 | us-gaap:DebtAndEquitySecuritiesUnrealizedGainLoss | summation-item | http://fasb.org/us-gaap/role/statement/StatementOfCashFlowsIndirect |
 | us-gaap:EquitySecuritiesFvNiGainLoss | summation-item | http://fasb.org/us-gaap/role/disclosure/InvestmentsDebtAndEquitySecuritiesCalcAlt1 |
 | us-gaap:DebtAndEquitySecuritiesUnrealizedGainLossAbstract | parent-child | http://fasb.org/us-gaap/role/disclosure/InvestmentsDebtAndEquitySecurities |
 | us-gaap:DebtAndEquitySecuritiesUnrealizedGainLossExcludingOtherThanTemporaryImpairmentAbstract | parent-child | http://fasb.org/us-gaap/role/disclosure/InvestmentsDebtAndEquitySecurities |
 | us-gaap:EquitySecuritiesFvNiGainLossAlternativeAbstract | parent-child | http://fasb.org/us-gaap/role/disclosure/InvestmentsDebtAndEquitySecurities |
 | us-gaap:EquitySecuritiesFvNiUnrealizedGainLossAbstract | parent-child | http://fasb.org/us-gaap/role/disclosure/InvestmentsDebtAndEquitySecurities |
 | us-gaap:DebtAndEquitySecuritiesUnrealizedGainLossExcludingOtherThanTemporaryImpairment | summation-item | http://fasb.org/us-gaap/role/disclosure/InvestmentsDebtAndEquitySecurities |
 | us-gaap:DebtAndEquitySecuritiesUnrealizedGainLossExcludingOtherThanTemporaryImpairmentAbstract | domain-member | http://fasb.org/us-gaap/role/disclosure/InvestmentsDebtAndEquitySecuritiesScheduleOfGainLossOnInvestmentsTable |
 | us-gaap:EquitySecuritiesFvNiUnrealizedGainLossAbstract | domain-member | http://fasb.org/us-gaap/role/disclosure/InvestmentsDebtAndEquitySecuritiesScheduleOfTradingSecuritiesAndOtherTradingAssetsTable |