 | us-gaap:InvestmentIncomeNetAbstract | parent-child | http://fasb.org/us-gaap/role/statement/StatementOfIncomeAlternative |
 | us-gaap:InvestmentIncomeNetAbstract | domain-member | http://fasb.org/us-gaap/role/statement/StatementOfIncomeAlternativeStatementTable |
 | us-gaap:InvestmentIncomeNetAbstract | parent-child | http://fasb.org/us-gaap/role/statement/StatementOfIncomeRealEstateExcludingREITs |
 | us-gaap:InvestmentIncomeNetAbstract | domain-member | http://fasb.org/us-gaap/role/statement/StatementOfIncomeRealEstateExcludingREITsStatementTable |
 | us-gaap:InvestmentIncomeNetAbstract | parent-child | http://fasb.org/us-gaap/role/statement/StatementOfIncomeRealEstateInvestmentTrusts |
 | us-gaap:InvestmentIncomeNetAbstract | domain-member | http://fasb.org/us-gaap/role/statement/StatementOfIncomeRealEstateInvestmentTrustsStatementTable |
 | us-gaap:InvestmentIncomeNetAbstract | parent-child | http://fasb.org/us-gaap/role/statement/StatementOfIncome |
 | us-gaap:InvestmentIncomeNet | summation-item | http://fasb.org/us-gaap/role/statement/StatementOfIncome |
 | us-gaap:InvestmentIncomeNetAbstract | domain-member | http://fasb.org/us-gaap/role/statement/StatementOfIncomeStatementTable |
 | us-gaap:NetInvestmentIncomeAbstract | parent-child | http://fasb.org/us-gaap/role/statement/StatementOfIncomeInsuranceBasedRevenue |
 | us-gaap:NetInvestmentIncomeAbstract | domain-member | http://fasb.org/us-gaap/role/statement/StatementOfIncomeInsuranceBasedRevenueStatementTable |
 | us-gaap:InvestmentIncomeNetAbstract | parent-child | http://fasb.org/us-gaap/role/disclosure/InvestmentsDebtAndEquitySecurities |
 | us-gaap:InvestmentIncomeNetAbstract | domain-member | http://fasb.org/us-gaap/role/disclosure/InvestmentsDebtAndEquitySecuritiesScheduleOfInvestmentIncomeReportedAmountsByCategoryTable |
 | us-gaap:ScheduleOfInvestmentIncomeReportedAmountsByCategoryLineItems | parent-child | http://fasb.org/us-gaap/role/disclosure/FinancialServicesInsurance |
 | us-gaap:ScheduleOfInvestmentIncomeReportedAmountsByCategoryLineItems | domain-member | http://fasb.org/us-gaap/role/disclosure/FinancialServicesInsuranceScheduleOfInvestmentIncomeReportedAmountsByCategoryTable |