Financial Instruments (Effect of Derivative Instruments on Income and Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Derivatives in Net Investment Hedging Relationship:
Revenues	$ 161,857	$ 136,819	$ 110,855
Other income (expense), net	5,394	7,389	1,015
Revenues
Foreign exchange contracts
Total gains (losses)	455	(138)	(169)
Other income (expense), net
Foreign exchange contracts
Total gains (losses)	(145)	169	(124)
Foreign exchange contracts
Derivatives in Net Investment Hedging Relationship:
Total	155	494	(955)
Foreign exchange contracts \| Derivatives in Cash Flow Hedging Relationship
Derivatives in Cash Flow Hedging Relationship
Amount included in the assessment of effectiveness	38	332	(955)
Amount excluded from the assessment of effectiveness	(14)	26	0
Foreign exchange contracts \| Derivatives in Cash Flow Hedging Relationship \| Revenues
Foreign exchange contracts
Amount of gains (losses) reclassified from AOCI to income	367	(139)	(169)
Amount excluded from the assessment of effectiveness recognized in earnings based on an amortization approach	88	1	0
Amount excluded from the assessment of effectiveness	0	0	0
Foreign exchange contracts \| Derivatives in Cash Flow Hedging Relationship \| Other income (expense), net
Foreign exchange contracts
Amount of gains (losses) reclassified from AOCI to income	0	0	0
Amount excluded from the assessment of effectiveness recognized in earnings based on an amortization approach	0	0	0
Amount excluded from the assessment of effectiveness	0	0	83
Foreign exchange contracts \| Derivatives in Net Investment Hedging Relationship:
Derivatives in Net Investment Hedging Relationship:
Amount included in the assessment of effectiveness	131	136	0
Foreign exchange contracts \| Derivatives in Net Investment Hedging Relationship: \| Revenues
Net Investment Hedge, Foreign Exchange Contracts [Abstract]
Amount excluded from the assessment of effectiveness	0	0	0
Foreign exchange contracts \| Derivatives in Net Investment Hedging Relationship: \| Other income (expense), net
Net Investment Hedge, Foreign Exchange Contracts [Abstract]
Amount excluded from the assessment of effectiveness	243	78	0
Foreign exchange contracts \| Derivatives in Fair Value Hedging Relationship \| Revenues
Foreign exchange contracts
Hedged items	0	0	0
Derivatives designated as hedging instruments	0	0	0
Amount excluded from the assessment of effectiveness	0	0	0
Foreign exchange contracts \| Derivatives in Fair Value Hedging Relationship \| Other income (expense), net
Foreign exchange contracts
Hedged items	(19)	(96)	197
Derivatives designated as hedging instruments	19	96	(197)
Amount excluded from the assessment of effectiveness	25	37	23
Fair Value of Derivatives Not Designated as Hedging Instruments \| Foreign exchange contracts \| Revenues
Foreign exchange contracts
Derivatives not designated as hedging instruments	0	0	0
Fair Value of Derivatives Not Designated as Hedging Instruments \| Foreign exchange contracts \| Other income (expense), net
Foreign exchange contracts
Derivatives not designated as hedging instruments	$ (413)	$ 54	$ (230)

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