Financial Instruments (Fair Values of Outstanding Derivative Instruments) (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Derivative Assets:
Derivative Assets	$ 554	$ 397
Derivative Liabilities:
Derivative Liabilities	400	1,554
Level 2
Derivative Assets:
Derivative Assets	509	365
Derivative Liabilities:
Derivative Liabilities	355	1,522
Level 2 | Other current and non-current assets
Derivative Assets:
Derivative Assets	470
Level 2 | Other current and non-current assets | Foreign exchange contracts
Derivative Assets:
Derivative Assets		349
Level 2 | Other current and non-current assets | Other contracts
Derivative Assets:
Derivative Assets	39	16
Level 2 | Accrued expenses and other liabilities, current and non-current
Derivative Liabilities:
Derivative Liabilities	262
Level 2 | Accrued expenses and other liabilities, current and non-current | Foreign exchange contracts
Derivative Liabilities:
Derivative Liabilities		580
Level 2 | Accrued expenses and other liabilities, current and non-current | Other contracts
Derivative Liabilities:
Derivative Liabilities	93	942
Fair Value of Derivatives Designated as Hedging Instruments | Level 2
Derivative Assets:
Derivative Assets	355	33
Derivative Liabilities:
Derivative Liabilities	61	395
Fair Value of Derivatives Designated as Hedging Instruments | Level 2 | Other current and non-current assets
Derivative Assets:
Derivative Assets	355
Fair Value of Derivatives Designated as Hedging Instruments | Level 2 | Other current and non-current assets | Foreign exchange contracts
Derivative Assets:
Derivative Assets		33
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	61
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		395
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	154	332
Derivative Liabilities:
Derivative Liabilities	294	1,127
Fair Value of Derivatives Not Designated as Hedging Instruments | Level 2 | Other current and non-current assets
Derivative Assets:
Derivative Assets	115
Fair Value of Derivatives Not Designated as Hedging Instruments | Level 2 | Other current and non-current assets | Foreign exchange contracts
Derivative Assets:
Derivative Assets		316
Fair Value of Derivatives Not Designated as Hedging Instruments | Level 2 | Other current and non-current assets | Other contracts
Derivative Assets:
Derivative Assets	39	16
Fair Value of Derivatives Not Designated as Hedging Instruments | Level 2 | Accrued expenses and other liabilities, current and non-current
Derivative Liabilities:
Derivative Liabilities	201
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		185
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	$ 93	$ 942