Provision (Benefit) for Income Taxes Tax Provison (Benefit) Table (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Current :
Federal	$ 0	$ (9)	$ (17)
State	(7)	2	7
Foreign	(55)	10	(13)
Total	(62)	3	(23)
Deferred:
Federal	(317)	1,108	348
State	(25)	119	40
Foreign	5	19	36
Total	(337)	1,246	424
Provision (benefit) for income taxes	$ (399)	$ 1,249	$ 401