Supplemental Financial Statement Information (Effects on Net Income of Amounts Reclassified from AOCI) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Revenue	$ 36,339	$ 31,146
Other income (expense), net	1,538	2,910
Benefit (provision) for income taxes	(1,489)	(1,142)
Net income	6,657	9,401
Gains (Losses) Reclassified from AOCI to the Consolidated Statements of Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income	97	(233)
Gains (Losses) Reclassified from AOCI to the Consolidated Statements of Income | Unrealized gains (losses) on available-for-sale investments
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other income (expense), net	(2)	(39)
Benefit (provision) for income taxes	(5)	0
Net income	(7)	(39)
Gains (Losses) Reclassified from AOCI to the Consolidated Statements of Income | Unrealized gains (losses) on cash flow hedges
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income	104	(194)
Gains (Losses) Reclassified from AOCI to the Consolidated Statements of Income | Unrealized gains (losses) on cash flow hedges | Foreign exchange contracts
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Revenue	128	(247)
Gains (Losses) Reclassified from AOCI to the Consolidated Statements 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
Benefit (provision) for income taxes	$ (25)	$ 52