Derivatives (Embedded Derivatives) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Net embedded derivatives within asset host contracts	$ 104	$ 160
Net embedded derivatives within liability host contracts	137	(46)
Ceded guaranteed minimum benefits | Premiums, reinsurance and other receivables
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Net embedded derivatives within asset host contracts	351	324
Direct guaranteed minimum benefits | Policyholder account balances [Member]
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Net embedded derivatives within liability host contracts	(830)	(1,126)
Funds withheld on assumed reinsurance | Other invested assets
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Net embedded derivatives within asset host contracts	56	53
Assumed guaranteed minimum benefits | Policyholder account balances [Member]
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Net embedded derivatives within liability host contracts	868	973
Funds withheld on ceded reinsurance | Other liabilities
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Net embedded derivatives within liability host contracts	71	83
Other | Policyholder account balances [Member]
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Net embedded derivatives within liability host contracts	28	24
Options embedded in debt or equity securities [Member] | Investments
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Net embedded derivatives within asset host contracts	$ (303)	$ (217)