Derivative Financial Instruments (Details 12) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Embedded Derivative, Fair Value of Embedded Derivative Asset	$ 256	$ 293
Embedded Derivative, Fair Value of Embedded Derivative Liability	2,758	4,584
Ceded Guaranteed Minimum Benefit [Member]
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Embedded Derivative, Fair Value of Embedded Derivative Asset	296	327
Direct Guaranteed Minimum Benefit [Member]
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Embedded Derivative, Fair Value of Embedded Derivative Liability	559	2,104
Funds withheld on assumed reinsurance [Member]
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Embedded Derivative, Fair Value of Embedded Derivative Asset	33	35
Embedded Derivative, Fair Value of Embedded Derivative Liability	119	122
Assumed Guaranteed Minimum Benefit [Member]
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Embedded Derivative, Fair Value of Embedded Derivative Liability	2,064	2,340
Other [Member]
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Embedded Derivative, Fair Value of Embedded Derivative Asset	1	1
Embedded Derivative, Fair Value of Embedded Derivative Liability	16	18
Options embedded in debt or equity securities [Member]
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Embedded Derivative, Fair Value of Embedded Derivative Asset	$ (74)	$ (70)