CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 210	$ 192	$ 657	$ 556
Other comprehensive (loss) income:
Foreign currency translation adjustments	(28)	(18)	(47)	(18)
Derivative instrument adjustments, net of tax	2	3	9	4
Unrealized (loss) gain on available-for-sale securities, net of tax	(3)	0	(5)	2
Reclassification of (gains) losses, net of tax	(3)	1	(7)	3
Total other comprehensive loss, net of tax	(32)	(14)	(50)	(9)
Comprehensive income	$ 178	$ 178	$ 607	$ 547