Annual report pursuant to Section 13 and 15(d)

SUBSEQUENT EVENTS (Details)

v3.20.4
SUBSEQUENT EVENTS (Details) - USD ($)
12 Months Ended
Mar. 12, 2021
Feb. 18, 2021
Feb. 17, 2021
Feb. 09, 2021
Feb. 03, 2021
Jan. 04, 2021
May 15, 2018
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Nov. 30, 2019
Oct. 21, 2019
Jul. 01, 2019
Subsequent Event [Line Items]                          
Repayments of lines of credit               $ 0 $ 0 $ 420,105,000      
Long-term debt               $ 944,843,000 $ 1,118,161,000        
Unsecured Ven Bakken Note | Unsecured Debt                          
Subsequent Event [Line Items]                          
Principal amount                         $ 130,000,000.0
Interest rate percentage                         6.00%
8.5% Second Lien Notes due 2023                          
Subsequent Event [Line Items]                          
Long-term debt                       $ 200,000,000.0  
8.5% Second Lien Notes due 2023 | Second Lien Notes                          
Subsequent Event [Line Items]                          
Interest rate percentage             8.50%            
Long-term debt                     $ 200,000,000.0    
8.5% Second Lien Notes due 2023 | Second Lien Notes | Period One                          
Subsequent Event [Line Items]                          
Redemption price percentage             104.00%            
8.5% Second Lien Notes due 2023 | Second Lien Notes | Period Two                          
Subsequent Event [Line Items]                          
Redemption price percentage             102.00%            
8.5% Second Lien Notes due 2023 | Second Lien Notes | Period Three                          
Subsequent Event [Line Items]                          
Redemption price percentage             100.00%            
Subsequent Event                          
Subsequent Event [Line Items]                          
Number of shares issued in transaction (in shares)       14,375,000                  
Offering price (in dollars per share)       $ 9.75                  
Net proceeds from sale of stock       $ 132,400,000                  
Subsequent Event | Period One                          
Subsequent Event [Line Items]                          
Redemption price percentage   100.00%                      
Subsequent Event | Period Two                          
Subsequent Event [Line Items]                          
Redemption price percentage   104.063%                      
Subsequent Event | Period Three                          
Subsequent Event [Line Items]                          
Redemption price percentage   102.031%                      
Subsequent Event | Period Four                          
Subsequent Event [Line Items]                          
Redemption price percentage   100.00%                      
Subsequent Event | Revolving Credit Facility                          
Subsequent Event [Line Items]                          
Maximum borrowing capacity         $ 600,000,000.0                
Subsequent Event | Unsecured Ven Bakken Note | Unsecured Debt                          
Subsequent Event [Line Items]                          
Repayments of lines of credit   $ 65,000,000.0       $ 65,000,000.0              
Subsequent Event | 8.125% Senior Unsecured Notes Due 2028 | Senior Loans                          
Subsequent Event [Line Items]                          
Principal amount   $ 550,000,000.0                      
Interest rate percentage   8.125%                      
Proceeds from the issuance of senior notes   $ 537,000,000.0                      
Debt default term   30 days                      
Indebtedness amount   $ 35,000,000.0                      
Judgment period   60 days                      
Subsequent Event | 8.5% Second Lien Notes due 2023 | Second Lien Notes                          
Subsequent Event [Line Items]                          
Aggregate principal amount redeemed   $ 272,100,000 $ 272,100,000                    
Redemption price percentage     94.60%                    
Repurchase amount   283,300,000                      
Long-term debt   $ 15,700,000                      
Reliance | Subsequent Event                          
Subsequent Event [Line Items]                          
Cash consideration payable $ 126,400,000       $ 175,000,000.0                
Warrants issued in purchase agreement (in shares)         3,250,000                
Warrant price per share (in dollars per share)         $ 14.00                
Ownership interest acquired         70.00%                
Cash consideration payable adjustment         $ 48,600,000                
Reliance | Subsequent Event | Northern Oil and Gas And Arch Investment Partners                          
Subsequent Event [Line Items]                          
Cash consideration payable         $ 250,000,000.0                
Reliance | Subsequent Event | Arch Investment Partners, LLC                          
Subsequent Event [Line Items]                          
Ownership interest acquired         30.00%                
Aggregate cash purchase price payable         30.00%