Other Comprehensive Income (Details) (USD $) In Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Pre-tax
Unrealized net holding gains and losses arising during the period, net of related offsets, Pre-tax	$ 676	$ 492	$ 1,044	$ 1,574
Less: reclassification adjustment of realized capital gains and losses, Pre-tax	111	(142)	257	(268)
Unrealized net capital gains and losses, Pre-tax	565	634	787	1,842
Unrealized foreign currency translation adjustments, Pre-tax	7	(27)	22	(5)
Unrecognized pension and other postretirement benefit cost, Pre-tax	24	31	47	57
Other comprehensive income, Pre-tax	596	638	856	1,894
Tax
Unrealized net holding gains and losses arising during the period, net of related offsets, Tax	(237)	(172)	(366)	(550)
Less: reclassification adjustment of realized capital gains and losses, Tax	(39)	50	(90)	94
Unrealized net capital gains and losses, Tax	(198)	(222)	(276)	(644)
Unrealized foreign currency translation adjustments, Tax	(3)	10	(8)	2
Unrecognized pension and other postretirement benefit cost, Tax	(7)	(10)	(15)	(19)
Other comprehensive income, Tax	(208)	(222)	(299)	(661)
After-tax
Unrealized net holding gains and losses arising during the period, net of related offsets, After-tax	439	320	678	1,024
Less: reclassification adjustment of realized capital gains and losses, After-tax	72	(92)	167	(174)
Unrealized net capital gains and losses, After-tax	367	412	511	1,198
Unrealized foreign currency translation adjustments, After-tax	4	(17)	14	(3)
Unrecognized pension and other postretirement benefit cost, After-tax	17	21	32	38
Other comprehensive income, After-tax	388	416	557	1,233
Net (loss) income	(620)	145	(101)	265
Comprehensive (loss) income	$ (232)	$ 561	$ 456	$ 1,498