Derivative Financial Instruments - Open Commodity Derivative Instruments (Details) - bbl bbl in Millions |
12 Months Ended | |
|---|---|---|
Dec. 31, 2018 |
Dec. 31, 2017 |
|
| 2-1-1 Crack spreads | ||
| Derivative [Line Items] | ||
| Number of barrels | 0 | 7 |
| Distillate Crack spreads | ||
| Derivative [Line Items] | ||
| Number of barrels | 0 | 4 |
| Gasoline Crack spreads | ||
| Derivative [Line Items] | ||
| Number of barrels | 0 | 4 |
| Canadian crude oil | ||
| Derivative [Line Items] | ||
| Number of barrels | 2 | 6 |