareBasedCompensation


Share
Period End2021-06-302021-03-312020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value-8.26.7-1.00.5-0.92.60.63.84.46.70.00.01.20.21.11.70.51.00.81.4-0.62.71.41.00.90.31.41.00.51.11.31.20.80.81.10.81.00.31.10.80.80.9
Percentage of ShareBasedCompensation100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Net Cash Provided By Used In Investing Activities

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:NetCashProvidedByUsedInInvestingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value59-9.0-64.6-32.6552043-25.59.846-6.023-8.8-24.8-26.725-12.1-7.0-63.8-19.1-13.3-31.4-33.5-42.3-22.9-69.0-26.8-22.4-6.7-0.6-6.0-21.53.21.3-24.7-0.9-21.65616510648-74.7-39.0-16.1
Percentage of NetCashProvidedByUsedInInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax14.4-2.26.2-8.312.79.411.7-7.62.912.7-2.36.8-2.6-7.7-7.47.1-3.4-2.0-17.5-5.4-3.8-9.3-9.7-12.1-6.8-20.6-9.1-7.7-2.3-0.2-2.1-7.31.10.5-8.3-0.3-7.520.241.327.512.6-19.6-10.9-4.7

Net Cash Provided By Used In Financing Activities

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:NetCashProvidedByUsedInFinancingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value-3.4-3.7-3.3-64.6-3.156-3.3-3.5-1.3-3.9-0.6-6.80.24.9-0.1-2.3-1.6-3.0-6.118-1.4-3.5-0.6-3.6-2.6-3.5-3.1-3.7-2.6-3.7-2.4-18.8-2.6-4.0-3.4-6.0-5.3-6.0-5.1-6.0-4.8-5.6-5.0-6.1
Percentage of NetCashProvidedByUsedInFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-0.8-0.90.3-16.5-0.726.3-0.9-1.0-0.4-1.1-0.2-2.00.11.5-0.0-0.6-0.4-0.9-1.75.1-0.4-1.0-0.2-1.0-0.8-1.0-1.0-1.3-0.9-1.3-0.8-6.4-0.9-1.4-1.1-2.1-1.8-2.1-1.3-1.5-1.2-1.5-1.4-1.8

Payments Of Dividends Common Stock

us-gaap:PaymentsOfDividendsCommonStock

us-gaap:PaymentsOfDividendsCommonStock


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value4.34.54.44.44.34.44.44.34.34.44.34.14.44.34.24.24.24.34.24.14.24.14.24.04.24.14.24.04.14.24.04.04.14.04.26.06.16.06.15.96.16.06.06.0
Percentage of PaymentsOfDividendsCommonStock100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Debt Instrument Interest Rate Stated Percentage

us-gaap:DebtInstrumentInterestRateStatedPercentage us-gaap:LongtermDebtType

us-gaap:DebtInstrumentInterestRateStatedPercentage

us-gaap:NotesPayableToBanks


Debt
Period End2020-12-312020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value3.960.03960.03960.03960.03960.03960.03960.03960.03960.03960
Percentage of DebtInstrumentInterestRateStatedPercentage100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.00.00.00.00.00.00.00.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations us-gaap:NotesPayableToBanks0.00.00.00.00.00.00.00.00.00.00.0

us-gaap:SubordinatedDebt


Debt
Period End2020-12-312020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302011-12-31
Value4.430.04550.05780.06110.06330.06720.0682610.06940.06520.0650.06210.05680.05520.0540.05250.05130.05040.04870.04610.04610.04530.04480.04460.04440.04430.04430.04440.04440.04460.04470.04490.04510.04620.04670.0473
Percentage of DebtInstrumentInterestRateStatedPercentage111.9114.9146.0154.3159.8169.7172.4175.3164.6164.10.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of LongTermDebtAndCapitalLeaseObligations us-gaap:SubordinatedDebt0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber


Share
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-31
Value700000.0800000.01000000.01700000.02800000.03400000.03700000.03900000.03900000.03800000.03400000.03100000.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber us-gaap:ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRange

stfc:ExercisePricesRangeOne


Share
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-31
Value300000.0400000.0600000.01000000.01400000.01700000.02100000.02200000.02100000.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber42.950.060.058.850.050.056.856.453.8

stfc:ExercisePricesRangeTwo


Share
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-31
Value400000.0400000.0400000.0700000.01400000.01400000.01300000.01000000.01100000.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber57.150.040.041.250.041.235.125.628.2

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

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice


Share
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-31
Value19.2819.1818.519.2220.6721.4421.2922.0122.2522.7923.5324.02
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice us-gaap:ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRange

stfc:ExercisePricesRangeOne


Share
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-31
Value16.3316.6716.3116.5316.4416.5316.4716.4716.66
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice84.786.988.286.079.577.177.474.874.9

stfc:ExercisePricesRangeTwo


Share
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-31
Value21.9722.022.023.0724.5725.0125.8427.1827.17
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice114.0114.7118.9120.0118.9116.7121.4123.5122.1

Deferred Tax Assets Valuation Allowance

us-gaap:DeferredTaxAssetsValuationAllowance

us-gaap:DeferredTaxAssetsValuationAllowance


Deferred
Period End2020-12-312020-09-302014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302011-12-31
Value0.30.50.0746975821001079010098105103
Percentage of DeferredTaxAssetsValuationAllowance100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

stfc:AcquisitionAndOperatingExpenses

stfc:AcquisitionAndOperatingExpenses


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
Value107121124123119114116109107107116110111110121112109112105109107107108109105103849197888890878888868387126121116117114104104
Percentage of AcquisitionAndOperatingExpenses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

stfc:AdjustmentsToAdditionalPaidInCapitalStockOptionsGranted us-gaap:StatementEquityComponents

stfc:AdjustmentsToAdditionalPaidInCapitalStockOptionsGranted

us-gaap:AdditionalPaidInCapital


Adjustments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-7800000.06200000.0200000.01200000.01100000.01100000.0400000.02000000.01500000.03500000.02400000.01800000.02600000.02300000.0
Percentage of AdjustmentsToAdditionalPaidInCapitalStockOptionsGranted100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

stfc:AssumedPremiumsUnderPoolingArrangement

stfc:AssumedPremiumsUnderPoolingArrangement


Assumed
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-30
Value369355353340330319307302306307314319320317325322319319311315270268262266263261261258254356352
Percentage of AssumedPremiumsUnderPoolingArrangement100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

stfc:CashDividendsPaidToAffiliates us-gaap:StatementEquityComponents

stfc:CashDividendsPaidToAffiliates

us-gaap:RetainedEarnings


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-30
Value2.62.62.62.65.22.62.62.6
Percentage of CashDividendsPaidToAffiliates100.0100.0100.0100.0100.0100.0100.0100.0

stfc:CorporateExpenses us-gaap:ConsolidationItems

stfc:CorporateExpenses

us-gaap:MaterialReconcilingItems


Corporate
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302013-09-302013-06-302012-09-302012-06-30
Value-2000000.0-3000000.0-2600000.0-900000.0-300000.0-2400000.0200000.0-1900000.0-2900000.0-5000000.0-2800000.0-900000.0-3900000.0-1000000.0-1500000.0-700000.0-1100000.0-900000.0-1400000.0-1100000.0-1000000.0-800000.00-600000.0-1000000.01600000.01500000.01100000.01400000.0
Percentage of CorporateExpenses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0

stfc:GaapExpenseAdjustments us-gaap:ConsolidationItems

stfc:GaapExpenseAdjustments

us-gaap:MaterialReconcilingItems


Gaap
Period End2021-06-302020-06-302013-09-302013-06-302012-09-302012-06-30
Value5.78.70.4-7.2-2.4-0.1
Percentage of GaapExpenseAdjustments100.0100.0100.0100.0100.0100.0

stfc:GaapExpenseAdjustments us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:MaterialReconcilingItems, us-gaap:MaterialReconcilingItems


Gaap
Period End2021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-30
Value-1.35.68.75.97.26.14.10.80.6-4.0-2.81.4-5.42.44.6-1.20.96.5
Percentage of GaapExpenseAdjustments0.00.0100.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

stfc:IncomeTaxReconciliationTaxExemptIncomeAndDividendDeduction

stfc:IncomeTaxReconciliationTaxExemptIncomeAndDividendDeduction


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-31
Value0.60.60.60.60.40.70.20.70.70.70.60.50.50.71.31.41.51.51.61.61.92.02.12.12.32.22.22.12.12.12.22.52.42.3-15.82.32.22.2
Percentage of IncomeTaxReconciliationTaxExemptIncomeAndDividendDeduction100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

stfc:IncomeTaxReconciliationTaxExemptIncomeAndDividendDeductionsTaxRate

stfc:IncomeTaxReconciliationTaxExemptIncomeAndDividendDeductionsTaxRate


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-30
Value-14.2-11.3-18.3-4.1-0.0090.0050.01-0.0530.09-0.011-0.139-0.013-0.0650.208-1.1350.124-0.1240.291-0.772-0.2260.074-0.528-0.031-0.07-0.67-0.07-0.18-0.16-0.68-0.080.01-0.13-0.38-0.12-1.50.410.791.150.050.050.02
Percentage of IncomeTaxReconciliationTaxExemptIncomeAndDividendDeductionsTaxRate100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

stfc:IncreaseDecreaseInAccruedInvestmentIncomeAndOtherAssets

stfc:IncreaseDecreaseInAccruedInvestmentIncomeAndOtherAssets


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value-4600000.01300000.0-1400000.00-2100000.01500000.0-3000000.04100000.0-5900000.04100000.0-6900000.0800000.0-1600000.03800000.0-1500000.0-1900000.0-600000.0500000.01100000.03000000.0-3300000.03700000.0-2100000.03900000.0-1400000.02000000.0500000.0-300000.0-1900000.01500000.0-400000.0700000.0-1400000.03400000.01400000.02500000.0-3300000.0800000.0-2600000.01200000.0-1800000.02400000.0-1600000.0700000.0
Percentage of IncreaseDecreaseInAccruedInvestmentIncomeAndOtherAssets100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

stfc:IncreaseDecreaseInReinsuranceRecoverableAndPrepaidReinsurancePremiums

stfc:IncreaseDecreaseInReinsuranceRecoverableAndPrepaidReinsurancePremiums


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value-4.60.5-11.0-1.3-2.726-46.0-24.145330.3-0.23.5-1.0-2.12.9-2.11.1-0.5-1.8-0.80.1-1.8-0.91.3-1.60.61.1-0.40.6-1.7-2.11.4-1.2-5.3-7.5-5.32.1-5.08.04.6-0.6-2.14.3
Percentage of IncreaseDecreaseInReinsuranceRecoverableAndPrepaidReinsurancePremiums100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

stfc:IncurredClaimPropertyCasualtyAndLiabilityToAffiliates

stfc:IncurredClaimPropertyCasualtyAndLiabilityToAffiliates


Incurred
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-31
Value10711348731024505634244612883861008693675974131143142137164131133167156
Percentage of IncurredClaimPropertyCasualtyAndLiabilityToAffiliates100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

stfc:InterestExpenseDebtToAffiliates

stfc:InterestExpenseDebtToAffiliates


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value100000.0200000.0200000.0100000.0300000.0200000.0400000.0200000.0300000.0200000.0300000.0200000.0300000.0200000.0200000.0200000.0200000.0200000.0200000.0200000.0200000.0200000.0200000.0100000.0200000.0200000.0200000.0200000.0100000.0200000.02700000.0100000.0200000.0200000.0100000.0200000.0200000.0200000.0200000.0100000.0200000.0200000.0200000.0200000.0200000.0
Percentage of InterestExpenseDebtToAffiliates100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

stfc:LossesAndLossExpensesAssumedFromExternalInsurersAndReinsurers

stfc:LossesAndLossExpensesAssumedFromExternalInsurersAndReinsurers


Losses
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-30
Value21141415111416141012102.20.91.60.90.81.10.80.60.80.80.80.70.90.6-0.21.21.00.92.33.5
Percentage of LossesAndLossExpensesAssumedFromExternalInsurersAndReinsurers100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

stfc:LossesAndLossExpensesAssumedUnderPoolingArrangement

stfc:LossesAndLossExpensesAssumedUnderPoolingArrangement


Losses
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-30
Value299280251271239209235200183205202254230234232263225207225195185190171179186173201202191314400
Percentage of LossesAndLossExpensesAssumedUnderPoolingArrangement100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

stfc:LossesAndLossExpensesCededToExternalInsurersAndReinsurers

stfc:LossesAndLossExpensesCededToExternalInsurersAndReinsurers


Losses
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-30
Value3.03.39.912330.65.00.61.90.21.32.7-1.02.0-0.30.51.91.22.5-0.12.71.22.50.83.11.04.5-1.25.8107.7
Percentage of LossesAndLossExpensesCededToExternalInsurersAndReinsurers100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

stfc:LossesAndLossExpensesCededUnderPoolingArrangement

stfc:LossesAndLossExpensesCededUnderPoolingArrangement


Losses
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-30
Value192167202198228185185143148181156125147148131176131140165121131143142137164131133167156182265
Percentage of LossesAndLossExpensesCededUnderPoolingArrangement100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

stfc:NetAcquisitionandOperatingExpenses

stfc:NetAcquisitionandOperatingExpenses


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value2737362421201417122456-26.83543397871806873687012452587739364238
Percentage of NetAcquisitionandOperatingExpenses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

stfc:NetAssumedLossesAndLossExpensesIncurred

stfc:NetAssumedLossesAndLossExpensesIncurred


Net
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-30
Value1261245276-10.938617043365512885851028792675775514627412040643630124131
Percentage of NetAssumedLossesAndLossExpensesIncurred100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

stfc:NetInvestmentIncomeFromAffiliates

stfc:NetInvestmentIncomeFromAffiliates


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value700000.0700000.0700000.0700000.0700000.0700000.01300000.0700000.0400000.01200000.01200000.01300000.01200000.01200000.01200000.01300000.01200000.01200000.01200000.01300000.01200000.01200000.01200000.01300000.01200000.01200000.01200000.01300000.01200000.01200000.01200000.01300000.01200000.01200000.01200000.01300000.01200000.01200000.01200000.01300000.01200000.01200000.01200000.01300000.01200000.0
Percentage of NetInvestmentIncomeFromAffiliates100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

stfc:OtherComprehensiveIncomeReclassificationOfDefinedBenefitPlanNetActuarialLossBeforeTax

stfc:OtherComprehensiveIncomeReclassificationOfDefinedBenefitPlanNetActuarialLossBeforeTax


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-31
Value4.44.52.73.73.63.72.42.42.42.46.82.22.02.21.92.11.92.12.32.42.32.42.92.82.92.91.51.62.21.62.52.22.2-2.22.02.01.91.92.01.81.71.7
Percentage of OtherComprehensiveIncomeReclassificationOfDefinedBenefitPlanNetActuarialLossBeforeTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

stfc:PaymentsToAcquireTreasuryStock

stfc:PaymentsToAcquireTreasuryStock


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-31
Value0400000.0000900000.0000500000.00100000.00100000.0100000.000200000.0000200000.00100000.0100000.0100000.0000100000.0000100000.00
Percentage of PaymentsToAcquireTreasuryStock0.0100.00.00.00.0100.00.00.00.0100.00.0100.00.0100.0100.00.00.0100.00.00.00.0100.00.0100.0100.0100.00.00.00.0100.00.00.00.0100.00.0

stfc:PremiumsCededUnderPoolingArrangement

stfc:PremiumsCededUnderPoolingArrangement


Premiums
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-30
Value277277283279272263254243234226216203202202204204206207208209215216215215213210203199196198202
Percentage of PremiumsCededUnderPoolingArrangement100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

stfc:PremiumsEarnedNetPropertyAndCasualtyToAffiliates

stfc:PremiumsEarnedNetPropertyAndCasualtyToAffiliates


Premiums
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value9278696158555359718198115118114121117113112102105215216215216215213210208203199196197198202205206205204
Percentage of PremiumsEarnedNetPropertyAndCasualtyToAffiliates100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AssumedPremiumsEarned

us-gaap:AssumedPremiumsEarned


Assumed
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-30
Value2021212020212018119617141012702.31.31.112881.21.01.412671.11.01.110701.21.11.010521.21.10.410391.11.0
Percentage of AssumedPremiumsEarned100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value49-31.6-40.7-43.2484839-6.5-27.512
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CededPremiumsEarned

us-gaap:CededPremiumsEarned


Ceded
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-30
Value8.59.07.77.1106.66.35.99035.95.45.48004.96.16.18006.06.56.88068.78.58.98436.56.06.08375.46.75.57876.68.1
Percentage of CededPremiumsEarned100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CommonStockDividendsPerShareCashPaid

us-gaap:CommonStockDividendsPerShareCashPaid


Common
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value0.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.150.150.150.150.150.150.150.150.150.15
Percentage of CommonStockDividendsPerShareCashPaid100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CurrentIncomeTaxExpenseBenefit

us-gaap:CurrentIncomeTaxExpenseBenefit


Current
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-30
Value100000.00-400000.00000-400000.00-100000.00-1000000.0400000.0-100000.0200000.0-100000.0-200000.0-1500000.000-400000.02700000.0200000.0400000.0-1800000.01200000.0100000.0
Percentage of CurrentIncomeTaxExpenseBenefit100.00.0100.00.00.00.00.0100.00.0100.00.0100.0100.0100.0100.0100.0100.0100.00.00.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DebtSecuritiesAvailableForSaleRealizedGain

us-gaap:DebtSecuritiesAvailableForSaleRealizedGain


Debt
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value900000.03000000.0-1600000.01300000.01900000.03600000.0700000.01200000.01500000.0100000.0300000.00
Percentage of DebtSecuritiesAvailableForSaleRealizedGain100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0

us-gaap:DebtSecuritiesAvailableForSaleRealizedGainLoss

us-gaap:DebtSecuritiesAvailableForSaleRealizedGainLoss


Debt
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value-800000.01500000.0-3500000.0-200000.01000000.02400000.0700000.01200000.01500000.0100000.0300000.00
Percentage of DebtSecuritiesAvailableForSaleRealizedGainLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0

us-gaap:DebtSecuritiesAvailableForSaleRealizedLoss

us-gaap:DebtSecuritiesAvailableForSaleRealizedLoss


Debt
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-06-302019-03-31
Value1700000.01500000.01900000.01500000.0900000.01200000.000
Percentage of DebtSecuritiesAvailableForSaleRealizedLoss100.0100.0100.0100.0100.0100.00.00.0

us-gaap:DeferredPolicyAcquisitionCostsAdditions

us-gaap:DeferredPolicyAcquisitionCostsAdditions


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value6860-42.19810091-44.9949284
Percentage of DeferredPolicyAcquisitionCostsAdditions100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredPolicyAcquisitionCostsDisposition

us-gaap:DeferredPolicyAcquisitionCostsDisposition


Deferred
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value6261949388898781
Percentage of DeferredPolicyAcquisitionCostsDisposition100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DefinedBenefitPlanAmortizationOfGainsLosses us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanAmortizationOfGainsLosses

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2021-06-302020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-30
Value100000.0-100000.00-100000.0-100000.00100000.0100000.00-100000.0-100000.00-100000.0-100000.0
Percentage of DefinedBenefitPlanAmortizationOfGainsLosses100.0100.00.0100.0100.00.0100.0100.00.0100.0100.00.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-30
Value-3500000.0-3500000.0-2300000.0-2300000.0-2300000.0-1500000.0-1500000.01500000.02100000.0-2000000.0-2100000.0-2000000.0-1900000.0-2000000.0-2300000.0
Percentage of DefinedBenefitPlanAmortizationOfGainsLosses-3500.00.02300.00.02300.01500.00.01500.02100.00.02100.02000.00.02000.02300.0

us-gaap:DefinedBenefitPlanAmortizationOfPriorServiceCostCredit us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanAmortizationOfPriorServiceCostCredit

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
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-1400000.0-1400000.0-1400000.0-1400000.0-1300000.0-1400000.0-1400000.0-1400000.0-1300000.0-1400000.0-1400000.0-1400000.0-1300000.0-1400000.0-1400000.0-1300000.0-1400000.0-1400000.0-1400000.0-1300000.0
Percentage of DefinedBenefitPlanAmortizationOfPriorServiceCostCredit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DefinedBenefitPlanContributionsByEmployer

us-gaap:DefinedBenefitPlanContributionsByEmployer


Defined
Period End2021-06-302021-03-312020-12-312017-12-312016-12-31
Value5.05.00.00.2-21.5
Percentage of DefinedBenefitPlanContributionsByEmployer100.0100.00.0100.0100.0

us-gaap:DefinedBenefitPlanExpectedReturnOnPlanAssets us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedReturnOnPlanAssets

us-gaap:PensionPlansDefinedBenefit


Defined
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
Value4.24.34.44.44.34.45.34.24.1-4.231-4.54.54.54.14.24.24.23.83.9
Percentage of DefinedBenefitPlanExpectedReturnOnPlanAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DefinedBenefitPlanInterestCost us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanInterestCost

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2021-06-302020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value0.1-0.20.20.10.10.20.20.10.20.10.20.10.20.30.10.20.20.30.2
Percentage of DefinedBenefitPlanInterestCost100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
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
Value2.12.12.52.42.42.42.92.92.82.92.72.72.62.72.82.92.82.93.03.0
Percentage of DefinedBenefitPlanInterestCost2100.00.0-1250.01200.02400.02400.01450.01450.02800.01450.02700.01350.02600.01350.0933.32900.01400.01450.01000.01500.0

us-gaap:DefinedBenefitPlanNetPeriodicBenefitCost us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanNetPeriodicBenefitCost

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-30
Value-1.4-1.4-1.1-1.2-1.2-1.1-1.2-1.1-1.1-1.2-1.1-1.1-1.2-1.1-1.0
Percentage of DefinedBenefitPlanNetPeriodicBenefitCost100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-30
Value2.62.61.51.61.51.01.21.21.51.41.62.11.82.43.0
Percentage of DefinedBenefitPlanNetPeriodicBenefitCost-185.7-185.7-136.4-133.3-125.0-90.9-100.0-109.1-136.4-116.7-145.5-190.9-150.0-218.2-300.0

us-gaap:DefinedBenefitPlanServiceCost us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanServiceCost

us-gaap:PensionPlansDefinedBenefit


Defined
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
Value1.21.31.21.21.21.21.00.81.01.01.31.21.31.31.31.41.31.71.51.6
Percentage of DefinedBenefitPlanServiceCost100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DepreciationAmortizationAndAccretionNet

us-gaap:DepreciationAmortizationAndAccretionNet


Depreciation
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value2.01.83.01.94.11.63.22.40.73.12.22.11.72.92.63.83.03.13.14.13.04.44.93.51.85.55.12.21.03.44.03.12.14.31.13.8-0.52.72.42.1-1.32.12.32.7
Percentage of DepreciationAmortizationAndAccretionNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DividendsCommonStockCash us-gaap:StatementEquityComponents

us-gaap:DividendsCommonStockCash

us-gaap:CommonStock


Dividends
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value4.34.54.44.44.34.44.44.34.34.44.44.14.44.3
Percentage of DividendsCommonStockCash100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate

us-gaap:EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate


Effective
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-232017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-30
Value21.021.021.00.210.2100.210.210.2100.210.210.210.3500.350.350.3500.350.350.3500.350.350.3500.350.350.3500.350.350.3500.350.350.3500.350.35
Percentage of EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate100.0100.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0

us-gaap:EffectiveIncomeTaxRateReconciliationDeductions

us-gaap:EffectiveIncomeTaxRateReconciliationDeductions


Effective
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302016-12-312016-09-30
Value84.836.321.40.1760.2040.0040.0940.1930.199-0.1730.1860.2170.3610.0280.1480.157-0.2640.362
Percentage of EffectiveIncomeTaxRateReconciliationDeductions100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:EffectiveIncomeTaxRateReconciliationOtherAdjustments

us-gaap:EffectiveIncomeTaxRateReconciliationOtherAdjustments


Effective
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-30
Value78.026.65.64.5-0.025-0.011-0.006-0.063-0.1070-0.034-0.0110.072-0.0571.163-0.326-0.069-0.4240.508-0.486-0.4070.378-0.0070.0280.52-0.030.0200.240.010-0.010.010.010.070.02-0.11-0.050.030.03
Percentage of EffectiveIncomeTaxRateReconciliationOtherAdjustments100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:EquitySecuritiesFvNiGainLoss us-gaap:FinancialInstrument

us-gaap:EquitySecuritiesFvNiGainLoss

stfc:OtherInvestedAssets


Equity
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value3.05.28.32.05.8-15.45.1-0.31.23.9-6.00.4
Percentage of EquitySecuritiesFvNiGainLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:EquitySecurities


Equity
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-30
Value24311869-122.4-5.97.64217
Percentage of EquitySecuritiesFvNiGainLoss830.0605.8910.01191.4794.81966.7633.31082.14350.0

us-gaap:EquitySecuritiesFvNiRealizedGainLoss us-gaap:FinancialInstrument

us-gaap:EquitySecuritiesFvNiRealizedGainLoss

us-gaap:EquitySecurities


Equity
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value-42.3-9.50.90.7-1.81.2-1.90.31.0
Percentage of EquitySecuritiesFvNiRealizedGainLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:EquitySecuritiesFvNiUnrealizedGain

us-gaap:EquitySecuritiesFvNiUnrealizedGain


Equity
Period End2021-03-31
Value27
Percentage of EquitySecuritiesFvNiUnrealizedGain100.0

us-gaap:EquitySecuritiesFvNiUnrealizedGain us-gaap:FinancialInstrument

stfc:OtherInvestedAssets


Equity
Period End2021-03-31
Value5.2
Percentage of EquitySecuritiesFvNiUnrealizedGain18.7

us-gaap:EquitySecuritiesFvNiUnrealizedGainLoss

us-gaap:EquitySecuritiesFvNiUnrealizedGainLoss


Equity
Period End2021-06-302020-06-30
Value1978
Percentage of EquitySecuritiesFvNiUnrealizedGainLoss100.0100.0

us-gaap:EquitySecuritiesFvNiUnrealizedGainLoss us-gaap:FinancialInstrument

stfc:OtherInvestedAssets


Equity
Period End2021-06-302020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value3.08.42.05.8-15.45.1-0.31.23.9-6.00.4
Percentage of EquitySecuritiesFvNiUnrealizedGainLoss15.20.00.07.40.00.00.00.00.00.00.0

us-gaap:EquitySecurities


Equity
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value6078-123.317-4.16.444-62.516
Percentage of EquitySecuritiesFvNiUnrealizedGainLoss0.0100.00.00.00.00.00.00.00.0

us-gaap:EquitySecuritiesFvNiUnrealizedLoss

us-gaap:EquitySecuritiesFvNiUnrealizedLoss


Equity
Period End2021-03-31
Value123
Percentage of EquitySecuritiesFvNiUnrealizedLoss100.0

us-gaap:EquitySecuritiesFvNiUnrealizedLoss us-gaap:FinancialInstrument

stfc:OtherInvestedAssets


Equity
Period End2021-03-31
Value15
Percentage of EquitySecuritiesFvNiUnrealizedLoss12.5

us-gaap:ExcessTaxBenefitFromShareBasedCompensationOperatingActivities

us-gaap:ExcessTaxBenefitFromShareBasedCompensationOperatingActivities


Excess
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302016-12-312016-09-302015-12-312015-09-302014-12-312014-09-30
Value0400000.0-100000.00200000.0200000.0100000.0400000.0200000.0-900000.0-200000.0200000.00-1300000.00100000.0-200000.0400000.0000
Percentage of ExcessTaxBenefitFromShareBasedCompensationOperatingActivities0.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.00.0100.0100.0100.00.00.00.0

us-gaap:FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresRepaymentAndPenalties us-gaap:FederalHomeLoanBankAdvancesBranchOfFHLBBank

us-gaap:FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresRepaymentAndPenalties

srt:FederalHomeLoanBankOfCincinnati


Federal
Period End2020-12-31
Value0.0
Percentage of FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresRepaymentAndPenalties0.0

us-gaap:FederalIncomeTaxExpenseBenefitContinuingOperations

us-gaap:FederalIncomeTaxExpenseBenefitContinuingOperations


Federal
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-30
Value3.62.03.27.3-29.47.61.2-1.412-8.07.61.7-1.28.6-1.71.9-1.10.6-2.7-0.50.8-2.39.20.78.5-82.51.20.10.6-0.10.20.10.30.0-0.1
Percentage of FederalIncomeTaxExpenseBenefitContinuingOperations100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0

us-gaap:GainLossOnSaleOfInvestments

us-gaap:GainLossOnSaleOfInvestments


Gain
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value2738662075-135.224-5.01044-67.91712-11.72120157.8198.86.51.34.3105.43.83.11.65.3107.57.51.56.78.27.06.77.112106.58.28.62.8
Percentage of GainLossOnSaleOfInvestments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ImpairmentOfLongLivedAssetsToBeDisposedOf

us-gaap:ImpairmentOfLongLivedAssetsToBeDisposedOf


Impairment
Period End2021-06-302020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value-400000.000200000.0001300000.0000
Percentage of ImpairmentOfLongLivedAssetsToBeDisposedOf100.00.00.0100.00.00.0100.00.00.00.0

us-gaap:IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate

us-gaap:IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-30
Value0.91.2213.18.7-30.28.52.7-1.612-6.88.61.6-0.713-3.94.1-1.8112.6-8.71.30.2101.211-6.04.61.19.75.76.62.27.07.3-1.9-0.9-0.722-18.3-48.7
Percentage of IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncomeTaxReconciliationOtherAdjustments

us-gaap:IncomeTaxReconciliationOtherAdjustments


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-30
Value3.31.4-0.60.7-1.01.5-0.7-0.80.90.0-0.6-0.50.60.2-3.43.6-0.72.2-9.3-3.7101.5-0.40.81.8-0.90.10.10.70.20.2-0.30.10.20.2-0.10.30.1-3.4-1.2-0.4
Percentage of IncomeTaxReconciliationOtherAdjustments100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInAccruedIncomeTaxesPayable

us-gaap:IncreaseDecreaseInAccruedIncomeTaxesPayable


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302011-12-312011-09-302010-12-312010-09-30
Value3.62.4253.17.3-29.27.81.3-0.612-9.48.01.6-1.046-1.52.1-0.95.9-2.4-0.11.1-3.99.8-1.29.0-82.61.2-0.90.7-0.40.3-0.50.35.95.3-34.96.75.5-2.2
Percentage of IncreaseDecreaseInAccruedIncomeTaxesPayable100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInDeferredPolicyAcquisitionCosts

us-gaap:IncreaseDecreaseInDeferredPolicyAcquisitionCosts


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value6.0-1.0-1.53.76.72.2-3.25.24.82.4-2.6-0.1-0.5-5.2-4.3-2.91.0-5.8-4.02.04.3-1.6-4.90.56.10.9172.47.32.9-1.8-1.85.92.8-2.20.3-0.62.5-27.04.510-1.10.011
Percentage of IncreaseDecreaseInDeferredPolicyAcquisitionCosts100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0

us-gaap:IncreaseDecreaseInPensionAndPostretirementObligations

us-gaap:IncreaseDecreaseInPensionAndPostretirementObligations


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value-5300000.0-6400000.0100000.0-6500000.0-9600000.0-900000.0-2300000.0-900000.0-11200000.0-100000.0-6300000.0-5100000.0-5200000.0-300000.0100000.0-3100000.0-3100000.0-2900000.01800000.0-26800000.0-2000000.0-1800000.0-200000.0-4200000.0-900000.0-700000.0700000.0-5300000.0-4400000.01700000.02100000.0-4100000.0-1600000.0-1700000.02200000.0-4500000.0-1200000.0-1100000.0-12700000.0-4000000.01100000.05700000.0-100000.01400000.0
Percentage of IncreaseDecreaseInPensionAndPostretirementObligations100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInPremiumsReceivable

us-gaap:IncreaseDecreaseInPremiumsReceivable


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-31
Value1900000.01700000.0100000.0-5000000.05900000.0-1400000.02300000.0
Percentage of IncreaseDecreaseInPremiumsReceivable100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInPropertyAndCasualtyInsuranceLiabilities

us-gaap:IncreaseDecreaseInPropertyAndCasualtyInsuranceLiabilities


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value-5.415-40.8-14.01819-26.2-42.56.3-17.9-51.9-35.8-13.1-8.0-24.94616351622593031-1.5251421-1.511-8.27.9-3.7112.1-3.7121313-30.22782131.64.3
Percentage of IncreaseDecreaseInPropertyAndCasualtyInsuranceLiabilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInUnearnedPremiums

us-gaap:IncreaseDecreaseInUnearnedPremiums


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value423.3-7.62540160.027343.3-11.45.50.9-22.6-18.73.120-11.3-16.41022-15.5-21.25.228-8.2837.3272.9-10.5-5.8222.8-9.90.1129.0-116.61835-6.9-9.933
Percentage of IncreaseDecreaseInUnearnedPremiums100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncrementalCommonSharesAttributableToShareBasedPaymentArrangements

us-gaap:IncrementalCommonSharesAttributableToShareBasedPaymentArrangements


Incremental
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-30
Value800000.0700000.0500000.0300000.000500000.00600000.0100000.0600000.0600000.0000400000.00400000.0500000.00400000.0100000.0800000.0500000.0400000.00600000.0400000.0500000.0-100000.0300000.0300000.0200000.00100000.0
Percentage of IncrementalCommonSharesAttributableToShareBasedPaymentArrangements100.0100.0100.0100.00.00.0100.00.0100.0100.0100.0100.00.00.00.0100.00.0100.0100.00.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.00.0100.0

us-gaap:IncurredClaimsPropertyCasualtyAndLiability

us-gaap:IncurredClaimsPropertyCasualtyAndLiability


Incurred
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
Value299280210251271239207208234194175191217212200253230234222232262225235207224195224184190171181178186173183201201191220315401242204232252
Percentage of IncurredClaimsPropertyCasualtyAndLiability100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:InvestmentIncomeInterest

us-gaap:InvestmentIncomeInterest


Investment
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-30
Value171718171919211922212120221919192018191718192015181921181719201720172118192025
Percentage of InvestmentIncomeInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:InvestmentIncomeInterest us-gaap:FinancialInstrument

us-gaap:CashAndCashEquivalents


Investment
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-30
Value1.10.90.90.81.01.11.41.71.7
Percentage of InvestmentIncomeInterest6.25.05.04.55.25.76.48.78.1

us-gaap:DebtSecurities


Investment
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-30
Value151515141515171516
Percentage of InvestmentIncomeInterest87.086.083.381.078.678.979.477.077.7

us-gaap:EquitySecurities


Investment
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-30
Value1.21.62.12.63.13.03.12.83.0
Percentage of InvestmentIncomeInterest6.88.911.714.516.115.514.214.314.2

us-gaap:InvestmentIncomeInvestmentExpense

us-gaap:InvestmentIncomeInvestmentExpense


Investment
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-30
Value0300000.0200000.0100000.0200000.0300000.0200000.0100000.0100000.0200000.00300000.0300000.0400000.0300000.0300000.0300000.0300000.0300000.0500000.0400000.0400000.0500000.0400000.0600000.0500000.0500000.0500000.0500000.0500000.0500000.0600000.0500000.0500000.0500000.0400000.0500000.0600000.0500000.0600000.0600000.0
Percentage of InvestmentIncomeInvestmentExpense0.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidCurrentYear1

us-gaap:LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidCurrentYear1


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
Value1971051781911547416416713959142137113631431271146013112710752
Percentage of LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidCurrentYear1100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidPriorYears1

us-gaap:LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidPriorYears1


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
Value1031586172941717581931528589120156808197139748095142
Percentage of LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseClaimsPaidPriorYears1100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:StatementEquityComponents

us-gaap:OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax

us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:AccumulatedDefinedBenefitPlansAdjustment


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-30
Value1.61.61.51.61.61.61.51.61.61.62.21.41.31.41.41.31.41.41.41.31.41.41.31.31.41.41.41.31.41.45.70.01.41.45.4-0.11.3
Percentage of OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditBeforeTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeTax

us-gaap:OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeTax


Other
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302013-03-312012-03-31
Value18-58.74.83728213334-14.7-6.7-7.1
Percentage of OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax

us-gaap:OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-30
Value14-46.30.43.73022-9.716262711-11.6-9.1-29.3-11.0-6.05.215-47.8-1.720231.7-22.9-28.68.39.7-18.5268.12.96.0-61.313-13.229-5.91519-10.414
Percentage of OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax us-gaap:StatementEquityComponents

us-gaap:AccumulatedOtherComprehensiveIncome


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value14-46.30.43.73022-9.716262711-11.6-9.1-29.3
Percentage of OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossAvailableForSaleSecuritiesTax

us-gaap:OtherComprehensiveIncomeLossAvailableForSaleSecuritiesTax


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302011-12-312011-09-302011-06-30
Value3.9-12.40.11.17.96.0-2.64.57.07.23.2-3.1-2.4-7.8-6.9-3.22.88.0-25.8-0.811120.9-12.4-15.44.55.40.63.54.2-1.9-1.4-7.3-0.3-0.60.30.310-5.6-7.8
Percentage of OtherComprehensiveIncomeLossAvailableForSaleSecuritiesTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax

us-gaap:OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-30
Value14-45.1-29.83.53024-15.0172727-15.2-11.6-8.1-29.01.87.21520-37.94.024249.8-15.8-25.112-47.2-16.929184213-59.819-12.6360.8
Percentage of OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax us-gaap:StatementEquityComponents

us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-30
Value14-45.1-2.43.53024-9.11727270.8-11.6-8.1-29.02.87.21520-34.94.024244.5-15.8-25.1125.6-16.931181013-59.819-5.2360.8
Percentage of OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax100.0100.08.1100.0100.0100.060.7100.0100.0100.0-5.3100.0100.0100.0155.6100.0100.0100.092.1100.0100.0100.045.9100.0100.0100.0-11.9100.0105.4100.024.2100.0100.0100.041.3100.0100.0

us-gaap:OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax

us-gaap:OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-30
Value-2.2-2.320-1.7-1.6-1.64.0-0.6-0.7-0.6-0.2-0.6-0.6-0.60.2-0.5-0.3-0.41.4-0.7-0.7-0.6-4.5-0.9-1.0-1.034-0.30.8-0.2-33.4-0.90.90.96.9-0.80.60.7-41.7-0.81.1
Percentage of OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax us-gaap:StatementEquityComponents

us-gaap:AccumulatedOtherComprehensiveIncome


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-2.2-2.320-1.7-1.6-1.64.0-0.6-0.7-0.62.0-1.3-1.4-1.3
Percentage of OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0-1000.0216.7233.3216.7

us-gaap:OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax

us-gaap:OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax


Other
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-31
Value-600000.0-600000.0-400000.0-400000.0-500000.0-200000.0-100000.0-200000.0-200000.0-100000.0-200000.0-300000.0-200000.0-300000.0-400000.0-200000.0-400000.0-600000.0-500000.0-500000.0000
Percentage of OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.0

us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax

us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-30
Value-0.81.5-3.5-0.21.02.40.71.21.50.10.30.01.30.42120157.8198.86.51.34.3105.44.23.11.65.3107.57.5-1.56.78.07.0-6.7
Percentage of OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:StatementEquityComponents

us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax

us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:AccumulatedDefinedBenefitPlansAdjustment


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-30
Value4.44.52.73.73.63.72.42.42.42.46.82.22.02.21.92.11.92.12.32.42.32.42.92.82.92.91.51.62.21.62.52.22.22.32.02.01.9
Percentage of OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetTransitionAssetObligationBeforeTax

us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetTransitionAssetObligationBeforeTax


Other
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-30
Value1600000.01600000.01600000.01600000.01600000.01600000.01600000.01600000.01400000.01300000.01400000.01300000.01400000.01400000.01300000.01400000.01400000.01300000.01400000.01400000.01300000.01400000.01400000.01300000.0100000.01400000.01300000.0
Percentage of OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetTransitionAssetObligationBeforeTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax

us-gaap:OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-31
Value17-57.2-3.04.63831-11.622343415-14.7-10.2-36.73.4112330-53.76.338376.9-24.5-38.61718-16.334238.512-67.119-5.8360.52242-5.82815
Percentage of OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax

us-gaap:OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value3.9-12.40.11.17.96.0-2.64.5-7.0-7.2-23.43.12.47.88.33.2
Percentage of OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherExpenses

us-gaap:OtherExpenses


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value2.43.73.71.11.23.32.32.53.62.9
Percentage of OtherExpenses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsForLossesAndLossAdjustmentExpense

us-gaap:PaymentsForLossesAndLossAdjustmentExpense


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value301264240264249245239249232211227226233219223208212199205207202195
Percentage of PaymentsForLossesAndLossAdjustmentExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsToAcquireAvailableForSaleSecuritiesDebt

us-gaap:PaymentsToAcquireAvailableForSaleSecuritiesDebt


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value11923919818115812213212519713782591089996164124120174122131160114141105212105998913710082628111117018276317673188219143
Percentage of PaymentsToAcquireAvailableForSaleSecuritiesDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsToAcquireAvailableForSaleSecuritiesEquity

us-gaap:PaymentsToAcquireAvailableForSaleSecuritiesEquity


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value3.59.423222616141810199.23.816618135303965321430221056.4192310463825211524304740244.51219569.212
Percentage of PaymentsToAcquireAvailableForSaleSecuritiesEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsToAcquireOtherInvestments

us-gaap:PaymentsToAcquireOtherInvestments


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value0.40.10.30.40.36.60.4101.61.00.70.20.40.50.40.30.50.20.50.30.30.40.42.20.43.90.30.60.50.40.34.70.30.20.40.00.20.50.40.10.20.50.64.1
Percentage of PaymentsToAcquireOtherInvestments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PremiumsEarnedNetOtherInsurance

us-gaap:PremiumsEarnedNetOtherInsurance


Premiums
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-30
Value1039083756870667283901031121131091161121081049597494642464445525151153149
Percentage of PremiumsEarnedNetOtherInsurance100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PremiumsEarnedNetPropertyAndCasualty

us-gaap:PremiumsEarnedNetPropertyAndCasualty


Premiums
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value369355353340330319307302-610.9306307314-498.4319320317-496.1325322319-508.9319311315-588.6270268262264266263261267261258254369356352350327318309
Percentage of PremiumsEarnedNetPropertyAndCasualty100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PremiumsReceivableAllowanceForDoubtfulAccountsPeriodIncreaseDecrease

us-gaap:PremiumsReceivableAllowanceForDoubtfulAccountsPeriodIncreaseDecrease


Premiums
Period End2020-12-312020-09-302020-06-30
Value1500000.01100000.01900000.0
Percentage of PremiumsReceivableAllowanceForDoubtfulAccountsPeriodIncreaseDecrease100.0100.0100.0

us-gaap:PremiumsReceivableAllowanceForDoubtfulAccountsWriteOffsAgainstAllowance

us-gaap:PremiumsReceivableAllowanceForDoubtfulAccountsWriteOffsAgainstAllowance


Premiums
Period End2020-12-312020-09-302020-06-30
Value1400000.01100000.01900000.0
Percentage of PremiumsReceivableAllowanceForDoubtfulAccountsWriteOffsAgainstAllowance100.0100.0100.0

us-gaap:ProceedsFromIssuanceOfCommonStock

us-gaap:ProceedsFromIssuanceOfCommonStock


Proceeds
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302011-12-312011-09-302010-12-312010-09-302003-05-31
Value0.91.21.1-0.21.21.81.10.83.01.03.7-2.65.09.34.21.92.61.5-2.00.92.50.83.30.51.70.71.10.31.50.61.70.71.50.10.80.01.0-0.11.0-0.10.5
Percentage of ProceedsFromIssuanceOfCommonStock100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0

us-gaap:ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities

us-gaap:ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities


Proceeds
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value100102109881186711963771254970545541974054637540603755648351426968513646403970628481985789151100
Percentage of ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ProceedsFromSaleOfAvailableForSaleSecurities

us-gaap:ProceedsFromSaleOfAvailableForSaleSecurities


Proceeds
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value821374884121977164141783716628011012710298112609299651512484504560106
Percentage of ProceedsFromSaleOfAvailableForSaleSecurities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ProceedsFromSaleOfAvailableForSaleSecuritiesDebt

us-gaap:ProceedsFromSaleOfAvailableForSaleSecuritiesDebt


Proceeds
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value29106122710483605013365288.84515284857507311507538736.46228333071351919383812312445653148212322
Percentage of ProceedsFromSaleOfAvailableForSaleSecuritiesDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ProceedsFromSaleOfAvailableForSaleSecuritiesEquity

us-gaap:ProceedsFromSaleOfAvailableForSaleSecuritiesEquity


Proceeds
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value52313456161311147.6128.57.51665817944473948412327771821221130343230152837231427445535452320
Percentage of ProceedsFromSaleOfAvailableForSaleSecuritiesEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ProceedsFromSaleOfOtherInvestments

us-gaap:ProceedsFromSaleOfOtherInvestments


Proceeds
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value1.00.30.40.30.20.40.30.40.30.30.30.20.40.30.30.30.20.30.10.30.20.20.20.20.10.20.10.20.10.20.20.10.20.20.20.10.20.210100.20.30.30.1
Percentage of ProceedsFromSaleOfOtherInvestments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ProceedsFromSaleOfPropertyPlantAndEquipment

us-gaap:ProceedsFromSaleOfPropertyPlantAndEquipment


Proceeds
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-09-30
Value000200000.0001600000.000
Percentage of ProceedsFromSaleOfPropertyPlantAndEquipment0.00.00.0100.00.00.0100.00.00.0

us-gaap:ProceedsFromShortTermDebt

us-gaap:ProceedsFromShortTermDebt


Proceeds
Period End2020-12-312020-09-302020-06-302020-03-312019-06-302019-03-31
Value0.00.00.0600.00.0
Percentage of ProceedsFromShortTermDebt0.00.00.0100.00.00.0

us-gaap:ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax

us-gaap:ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax


Reclassification
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-2.8-1.1-9.4-1.9-0.80.3-1.30.30.5-0.560-0.60.4-0.313129.94.7115.03.60.23.66.22.53.2-22.71.34.5106.66.70.75.87.56.26.2
Percentage of ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome

us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome


Reclassification
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302012-12-31
Value-2.8-1.1-9.4-1.9-0.80.3-1.30.30.5-0.5-4.2-0.60.4-0.313129.94.7115.03.60.23.66.22.51.7-22.71.34.5106.66.77.5
Percentage of ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0-6.9100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.053.1100.0100.0100.0100.0100.0100.0100.0

us-gaap:ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax us-gaap:StatementEquityComponents

us-gaap:AccumulatedDefinedBenefitPlansAdjustment


Reclassification
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-2.2-2.3-6.6-1.7-1.6-1.6-1.9-0.6-0.7-0.680-0.6-0.6-0.6-0.8-0.5-0.3-0.4-1.6-0.7-0.7-0.60.8-0.9-1.0-1.0-18.6-0.3-0.8-0.2-0.9-0.9-0.9-0.9-0.5-0.8-0.6
Percentage of ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax78.6209.170.289.5200.0-533.3146.2-200.0-140.0120.0132.0100.0-150.0200.0-6.2-3.9-3.0-8.5-14.2-14.0-19.4-300.022.2-14.5-40.0-31.281.9-23.1-17.8-1.9-13.6-13.4-128.6-15.5-6.7-12.9-9.7

us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss


Reclassification
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-0.61.2-2.8-0.20.81.90.60.91.20.1-19.40.01.00.31313105.1125.74.30.82.87.13.54.2-4.11.65.3107.57.61.56.78.07.06.7
Percentage of ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax21.4-109.129.810.5-100.0633.3-46.2300.0240.0-20.0-32.0-0.0250.0-100.0106.2103.9103.0108.5114.2114.0119.4400.077.8114.5140.0131.218.1123.1117.8101.9113.6113.4214.3115.5106.7112.9108.1

us-gaap:RepaymentsOfShortTermDebt

us-gaap:RepaymentsOfShortTermDebt


Repayments
Period End2020-12-31
Value0.0
Percentage of RepaymentsOfShortTermDebt0.0

us-gaap:StockIssuedDuringPeriodSharesNewIssues us-gaap:StatementEquityComponents

us-gaap:StockIssuedDuringPeriodSharesNewIssues

us-gaap:CommonStock


Stock
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value100000.0200000.00100000.0200000.0100000.00200000.0100000.0200000.0100000.0200000.0300000.0
Percentage of StockIssuedDuringPeriodSharesNewIssues100.0100.00.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0

us-gaap:StockIssuedDuringPeriodValueStockOptionsExercised us-gaap:StatementEquityComponents

us-gaap:StockIssuedDuringPeriodValueStockOptionsExercised

us-gaap:TreasuryStock


Stock
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-100000.0500000.0000900000.0-1000000.000-500000.0-400000.0100000.00-100000.0
Percentage of StockIssuedDuringPeriodValueStockOptionsExercised100.0100.00.00.00.0100.0100.00.00.0100.0100.0100.00.0100.0

us-gaap:StockholdersEquityPeriodIncreaseDecrease us-gaap:CumulativeEffectPeriodOfAdoption, us-gaap:AdjustmentsForNewAccountingPronouncements, us-gaap:StatementEquityComponents

us-gaap:StockholdersEquityPeriodIncreaseDecrease

srt:CumulativeEffectPeriodOfAdoptionAdjustment, us-gaap:AccountingStandardsUpdate201613, us-gaap:RetainedEarnings


Stockholders
Period End2020-12-312020-09-302020-06-302020-03-31
Value0.00.00.0-0.5
Percentage of StockholdersEquityPeriodIncreaseDecrease0.00.00.0100.0

us-gaap:SupplementalInformationForPropertyCasualtyInsuranceUnderwritersCurrentYearClaimsAndClaimsAdjustmentExpense

us-gaap:SupplementalInformationForPropertyCasualtyInsuranceUnderwritersCurrentYearClaimsAndClaimsAdjustmentExpense


Supplemental
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
Value312311228261271246220225251215197210235232212262246243228229242215
Percentage of SupplementalInformationForPropertyCasualtyInsuranceUnderwritersCurrentYearClaimsAndClaimsAdjustmentExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense

us-gaap:SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense


Supplemental
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
Value13301810.00.17.513171621137-95.91720129.2159.76.4-3.2-20.6-9.6
Percentage of SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense us-gaap:LiabilityForCatastropheClaimsByCatastrophicEvent

stfc:InsuranceSegments


Supplemental
Period End2021-03-31
Value3.8
Percentage of SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense12.5

us-gaap:SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense us-gaap:NoncatastrophicEvent

stfc:BusinessInsuranceSegments


Supplemental
Period End2021-06-302021-03-312017-12-312017-09-302017-06-302017-03-31
Value-60.32177-10.7-14.8-7.6
Percentage of SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense-463.871.5642.5-116.3-94.3-78.4

stfc:Homeowners


Supplemental
Period End2021-03-312020-03-312019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value2.12.20.60.11.52.92.8-0.40.0-0.92.8
Percentage of SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense6.929.32.80.1-1.616.213.7-3.30.0-5.728.9

stfc:InsuranceSegments


Supplemental
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-03-31
Value15241923-10.516172020
Percentage of SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense122.380.7193.023000.0-140.092.0105.697.7100.0

stfc:MiddleMarketCommercial


Supplemental
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value5.48.12.46.313-5.14.61.22.93.16.91.9-2.15.5
Percentage of SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense41.526.613.363.013100.0-68.033.86.917.914.55.0-2.0-11.727.0

stfc:PersonalAuto


Supplemental
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302016-12-312016-09-302016-06-302016-03-31
Value-39.48.05.95.2-21.71.23.06.8-42.97.37.24.06.7-0.5-16.40.64.73.2
Percentage of SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense-218.980.05900.069.3-159.66.918.531.8-31.1-7.640.219.655.8-5.4-256.2-18.8-22.8-33.3

stfc:PersonalInsuranceSegments


Supplemental
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312017-12-312017-09-302017-06-302017-03-312016-03-31
Value2.9-41.98.118-6.4-0.50.7-0.92.33.4
Percentage of SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense9.5-232.881.018500.0-85.3-4.27.6-5.723.7-35.4

stfc:Smallcommercial


Supplemental
Period End2020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302017-03-31
Value7.514-5.44.12.94.81.82.0
Percentage of SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense75.014400.0-72.023.417.922.4-1.920.6

stfc:SpecialtyInsurance


Supplemental
Period End2020-09-302019-03-312018-09-302018-06-302018-03-312017-09-30
Value-0.91.3-1.8-2.1-0.31.2
Percentage of SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense-9.06.11.9-11.7-1.513.0

stfc:Workerscompensation


Supplemental
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-03-31
Value6.98.58.7999999999999997.30000000000000212-4.07.54.44.54.54.92.53.62.3-1.9
Percentage of SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense53.127.948.973.012800.0-53.355.125.127.821.03.6-2.620.111.3-19.6

dei:EntityCommonStockSharesOutstanding

dei:EntityCommonStockSharesOutstanding


Entity
Period End2021-07-302021-04-302020-10-30
Value444443
Percentage of EntityCommonStockSharesOutstanding100.0100.0100.0

stfc:AvailableForSaleDebtSecuritiesWithInsuranceRegulators

stfc:AvailableForSaleDebtSecuritiesWithInsuranceRegulators


Available
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302011-12-31
Value9.69.49.79.69.29.19.39.39.29.18.98.99.09.19.39.39.39.39.29.29.39.18.88.98.98.88.88.88.88.78.78.68.61010.09.710.09.9
Percentage of AvailableForSaleDebtSecuritiesWithInsuranceRegulators100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

stfc:DeferredPolicyAcquisitionCostsAssumed us-gaap:RelatedPartyTransactionsByRelatedParty

stfc:DeferredPolicyAcquisitionCostsAssumed

srt:AffiliatedEntity


Deferred
Period End2020-12-312019-12-312018-12-31
Value122111101
Percentage of DeferredPolicyAcquisitionCostsAssumed100.0100.0100.0

stfc:DeferredPolicyAcquisitionCostsCeded us-gaap:RelatedPartyTransactionsByRelatedParty

stfc:DeferredPolicyAcquisitionCostsCeded

srt:AffiliatedEntity


Deferred
Period End2020-12-312019-12-312018-12-31
Value-92.19082
Percentage of DeferredPolicyAcquisitionCostsCeded100.0100.0100.0

stfc:DeferredPolicyAcquisitionsCostsfromAffiliates

stfc:DeferredPolicyAcquisitionsCostsfromAffiliates


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312013-12-31
Value37323027242120535548485052556440474750525450-15.05153494619
Percentage of DeferredPolicyAcquisitionsCostsfromAffiliates100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

stfc:DeferredPolicyAcquisitionsCostsfromAffiliates us-gaap:RelatedPartyTransactionsByRelatedParty

srt:AffiliatedEntity


Deferred
Period End2020-12-312019-12-312018-12-31
Value302019
Percentage of DeferredPolicyAcquisitionsCostsfromAffiliates100.0100.041.2

stfc:DeferredTaxAssetOtherLiability

stfc:DeferredTaxAssetOtherLiability


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302011-12-31
Value1213149.21621221918151717151514141314
Percentage of DeferredTaxAssetOtherLiability100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

stfc:DeferredTaxAssetsLossesAndLossExpensesPayableDiscounting

stfc:DeferredTaxAssetsLossesAndLossExpensesPayableDiscounting


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302011-12-31
Value101019221919212121212125252525262525
Percentage of DeferredTaxAssetsLossesAndLossExpensesPayableDiscounting100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

stfc:DeferredTaxLiabilitiesDeferralOfPolicyAcquisitionCosts

stfc:DeferredTaxLiabilitiesDeferralOfPolicyAcquisitionCosts


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302011-12-31
Value252321244545443837343334353332333232
Percentage of DeferredTaxLiabilitiesDeferralOfPolicyAcquisitionCosts100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

stfc:InvestableAssets

stfc:InvestableAssets


Investable
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302011-12-31
Value28592825287027822770266727472742270927012658269727112723278127732733268726632675263725832529248624712506244424052383235123312301227823462327231523002585
Percentage of InvestableAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

stfc:LossesAndLossExpensesPayableFromAffiliate

stfc:LossesAndLossExpensesPayableFromAffiliate


Losses
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value441454438450461457500521563583593619646677711723660-646.8630606572554532506507504494443437425438425424434435414377368376570545375
Percentage of LossesAndLossExpensesPayableFromAffiliate100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

stfc:LossesAndLossExpensesPayableFromAffiliates

stfc:LossesAndLossExpensesPayableFromAffiliates


Losses
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value438500593711630532494438
Percentage of LossesAndLossExpensesPayableFromAffiliates100.0100.0100.0100.0100.0100.0100.0100.0

stfc:LossesAndLossExpensesPayableFromAffiliates us-gaap:RelatedPartyTransactionsByRelatedParty

srt:AffiliatedEntity


Losses
Period End2020-12-312019-12-312018-12-31
Value438500593
Percentage of LossesAndLossExpensesPayableFromAffiliates100.0100.0100.0

stfc:MortgageBackedSecuritiesAmortizedCost

stfc:MortgageBackedSecuritiesAmortizedCost


Mortgage
Period End2021-06-302021-03-312020-12-312020-09-30
Value742730639557
Percentage of MortgageBackedSecuritiesAmortizedCost100.0100.0100.0100.0

stfc:MortgageBackedSecuritiesFairValue

stfc:MortgageBackedSecuritiesFairValue


Mortgage
Period End2021-06-302021-03-312020-12-312020-09-30
Value752734660581
Percentage of MortgageBackedSecuritiesFairValue100.0100.0100.0100.0

stfc:NetOtherLiabilitiesfromAffiliates

stfc:NetOtherLiabilitiesfromAffiliates


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312013-12-31
Value19172218121019131111177017171518171611106.37.1-8.4-6.8-3.4-2.8-5.120
Percentage of NetOtherLiabilitiesfromAffiliates100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

stfc:NetOtherLiabilitiesfromAffiliates us-gaap:RelatedPartyTransactionsByRelatedParty

srt:AffiliatedEntity


Net
Period End2020-12-312019-12-312018-12-31
Value221917
Percentage of NetOtherLiabilitiesfromAffiliates100.0100.0100.0

stfc:NumberOfSecuritiesAvailableForIssuanceUnderEquityCompensationPlans us-gaap:AwardType

stfc:NumberOfSecuritiesAvailableForIssuanceUnderEquityCompensationPlans

us-gaap:StockCompensationPlan


Number
Period End2020-12-31
Value1600000.0
Percentage of NumberOfSecuritiesAvailableForIssuanceUnderEquityCompensationPlans100.0

stfc:OtherInvestedAssetsFairValueDisclosure stfc:InternationalFundName, us-gaap:DefinedBenefitPlanByPlanAssetCategories, us-gaap:RetirementPlanType

stfc:OtherInvestedAssetsFairValueDisclosure

stfc:SilchesterInternational, us-gaap:PrivateEquityFundsForeign, us-gaap:PensionPlansDefinedBenefit


Other
Period End2020-12-312019-12-312018-12-312017-12-31
Value47383241
Percentage of OtherInvestedAssetsFairValueDisclosure100.0100.0100.0100.0

stfc:OtherLiabilitiesAssumed us-gaap:RelatedPartyTransactionsByRelatedParty

stfc:OtherLiabilitiesAssumed

srt:AffiliatedEntity


Other
Period End2020-12-312019-12-312018-12-31
Value993642
Percentage of OtherLiabilitiesAssumed100.0100.0100.0

stfc:OtherLiabilitiesCeded us-gaap:RelatedPartyTransactionsByRelatedParty

stfc:OtherLiabilitiesCeded

srt:AffiliatedEntity


Other
Period End2020-12-312019-12-312018-12-31
Value-77.11724
Percentage of OtherLiabilitiesCeded100.0100.0100.0

stfc:PostretirementPlanEstimatedFutureSubsidy

stfc:PostretirementPlanEstimatedFutureSubsidy


Postretirement
Period End2020-12-31
Value300000.0
Percentage of PostretirementPlanEstimatedFutureSubsidy100.0

stfc:SegmentAssets

stfc:SegmentAssets


Segment
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-31
Value287027472658278126632529244423312327
Percentage of SegmentAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0

stfc:SegmentAssets us-gaap:StatementBusinessSegments

stfc:InvestmentOperationsSegment


Segment
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-31
Value287027472658278126632529244423312327
Percentage of SegmentAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0

stfc:StatutoryAccountingPoliciesStatutoryPercentAvailableforDividendPaymentswithoutRegulatoryApproval

stfc:StatutoryAccountingPoliciesStatutoryPercentAvailableforDividendPaymentswithoutRegulatoryApproval


Statutory
Period End2020-12-31
Value10.0
Percentage of StatutoryAccountingPoliciesStatutoryPercentAvailableforDividendPaymentswithoutRegulatoryApproval100.0

stfc:SupplementalExecutiveRetirementPlanCurrent us-gaap:RetirementPlanType

stfc:SupplementalExecutiveRetirementPlanCurrent

us-gaap:PensionCosts


Supplemental
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value1311117.06.8
Percentage of SupplementalExecutiveRetirementPlanCurrent100.0100.0100.0100.0100.0

stfc:UnearnedPremiumsAssumed us-gaap:InvestmentsInAndAdvancesToAffiliatesCategorization

stfc:UnearnedPremiumsAssumed

stfc:PriorToReinsuranceTransactionWithStateAutoMutual


Unearned
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-31
Value393635211.31.21.01.01.01.1
Percentage of UnearnedPremiumsAssumed100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

stfc:UnearnedPremiumsAssumed us-gaap:RelatedPartyTransactionsByRelatedParty

srt:AffiliatedEntity


Unearned
Period End2020-12-312019-12-312018-12-31
Value715641577
Percentage of UnearnedPremiumsAssumed1810.41748.51627.0

stfc:UnearnedPremiumsCeded us-gaap:InvestmentsInAndAdvancesToAffiliatesCategorization

stfc:UnearnedPremiumsCeded

stfc:PriorToReinsuranceTransactionWithStateAutoMutual


Unearned
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-31
Value-8.37.5-6.6-6.4-6.1-6.8-6.1-4.73.97.9
Percentage of UnearnedPremiumsCeded100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

stfc:UnearnedPremiumsCeded us-gaap:RelatedPartyTransactionsByRelatedParty

srt:AffiliatedEntity


Unearned
Period End2020-12-312019-12-312018-12-31
Value-262.7525465
Percentage of UnearnedPremiumsCeded3165.17000.0-7048.5

stfc:UnearnedPremiumsDirect us-gaap:InvestmentsInAndAdvancesToAffiliatesCategorization

stfc:UnearnedPremiumsDirect

stfc:PriorToReinsuranceTransactionWithStateAutoMutual


Unearned
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-31
Value507495436402395400409411398370
Percentage of UnearnedPremiumsDirect100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

stfc:UnearnedPremiumsFromAffiliates

stfc:UnearnedPremiumsFromAffiliates


Unearned
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value4944664524501441261161111041031121211351571872172342222202272262122142202232052011031038578779485818610110898310299234
Percentage of UnearnedPremiumsFromAffiliates100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

stfc:UnearnedPremiumsFromAffiliates us-gaap:InvestmentsInAndAdvancesToAffiliatesCategorization

stfc:PriorToReinsuranceTransactionWithStateAutoMutual


Unearned
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-31
Value538525465417390395404407395363
Percentage of UnearnedPremiumsFromAffiliates119.1449.9413.8222.2176.9184.5200.6520.3483.3369.8

stfc:UnearnedPremiumsFromAffiliates us-gaap:RelatedPartyTransactionsByRelatedParty

srt:AffiliatedEntity


Unearned
Period End2020-12-312019-12-312018-12-31
Value452116112
Percentage of UnearnedPremiumsFromAffiliates100.0100.0100.0

stfc:UnpaidLossesAndLossAdjustmentExpenseDirect us-gaap:InvestmentsInAndAdvancesToAffiliatesCategorization

stfc:UnpaidLossesAndLossAdjustmentExpenseDirect

stfc:PriorToReinsuranceTransactionWithStateAutoMutual


Unpaid
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-31
Value581540530535545515484516499517
Percentage of UnpaidLossesAndLossAdjustmentExpenseDirect100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AccruedInvestmentIncomeReceivable

us-gaap:AccruedInvestmentIncomeReceivable


Accrued
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value263129313133313430363239394036383946403936393638353633333335333534343130403030312638
Percentage of AccruedInvestmentIncomeReceivable100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AlternativeInvestment us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FinancialInstrument

us-gaap:AlternativeInvestment

us-gaap:FairValueInputsLevel1, stfc:OtherInvestedAssets


Alternative
Period End2020-12-312019-12-312018-12-31
Value151310
Percentage of AlternativeInvestment100.0100.0100.0

us-gaap:AlternativeInvestment us-gaap:FinancialInstrument

stfc:OtherInvestedAssets


Alternative
Period End2020-12-312019-12-312018-12-31
Value151310
Percentage of AlternativeInvestment100.0100.0100.0

us-gaap:AssumedLiabilityForUnpaidClaimsAndClaimsAdjustmentExpense us-gaap:InvestmentsInAndAdvancesToAffiliatesCategorization

us-gaap:AssumedLiabilityForUnpaidClaimsAndClaimsAdjustmentExpense

stfc:PriorToReinsuranceTransactionWithStateAutoMutual


Assumed
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-31
Value3025229.25.05.04.55.07.712
Percentage of AssumedLiabilityForUnpaidClaimsAndClaimsAdjustmentExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AssumedLiabilityForUnpaidClaimsAndClaimsAdjustmentExpense us-gaap:RelatedPartyTransactionsByRelatedParty

srt:AffiliatedEntity


Assumed
Period End2020-12-312019-12-312018-12-31
Value102610521141
Percentage of AssumedLiabilityForUnpaidClaimsAndClaimsAdjustmentExpense3386.54112.95117.9

us-gaap:AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax

us-gaap:AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax


Available
Period End2020-12-312019-12-312018-12-31
Value1215614
Percentage of AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax100.0100.0100.0

us-gaap:AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax us-gaap:FinancialInstrument

us-gaap:CorporateDebtSecurities


Available
Period End2020-12-312019-12-312018-12-31
Value23110.6
Percentage of AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax19.220.84.2

us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprises


Available
Period End2020-12-312019-12-312018-12-31
Value22113.3
Percentage of AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax18.819.822.9

us-gaap:USStatesAndPoliticalSubdivisions


Available
Period End2020-12-312019-12-312018-12-31
Value30217.3
Percentage of AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax24.937.550.7

us-gaap:USTreasuryAndGovernment


Available
Period End2020-12-312019-12-312018-12-31
Value45123.2
Percentage of AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax37.121.922.2

us-gaap:AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax

us-gaap:AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax


Available
Period End2020-12-312019-12-312018-12-31
Value1.78.343
Percentage of AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax100.0100.0100.0

us-gaap:AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax us-gaap:FinancialInstrument

us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprises


Available
Period End2020-12-312019-12-312018-12-31
Value1.54.621
Percentage of AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax88.255.449.4

us-gaap:USStatesAndPoliticalSubdivisions


Available
Period End2020-12-312019-12-312018-12-31
Value0.20.00.9
Percentage of AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax11.80.02.1

us-gaap:AvailableForSaleDebtSecuritiesAmortizedCostBasis

us-gaap:AvailableForSaleDebtSecuritiesAmortizedCostBasis


Available
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302013-12-31
Value21342147211720471983205120802129211921302188218522062199217321492138210420952061202919911972193819271894183118151804
Percentage of AvailableForSaleDebtSecuritiesAmortizedCostBasis100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AvailableForSaleDebtSecuritiesAmortizedCostBasis us-gaap:FinancialInstrument

us-gaap:CorporateDebtSecurities


Available
Period End2020-12-312019-12-312018-12-31
Value459460551
Percentage of AvailableForSaleDebtSecuritiesAmortizedCostBasis21.722.125.2

us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprises


Available
Period End2020-12-312019-12-312018-12-31
Value639646789
Percentage of AvailableForSaleDebtSecuritiesAmortizedCostBasis30.231.136.1

us-gaap:USStatesAndPoliticalSubdivisions


Available
Period End2020-12-312019-12-312018-12-31
Value511404408
Percentage of AvailableForSaleDebtSecuritiesAmortizedCostBasis24.219.418.7

us-gaap:USTreasuryAndGovernment


Available
Period End2020-12-312019-12-312018-12-31
Value506569438
Percentage of AvailableForSaleDebtSecuritiesAmortizedCostBasis23.927.420.0

us-gaap:AvailableForSaleSecurities

us-gaap:AvailableForSaleSecurities


Available
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302018-12-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302011-12-31
Value221422092237216620972128212721892159261425862609256725372530250924602396236023452363228222472237219821762172213922112197218021742159
Percentage of AvailableForSaleSecurities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax

us-gaap:AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax


Available
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302018-12-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302013-12-31
Value877712112211688566514126136140135118172176150125-121.4-155.0186-172.6-160.8-160.7
Percentage of AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax us-gaap:FinancialInstrument

us-gaap:CorporateDebtSecurities


Available
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302018-12-31
Value18172321205.011100.6
Percentage of AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax20.922.019.218.017.45.620.816.64.2

us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprises


Available
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302018-12-31
Value16152225262411183.3
Percentage of AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax19.019.918.820.723.027.919.827.722.9

us-gaap:USStatesAndPoliticalSubdivisions


Available
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302018-12-31
Value25223026252021217.3
Percentage of AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax29.328.424.921.922.123.537.533.250.7

us-gaap:USTreasuryAndGovernment


Available
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302018-12-31
Value26234548433812143.2
Percentage of AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax30.829.737.139.437.542.921.922.522.2

us-gaap:AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax

us-gaap:AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax


Available
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302018-12-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302013-12-31
Value7.4151.72.81.8128.35.44330221719256.67.91324-22.6-20.98.0-7.3-10.6-34.5
Percentage of AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax us-gaap:FinancialInstrument

us-gaap:CorporateDebtSecurities


Available
Period End2021-06-302021-03-312020-06-302020-03-312019-12-312019-09-302018-12-31
Value0.32.20.37.20.41.111
Percentage of AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax4.113.816.760.04.820.427.1

us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprises


Available
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302018-12-31
Value6.9111.51.31.54.64.63.121
Percentage of AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax93.271.788.246.483.338.355.457.449.4

us-gaap:USStatesAndPoliticalSubdivisions


Available
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302018-12-31
Value0.11.90.21.50.00.00.00.00.9
Percentage of AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax1.411.911.853.60.00.00.00.02.1

us-gaap:USTreasuryAndGovernment


Available
Period End2021-06-302021-03-312020-06-302020-03-312019-12-312019-09-302018-12-31
Value0.10.40.00.23.31.29.2
Percentage of AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax1.42.50.01.739.822.221.3

us-gaap:AvailableForSaleSecuritiesAmortizedCost

us-gaap:AvailableForSaleSecuritiesAmortizedCost


Available
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302018-12-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302011-12-31
Value213421472117204719832051208021292188251724722485245124442364234023232295226122112185211720972068205920502047201820222021199020132007
Percentage of AvailableForSaleSecuritiesAmortizedCost100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AvailableForSaleSecuritiesAmortizedCost us-gaap:FinancialInstrument

us-gaap:CorporateDebtSecurities


Available
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302018-12-31
Value457488459451493470460492551
Percentage of AvailableForSaleSecuritiesAmortizedCost21.422.721.722.124.922.922.123.125.2

us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprises


Available
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302018-12-31
Value742730639557579629646705789
Percentage of AvailableForSaleSecuritiesAmortizedCost34.834.030.227.229.230.731.133.136.1

us-gaap:USStatesAndPoliticalSubdivisions


Available
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302018-12-31
Value473480511527391392404415408
Percentage of AvailableForSaleSecuritiesAmortizedCost22.222.424.225.819.719.119.419.518.7

us-gaap:USTreasuryAndGovernment


Available
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302018-12-31
Value461448506510518559569516438
Percentage of AvailableForSaleSecuritiesAmortizedCost21.620.923.925.026.227.327.424.320.0

us-gaap:AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss

us-gaap:AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss


Available
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302018-12-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302013-12-31
Value0.10.10.20.20.84.34.735156.51.31.43.31.93.45.67.72.63.43.05.28.56.5
Percentage of AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss us-gaap:FinancialInstrument

us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprises


Available
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302018-12-31
Value0.10.10.20.20.73.12.818
Percentage of AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss100.0100.0100.0100.087.572.159.652.9

us-gaap:AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLoss

us-gaap:AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLoss


Available
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302018-12-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302013-12-31
Value7.4151.72.81.8128.35.44330221719256.67.9132422208.07.31034
Percentage of AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLoss us-gaap:FinancialInstrument

us-gaap:CorporateDebtSecurities


Available
Period End2021-06-302021-03-312020-06-302020-03-312019-12-312019-09-302018-12-31
Value0.32.20.37.20.41.111
Percentage of AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLoss4.113.816.760.04.820.427.1

us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprises


Available
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302018-12-31
Value6.9111.51.31.54.64.63.121
Percentage of AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLoss93.271.788.246.483.338.355.457.449.4

us-gaap:USStatesAndPoliticalSubdivisions


Available
Period End2021-06-302021-03-312020-12-312020-09-302019-09-302018-12-31
Value0.11.90.21.50.00.9
Percentage of AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLoss1.411.911.853.60.02.1

us-gaap:USTreasuryAndGovernment


Available
Period End2021-06-302021-03-312020-06-302020-03-312019-12-312019-09-302018-12-31
Value0.10.40.00.23.31.29.2
Percentage of AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLoss1.42.50.01.739.822.221.3

us-gaap:AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue

us-gaap:AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue


Available
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302018-12-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302011-12-31
Value44663917319519036959851814341089932837889950342182352772586681375297410438654616531525269225108204123
Percentage of AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue us-gaap:FinancialInstrument

us-gaap:CorporateDebtSecurities


Available
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302018-12-31
Value421101.515942114077433
Percentage of AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue9.517.30.97.749.657.46.814.930.2

us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprises


Available
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302018-12-31
Value3283651438593135264212555
Percentage of AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue73.757.182.443.748.836.644.240.938.7

us-gaap:USStatesAndPoliticalSubdivisions


Available
Period End2021-06-302021-03-312020-12-312020-09-302019-09-302018-12-31
Value3.811119944.1103
Percentage of AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue0.917.511.248.20.87.2

us-gaap:USTreasuryAndGovernment


Available
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302018-12-31
Value71519.60.73.022293225342
Percentage of AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue15.98.15.50.41.66.049.043.523.9

us-gaap:AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss

us-gaap:AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss


Available
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302018-12-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302013-12-31
Value7.4151.62.61.6114.00.78.115151518224.74.57.91620175.02.12.128
Percentage of AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss us-gaap:FinancialInstrument

us-gaap:CorporateDebtSecurities


Available
Period End2021-06-302021-03-312020-06-302020-03-312019-12-312019-09-302018-12-31
Value0.32.20.37.10.00.33.0
Percentage of AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss4.113.918.863.40.042.937.0

us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprises


Available
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302018-12-31
Value6.9111.41.11.33.91.50.32.8
Percentage of AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss93.271.587.542.381.234.837.542.934.6

us-gaap:USStatesAndPoliticalSubdivisions


Available
Period End2021-06-302021-03-312020-12-312020-09-302019-09-302018-12-31
Value0.11.90.21.50.00.5
Percentage of AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss1.412.012.557.70.06.2

us-gaap:USTreasuryAndGovernment


Available
Period End2021-06-302021-03-312020-06-302020-03-312019-12-312019-09-302018-12-31
Value0.10.40.00.22.50.11.8
Percentage of AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss1.42.50.01.862.514.322.2

us-gaap:AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue

us-gaap:AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue


Available
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302018-12-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302011-12-31
Value4376291661861753412621125605746807868488912761002026624845692541201721235335304894882251816816874
Percentage of AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue us-gaap:FinancialInstrument

us-gaap:CorporateDebtSecurities


Available
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302018-12-31
Value421101.515942050.020244
Percentage of AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue9.717.60.98.154.060.30.018.143.6

us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprises


Available
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302018-12-31
Value320354136767711312650169
Percentage of AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue73.256.481.640.944.333.148.245.330.3

us-gaap:USStatesAndPoliticalSubdivisions


Available
Period End2021-06-302021-03-312020-12-312020-09-302019-09-302018-12-31
Value3.811119940.063
Percentage of AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue0.917.811.750.60.011.4

us-gaap:USTreasuryAndGovernment


Available
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302018-12-31
Value71519.60.73.0221364183
Percentage of AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue16.28.25.80.41.76.551.836.614.8

us-gaap:AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue

us-gaap:AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue


Available
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302018-12-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302011-12-31
Value8.4107.09.4152833640687451525250405865821501101021111201762373151218542374343403549
Percentage of AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue us-gaap:FinancialInstrument

us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprises


Available
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302018-12-31
Value8.4107.09.41522137161385
Percentage of AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue100.0100.0100.0100.0100.078.641.039.644.1

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost


Available
Period End2021-06-302021-03-312020-12-312020-09-30
Value154165161168
Percentage of AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost100.0100.0100.0100.0

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue


Available
Period End2021-06-302021-03-312020-12-312020-09-30
Value162170172178
Percentage of AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue100.0100.0100.0100.0

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost


Available
Period End2021-06-302021-03-312020-12-312020-09-30
Value571536510519
Percentage of AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost100.0100.0100.0100.0

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue


Available
Period End2021-06-302021-03-312020-12-312020-09-30
Value596562540548
Percentage of AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue100.0100.0100.0100.0

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost


Available
Period End2021-06-302021-03-312020-12-312020-09-30
Value530556665682
Percentage of AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost100.0100.0100.0100.0

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue


Available
Period End2021-06-302021-03-312020-12-312020-09-30
Value566582721737
Percentage of AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue100.0100.0100.0100.0

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost


Available
Period End2021-06-302021-03-312020-12-312020-09-30
Value135158140119
Percentage of AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost100.0100.0100.0100.0

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue


Available
Period End2021-06-302021-03-312020-12-312020-09-30
Value136159141120
Percentage of AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue100.0100.0100.0100.0

us-gaap:AvailableForSaleSecuritiesDebtSecurities

us-gaap:AvailableForSaleSecuritiesDebtSecurities


Available
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value221422092237216620972128212721892157213621592141217821812192217821672123210921432123205520001979195919641891186718491840183018441820189519051883191119041934204120561900
Percentage of AvailableForSaleSecuritiesDebtSecurities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AvailableForSaleSecuritiesDebtSecurities us-gaap:FairValueByFairValueHierarchyLevel

us-gaap:FairValueInputsLevel2


Available
Period End2020-12-312019-12-312018-12-31
Value223721272159
Percentage of AvailableForSaleSecuritiesDebtSecurities100.0100.0100.0

us-gaap:AvailableForSaleSecuritiesDebtSecurities us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FinancialInstrument

us-gaap:FairValueInputsLevel2, us-gaap:CorporateDebtSecurities


Available
Period End2020-12-312019-12-312018-12-31
Value483471540
Percentage of AvailableForSaleSecuritiesDebtSecurities21.622.225.0

us-gaap:FairValueInputsLevel2, us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprises


Available
Period End2020-12-312019-12-312018-12-31
Value660652771
Percentage of AvailableForSaleSecuritiesDebtSecurities29.530.735.7

us-gaap:FairValueInputsLevel2, us-gaap:USStatesAndPoliticalSubdivisions


Available
Period End2020-12-312019-12-312018-12-31
Value541425414
Percentage of AvailableForSaleSecuritiesDebtSecurities24.220.019.2

us-gaap:FairValueInputsLevel2, us-gaap:USTreasuryAndGovernment


Available
Period End2020-12-312019-12-312018-12-31
Value551578432
Percentage of AvailableForSaleSecuritiesDebtSecurities24.727.220.0

us-gaap:AvailableForSaleSecuritiesDebtSecurities us-gaap:FinancialInstrument

us-gaap:CorporateDebtSecurities


Available
Period End2020-12-312019-12-312018-12-31
Value483471540
Percentage of AvailableForSaleSecuritiesDebtSecurities21.622.225.0

us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprises


Available
Period End2020-12-312019-12-312018-12-31
Value660652771
Percentage of AvailableForSaleSecuritiesDebtSecurities29.530.735.7

us-gaap:USStatesAndPoliticalSubdivisions


Available
Period End2020-12-312019-12-312018-12-31
Value541425414
Percentage of AvailableForSaleSecuritiesDebtSecurities24.220.019.2

us-gaap:USTreasuryAndGovernment


Available
Period End2020-12-312019-12-312018-12-31
Value551578432
Percentage of AvailableForSaleSecuritiesDebtSecurities24.727.220.0

us-gaap:AvailableForSaleSecuritiesEquitySecurities

us-gaap:AvailableForSaleSecuritiesEquitySecurities


Available
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value375399389339354275395373374363315376362350365354391395382297300318310298297310310297300274265251248248228235204179167182262256
Percentage of AvailableForSaleSecuritiesEquitySecurities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CededPremiumsPayable us-gaap:InvestmentsInAndAdvancesToAffiliatesCategorization

us-gaap:CededPremiumsPayable

stfc:PriorToReinsuranceTransactionWithStateAutoMutual


Ceded
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-31
Value2413-5.5-3.1-3.6-5.9-9.6-9.11325
Percentage of CededPremiumsPayable100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CededPremiumsPayable us-gaap:RelatedPartyTransactionsByRelatedParty

srt:AffiliatedEntity


Ceded
Period End2020-12-312019-12-312018-12-31
Value587552547
Percentage of CededPremiumsPayable2416.94059.6-9958.2

us-gaap:DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger

us-gaap:DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger


Debt
Period End2020-12-312019-12-312018-12-31
Value7.0336874
Percentage of DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger100.0100.0100.0

us-gaap:DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger us-gaap:FinancialInstrument

us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprises


Debt
Period End2020-12-312019-12-312018-12-31
Value7.0137385
Percentage of DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger100.041.044.1

us-gaap:DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss

us-gaap:DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss


Debt
Period End2020-12-312019-12-312018-12-31
Value0.14.335
Percentage of DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss100.0100.0100.0

us-gaap:DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss us-gaap:FinancialInstrument

us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprises


Debt
Period End2020-12-312019-12-312018-12-31
Value0.13.118
Percentage of DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss100.072.152.9

us-gaap:DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months

us-gaap:DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months


Debt
Period End2020-12-312019-12-312018-12-31
Value166262560
Percentage of DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months100.0100.0100.0

us-gaap:DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months us-gaap:FinancialInstrument

us-gaap:CorporateDebtSecurities


Debt
Period End2020-12-312019-12-312018-12-31
Value1.50.0244
Percentage of DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months0.90.043.6

us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprises


Debt
Period End2020-12-312019-12-312018-12-31
Value136126169
Percentage of DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months81.648.230.3

us-gaap:USStatesAndPoliticalSubdivisions


Debt
Period End2020-12-312018-12-31
Value1963
Percentage of DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months11.711.4

us-gaap:USTreasuryAndGovernment


Debt
Period End2020-12-312019-12-312018-12-31
Value9.613683
Percentage of DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months5.851.814.8

us-gaap:DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss

us-gaap:DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss


Debt
Period End2020-12-312019-12-312018-12-31
Value1600000.04000000.08100000.0
Percentage of DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss100.0100.0100.0

us-gaap:DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss us-gaap:FinancialInstrument

us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprises


Debt
Period End2020-12-312019-12-312018-12-31
Value1400000.01500000.02800000.0
Percentage of DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss87.537.534.6

us-gaap:USStatesAndPoliticalSubdivisions


Debt
Period End2020-12-312018-12-31
Value200000.0500000.0
Percentage of DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss12.56.2

us-gaap:DebtSecuritiesAvailableForSaleUnrealizedLossPosition

us-gaap:DebtSecuritiesAvailableForSaleUnrealizedLossPosition


Debt
Period End2020-12-312019-12-312018-12-31
Value1735981434
Percentage of DebtSecuritiesAvailableForSaleUnrealizedLossPosition100.0100.0100.0

us-gaap:DebtSecuritiesAvailableForSaleUnrealizedLossPosition us-gaap:FinancialInstrument

us-gaap:CorporateDebtSecurities


Debt
Period End2020-12-312019-12-312018-12-31
Value1.540433
Percentage of DebtSecuritiesAvailableForSaleUnrealizedLossPosition0.96.830.2

us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprises


Debt
Period End2020-12-312019-12-312018-12-31
Value143264555
Percentage of DebtSecuritiesAvailableForSaleUnrealizedLossPosition82.444.238.7

us-gaap:USStatesAndPoliticalSubdivisions


Debt
Period End2020-12-312018-12-31
Value19103
Percentage of DebtSecuritiesAvailableForSaleUnrealizedLossPosition11.27.2

us-gaap:USTreasuryAndGovernment


Debt
Period End2020-12-312019-12-312018-12-31
Value9.6293342
Percentage of DebtSecuritiesAvailableForSaleUnrealizedLossPosition5.549.023.9

us-gaap:DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss

us-gaap:DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss


Debt
Period End2020-12-312019-12-312018-12-31
Value1.78.343
Percentage of DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss100.0100.0100.0

us-gaap:DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss us-gaap:FinancialInstrument

us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprises


Debt
Period End2020-12-312019-12-312018-12-31
Value1.54.621
Percentage of DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss88.255.449.4

us-gaap:USStatesAndPoliticalSubdivisions


Debt
Period End2020-12-312018-12-31
Value0.20.9
Percentage of DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss11.82.1

us-gaap:DeferredIncomeTaxAssetsNet

us-gaap:DeferredIncomeTaxAssetsNet


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312018-12-312017-12-312016-12-31
Value293727444964422.86149
Percentage of DeferredIncomeTaxAssetsNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredIncomeTaxAssetsNet us-gaap:ConsolidatedEntities

srt:ParentCompany


Deferred
Period End2020-12-312019-12-31
Value1415
Percentage of DeferredIncomeTaxAssetsNet51.336.0

us-gaap:DeferredIncomeTaxLiabilities

us-gaap:DeferredIncomeTaxLiabilities


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302011-12-31
Value7344215577801029096837878779993998985
Percentage of DeferredIncomeTaxLiabilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredPolicyAcquisitionCosts

us-gaap:DeferredPolicyAcquisitionCosts


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-312009-12-31
Value127121122123120113111114109104101104104105117122125124129133131127129134133127126109107999698100949194939411817216715095
Percentage of DeferredPolicyAcquisitionCosts100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredTaxAssetsCapitalLossCarryforwards

us-gaap:DeferredTaxAssetsCapitalLossCarryforwards


Deferred
Period End2020-12-31
Value6100000.0
Percentage of DeferredTaxAssetsCapitalLossCarryforwards100.0

us-gaap:DeferredTaxAssetsGross

us-gaap:DeferredTaxAssetsGross


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302011-12-31
Value1018699112180183199169169166172188193191195198194189
Percentage of DeferredTaxAssetsGross100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredTaxAssetsOperatingLossCarryforwards

us-gaap:DeferredTaxAssetsOperatingLossCarryforwards


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302011-12-31
Value191215345841584950505656626366716356
Percentage of DeferredTaxAssetsOperatingLossCarryforwards100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredTaxAssetsOther

us-gaap:DeferredTaxAssetsOther


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302011-12-31
Value1100000.01100000.0800000.02500000.08800000.04900000.04700000.07100000.08500000.08300000.09200000.07600000.07200000.07400000.07900000.08200000.09300000.09200000.0
Percentage of DeferredTaxAssetsOther100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredTaxAssetsTaxCreditCarryforwards

us-gaap:DeferredTaxAssetsTaxCreditCarryforwards


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302011-12-31
Value1900000.02500000.02700000.03700000.03300000.04800000.01900000.03800000.02400000.02300000.01700000.01800000.01300000.01200000.0900000.0800000.0700000.0700000.0
Percentage of DeferredTaxAssetsTaxCreditCarryforwards100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredTaxAssetsTaxCreditCarryforwardsForeign

us-gaap:DeferredTaxAssetsTaxCreditCarryforwardsForeign


Deferred
Period End2020-12-312020-09-30
Value300000.0500000.0
Percentage of DeferredTaxAssetsTaxCreditCarryforwardsForeign100.0100.0

us-gaap:DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPostretirementBenefits

us-gaap:DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPostretirementBenefits


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302011-12-31
Value192021132636412224252435373839363839
Percentage of DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPostretirementBenefits100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsUnearnedPremiumsReserve

us-gaap:DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsUnearnedPremiumsReserve


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302011-12-31
Value302724254242423635343334353333343332
Percentage of DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsUnearnedPremiumsReserve100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredTaxLiabilitiesInvestments

us-gaap:DeferredTaxLiabilitiesInvestments


Deferred
Period End2020-12-312019-12-312018-12-31
Value48210.0
Percentage of DeferredTaxLiabilitiesInvestments100.0100.00.0

us-gaap:DefinedBenefitPlanAccumulatedBenefitObligation us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanAccumulatedBenefitObligation

us-gaap:PensionCosts


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value522453406287267
Percentage of DefinedBenefitPlanAccumulatedBenefitObligation100.0100.0100.0100.0100.0

us-gaap:DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value1.950.0310.04120.0350.04
Percentage of DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value2.320.0310.04120.0350.04
Percentage of DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate119.0100.0100.0100.0100.0

us-gaap:DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfCompensationIncrease us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfCompensationIncrease

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value3.00.03250.03250.03250.035
Percentage of DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfCompensationIncrease100.0100.0100.0100.0100.0

us-gaap:DefinedBenefitPlanBenefitObligation us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanBenefitObligation

us-gaap:PensionCosts


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value549478428304284281
Percentage of DefinedBenefitPlanBenefitObligation100.0100.0100.0100.0100.0100.0

us-gaap:PostretirementBenefitCosts


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value102525181820
Percentage of DefinedBenefitPlanBenefitObligation1.95.26.06.06.67.2

us-gaap:DefinedBenefitPlanExpectedAmortizationNextFiscalYear

us-gaap:DefinedBenefitPlanExpectedAmortizationNextFiscalYear


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value1201136364
Percentage of DefinedBenefitPlanExpectedAmortizationNextFiscalYear100.0100.0100.0100.0

us-gaap:DefinedBenefitPlanExpectedAmortizationOfGainLossNextFiscalYear

us-gaap:DefinedBenefitPlanExpectedAmortizationOfGainLossNextFiscalYear


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value-157400000.0-157100000.0-111600000.0-118500000.0
Percentage of DefinedBenefitPlanExpectedAmortizationOfGainLossNextFiscalYear100.0100.0100.0100.0

us-gaap:DefinedBenefitPlanExpectedAmortizationOfPriorServiceCostCreditNextFiscalYear

us-gaap:DefinedBenefitPlanExpectedAmortizationOfPriorServiceCostCreditNextFiscalYear


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value-37000000.0-43400000.0-48600000.0-54100000.0
Percentage of DefinedBenefitPlanExpectedAmortizationOfPriorServiceCostCreditNextFiscalYear100.0100.0100.0100.0

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value3.18.48.95.9
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value12312312076
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter3967.71465.51351.71291.5

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths


Defined
Period End2020-12-312019-12-312018-12-31
Value0.62.52.4
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths100.0100.0100.0

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths us-gaap:RetirementPlanType

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value0.72.12.31.5
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths116.784.095.80.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value18181711
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths3050.0728.0737.50.0

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsRemainderOfFiscalYear

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsRemainderOfFiscalYear


Defined
Period End2021-06-302021-03-31
Value5000000.010000000.0
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsRemainderOfFiscalYear100.0100.0

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value0.61.81.91.3
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value21212012
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive3600.01200.01094.7992.3

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value0.61.82.01.4
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value20201912
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour3433.31150.0985.0892.9

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value0.61.92.11.4
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value19191812
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree3266.71031.6900.0857.1

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value0.62.02.21.5
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value18181811
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo3150.0940.0831.8766.7

us-gaap:DefinedBenefitPlanFairValueOfPlanAssets us-gaap:DefinedBenefitPlanByPlanAssetCategories, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanFairValueOfPlanAssets

stfc:LargeCapEquitySecurities, us-gaap:FairValueInputsLevel1, us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-31
Value1169182
Percentage of DefinedBenefitPlanFairValueOfPlanAssets100.0100.0100.0

stfc:MutualandexchangetradedfundsDomain, us-gaap:FairValueInputsLevel1, us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-31
Value564943
Percentage of DefinedBenefitPlanFairValueOfPlanAssets48.354.152.7

stfc:UsGovernmentAgencyMbs, us-gaap:FairValueInputsLevel2, us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-31
Value3.94.05.2
Percentage of DefinedBenefitPlanFairValueOfPlanAssets3.44.46.3

stfc:UsTreasurySecuritiesAndObligationsOfGovernmentAgencies, us-gaap:FairValueInputsLevel2, us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-31
Value909890
Percentage of DefinedBenefitPlanFairValueOfPlanAssets77.9107.3110.1

us-gaap:CorporateDebtSecurities, us-gaap:FairValueInputsLevel2, us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-31
Value183153121
Percentage of DefinedBenefitPlanFairValueOfPlanAssets158.3166.6147.5

us-gaap:DefinedBenefitPlanDebtSecurity, us-gaap:FairValueInputsLevel2, us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-31
Value278255217
Percentage of DefinedBenefitPlanFairValueOfPlanAssets239.5278.2263.9

us-gaap:DefinedBenefitPlanEquitySecurities, us-gaap:FairValueInputsLevel1, us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-31
Value172141125
Percentage of DefinedBenefitPlanFairValueOfPlanAssets148.3154.1152.7

us-gaap:DefinedBenefitPlanFairValueOfPlanAssets us-gaap:DefinedBenefitPlanByPlanAssetCategories, us-gaap:RetirementPlanType

stfc:LargeCapEquitySecurities, us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-31
Value1169182
Percentage of DefinedBenefitPlanFairValueOfPlanAssets100.0100.0100.0

stfc:MutualandexchangetradedfundsDomain, us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-31
Value564943
Percentage of DefinedBenefitPlanFairValueOfPlanAssets48.354.152.7

stfc:UsGovernmentAgencyMbs, us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-31
Value3.94.05.2
Percentage of DefinedBenefitPlanFairValueOfPlanAssets3.44.46.3

stfc:UsTreasurySecuritiesAndObligationsOfGovernmentAgencies, us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-31
Value909890
Percentage of DefinedBenefitPlanFairValueOfPlanAssets77.9107.3110.1

us-gaap:CorporateDebtSecurities, us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-31
Value183153121
Percentage of DefinedBenefitPlanFairValueOfPlanAssets158.3166.6147.5

us-gaap:DefinedBenefitPlanDebtSecurity, us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-31
Value278255217
Percentage of DefinedBenefitPlanFairValueOfPlanAssets239.5278.2263.9

us-gaap:DefinedBenefitPlanEquitySecurities, us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-31
Value172141125
Percentage of DefinedBenefitPlanFairValueOfPlanAssets148.3154.1152.7

us-gaap:DefinedBenefitPlanFairValueOfPlanAssets us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:RetirementPlanType

us-gaap:FairValueInputsLevel1, us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-31
Value172141125
Percentage of DefinedBenefitPlanFairValueOfPlanAssets148.3154.1152.7

us-gaap:FairValueInputsLevel2, us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-31
Value278255217
Percentage of DefinedBenefitPlanFairValueOfPlanAssets239.5278.2263.9

us-gaap:DefinedBenefitPlanFairValueOfPlanAssets us-gaap:RetirementPlanType

us-gaap:PensionCosts


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value506442381265235204
Percentage of DefinedBenefitPlanFairValueOfPlanAssets436.1481.1463.70.00.00.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-31
Value450397342
Percentage of DefinedBenefitPlanFairValueOfPlanAssets387.8432.3416.6

us-gaap:DefinedBenefitPlanFundedStatusOfPlan us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanFundedStatusOfPlan

us-gaap:PensionCosts


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value-56000000.0-47900000.0-57500000.0-46200000.0-55600000.0
Percentage of DefinedBenefitPlanFundedStatusOfPlan100.0100.0100.0100.0100.0

us-gaap:PostretirementBenefitCosts


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value-10200000.0-25000000.0-25500000.0-18300000.0-18800000.0
Percentage of DefinedBenefitPlanFundedStatusOfPlan18.252.244.339.633.8

us-gaap:DueFromAffiliateCurrent

us-gaap:DueFromAffiliateCurrent


Due
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-31
Value389404404386371347323310294297295269268
Percentage of DueFromAffiliateCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DueFromAffiliates

us-gaap:DueFromAffiliates


Due
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302018-12-312018-09-302017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302013-12-312013-09-302012-12-312011-06-302010-12-31
Value1854222117340.0100.03.8221.10.021284.35.921350.04011270.0120.06.26.5
Percentage of DueFromAffiliates100.0100.0100.0100.0100.0100.00.0100.00.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.00.0100.00.0100.0100.0

us-gaap:DueFromAffiliates us-gaap:ConsolidatedEntities

srt:ParentCompany


Due
Period End2020-12-31
Value0.8
Percentage of DueFromAffiliates0.0

us-gaap:DueToAffiliateCurrentAndNoncurrent

us-gaap:DueToAffiliateCurrentAndNoncurrent


Due
Period End2021-06-302021-03-312020-12-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312015-12-312015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-31
Value1622110.00.00.018220.07.1112.70.00.00.02.40.06.20.00.00.08.31.30.08.38.63.54.42.0349
Percentage of DueToAffiliateCurrentAndNoncurrent100.0100.0100.00.00.00.0100.0100.00.0100.0100.0100.00.00.00.0100.00.0100.00.00.00.0100.0100.00.0100.0100.0100.0100.0100.0100.0

us-gaap:DueToRelatedPartiesCurrentAndNoncurrent

us-gaap:DueToRelatedPartiesCurrentAndNoncurrent


Due
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value151515151515151515151515151515151515151515151515151515151515151515151515151515151515
Percentage of DueToRelatedPartiesCurrentAndNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized

us-gaap:EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized


Employee
Period End2020-12-312019-12-312018-12-31
Value4900000.06600000.05300000.0
Percentage of EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized100.0100.0100.0

us-gaap:EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized us-gaap:AwardType

stfc:RestrictedStockUnitsRSUsPerformanceBasedShares


Employee
Period End2020-12-312019-12-312018-12-31
Value4400000.05900000.06400000.0
Percentage of EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized89.889.4120.8

stfc:RestrictedStockUnitsRSUsServiceBasedShares


Employee
Period End2020-12-312019-12-312018-12-31
Value500000.0700000.01600000.0
Percentage of EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized10.210.630.2

us-gaap:EquityMethodInvestments us-gaap:ConsolidatedEntities

us-gaap:EquityMethodInvestments

srt:ParentCompany


Equity
Period End2020-12-312019-12-312018-12-312017-12-31
Value11081059913933
Percentage of EquityMethodInvestments100.0100.0100.0100.0

us-gaap:ExcessTierOneRiskBasedCapitalToRiskWeightedAssets

us-gaap:ExcessTierOneRiskBasedCapitalToRiskWeightedAssets


Excess
Period End2020-12-31
Value400.0
Percentage of ExcessTierOneRiskBasedCapitalToRiskWeightedAssets100.0

us-gaap:FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresAmountOfAvailableUnusedFunds us-gaap:FederalHomeLoanBankAdvancesBranchOfFHLBBank

us-gaap:FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresAmountOfAvailableUnusedFunds

srt:FederalHomeLoanBankOfCincinnati


Federal
Period End2020-12-31
Value100
Percentage of FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresAmountOfAvailableUnusedFunds100.0

us-gaap:FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresCollateralPledged1

us-gaap:FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresCollateralPledged1


Federal
Period End2020-12-31
Value106
Percentage of FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresCollateralPledged1100.0

us-gaap:FederalHomeLoanBankStock us-gaap:FairValueByFairValueHierarchyLevel

us-gaap:FederalHomeLoanBankStock

us-gaap:FairValueInputsLevel3


Federal
Period End2021-06-302021-03-312020-09-30
Value101112
Percentage of FederalHomeLoanBankStock100.0100.0100.0

us-gaap:FinancialInstrumentsOwnedAndPledgedAsCollateralAtFairValue

us-gaap:FinancialInstrumentsOwnedAndPledgedAsCollateralAtFairValue


Financial
Period End2021-06-302021-03-312020-12-312020-09-30
Value32303231
Percentage of FinancialInstrumentsOwnedAndPledgedAsCollateralAtFairValue100.0100.0100.0100.0

us-gaap:IncomeTaxesReceivable

us-gaap:IncomeTaxesReceivable


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value1.71.71.76.76.76.76.36.36.36.35.95.95.75.74.86.76.66.86.76.44.94.94.90.33.00.71.10.00.50.00.30.05.911121212127.6
Percentage of IncomeTaxesReceivable100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.00.0100.00.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:Investments

us-gaap:Investments


Investments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value275127662780265025952541266927032664262925982648267026622689266226842642261226052584253524712435242124382357232223122273225122472209228222682251224422162229235924742307
Percentage of Investments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:InvestmentsFairValueDisclosure

us-gaap:InvestmentsFairValueDisclosure


Investments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value26072624264225192465241625362575254525122484252925512542256825432568252825012449243223822319
Percentage of InvestmentsFairValueDisclosure100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:InvestmentsFairValueDisclosure us-gaap:FairValueByFairValueHierarchyLevel

us-gaap:FairValueInputsLevel1


Investments
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value405408325376392318
Percentage of InvestmentsFairValueDisclosure15.316.113.114.615.713.7

us-gaap:FairValueInputsLevel2


Investments
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value223721272159219221051997
Percentage of InvestmentsFairValueDisclosure84.783.986.985.484.286.1

us-gaap:InvestmentsFairValueDisclosure us-gaap:FinancialInstrument

stfc:LargeCapSecurities


Investments
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
Value15814913412011186104998888779596
Percentage of InvestmentsFairValueDisclosure6.15.75.14.84.53.64.13.83.53.53.13.83.8

stfc:MutualandexchangetradedfundsDomain


Investments
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
Value216250255219242188290274286275237280268
Percentage of InvestmentsFairValueDisclosure8.39.59.78.79.87.811.510.611.310.99.611.110.5

stfc:OtherInvestedAssets


Investments
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
Value16151514131213121312101110
Percentage of InvestmentsFairValueDisclosure0.60.60.60.60.50.50.50.50.50.50.40.40.4

us-gaap:CorporateDebtSecurities


Investments
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
Value475503483473513467471502519516540525529
Percentage of InvestmentsFairValueDisclosure18.219.218.318.820.819.418.619.520.420.521.820.820.6

us-gaap:EquitySecurities


Investments
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
Value375399389339354275395373374363315376365
Percentage of InvestmentsFairValueDisclosure14.415.214.713.514.411.415.614.514.714.512.714.914.2

us-gaap:FixedMaturities


Investments
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
Value2214220922372166209721282127218921572136215921412192
Percentage of InvestmentsFairValueDisclosure85.084.284.786.085.188.183.985.084.885.086.984.785.4

us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprises


Investments
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
Value752734660581604649652720727746771774700
Percentage of InvestmentsFairValueDisclosure28.928.025.023.124.526.925.728.028.629.731.130.627.3

us-gaap:USStatesAndPoliticalSubdivisions


Investments
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
Value498500541552417413425437441472414438525
Percentage of InvestmentsFairValueDisclosure19.119.120.521.916.917.116.817.017.318.816.717.420.5

us-gaap:USTreasuryAndGovernment


Investments
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
Value488471551559562597578530469401432402436
Percentage of InvestmentsFairValueDisclosure18.717.920.922.222.824.722.820.618.416.017.415.917.0

us-gaap:LiabilityForClaimsAndClaimsAdjustmentExpense us-gaap:InvestmentsInAndAdvancesToAffiliatesCategorization

us-gaap:LiabilityForClaimsAndClaimsAdjustmentExpense

stfc:PriorToReinsuranceTransactionWithStateAutoMutual


Liability
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value587552547541547514479512
Percentage of LiabilityForClaimsAndClaimsAdjustmentExpense100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:LiabilityForClaimsAndClaimsAdjustmentExpensePropertyCasualtyLiability

us-gaap:LiabilityForClaimsAndClaimsAdjustmentExpensePropertyCasualtyLiability


Liability
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-312009-12-31
Value106010661050109111051086106610921135112811461198123412471255128012331217118111651143108310531021102399798396196295195995295594494294593392090711401113893840
Percentage of LiabilityForClaimsAndClaimsAdjustmentExpensePropertyCasualtyLiability100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet

us-gaap:LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet


Liability
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-31
Value10411042102610561068104610521085112611241141119312291245125212751230121211781161113710771047973950928881874819
Percentage of LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:NotesPayable

us-gaap:NotesPayable


Notes
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value122122122122182182122122122122122122122122122122122122122122100100100100100100100100100100100100115115115116116116116116116116
Percentage of NotesPayable100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:NotesPayable us-gaap:ConsolidatedEntities

srt:ParentCompany


Notes
Period End2020-12-312019-12-312018-12-312017-12-31
Value116116116116
Percentage of NotesPayable95.595.695.595.4

us-gaap:NotesPayableFairValueDisclosure us-gaap:FairValueByMeasurementBasis

us-gaap:NotesPayableFairValueDisclosure

us-gaap:CarryingReportedAmountFairValueDisclosure


Notes
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
Value122122122122182182122122122122122122122122122122122122122122100100100100100100100100100100100100115115
Percentage of NotesPayableFairValueDisclosure100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:EstimateOfFairValueFairValueDisclosure


Notes
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
Value139136144145204196134136133129125122123121121122121121121122101100101101101102101101102102101106117115
Percentage of NotesPayableFairValueDisclosure114.5112.0117.9119.3112.5108.0110.2112.1109.0105.8102.5100.2101.499.299.8100.199.899.599.8100.2100.6100.1100.2100.5100.6101.2101.1101.1101.3101.2100.4105.8101.699.9

us-gaap:NotesPayableFairValueDisclosure us-gaap:FairValueByMeasurementBasis, us-gaap:LongtermDebtType

us-gaap:CarryingReportedAmountFairValueDisclosure, us-gaap:NotesPayableToBanks


Notes
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
Value858585858585858585858585850.0
Percentage of NotesPayableFairValueDisclosure69.969.969.969.946.846.869.969.969.969.969.969.969.90.0

us-gaap:CarryingReportedAmountFairValueDisclosure, us-gaap:SubordinatedDebt


Notes
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
Value15151515151515151515151515151515151515151515151515151515151515151515
Percentage of NotesPayableFairValueDisclosure12.512.512.512.58.48.312.512.512.512.512.512.512.512.412.412.412.412.412.412.415.115.115.415.415.415.415.415.415.415.415.415.413.413.4

us-gaap:EstimateOfFairValueFairValueDisclosure, stfc:FederalHomeLoanBankAdvancesDue2030


Notes
Period End2021-06-302021-03-312020-12-312020-09-30
Value20202121
Percentage of NotesPayableFairValueDisclosure17.016.517.717.9

us-gaap:EstimateOfFairValueFairValueDisclosure, us-gaap:NotesPayableToBanks


Notes
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
Value1031011071081081009710096928986870.0
Percentage of NotesPayableFairValueDisclosure84.982.987.789.059.454.980.282.079.176.173.070.872.00.0

us-gaap:EstimateOfFairValueFairValueDisclosure, us-gaap:SubordinatedDebt


Notes
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
Value15151515151515151515151515151515151515151515151515151515151515151515
Percentage of NotesPayableFairValueDisclosure12.512.512.512.58.38.312.512.512.512.512.512.512.512.412.412.412.412.412.412.415.115.115.415.415.415.415.415.415.415.415.415.413.413.4

us-gaap:NotesPayableFairValueDisclosure us-gaap:LongtermDebtType

us-gaap:NotesPayableOtherPayables


Notes
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value1351221021051021009895
Percentage of NotesPayableFairValueDisclosure110.7100.783.686.383.999.397.995.0

us-gaap:NotesPayableFairValueDisclosure us-gaap:LongtermDebtType, us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:NotesPayableOtherPayables, stfc:Milbank


Notes
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value2018151515151414
Percentage of NotesPayableFairValueDisclosure16.615.112.512.912.614.914.714.3

us-gaap:NotesPayableOtherPayables, stfc:StateAutoPC


Notes
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value114104868987858381
Percentage of NotesPayableFairValueDisclosure94.185.671.173.471.384.483.280.8

us-gaap:NotesReceivableFairValueDisclosure us-gaap:AccountsNotesLoansAndFinancingReceivableByReceivableType, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementBasis, us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:NotesReceivableFairValueDisclosure

stfc:NoteReceivableFromAffiliate2019, us-gaap:FairValueInputsLevel2, us-gaap:CarryingReportedAmountFairValueDisclosure, srt:AffiliatedEntity


Notes
Period End2020-12-312019-12-312018-12-31
Value70700.0
Percentage of NotesReceivableFairValueDisclosure100.0100.00.0

stfc:NoteReceivableFromAffiliate2019, us-gaap:FairValueInputsLevel2, us-gaap:EstimateOfFairValueFairValueDisclosure, srt:AffiliatedEntity