Supplemental Financial Statement Information (Schedule of Other Income (Expense), Net) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Balance Sheet Components Disclosure [Abstract]
Interest income	$ 306	$ 318	$ 912	$ 895
Interest expense	(27)	(29)	(73)	(91)
Foreign currency exchange losses, net	(53)	(123)	(101)	(437)
Gain (loss) on marketable securities, net	(44)	50	(81)	(126)
Gain (loss) on non-marketable investments, net	(32)	40	(79)	(78)
Other	47	22	115	53
Other income (expense), net	197	278	693	216
Interest costs capitalized	$ 13	$ 0	$ 32	$ 0