Investments (Details 23) (USD $) In Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Entity Sector Industry Classifications [Abstract]
Fixed maturity securities other than temporary impairment losses recognized in earnings, net	$ 284	$ 119	$ 530	$ 357
Fixed maturity securities [Member]
Entity Sector Industry Classifications [Abstract]
Fixed maturity securities other than temporary impairment losses recognized in earnings, net	284	119	530	357
Communications Domestic Corporate Debt Securities [Member]
Entity Sector Industry Classifications [Abstract]
Fixed maturity securities other than temporary impairment losses recognized in earnings, net	12	9	26	12
Consumer Domestic Corporate Debt Securities [Member]
Entity Sector Industry Classifications [Abstract]
Fixed maturity securities other than temporary impairment losses recognized in earnings, net	6	8	35	31
Utility Domestic Corporate Debt Securities [Member]
Entity Sector Industry Classifications [Abstract]
Fixed maturity securities other than temporary impairment losses recognized in earnings, net	6	0	7	3
Finance Domestic Corporate Debt Securities [Member]
Entity Sector Industry Classifications [Abstract]
Fixed maturity securities other than temporary impairment losses recognized in earnings, net	7	54	48	82
Corporate fixed maturity securities [Member]
Entity Sector Industry Classifications [Abstract]
Fixed maturity securities other than temporary impairment losses recognized in earnings, net	31	71	116	128
Foreign government debt securities [Member]
Entity Sector Industry Classifications [Abstract]
Fixed maturity securities other than temporary impairment losses recognized in earnings, net	206	0	295	0
RMBS [Member]
Entity Sector Industry Classifications [Abstract]
Fixed maturity securities other than temporary impairment losses recognized in earnings, net	34	19	88	76
ABS [Member]
Entity Sector Industry Classifications [Abstract]
Fixed maturity securities other than temporary impairment losses recognized in earnings, net	8	26	23	89
CMBS [Member]
Entity Sector Industry Classifications [Abstract]
Fixed maturity securities other than temporary impairment losses recognized in earnings, net	$ 5	$ 3	$ 8	$ 64