Financial Instruments (Effect of Derivative Instruments on Income and Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Derivatives in Net Investment Hedging Relationship:
Revenues	$ 38,297	$ 38,944	$ 79,456	$ 75,283
Other income (expense), net	1,894	2,967	1,674	4,505
Revenues
Foreign exchange contracts
Total gains (losses)	151	108	200	245
Other income (expense), net
Foreign exchange contracts
Total gains (losses)	(246)	162	34	(23)
Foreign exchange contracts
Derivatives in Net Investment Hedging Relationship:
Total	(214)	(114)	330	(86)
Foreign exchange contracts | Revenues | Fair Value of Derivatives Not Designated as Hedging Instruments
Foreign exchange contracts
Derivatives not designated as hedging instruments	0	0	0	0
Foreign exchange contracts | Other income (expense), net | Fair Value of Derivatives Not Designated as Hedging Instruments
Foreign exchange contracts
Derivatives not designated as hedging instruments	(69)	95	160	(154)
Other derivatives | Revenues | Fair Value of Derivatives Not Designated as Hedging Instruments
Foreign exchange contracts
Derivatives not designated as hedging instruments	0	0	0	0
Other derivatives | Other income (expense), net | Fair Value of Derivatives Not Designated as Hedging Instruments
Foreign exchange contracts
Derivatives not designated as hedging instruments	(211)	0	(239)	0
Derivatives in Cash Flow Hedging Relationship | Foreign exchange contracts
Derivatives in Cash Flow Hedging Relationship:
Amount included in the assessment of effectiveness	(44)	(42)	368	(48)
Amount excluded from the assessment of effectiveness	(49)	11	3	(19)
Derivatives in Cash Flow Hedging Relationship | Foreign exchange contracts | Revenues
Foreign exchange contracts
Amount of gains (losses) reclassified from AOCI to income	140	85	166	213
Amount excluded from the assessment of effectiveness recognized in earnings based on an amortization approach	11	23	34	32
Derivatives in Cash Flow Hedging Relationship | Foreign exchange contracts | Other income (expense), net
Foreign exchange contracts
Amount of gains (losses) reclassified from AOCI to income	0	0	0	0
Amount excluded from the assessment of effectiveness recognized in earnings based on an amortization approach	0	0	0	0
Derivatives in Net Investment Hedging Relationship: | Foreign exchange contracts
Derivatives in Net Investment Hedging Relationship:
Amount included in the assessment of effectiveness	(121)	(83)	(41)	(19)
Derivatives in Net Investment Hedging Relationship: | Foreign exchange contracts | Revenues
Foreign exchange contracts
Amount excluded from the assessment of effectiveness	0	0	0	0
Derivatives in Net Investment Hedging Relationship: | Foreign exchange contracts | Other income (expense), net
Foreign exchange contracts
Amount excluded from the assessment of effectiveness	33	57	111	111
Derivatives in Fair Value Hedging Relationship | Foreign exchange contracts | Revenues
Foreign exchange contracts
Hedged items	0	0	0	0
Derivatives designated as hedging instruments	0	0	0	0
Amount excluded from the assessment of effectiveness	0	0	0	0
Derivatives in Fair Value Hedging Relationship | Foreign exchange contracts | Other income (expense), net
Foreign exchange contracts
Hedged items	9	(13)	(8)	9
Derivatives designated as hedging instruments	(9)	13	8	(9)
Amount excluded from the assessment of effectiveness	$ 1	$ 10	$ 2	$ 20