Financial Instruments (Derivative Notional Amounts) (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Foreign exchange contracts | Derivatives Designated as Hedging Instruments: | Cash flow hedges
Derivative Instruments, Gain (Loss) [Line Items]
Derivative notional amount	$ 7,388	$ 13,207
Foreign exchange contracts | Derivatives Designated as Hedging Instruments: | Fair value hedges
Derivative Instruments, Gain (Loss) [Line Items]
Derivative notional amount	476	455
Foreign exchange contracts | Derivatives Designated as Hedging Instruments: | Net investment hedges
Derivative Instruments, Gain (Loss) [Line Items]
Derivative notional amount	9,812	9,318
Foreign exchange contracts | Derivatives Not Designated as Hedging Instruments:
Derivative Instruments, Gain (Loss) [Line Items]
Derivative notional amount	38,367	43,497
Other contracts | Derivatives Not Designated as Hedging Instruments:
Derivative Instruments, Gain (Loss) [Line Items]
Derivative notional amount	$ 1,999	$ 117