Consolidated Statements of Comprehensive Income (unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 59	$ 201
Unrealized holding gains (losses) arising during the period on:
Investments with no other-than-temporary impairment, net of tax provision (benefit) of $31, and $1	95	18
Investments with other-than-temporary impairment, net of tax provision (benefit) of $(10) and $(2)	(17)	(2)
Unrealized holding gains (losses) arising during the period, net of tax	78	16
Less: reclassification adjustment for gains (losses) included in net income (loss), net of tax provision (benefit) of $(4) and $6	(6)	10
Change in net unrealized gains on investments	84	6
Other, net of tax provision	(2)	(6)
Other comprehensive income (loss)	82	0
Comprehensive income (loss)	$ 141	$ 201