XML 137 R110.htm IDEA: XBRL DOCUMENT v2.4.1.9
Investments and Cash - Fixed Maturity Securities and Short Term Investments (Details) (USD $)
In Millions, unless otherwise specified
Dec. 31, 2014
Dec. 31, 2013
Investments    
Percent of Total 100.00%ago_PercentageofAvailableforsaleSecuritiesatAmortizedCost [1] 100.00%ago_PercentageofAvailableforsaleSecuritiesatAmortizedCost [1]
Amortized Cost $ 10,739us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis $ 10,392us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis
Gross Unrealized Gains 552us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax 370us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
Gross Unrealized Losses (33)us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax (147)us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
Fixed-maturity securities 11,258us-gaap_AvailableForSaleSecuritiesDebtSecurities 10,615us-gaap_AvailableForSaleSecuritiesDebtSecurities
AOCI(2) Gain (Loss) on Securities with Other-Than-Temporary Impairment 8us-gaap_AccumulatedOtherComprehensiveIncomeLossOtherThanTemporaryImpairmentNotCreditLossNetOfTaxDebtSecurities [2] (37)us-gaap_AccumulatedOtherComprehensiveIncomeLossOtherThanTemporaryImpairmentNotCreditLossNetOfTaxDebtSecurities [2]
Fixed Maturities [Member]    
Investments    
Percent of Total 93.00%ago_PercentageofAvailableforsaleSecuritiesatAmortizedCost
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember		 [1] 91.00%ago_PercentageofAvailableforsaleSecuritiesatAmortizedCost
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember		 [1]
Amortized Cost 9,972us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember		 9,488us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
Gross Unrealized Gains 552us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember		 370us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
Gross Unrealized Losses (33)us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember		 (147)us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
Fixed-maturity securities 10,491us-gaap_AvailableForSaleSecuritiesDebtSecurities
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember		 9,711us-gaap_AvailableForSaleSecuritiesDebtSecurities
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
AOCI(2) Gain (Loss) on Securities with Other-Than-Temporary Impairment 8us-gaap_AccumulatedOtherComprehensiveIncomeLossOtherThanTemporaryImpairmentNotCreditLossNetOfTaxDebtSecurities
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember		 [2] (37)us-gaap_AccumulatedOtherComprehensiveIncomeLossOtherThanTemporaryImpairmentNotCreditLossNetOfTaxDebtSecurities
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember		 [2]
Short-term Investments [Member]    
Investments    
Percent of Total 7.00%ago_PercentageofAvailableforsaleSecuritiesatAmortizedCost
/ us-gaap_InvestmentTypeAxis
= us-gaap_ShortTermInvestmentsMember		 [1] 9.00%ago_PercentageofAvailableforsaleSecuritiesatAmortizedCost
/ us-gaap_InvestmentTypeAxis
= us-gaap_ShortTermInvestmentsMember		 [1]
Amortized Cost 767us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis
/ us-gaap_InvestmentTypeAxis
= us-gaap_ShortTermInvestmentsMember		 904us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis
/ us-gaap_InvestmentTypeAxis
= us-gaap_ShortTermInvestmentsMember
Gross Unrealized Gains 0us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_ShortTermInvestmentsMember		 0us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_ShortTermInvestmentsMember
Gross Unrealized Losses 0us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_ShortTermInvestmentsMember		 0us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_ShortTermInvestmentsMember
Fixed-maturity securities 767us-gaap_AvailableForSaleSecuritiesDebtSecurities
/ us-gaap_InvestmentTypeAxis
= us-gaap_ShortTermInvestmentsMember		 904us-gaap_AvailableForSaleSecuritiesDebtSecurities
/ us-gaap_InvestmentTypeAxis
= us-gaap_ShortTermInvestmentsMember
AOCI(2) Gain (Loss) on Securities with Other-Than-Temporary Impairment 0us-gaap_AccumulatedOtherComprehensiveIncomeLossOtherThanTemporaryImpairmentNotCreditLossNetOfTaxDebtSecurities
/ us-gaap_InvestmentTypeAxis
= us-gaap_ShortTermInvestmentsMember		 [2] 0us-gaap_AccumulatedOtherComprehensiveIncomeLossOtherThanTemporaryImpairmentNotCreditLossNetOfTaxDebtSecurities
/ us-gaap_InvestmentTypeAxis
= us-gaap_ShortTermInvestmentsMember		 [2]
Obligations of state and political subdivisions [Member]    
Investments    
Amortized Cost 4,619us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USStatesAndPoliticalSubdivisionsMember		 [3] 4,411us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USStatesAndPoliticalSubdivisionsMember		 [3]
Fixed-maturity securities 4,949us-gaap_AvailableForSaleSecuritiesDebtSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USStatesAndPoliticalSubdivisionsMember		 [3] 4,554us-gaap_AvailableForSaleSecuritiesDebtSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USStatesAndPoliticalSubdivisionsMember		 [3]
Obligations of state and political subdivisions [Member] | Fixed Maturities [Member]    
Investments    
Percent of Total 50.00%ago_PercentageofAvailableforsaleSecuritiesatAmortizedCost
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USStatesAndPoliticalSubdivisionsMember		 [1] 47.00%ago_PercentageofAvailableforsaleSecuritiesatAmortizedCost
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USStatesAndPoliticalSubdivisionsMember		 [1]
Amortized Cost 5,416us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USStatesAndPoliticalSubdivisionsMember		 4,899us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USStatesAndPoliticalSubdivisionsMember
Gross Unrealized Gains 380us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USStatesAndPoliticalSubdivisionsMember		 219us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USStatesAndPoliticalSubdivisionsMember
Gross Unrealized Losses (1)us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USStatesAndPoliticalSubdivisionsMember		 (39)us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USStatesAndPoliticalSubdivisionsMember
Fixed-maturity securities 5,795us-gaap_AvailableForSaleSecuritiesDebtSecurities
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USStatesAndPoliticalSubdivisionsMember		 5,079us-gaap_AvailableForSaleSecuritiesDebtSecurities
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USStatesAndPoliticalSubdivisionsMember
AOCI(2) Gain (Loss) on Securities with Other-Than-Temporary Impairment 7us-gaap_AccumulatedOtherComprehensiveIncomeLossOtherThanTemporaryImpairmentNotCreditLossNetOfTaxDebtSecurities
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USStatesAndPoliticalSubdivisionsMember		 [2] 4us-gaap_AccumulatedOtherComprehensiveIncomeLossOtherThanTemporaryImpairmentNotCreditLossNetOfTaxDebtSecurities
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USStatesAndPoliticalSubdivisionsMember		 [2]
US Treasury and Government [Member] | Fixed Maturities [Member]    
Investments    
Percent of Total 6.00%ago_PercentageofAvailableforsaleSecuritiesatAmortizedCost
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasuryAndGovernmentMember		 [1] 6.00%ago_PercentageofAvailableforsaleSecuritiesatAmortizedCost
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasuryAndGovernmentMember		 [1]
Amortized Cost 635us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasuryAndGovernmentMember		 674us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasuryAndGovernmentMember
Gross Unrealized Gains 31us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasuryAndGovernmentMember		 32us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasuryAndGovernmentMember
Gross Unrealized Losses (1)us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasuryAndGovernmentMember		 (6)us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasuryAndGovernmentMember
Fixed-maturity securities 665us-gaap_AvailableForSaleSecuritiesDebtSecurities
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasuryAndGovernmentMember		 700us-gaap_AvailableForSaleSecuritiesDebtSecurities
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasuryAndGovernmentMember
AOCI(2) Gain (Loss) on Securities with Other-Than-Temporary Impairment 0us-gaap_AccumulatedOtherComprehensiveIncomeLossOtherThanTemporaryImpairmentNotCreditLossNetOfTaxDebtSecurities
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasuryAndGovernmentMember		 [2] 0us-gaap_AccumulatedOtherComprehensiveIncomeLossOtherThanTemporaryImpairmentNotCreditLossNetOfTaxDebtSecurities
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasuryAndGovernmentMember		 [2]
Corporate securities [Member] | Fixed Maturities [Member]    
Investments    
Percent of Total 12.00%ago_PercentageofAvailableforsaleSecuritiesatAmortizedCost
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember		 [1] 13.00%ago_PercentageofAvailableforsaleSecuritiesatAmortizedCost
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember		 [1]
Amortized Cost 1,320us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember		 1,314us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
Gross Unrealized Gains 53us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember		 44us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
Gross Unrealized Losses (5)us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember		 (18)us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
Fixed-maturity securities 1,368us-gaap_AvailableForSaleSecuritiesDebtSecurities
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember		 1,340us-gaap_AvailableForSaleSecuritiesDebtSecurities
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
AOCI(2) Gain (Loss) on Securities with Other-Than-Temporary Impairment (2)us-gaap_AccumulatedOtherComprehensiveIncomeLossOtherThanTemporaryImpairmentNotCreditLossNetOfTaxDebtSecurities
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember		 [2] 0us-gaap_AccumulatedOtherComprehensiveIncomeLossOtherThanTemporaryImpairmentNotCreditLossNetOfTaxDebtSecurities
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember		 [2]
RMBS [Member] | Fixed Maturities [Member]    
Investments    
Percent of Total 12.00%ago_PercentageofAvailableforsaleSecuritiesatAmortizedCost
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_ResidentialMortgageBackedSecuritiesMember		 [1],[4] 11.00%ago_PercentageofAvailableforsaleSecuritiesatAmortizedCost
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_ResidentialMortgageBackedSecuritiesMember		 [1],[4]
Amortized Cost 1,255us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_ResidentialMortgageBackedSecuritiesMember		 [4] 1,160us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_ResidentialMortgageBackedSecuritiesMember		 [4]
Gross Unrealized Gains 51us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_ResidentialMortgageBackedSecuritiesMember		 [4] 34us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_ResidentialMortgageBackedSecuritiesMember		 [4]
Gross Unrealized Losses (21)us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_ResidentialMortgageBackedSecuritiesMember		 [4] (72)us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_ResidentialMortgageBackedSecuritiesMember		 [4]
Fixed-maturity securities 1,285us-gaap_AvailableForSaleSecuritiesDebtSecurities
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_ResidentialMortgageBackedSecuritiesMember		 [4] 1,122us-gaap_AvailableForSaleSecuritiesDebtSecurities
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_ResidentialMortgageBackedSecuritiesMember		 [4]
AOCI(2) Gain (Loss) on Securities with Other-Than-Temporary Impairment 0us-gaap_AccumulatedOtherComprehensiveIncomeLossOtherThanTemporaryImpairmentNotCreditLossNetOfTaxDebtSecurities
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_ResidentialMortgageBackedSecuritiesMember		 [2],[4] (43)us-gaap_AccumulatedOtherComprehensiveIncomeLossOtherThanTemporaryImpairmentNotCreditLossNetOfTaxDebtSecurities
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_ResidentialMortgageBackedSecuritiesMember		 [2],[4]
CMBS [Member] | Fixed Maturities [Member]    
Investments    
Percent of Total 6.00%ago_PercentageofAvailableforsaleSecuritiesatAmortizedCost
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CommercialMortgageBackedSecuritiesMember		 [1],[4] 5.00%ago_PercentageofAvailableforsaleSecuritiesatAmortizedCost
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CommercialMortgageBackedSecuritiesMember		 [1],[4]
Amortized Cost 639us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CommercialMortgageBackedSecuritiesMember		 [4] 536us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CommercialMortgageBackedSecuritiesMember		 [4]
Gross Unrealized Gains 20us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CommercialMortgageBackedSecuritiesMember		 [4] 17us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CommercialMortgageBackedSecuritiesMember		 [4]
Gross Unrealized Losses 0us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CommercialMortgageBackedSecuritiesMember		 [4] (4)us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CommercialMortgageBackedSecuritiesMember		 [4]
Fixed-maturity securities 659us-gaap_AvailableForSaleSecuritiesDebtSecurities
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CommercialMortgageBackedSecuritiesMember		 [4] 549us-gaap_AvailableForSaleSecuritiesDebtSecurities
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CommercialMortgageBackedSecuritiesMember		 [4]
AOCI(2) Gain (Loss) on Securities with Other-Than-Temporary Impairment 0us-gaap_AccumulatedOtherComprehensiveIncomeLossOtherThanTemporaryImpairmentNotCreditLossNetOfTaxDebtSecurities
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CommercialMortgageBackedSecuritiesMember		 [2],[4] 0us-gaap_AccumulatedOtherComprehensiveIncomeLossOtherThanTemporaryImpairmentNotCreditLossNetOfTaxDebtSecurities
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CommercialMortgageBackedSecuritiesMember		 [2],[4]
Asset-backed Securities [Member] | Fixed Maturities [Member]    
Investments    
Percent of Total 4.00%ago_PercentageofAvailableforsaleSecuritiesatAmortizedCost
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_AssetBackedSecuritiesMember		 [1] 6.00%ago_PercentageofAvailableforsaleSecuritiesatAmortizedCost
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_AssetBackedSecuritiesMember		 [1]
Amortized Cost 411us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_AssetBackedSecuritiesMember		 605us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_AssetBackedSecuritiesMember
Gross Unrealized Gains 9us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
/ us-gaap_InvestmentTypeAxis
= us-gaap_FixedMaturitiesMember
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
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AOCI(2) Gain (Loss) on Securities with Other-Than-Temporary Impairment 3us-gaap_AccumulatedOtherComprehensiveIncomeLossOtherThanTemporaryImpairmentNotCreditLossNetOfTaxDebtSecurities
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Foreign government securities [Member] | Fixed Maturities [Member]    
Investments    
Percent of Total 3.00%ago_PercentageofAvailableforsaleSecuritiesatAmortizedCost
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Fixed-maturity securities 302us-gaap_AvailableForSaleSecuritiesDebtSecurities
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AOCI(2) Gain (Loss) on Securities with Other-Than-Temporary Impairment $ 0us-gaap_AccumulatedOtherComprehensiveIncomeLossOtherThanTemporaryImpairmentNotCreditLossNetOfTaxDebtSecurities
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[1] Based on amortized cost.
[2] Accumulated OCI. See also Note 21, Other Comprehensive Income.
[3] Excludes $846 million and $525 million as of December 31, 2014 and 2013, respectively, of pre-refunded bonds, at fair value. The credit ratings are based on the underlying ratings and do not include any benefit from bond insurance.
[4] Government-agency obligations were approximately 44% of mortgage backed securities as of December 31, 2014 and 50% as of December 31, 2013 based on fair value.