Income Taxes - Components of United States and Foreign Tax (Benefit) Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Current Federal	$ 0	$ 0	$ (6)
Current Foreign	154	135	176
Current State	(1)	1	2
Current income tax expense	153	136	172
Deferred Federal	74	(2,103)	2
Deferred Foreign	5	84	(36)
Deferred State	0	49	0
Deferred income tax expense (benefit)	79	(1,970)	(34)
United States and Foreign Tax (Benefit) Expense	$ 232	$ (1,834)	$ 138