Quarterly report pursuant to Section 13 or 15(d)

Revenue (Narrative) (Details)

v3.21.2
Revenue (Narrative) (Details) - USD ($)
$ in Thousands
9 Months Ended
Sep. 30, 2021
Sep. 30, 2020
Jun. 20, 2026
Feb. 25, 2021
Feb. 24, 2021
Dec. 31, 2020
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]            
Interval period, between lifting 30 days          
Foreign income taxes receivable $ 2,056          
Foreign taxes payable attributable to sharing obligation           $ 900
Income taxes paid in-kind with crude oil $ 20,103 $ 8,738        
Minimum [Member]            
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]            
Lifting period, time to complete 1 day          
Maximum [Member]            
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]            
Lifting period, time to complete 2 days          
Prior Production Sharing Contract, Through September 17, 2018 [Member] | Government Of Gabon [Member]            
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]            
Monthly royalty rate, based on production at the published price 13.00%          
Production Sharing Contract, September 17, 2018 Through September 16, 2028 [Member]            
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]            
Purchase agreement payment period 30 days          
Production Sharing Contract, September 17, 2018 Through September 16, 2028 [Member] | Government Of Gabon [Member]            
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]            
Monthly royalty rate, based on production at the published price 13.00%          
Etame Marine Block [Member]            
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]            
Working interest ownership, percentage       58.80% 31.10%  
Etame Marine Block [Member] | Prior Production Sharing Contract, Through September 17, 2018 [Member] | Consortium [Member]            
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]            
Working interest ownership, percentage 7.50%          
Etame Marine Block [Member] | Production Sharing Contract, September 17, 2018 Through September 16, 2028 [Member] | Government Of Gabon [Member]            
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]            
Working interest ownership, percentage 7.50%          
Etame Marine Block [Member] | Scenario, Forecast [Member] | Production Sharing Contract, September 17, 2018 Through September 16, 2028 [Member] | Government Of Gabon [Member]            
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]            
Working interest ownership, percentage     10.00%