Financial Instruments - Notional Values of Derivative Instruments (Details) - USD ($) $ in Millions		Dec. 31, 2019	Dec. 31, 2018
Net Investment Hedging | Euro notes
Derivative [Line Items]
Notional Amount		$ 3,436	$ 3,514
Net Investment Hedging | British pound sterling notes
Derivative [Line Items]
Notional Amount		349	336
Net Investment Hedging | Swiss franc notes
Derivative [Line Items]
Notional Amount		1,448	1,424
Net Investment Hedging | Canadian dollar notes
Derivative [Line Items]
Notional Amount		462	440
Currency exchange contracts | Intercompany loans and forecasted interest payments
Derivative [Line Items]
Notional Amount		2,474	3,239
Currency exchange contracts | Forecasted transactions
Derivative [Line Items]
Notional Amount		3,993	2,396
Commodity contracts
Derivative [Line Items]
Notional Amount	[1]	7,238	6,706
Interest rate contracts
Derivative [Line Items]
Notional Amount		5,250	8,679
Net investment hedge contracts
Derivative [Line Items]
Notional Amount		6,864	$ 6,678
Net investment hedge contracts | Net Investment Hedging
Derivative [Line Items]
Notional Amount		$ 6,900

[1] During the fourth quarter of 2019, we changed how we report our commodity contract notional values from a net to a gross basis in line with how we report our other instruments. We have recast 2018 to be consistent with current year presentation.