CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 414	$ 247	$ 779	$ 466
Other comprehensive income (loss):
Foreign currency translation adjustments	162	3	350	25
Derivative instrument adjustments, net of tax	(6)	1	(8)	(4)
Unrealized loss on available-for-sale securities, net of tax	(1)	(1)	(2)	0
Reclassification of losses, net of tax	1	1	1	2
Total other comprehensive income, net of tax	156	4	341	23
Comprehensive income	$ 570	$ 251	$ 1,120	$ 489