Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 1,629	$ 724
Other comprehensive income (loss):
Foreign currency translation adjustments, net of tax of $(13) and $21	59	187
Net change in unrealized gains (losses) on available-for-sale debt securities:
Unrealized gains (losses), net of tax of $(1) and $9	(44)	(2)
Reclassification adjustment for losses (gains) included in “Other income (expense), net,” net of tax of $0 and $0	2	3
Net unrealized gains (losses) on available-for-sale debt securities	(42)	1
Total other comprehensive income (loss)	17	188
Comprehensive income	$ 1,646	$ 912