XML 1180 R122.htm IDEA: XBRL DOCUMENT v2.4.1.9
Investments (Concentrations of Credit Risk - Narrative) (Details) (USD $)
In Billions, unless otherwise specified
 12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]    
Securities holdings exposure in single issuer greater than stated percentage of Company's equity 10.00%us-gaap_ConcentrationRiskPercentage1  
Foreign government | Japan    
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]    
Government and agency fixed maturity securities 20.3us-gaap_FairValueConcentrationOfRiskInvestments
/ invest_InvestmentGeographicRegionAxis
= country_JP
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_ForeignGovernmentDebtSecuritiesMember		 $ 21.7us-gaap_FairValueConcentrationOfRiskInvestments
/ invest_InvestmentGeographicRegionAxis
= country_JP
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_ForeignGovernmentDebtSecuritiesMember
Fixed maturity and equity securities [Member] | Japan    
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]    
Government and agency fixed maturity securities 25.5us-gaap_FairValueConcentrationOfRiskInvestments
/ invest_InvestmentGeographicRegionAxis
= country_JP
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_SecuritiesAssetsMember		 $ 26.9us-gaap_FairValueConcentrationOfRiskInvestments
/ invest_InvestmentGeographicRegionAxis
= country_JP
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_SecuritiesAssetsMember