Quarterly report pursuant to Section 13 or 15(d)

Acquisitions and Dispositions (Narrative) (Details)

v3.21.2
Acquisitions and Dispositions (Narrative) (Details)
$ in Thousands
1 Months Ended 3 Months Ended 6 Months Ended
Feb. 25, 2021
USD ($)
Nov. 30, 2006
Jun. 30, 2021
USD ($)
Mar. 31, 2021
USD ($)
Jun. 30, 2020
USD ($)
Mar. 31, 2020
USD ($)
Jun. 30, 2021
USD ($)
$ / bbl
Jun. 30, 2020
USD ($)
Apr. 29, 2021
USD ($)
Feb. 24, 2021
Business Acquisition [Line Items]                    
Bargain purchase gain             $ (7,651)      
Revenues     $ 47,023   $ 17,974   86,797 $ 36,363    
Net income     $ 5,884 $ 9,869 $ 596 $ (52,800) 15,753 $ (52,204)    
Sasol Gabon S.A. [Member]                    
Business Acquisition [Line Items]                    
Bargain purchase gain $ (7,700)                  
Bargain purchase gain, net of tax 5,500                  
Bargain purchase gain, income tax benefit 2,200                  
Revenues             9,400      
Net income             $ 1,200      
Contingent consideration $ 5,000               $ 5,000  
Contingent consideration, measurement period of oil price             90 days      
Contingent consideration, oil price threshold | $ / bbl             60.00      
Discontinued Operations [Member] | Joint Operating With Republic Of Angola [Member]                    
Business Acquisition [Line Items]                    
Joint operation agreement related to third party in working interest percentage   40.00%                
Additional joint operation agreement related to third party in working interest percentage   10.00%                
Etame Marine Block [Member]                    
Business Acquisition [Line Items]                    
Working interest ownership, percentage 58.80%                 31.10%
Etame Marine Block [Member] | Sasol Gabon S.A. [Member]                    
Business Acquisition [Line Items]                    
Increase (decrease) in working interest ownership percentage 27.80%