Quarterly report pursuant to Section 13 or 15(d)

Note 2 - Long-term Debt (Details Textual)

v3.20.2
Note 2 - Long-term Debt (Details Textual) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended
Jun. 17, 2020
Oct. 18, 2018
Sep. 30, 2020
Sep. 30, 2019
Sep. 30, 2020
Sep. 30, 2019
Jun. 30, 2020
Dec. 31, 2019
Gain (Loss) on Extinguishment of Debt, Total     $ (0) $ (0) $ 47,469 $ (0)    
Credit Agreement [Member]                
Line of Credit Facility, Maximum Borrowing Capacity $ 215,000           $ 30,000  
Debt Instrument, Interest Rate, Increase (Decrease) 0.25%              
Credit Agreement, Leverage Ratio 2.00              
Credit Agreement, Minimum Percentage of Total Proved Reserves 90.00% 85.00%            
Debt Instrument, Interest Rate During Period         3.70%      
Letters of Credit Outstanding, Amount     4,400   $ 4,400     $ 5,800
Senior Second Lien Notes Due November 2023 [Member]                
Debt Instrument, Face Amount   $ 625,000 $ 552,460   552,460     $ 625,000
Debt Instrument, Interest Rate, Stated Percentage   9.75%            
Debt Instrument, Interest Rate, Effective Percentage   10.30%            
Extinguishment of Debt, Amount         72,500      
Repayments of Long-term Debt, Total         23,900      
Gain (Loss) on Extinguishment of Debt, Total         47,500      
Write off of Deferred Debt Issuance Cost         $ 1,100