Investments (Details 25) (USD $) In Millions	3 Months Ended	9 Months Ended
Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Balance, beginning of period	$ 401	$ 491	$ 443	$ 581
Additions:
Initial impairments - credit loss OTTI recognized on securities not previously impaired	6	13	32	94
Additional impairments - credit loss OTTI recognized on securities previously impaired	39	34	79	104
Reductions:
Due to sales (maturities, pay downs or prepayments) during the period of securities previously credit loss OTTI impaired	(8)	(97)	(63)	(231)
Due to securities de-recognized in connection with the adoption of new guidance related to the consolidation of VIEs	0	0	0	(100)
Due to securities impaired to net present value of expected future cash flows	(1)	0	(45)	0
Due to increases in cash flows- accretion of previous credit loss OTTI	0	(2)	(9)	(9)
Balance, end of period	$ 437	$ 439	$ 437	$ 439

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Reductions due to securities de-recognized in connection with the adoption of new guidance related to the consolidation of VIEs.

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