Consolidated Statements of Comprehensive Income (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 355	$ 384	$ 556	$ 459
Unrealized holding gains (losses) arising during the period on:
Investments with no other-than-temporary impairment, net of tax provision (benefit) of $4, $(1), $74 and $(99)	(5)	(11)	164	(280)
Investments with other-than-temporary impairment, net of tax provision (benefit) of $1, $(2), $(4) and $(17)	1	(2)	(8)	(34)
Unrealized holding gains (losses) arising during the period, net of tax	(4)	(13)	156	(314)
Less: reclassification adjustment for gains (losses) included in net income (loss), net of tax provision (benefit) of $(5), $(2), $(9) and $(4)	(10)	(3)	(19)	(4)
Change in net unrealized gains on investments	6	(10)	175	(310)
Other, net of tax provision	(5)	7	(2)	1
Other comprehensive income (loss)	1	(3)	173	(309)
Comprehensive income (loss)	$ 356	$ 381	$ 729	$ 150