Supplemental Financial Statement Information (Effects on Net Income of Amounts Reclassified from AOCI) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Revenue	$ 27,772	$ 22,451	$ 78,532	$ 64,208
Other income (expense), net	197	278	693	216
Benefit (provision) for income taxes	(1,247)	(984)	(3,493)	(3,148)
Net income	6,732	5,061	15,682	14,145
Total amount reclassified, net of tax	(172)	113	(64)	99
Gains (Losses) Reclassified from AOCI to the Consolidated Statement of Income | Unrealized gains (losses) on available-for-sale investments
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other income (expense), net	(47)	46	(98)	(137)
Benefit (provision) for income taxes	0	0	0	0
Net income	(47)	46	(98)	(137)
Gains (Losses) Reclassified from AOCI to the Consolidated Statement of Income | Unrealized gains (losses) on cash flow hedges
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Benefit (provision) for income taxes	65	(39)	1	(120)
Net income	(125)	67	34	236
Gains (Losses) Reclassified from AOCI to the Consolidated Statement of Income | Unrealized gains (losses) on cash flow hedges | Foreign exchange contracts
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Revenue	(191)	105	29	352
Gains (Losses) Reclassified from AOCI to the Consolidated Statement of Income | Unrealized gains (losses) on cash flow hedges | Interest rate contracts
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other income (expense), net	$ 1	$ 1	$ 4	$ 4