Investments (Details 5) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Investments
Impairment write-downs	$ (10)	$ (12)	$ (28)	$ (38)
Change in intent write-downs	(7)	(1)	(15)	(17)
Net other-than-temporary impairment losses recognized in earnings	(17)	(13)	(43)	(55)
Sales	6	(52)	90	(52)
Valuation of derivative instruments	(5)	(3)	(3)	(6)
Settlements of derivative instruments		11	17	41
Total realized capital gains and losses	(16)	(57)	61	(72)
Fixed income securities
Investments
Net other-than-temporary impairment losses recognized in earnings	(5)	(9)	(41)	(55)
Total realized capital gains and losses	(12)	(60)	(6)	(116)
Schedule of Available for Sale Securities
Gross gains on sales of fixed income securities	9	51	75	128
Gross losses on sales of fixed income securities	$ 16	$ 112	$ 40	$ 209