Financial Instruments (Derivative Notional Amounts) (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Foreign exchange contracts | Derivatives Designated as Hedging Instruments: | Cash flow hedges
Derivative Instruments, Gain (Loss) [Line Items]
Derivative notional amount	$ 15,941	$ 10,187
Foreign exchange contracts | Derivatives Designated as Hedging Instruments: | Fair value hedges
Derivative Instruments, Gain (Loss) [Line Items]
Derivative notional amount	2,578	1,569
Foreign exchange contracts | Derivatives Designated as Hedging Instruments: | Net investment hedges
Derivative Instruments, Gain (Loss) [Line Items]
Derivative notional amount	10,167	9,965
Foreign exchange contracts | Derivatives Not Designated as Hedging Instruments:
Derivative Instruments, Gain (Loss) [Line Items]
Derivative notional amount	43,795	39,861
Other contracts | Derivatives Not Designated as Hedging Instruments:
Derivative Instruments, Gain (Loss) [Line Items]
Derivative notional amount	$ 2,933	$ 2,399