Derivative and Financial Instruments - FX Balance Sheet (Details) - USD ($) $ in Millions |
Sep. 30, 2020 |
Dec. 31, 2019 |
|---|---|---|
| Prepaid Expenses and Other Current Assets [Member] | ||
| Derivatives, Fair Value [Line Items] | ||
| Foreign currency exchange derivative assets | $ 16 | $ 1 |
| Other Accruals [Member] | ||
| Derivatives, Fair Value [Line Items] | ||
| Foreign currency exchange derivative liabilities | 0 | 20 |
| Other liabilities and deferred credits [Member] | ||
| Derivatives, Fair Value [Line Items] | ||
| Foreign currency exchange derivative liabilities | $ 0 | $ 8 |