Investments (Details 5) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Investments
Impairment write-downs	$ (6)	$ (42)	$ (26)	$ (89)
Change in intent write-downs		(5)	(16)	(47)
Net other-than-temporary impairment losses recognized in earnings	(6)	(47)	(42)	(136)
Sales	9	112		224
Valuation of derivative instruments	(11)	(29)	(3)	(31)
Settlements of derivative instruments	15	4	30	10
EMA limited partnership income		32		50
Total realized capital gains and losses	7	72	(15)	117
Fixed income securities
Investments
Net other-than-temporary impairment losses recognized in earnings	(12)	(38)	(46)	(119)
Total realized capital gains and losses	(6)	48	(56)	65
Schedule of Available for Sale Securities
Gross gains on sales of fixed income securities	32	131	77	257
Gross losses on sales of fixed income securities	$ 31	$ 69	$ 97	$ 100