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	$ (49)	$ (70)	$ (88)	$ (184)
Change in intent write-downs	(1)	(16)	(45)	(85)
Net other-than-temporary impairment losses recognized in earnings	(50)	(86)	(133)	(269)
Sales	70	141	299	424
Valuation of derivative instruments	(10)	(50)	1	(28)
Settlements of derivative instruments	17	(3)	28	(92)
EMA limited partnership income		55		118
Total realized capital gains and losses	27	57	195	153
Fixed income securities
Investments
Net other-than-temporary impairment losses recognized in earnings	(27)	(64)	(91)	(219)
Total realized capital gains and losses	6	39	(23)	12
Schedule of Available for Sale Securities
Gross gains on sales of fixed income securities	72	177	187	388
Gross loss on sales of fixed income securities	$ 47	$ 98	$ 137	$ 186