Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 3,033	$ 2,371	$ 596
Other comprehensive income (loss):
Foreign currency translation adjustments, net of tax of $10, $(49), and $5	533	(279)	(210)
Net change in unrealized gains (losses) on available-for-sale securities:
Unrealized gains (losses), net of tax of $(5), $(12), and $5	(39)	9	(7)
Reclassification adjustment for losses (gains) included in “Other income (expense), net,” net of tax of $0, $0, and $0	7	8	5
Net unrealized gains (losses) on available-for-sale securities	(32)	17	(2)
Total other comprehensive income (loss)	501	(262)	(212)
Comprehensive income	$ 3,534	$ 2,109	$ 384