Invested Assets (Details 4) (USD $) In Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Change in unrealized appreciation or depreciation of investments carried at fair value [Abstract]
Change in unrealized appreciation of fixed maturities	$ 478	$ 589	$ 731	$ 1,031
Change in unrealized appreciation of equity securities	(276)	118	(170)	(67)
Change in unrealized appreciation of fixed maturities and equity securities	202	707	561	964
Deferred income tax	70	247	196	337
Total change in unrealized appreciation of fixed maturities and equity securities, Net of tax	$ 132	$ 460	$ 365	$ 627