Investments (Pretax Fixed Maturity Credit Loss Component Reflected Within Retained Earnings) (Details) (USD $) In Millions	3 Months Ended	9 Months Ended
Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Investments [Abstract]
Beginning balance of credit losses on fixed maturity securities	$ 82	$ 171	$ 141	$ 164
Additional credit losses for which an OTTI loss was previously recognized	11	4	29	26
Credit losses for securities for which an OTTI loss was not previously recognized	10	1	11	9
Reductions for securities sold during the period	(4)	(27)	(50)	(50)
Reductions for securities the Company intends to sell or more likely than not will be required to sell		(8)	(32)	(8)
Ending balance of credit losses on fixed maturity securities	$ 99	$ 141	$ 99	$ 141

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This item represents an increase to the cumulative amount of credit losses recognized in earnings for an other than temporary impairment (OTTI) of a debt security held for which a previous OTTI was recognized and the investor does not intend to sell the debt security and it is not more likely than not that the investor will be required to sell the debt security before recovery of its amortized cost basis.

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This item represents an increase to the cumulative amount of credit losses recognized in earnings for an other than temporary impairment (OTTI) of a debt security held for which no such other than temporary impairment (OTTI) was previously recognized.

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The cumulative amount of credit losses recognized in earnings related to debt securities held for which a portion of an other than temporary impairment (OTTI) was recognized in other comprehensive income (a component of shareholders' equity).

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