Other Comprehensive Income (Details) (USD $) In Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Pre-tax
Unrealized net holding gains and losses arising during the period, net of related offsets, Pre-tax	$ (110)	$ 1,593	$ 838	$ 3,134
Less: reclassification adjustment of realized capital gains and losses, Pre-tax	527	140	688	(161)
Unrealized net capital gains and losses, Pre-tax	(637)	1,453	150	3,295
Unrealized foreign currency translation adjustments, Pre-tax	(53)	17	(31)	12
Unrecognized pension and other postretirement benefit cost, Pre-tax	32	26	79	83
Other comprehensive (loss) income, Pre-tax	(658)	1,496	198	3,390
Tax
Unrealized net holding gains and losses arising during the period, net of related offsets, Tax	39	(557)	(294)	(1,096)
Less: reclassification adjustment of realized capital gains and losses, Tax	(184)	(49)	(241)	56
Unrealized net capital gains and losses, Tax	223	(508)	(53)	(1,152)
Unrealized foreign currency translation adjustments, Tax	19	(6)	11	(4)
Unrecognized pension and other postretirement benefit cost, Tax	(11)	(9)	(26)	(28)
Other comprehensive (loss) income, Tax	231	(523)	(68)	(1,184)
After-tax
Unrealized net holding gains and losses arising during the period, net of related offsets, After-tax	(71)	1,036	544	2,038
Less: reclassification adjustment of realized capital gains and losses, After-tax	343	91	447	(105)
Unrealized net capital gains and losses, After-tax	(414)	945	97	2,143
Unrealized foreign currency translation adjustments, After-tax	(34)	11	(20)	8
Unrecognized pension and other postretirement benefit cost, After-tax	21	17	53	55
Other comprehensive (loss) income, After-tax	(427)	973	130	2,206
Net income	165	367	64	632
Comprehensive (loss) income	$ (262)	$ 1,340	$ 194	$ 2,838