Financial Instruments - Notional Values of Hedging Instruments (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Net investment hedge debt | Euro notes
Derivative [Line Items]
Notional Amount	$ 3,381	$ 3,436
Net investment hedge debt | British pound sterling notes
Derivative [Line Items]
Notional Amount	327	349
Net investment hedge debt | Swiss franc notes
Derivative [Line Items]
Notional Amount	1,223	1,448
Net investment hedge debt | Canadian dollar notes
Derivative [Line Items]
Notional Amount	427	462
Currency exchange contracts | Intercompany loans and forecasted interest payments
Derivative [Line Items]
Notional Amount	2,544	2,474
Currency exchange contracts | Forecasted transactions
Derivative [Line Items]
Notional Amount	3,869	3,993
Commodity contracts
Derivative [Line Items]
Notional Amount	7,571	7,238
Interest rate contracts
Derivative [Line Items]
Notional Amount	4,250	5,250
Net investment hedge contracts
Derivative [Line Items]
Notional Amount	6,652	$ 6,864
Net investment hedge contracts | Net investment hedge debt
Derivative [Line Items]
Notional Amount	$ 6,700