Quarterly report pursuant to Section 13 or 15(d)

Dispositions (Narrative) (Details)

v3.20.2
Dispositions (Narrative) (Details)
$ in Thousands
1 Months Ended 3 Months Ended 9 Months Ended 12 Months Ended
Jul. 31, 2019
USD ($)
Nov. 30, 2006
Sep. 30, 2020
USD ($)
Sep. 30, 2019
USD ($)
Mar. 31, 2019
USD ($)
Sep. 30, 2020
USD ($)
item
Sep. 30, 2019
USD ($)
Dec. 31, 2015
item
Dec. 31, 2018
USD ($)
Business Acquisition [Line Items]                  
Income (loss) from discontinued operations, net of tax     $ 11 $ (61)   $ (41) $ 5,448    
Joint Operating With Republic Of Angola [Member]                  
Business Acquisition [Line Items]                  
Number of wells drilled | item               1  
Number of drilled wells required by agreement | item           3      
Stipulated payment for each exploration well, under PSA terms           $ 10,000      
Drilling commitment, net     5,000     5,000      
Liability for the potential payment                 $ 15,000
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%              
Liability for the potential payment       4,500     4,500    
Write off of receivable             3,300    
Income (loss) from discontinued operations, net of tax     $ 11 $ (61) $ 5,700 $ (41) $ 5,448    
Payment for settlement $ 4,500