 | us-gaap:DebtAndEquitySecuritiesRealizedGainLoss | summation-item | http://fasb.org/us-gaap/role/statement/StatementOfIncome |
 | us-gaap:DebtAndEquitySecuritiesRealizedGainLossAbstract | parent-child | http://fasb.org/us-gaap/role/statement/StatementOfIncomeInterestBasedRevenue |
 | us-gaap:DebtAndEquitySecuritiesRealizedGainLossAbstract | domain-member | http://fasb.org/us-gaap/role/statement/StatementOfIncomeInterestBasedRevenueStatementTable |
 | us-gaap:EquitySecuritiesFvNiGainLoss | summation-item | http://fasb.org/us-gaap/role/disclosure/InvestmentsDebtAndEquitySecuritiesCalcAlt1 |
 | us-gaap:DebtAndEquitySecuritiesRealizedGainLossAbstract | parent-child | http://fasb.org/us-gaap/role/disclosure/InvestmentsDebtAndEquitySecurities |
 | us-gaap:DebtAndEquitySecuritiesRealizedGainLossExcludingOtherThanTemporaryImpairmentAbstract | 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:EquitySecuritiesFvNiRealizedGainLossAbstract | parent-child | http://fasb.org/us-gaap/role/disclosure/InvestmentsDebtAndEquitySecurities |
 | us-gaap:DebtAndEquitySecuritiesRealizedGainLossExcludingOtherThanTemporaryImpairment | summation-item | http://fasb.org/us-gaap/role/disclosure/InvestmentsDebtAndEquitySecurities |
 | us-gaap:DebtAndEquitySecuritiesRealizedGainLossExcludingOtherThanTemporaryImpairmentAbstract | domain-member | http://fasb.org/us-gaap/role/disclosure/InvestmentsDebtAndEquitySecuritiesScheduleOfGainLossOnInvestmentsTable |
 | us-gaap:EquitySecuritiesFvNiRealizedGainLossAbstract | domain-member | http://fasb.org/us-gaap/role/disclosure/InvestmentsDebtAndEquitySecuritiesScheduleOfTradingSecuritiesAndOtherTradingAssetsTable |