Income Taxes - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Valuation Allowance [Line Items]
Effective income tax rate	24.70%	32.80%
Provision for income taxes	$ (120)	$ (107)
Cash paid for income taxes, net of refunds	37	$ 43
Accounting Standards Update 2016-09
Valuation Allowance [Line Items]
Provision for income taxes	$ 43