Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 297	$ 159	$ 498	$ 201
Unrealized holding gains (losses) arising during the period on:
Investments with no other-than-temporary impairment, net of tax provision (benefit) of $(54), $29, $(53) and $70	(136)	75	(118)	169
Investments with other-than-temporary impairment, net of tax provision (benefit) of $(1), $(8), $(3) and $(5)	(6)	(17)	(8)	(9)
Unrealized holding gains (losses) arising during the period, net of tax	(142)	58	(126)	160
Less: reclassification adjustment for gains (losses) included in net income (loss), net of tax provision (benefit) of $(4), $(3), $2 and $(4)	(5)	(7)	5	(9)
Change in net unrealized gains on investments	(137)	65	(131)	169
Other, net of tax provision	6	3	0	3
Other comprehensive income (loss)	(131)	68	(131)	172
Comprehensive income (loss)	$ 166	$ 227	$ 367	$ 373