Derivative Financial Instruments (Details 12) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Embedded Derivative, Fair Value of Embedded Derivative Asset	$ 309	$ 293
Embedded Derivative, Fair Value of Embedded Derivative Liability	4,391	4,584
Ceded Guaranteed Minimum Benefit [Member]
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Embedded Derivative, Fair Value of Embedded Derivative Asset	372	327
Direct Guaranteed Minimum Benefit [Member]
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Embedded Derivative, Fair Value of Embedded Derivative Liability	1,687	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	39	35
Embedded Derivative, Fair Value of Embedded Derivative Liability	126	122
Assumed Guaranteed Minimum Benefit [Member]
Embedded Derivative, Fair Value of Embedded Derivative, Net [Abstract]
Embedded Derivative, Fair Value of Embedded Derivative Liability	2,560	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	18	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	$ (103)	$ (70)