Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Pre- tax
Unrealized net holding gains and losses arising during the period, net of related offsets	$ (286)	$ 58	$ (726)	$ 525
Less: reclassification adjustment of realized capital gains and losses	178	21	346	(7)
Unrealized net capital gains and losses	(464)	37	(1,072)	532
Unrealized foreign currency translation adjustments	5	0	(6)	2
Other comprehensive (loss) income	(459)	37	(1,078)	534
Tax
Unrealized net holding gains and losses arising during the period, net of related offsets	224	(20)	496	(185)
Less: reclassification adjustment of realized capital gains and losses	62	(7)	121	2
Unrealized net capital gains and losses	162	(13)	375	(187)
Unrealized foreign currency translation adjustments	(2)	0	2	(1)
Other comprehensive (loss) income	160	(13)	377	(188)
After- tax
Unrealized net holding gains and losses arising during the period, net of related offsets	(62)	38	(230)	340
Less: reclassification adjustment of realized capital gains and losses	240	14	467	(5)
Unrealized net capital gains and losses	(302)	24	(697)	345
Unrealized foreign currency translation adjustments	3	0	(4)	1
Other comprehensive (loss) income, after-tax	$ (299)	$ 24	$ (701)	$ 346