Financial Instruments - Fair Value of Derivative Financial Instruments and Related Notional Amounts (Details) - USD ($) $ in Millions		Dec. 31, 2020	Dec. 31, 2019
Derivative [Line Items]
Derivative asset		$ 373	$ 992
Derivative liability		1,100	718
Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative asset		280	909
Derivative liability		1,005	662
Foreign exchange contracts [Member] | Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, notional amount	[1]	24,369	25,193
Derivative asset	[1]	145	591
Derivative liability	[1]	1,005	662
Foreign exchange contracts [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, notional amount		15,063	19,623
Derivative asset		94	82
Derivative liability		95	55
Interest rate contracts [Member] | Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, notional amount		1,950	6,645
Derivative asset		135	318
Derivative liability		0	0
Sales [Member] | Foreign exchange contracts [Member] | Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, notional amount		$ 5,000	$ 5,900

[1] The notional amount of outstanding foreign exchange contracts hedging our intercompany forecasted inventory sales was $5.0 billion as of December 31, 2020 and $5.9 billion as of December 31, 2019.