Other Comprehensive Income (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Pre-tax
Unrealized net holding gains and losses arising during the period, net of related offsets	$ (76)	$ 581	$ (860)	$ 1,116
Less: reclassification adjustment of realized capital gains and losses	(6)	(63)	35	(126)
Unrealized net capital gains and losses	(70)	644	(895)	1,242
Unrealized foreign currency translation adjustments		(5)		(2)
Other comprehensive (loss) income	(70)	639	(895)	1,240
Tax
Unrealized net holding gains and losses arising during the period, net of related offsets	27	(203)	302	(391)
Less: reclassification adjustment of realized capital gains and losses	2	22	(12)	44
Unrealized net capital gains and losses	25	(225)	314	(435)
Unrealized foreign currency translation adjustments		2		1
Other comprehensive (loss) income	25	(223)	314	(434)
After-tax
Unrealized net holding gains and losses arising during the period, net of related offsets	(49)	378	(558)	725
Less: reclassification adjustment of realized capital gains and losses	(4)	(41)	23	(82)
Unrealized net capital gains and losses	(45)	419	(581)	807
Unrealized foreign currency translation adjustments		(3)		(1)
Other comprehensive (loss) income, after-tax	(45)	416	(581)	806
Net (loss) income	(394)	103	(135)	284
Comprehensive (loss) income	$ (439)	$ 519	$ (716)	$ 1,090