Income Taxes - Differences in Provision for Income Taxes and Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
U.S. federal statutory rate	35.00%	35.00%	35.00%
State and local income taxes	(0.10%)	0.00%	1.00%
Foreign statutory rate differential	(34.70%)	(9.70%)	(10.60%)
Change in valuation allowance on deferred tax assets	5.40%	3.40%	(1.70%)
Nondeductible expenses	(1.10%)	(0.10%)	1.10%
Goodwill impairments	56.40%	1.00%	0.00%
Net U.S. tax on foreign source income	(5.80%)	(2.90%)	(3.20%)
All other	2.20%	(2.80%)	1.30%
Total	57.30%	23.90%	22.90%
Total income taxes paid (dollars in millions)	$ 548	$ 353	$ 329