CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 392	$ 70	$ 1,171	$ 536
Other comprehensive income (loss):
Foreign currency translation adjustments	107	2	457	27
Derivative instrument adjustments, net of tax	(5)	1	(13)	(3)
Unrealized gain (loss) on available-for-sale securities, net of tax	1	0	(1)	0
Reclassification of losses, net of tax	4	1	5	3
Net other comprehensive income (loss)	107	4	448	27
Comprehensive income	$ 499	$ 74	$ 1,619	$ 563