 | us-gaap:GainLossOnInvestmentsExcludingOtherThanTemporaryImpairmentsAbstract | parent-child | http://fasb.org/us-gaap/role/disclosure/InvestmentsDebtAndEquitySecurities |
 | us-gaap:OtherThanTemporaryImpairmentLossesInvestmentsAbstract | parent-child | http://fasb.org/us-gaap/role/disclosure/InvestmentsDebtAndEquitySecurities |
 | us-gaap:MarketableSecuritiesGainLossAbstract | parent-child | http://fasb.org/us-gaap/role/disclosure/InvestmentsDebtAndEquitySecurities |
 | us-gaap:DebtAndEquitySecuritiesGainLossAbstract | parent-child | http://fasb.org/us-gaap/role/disclosure/InvestmentsDebtAndEquitySecurities |
 | us-gaap:DebtAndEquitySecuritiesGainLossAlternativeAbstract | parent-child | http://fasb.org/us-gaap/role/disclosure/InvestmentsDebtAndEquitySecurities |
 | us-gaap:ScheduleOfGainLossOnInvestmentsTable | all | http://fasb.org/us-gaap/role/disclosure/InvestmentsDebtAndEquitySecuritiesScheduleOfGainLossOnInvestmentsTable |
 | us-gaap:GainLossOnInvestmentsExcludingOtherThanTemporaryImpairmentsAbstract | domain-member | http://fasb.org/us-gaap/role/disclosure/InvestmentsDebtAndEquitySecuritiesScheduleOfGainLossOnInvestmentsTable |
 | us-gaap:OtherThanTemporaryImpairmentLossesInvestmentsAbstract | domain-member | http://fasb.org/us-gaap/role/disclosure/InvestmentsDebtAndEquitySecuritiesScheduleOfGainLossOnInvestmentsTable |
 | us-gaap:MarketableSecuritiesGainLossAbstract | domain-member | http://fasb.org/us-gaap/role/disclosure/InvestmentsDebtAndEquitySecuritiesScheduleOfGainLossOnInvestmentsTable |
 | us-gaap:DebtAndEquitySecuritiesGainLossAbstract | domain-member | http://fasb.org/us-gaap/role/disclosure/InvestmentsDebtAndEquitySecuritiesScheduleOfGainLossOnInvestmentsTable |
 | us-gaap:DebtAndEquitySecuritiesGainLossAlternativeAbstract | domain-member | http://fasb.org/us-gaap/role/disclosure/InvestmentsDebtAndEquitySecuritiesScheduleOfGainLossOnInvestmentsTable |