Quarterly report pursuant to Section 13 or 15(d)

FAIR VALUE - Narrative (Details)

v3.19.3
FAIR VALUE - Narrative (Details) - USD ($)
9 Months Ended
Sep. 30, 2019
Sep. 30, 2018
Dec. 31, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Debt exchange derivative liabilities $ 0    
Long-term debt 1,140,072,000   $ 830,203,000
Asset retirement obligations 3,703,000 $ 1,644,000  
Second Lien Notes      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Long-term debt 684,500,000    
Unsecured VEN Bakken Note      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Long-term debt 128,584,000    
Senior Second Lien Notes Due 2023 | Estimated Fair Value      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Fair value of senior unsecured notes 709,100,000    
Term Loan Credit Agreement | Line of Credit      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Long-term debt $ 327,000,000.0