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Fair Value Measurements (Tables)
12 Months Ended
Dec. 31, 2019
Fair Value Disclosures [Abstract]  
Schedule of financial assets and liabilities at fair value

  Fair Value Measurements Using 
(in thousands)  Level 1   Level 2   Level 3   Total 
December 31, 2019                
Assets:                
Commodity derivatives  $-   $7,079   $-   $7,079 
Liabilities:                    
Commodity derivatives  $-   $556   $-   $556 
December 31, 2018                    
Assets:                    
Commodity derivatives  $-   $7,022   $-   $7,022