CONDENSED CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 407	$ 1,035
Other comprehensive income, net of reclassification adjustments:
Foreign currency translation gain (loss)	132	331
Unrealized gains (losses) on investments, net	(36)	(20)
Tax benefit (expense) on unrealized gains (losses) on investments, net	10	12
Unrealized gains (losses) on hedging activities, net	(29)	(34)
Tax benefit (expense) on unrealized gains (losses) on hedging activities, net	6	0
Other comprehensive income, net of tax	83	289
Comprehensive income	$ 490	$ 1,324