Quarterly report pursuant to Section 13 or 15(d)

Note 2 - Long-term Debt (Details Textual)

v3.20.1
Note 2 - Long-term Debt (Details Textual)
$ in Thousands
3 Months Ended
Oct. 18, 2018
USD ($)
Mar. 31, 2020
USD ($)
Mar. 31, 2019
USD ($)
Dec. 31, 2019
USD ($)
Gain (Loss) on Extinguishment of Debt, Total   $ 18,501  
Credit Agreement [Member]        
Line of Credit Facility, Maximum Borrowing Capacity $ 250,000      
Letters of Credit Outstanding, Amount   $ 5,800   $ 5,800
Credit Agreement, Maximum Leverage Ratio 3      
Credit Agreement, Minimum Current Ratio 1      
Credit Agreement, Minimum Percentage of Total Proved Reserves 85.00%      
Debt Instrument, Interest Rate During Period   4.50%    
Credit Agreement [Member] | Letter of Credit [Member]        
Line of Credit Facility, Maximum Borrowing Capacity $ 30,000      
Senior Second Lien Notes Due November 2023 [Member]        
Debt Instrument, Face Amount $ 625,000 $ 597,525   $ 625,000
Debt Instrument, Interest Rate, Stated Percentage 9.75%      
Debt Instrument, Interest Rate, Effective Percentage 10.40%      
Extinguishment of Debt, Amount   27,500    
Repayments of Long-term Debt, Total   8,500    
Gain (Loss) on Extinguishment of Debt, Total   18,500    
Write off of Deferred Debt Issuance Cost   $ 400