Basis of Presentation and Summary of Significant Accounting Policies - Credit Risk and Other Concentrations (Details) - Customer Concentration Risk - Sales Revenue, Net |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
|
| Shell Trading (US) Company | |||
| Concentration Risk [Line Items] | |||
| Concentration risk percent | 19.00% | 33.00% | 22.00% |
| BP America | |||
| Concentration Risk [Line Items] | |||
| Concentration risk percent | 18.00% | 16.00% | 0.00% |
| Eagleclaw Midstream Ventures, LLC | |||
| Concentration Risk [Line Items] | |||
| Concentration risk percent | 12.00% | 14.00% | 0.00% |
| Plains Marketing, LP | |||
| Concentration Risk [Line Items] | |||
| Concentration risk percent | 0.00% | 2.00% | 48.00% |
| Permian Transport and Trading | |||
| Concentration Risk [Line Items] | |||
| Concentration risk percent | 0.00% | 7.00% | 11.00% |