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, 2019
Dec. 31, 2018
Dec. 31, 2017
BP America      
Concentration Risk [Line Items]      
Concentration risk percent 37.00% 18.00% 16.00%
ExxonMobil Oil Corp [Member]      
Concentration Risk [Line Items]      
Concentration risk percent 26.00% 0.00% 0.00%
Shell Trading (US) Company      
Concentration Risk [Line Items]      
Concentration risk percent 11.00% 19.00% 33.00%
Eagleclaw Midstream Ventures, LLC      
Concentration Risk [Line Items]      
Concentration risk percent 8.00% 12.00% 14.00%