Financial Instruments (Fair Values of Outstanding Derivative Instruments) (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Derivative Assets:
Derivative Assets	$ 511	$ 365
Derivative Liabilities:
Derivative Liabilities	813	390
Level 2
Derivative Assets:
Derivative Assets	493	345
Derivative Liabilities:
Derivative Liabilities	795	382
Level 2 | Other current and non-current assets
Derivative Assets:
Derivative Assets	480
Level 2 | Other current and non-current assets | Foreign exchange contracts
Derivative Assets:
Derivative Assets		344
Level 2 | Other current and non-current assets | Other contracts
Derivative Assets:
Derivative Assets	13	1
Level 2 | Accrued expenses and other liabilities, current and non-current
Derivative Liabilities:
Derivative Liabilities	342
Level 2 | Accrued expenses and other liabilities, current and non-current | Foreign exchange contracts
Derivative Liabilities:
Derivative Liabilities		369
Level 2 | Accrued expenses and other liabilities, current and non-current | Other contracts
Derivative Liabilities:
Derivative Liabilities	453	13
Fair Value of Derivatives Designated as Hedging Instruments | Level 2
Derivative Assets:
Derivative Assets	291	91
Derivative Liabilities:
Derivative Liabilities	167	173
Fair Value of Derivatives Designated as Hedging Instruments | Level 2 | Other current and non-current assets
Derivative Assets:
Derivative Assets	291
Fair Value of Derivatives Designated as Hedging Instruments | Level 2 | Other current and non-current assets | Foreign exchange contracts
Derivative Assets:
Derivative Assets		91
Fair Value of Derivatives Designated as Hedging Instruments | Level 2 | Other current and non-current assets | Other contracts
Derivative Assets:
Derivative Assets	0	0
Fair Value of Derivatives Designated as Hedging Instruments | Level 2 | Accrued expenses and other liabilities, current and non-current
Derivative Liabilities:
Derivative Liabilities	167
Fair Value of Derivatives Designated as Hedging Instruments | Level 2 | Accrued expenses and other liabilities, current and non-current | Foreign exchange contracts
Derivative Liabilities:
Derivative Liabilities		173
Fair Value of Derivatives Designated as Hedging Instruments | Level 2 | Accrued expenses and other liabilities, current and non-current | Other contracts
Derivative Liabilities:
Derivative Liabilities	0	0
Fair Value of Derivatives Not Designated as Hedging Instruments | Level 2
Derivative Assets:
Derivative Assets	202	254
Derivative Liabilities:
Derivative Liabilities	628	209
Fair Value of Derivatives Not Designated as Hedging Instruments | Level 2 | Other current and non-current assets
Derivative Assets:
Derivative Assets	189
Fair Value of Derivatives Not Designated as Hedging Instruments | Level 2 | Other current and non-current assets | Foreign exchange contracts
Derivative Assets:
Derivative Assets		253
Fair Value of Derivatives Not Designated as Hedging Instruments | Level 2 | Other current and non-current assets | Other contracts
Derivative Assets:
Derivative Assets	13	1
Fair Value of Derivatives Not Designated as Hedging Instruments | Level 2 | Accrued expenses and other liabilities, current and non-current
Derivative Liabilities:
Derivative Liabilities	175
Fair Value of Derivatives Not Designated as Hedging Instruments | Level 2 | Accrued expenses and other liabilities, current and non-current | Foreign exchange contracts
Derivative Liabilities:
Derivative Liabilities		196
Fair Value of Derivatives Not Designated as Hedging Instruments | Level 2 | Accrued expenses and other liabilities, current and non-current | Other contracts
Derivative Liabilities:
Derivative Liabilities	$ 453	$ 13