Derivative and Financial Instruments - Commodity Gain (Loss) (Details) - Commodity Contract [Member] - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2020 |
Jun. 30, 2019 |
Jun. 30, 2020 |
Jun. 30, 2019 |
|
| Sales and other operating revenues [Member] | ||||
| Derivative Instruments, Gain (Loss) [Line Items] | ||||
| Gains (losses) from commodity derivatives | $ (50) | $ 45 | $ (3) | $ 64 |
| Other Income [Member] | ||||
| Derivative Instruments, Gain (Loss) [Line Items] | ||||
| Gains (losses) from commodity derivatives | 3 | 2 | 5 | 1 |
| Purchased commodities [Member] | ||||
| Derivative Instruments, Gain (Loss) [Line Items] | ||||
| Gains (losses) from commodity derivatives | $ 24 | $ (31) | $ (2) | $ (51) |