 | us-gaap:FixedIncomeInvestmentsMember | parent-child | http://fasb.org/us-gaap/role/disclosure/InvestmentHoldings |
 | us-gaap:FixedIncomeInvestmentsMember | domain-member | http://fasb.org/us-gaap/role/disclosure/InvestmentHoldings |
 | us-gaap:FixedIncomeInvestmentsMember | parent-child | http://fasb.org/us-gaap/role/disclosure/InvestmentsSoldNotYetPurchased |
 | us-gaap:FixedIncomeInvestmentsMember | domain-member | http://fasb.org/us-gaap/role/disclosure/InvestmentsSoldNotYetPurchasedInvestmentsSoldNotYetPurchasedTable |
 | us-gaap:FixedIncomeInvestmentsMember | parent-child | http://fasb.org/us-gaap/role/disclosure/SummaryOfInvestmentHoldings |
 | us-gaap:FixedIncomeInvestmentsMember | domain-member | http://fasb.org/us-gaap/role/disclosure/SummaryOfInvestmentHoldings |
 | us-gaap:FixedIncomeInvestmentsMember | parent-child | http://fasb.org/us-gaap/role/disclosure/OtherThanSecuritiesInvestmentHoldings |
 | us-gaap:FixedIncomeInvestmentsMember | domain-member | http://fasb.org/us-gaap/role/disclosure/OtherThanSecuritiesInvestmentHoldingsInvestmentHoldingsOtherThanSecuritiesTable |
 | us-gaap:FixedIncomeInvestmentsMember | parent-child | http://fasb.org/us-gaap/role/disclosure/InvestmentsFederalTaxNote |
 | us-gaap:FixedIncomeInvestmentsMember | domain-member | http://fasb.org/us-gaap/role/disclosure/InvestmentsFederalTaxNoteFederalIncomeTaxNoteTable |
 | us-gaap:ExtinguishmentOfDebtTypeDomain | parent-child | http://fasb.org/us-gaap/role/disclosure/Debt |
 | us-gaap:LongtermDebtTypeDomain | parent-child | http://fasb.org/us-gaap/role/disclosure/Debt |
 | us-gaap:LongtermDebtTypeDomain | domain-member | http://fasb.org/us-gaap/role/disclosure/DebtDebtInstrumentRedemptionTable |
 | us-gaap:LongtermDebtTypeDomain | domain-member | http://fasb.org/us-gaap/role/disclosure/DebtDebtInstrumentTable |
 | us-gaap:LongtermDebtTypeDomain | domain-member | http://fasb.org/us-gaap/role/disclosure/DebtObligationWithJointAndSeveralLiabilityArrangementTable |
 | us-gaap:ExtinguishmentOfDebtTypeDomain | domain-member | http://fasb.org/us-gaap/role/disclosure/DebtScheduleOfExtinguishmentOfDebtTable |
 | us-gaap:AllOtherCorporateBondsMember | parent-child | http://fasb.org/us-gaap/role/disclosure/SECScheduleArticle12-15SummaryOfInvestments-OtherThanInvestmentsInRelatedParties |
 | us-gaap:AllOtherCorporateBondsMember | domain-member | http://fasb.org/us-gaap/role/disclosure/SECScheduleArticle12-15SummaryOfInvestments-OtherThanInvestmentsInRelatedPartiesSummaryOfInvestmentsOtherThanInvestmentsInRelatedPartiesTable |
 | us-gaap:FixedIncomeInvestmentsMember | parent-child | http://fasb.org/us-gaap/role/disclosure/FinancialServicesInvestmentCompany |
 | us-gaap:FixedIncomeInvestmentsMember | domain-member | http://fasb.org/us-gaap/role/disclosure/FinancialServicesInvestmentCompanyInvestmentHoldingsTable |