CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
Net income	$ 859	$ 753	$ 626
Other comprehensive (loss) income:
Foreign currency translation adjustments	(123)	(41)	1
Other derivative instrument adjustments, net of tax	10	8	0
Unrealized (loss) gain on available-for-sale securities, net of tax	(7)	5	5
Reclassification of (gains) losses, net of tax	(6)	2	(6)
Total other comprehensive (loss) income, net of tax	(126)	(26)	0
Comprehensive income	$ 733	$ 727	$ 626