Income Taxes (Components of Income Taxes) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Federal:
Current	$ 2	$ 9	$ 0
Deferred	(361)	(59)	(127)
State:
Current	1	1	1
Deferred	(4)	(5)	1
Foreign:
Current	326	505	432
Deferred	(152)	21	64
Total	$ (188)	$ 472	$ 371