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	$ 197	$ 857	$ 921	$ 1,370
Other comprehensive income (loss):
Foreign currency translation adjustments, net of tax of $36, $(2), $13, and $(15)	194	11	381	113
Net change in unrealized gains (losses) on available-for-sale securities:
Unrealized gains (losses), net of tax of $(17), $3, $(17), and $2	(6)	31	(8)	37
Reclassification adjustment for losses (gains) included in “Other income (expense), net,” net of tax of $0, $0, $(1), and $0	2	1	5	2
Net unrealized gains (losses) on available-for-sale securities	(4)	32	(3)	39
Total other comprehensive income (loss)	190	43	378	152
Comprehensive income	$ 387	$ 900	$ 1,299	$ 1,522