CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 966	$ 892	$ 835
Other comprehensive income (loss):
Foreign currency translation adjustments	(29)	(326)	(371)
Unrealized gains (losses) on forward contracts designated as hedges, net of tax	33	(4)	0
Total other comprehensive income (loss)	4	(330)	(371)
Comprehensive income	$ 970	$ 562	$ 464