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	$ 1,979	$ 7,722	$ 6,939
Other comprehensive (loss) income, net of reclassification adjustments and taxes:
Foreign currency translation gains (losses)	81	(99)	(247)
Effective portion of cash flow hedges	(288)	(15)	7
Net unrealized (losses) gains on available-for-sale securities	(6)	122	(241)
Other	5	1	9
Other comprehensive (loss) income, net of tax	(208)	9	(472)
Comprehensive income	$ 1,771	$ 7,731	$ 6,467