Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement of Comprehensive Income [Abstract]
Net Income (Loss)	$ 343	$ 178	$ 618	$ 549
Other Comprehensive Income (Loss), Net of Tax, Changes In:
Net unrealized gains (losses) on investments with other-than-temporary impairments	3	2	7	(3)
Net unrealized gains (losses) on other investments	42	(36)	586	(289)
Net unrealized gains (losses) on investments	45	(34)	593	(292)
Foreign currency translation adjustment	(24)	(53)	(58)	(100)
Pension and postretirement benefits	6	4	17	52
Other comprehensive income (loss), net of tax	27	(83)	552	(340)
Total comprehensive income (loss)	$ 370	$ 95	$ 1,170	$ 209