Consolidated Statements of Comprehensive Income (unaudited) (Parenthetical) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Statement of Comprehensive Income [Abstract]
Investments with no other-than-temporary impairment, tax provision (benefit)	$ 31	$ (54)	$ 62	$ (53)
Investments with other-than-temporary impairment, tax provision (benefit)	(3)	(1)	(13)	(3)
Reclassification adjustment for gains (losses) included in net income (loss), tax provision (benefit)	$ 4	$ (4)	$ 0	$ 2