Financial Instruments - Derivative Instruments Fair Value and Measurement Inputs (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Derivative [Line Items]
Derivative fair value net asset (liability)	$ 174	$ (13)
Currency exchange contracts
Derivative [Line Items]
Derivative fair value net asset (liability)	17	35
Commodity contracts
Derivative [Line Items]
Derivative fair value net asset (liability)	81	(19)
Interest rate contracts
Derivative [Line Items]
Derivative fair value net asset (liability)	(171)	(338)
Net investment hedge contracts
Derivative [Line Items]
Derivative fair value net asset (liability)	247	309
Quoted Prices in Active Markets for Identical Assets (Level 1)
Derivative [Line Items]
Derivative fair value net asset (liability)	27	(1)
Quoted Prices in Active Markets for Identical Assets (Level 1) | Currency exchange contracts
Derivative [Line Items]
Derivative fair value net asset (liability)	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Commodity contracts
Derivative [Line Items]
Derivative fair value net asset (liability)	27	(1)
Quoted Prices in Active Markets for Identical Assets (Level 1) | Interest rate contracts
Derivative [Line Items]
Derivative fair value net asset (liability)	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Net investment hedge contracts
Derivative [Line Items]
Derivative fair value net asset (liability)	0	0
Significant Other Observable Inputs (Level 2)
Derivative [Line Items]
Derivative fair value net asset (liability)	147	(12)
Significant Other Observable Inputs (Level 2) | Currency exchange contracts
Derivative [Line Items]
Derivative fair value net asset (liability)	17	35
Significant Other Observable Inputs (Level 2) | Commodity contracts
Derivative [Line Items]
Derivative fair value net asset (liability)	54	(18)
Significant Other Observable Inputs (Level 2) | Interest rate contracts
Derivative [Line Items]
Derivative fair value net asset (liability)	(171)	(338)
Significant Other Observable Inputs (Level 2) | Net investment hedge contracts
Derivative [Line Items]
Derivative fair value net asset (liability)	247	309
Significant Unobservable Inputs (Level 3)
Derivative [Line Items]
Derivative fair value net asset (liability)	0	0
Significant Unobservable Inputs (Level 3) | Currency exchange contracts
Derivative [Line Items]
Derivative fair value net asset (liability)	0	0
Significant Unobservable Inputs (Level 3) | Commodity contracts
Derivative [Line Items]
Derivative fair value net asset (liability)	0	0
Significant Unobservable Inputs (Level 3) | Interest rate contracts
Derivative [Line Items]
Derivative fair value net asset (liability)	0	0
Significant Unobservable Inputs (Level 3) | Net investment hedge contracts
Derivative [Line Items]
Derivative fair value net asset (liability)	$ 0	$ 0