Derivatives (Embedded Derivatives) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Embedded Derivative, Fair Value of Embedded Derivative Asset	$ 507	$ (168)
Ceded Guaranteed Minimum Benefit [Member] | Premiums, reinsurance and other receivables
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Embedded Derivative, Fair Value of Embedded Derivative Asset	657	(62)
Direct Guaranteed Minimum Benefit [Member] | Policyholder account balances [Member]
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Embedded Derivative, Fair Value of Embedded Derivative Liability	(548)	(868)
Assumed Guaranteed Minimum Benefit [Member] | Policyholder account balances [Member]
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Embedded Derivative, Fair Value of Embedded Derivative Liability	72	0
Assumed Guaranteed Minimum Benefit [Member] | Other liabilities
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Embedded Derivative, Fair Value of Embedded Derivative Liability	1,200	758
Funds withheld on ceded reinsurance [Member] | Policyholder account balances [Member]
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Embedded Derivative, Fair Value of Embedded Derivative Liability	7	4
Other [Member] | Policyholder account balances [Member]
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Embedded Derivative, Fair Value of Embedded Derivative Liability	731	(106)
Options embedded in debt or equity securities [Member] | Investments
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Embedded Derivative, Fair Value of Embedded Derivative Asset	$ (150)	$ (106)