Income Taxes - Income Tax Reconciliation (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Income tax expense (benefit) at the U.S. federal tax rate of 35%	$ (33)	$ 48	$ 194
Foreign income tax differential	33	(72)	(86)
U.S. permanent book/tax differences	(5)	(2)	3
Tax audit settlements	(10)	(15)
Change in liability for unrecognized tax benefits	(7)		29
Nondeductible transaction costs	(1)	1	1
Goodwill impairment	5	0	0
U.S. valuation allowance	(3)	(8)
Valuation allowance releases			(25)
Settlement of UK London pension plan	77	0	0
Tax extenders legislation			(16)
Other, net	(1)		(2)
Total income tax expense (benefit)	$ 55	$ (48)	$ 98