Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Statement of Comprehensive Income [Abstract]
Investments with no other-than-temporary impairment, tax provision (benefit)	$ 17	$ 4	$ (36)	$ 74
Investments with other-than-temporary impairment, tax provision (benefit)	(9)	1	(12)	(4)
Reclassification adjustment for gains (losses) included in net income (loss), tax provision (benefit)	$ (6)	$ (5)	$ (4)	$ (9)