Annual report pursuant to Section 13 and 15(d)

Crude Oil and Natural Gas Properties and Equipment (Narrative) (Details)

v3.22.0.1
Crude Oil and Natural Gas Properties and Equipment (Narrative) (Details)
 1 Months Ended 3 Months Ended 12 Months Ended 24 Months Ended
Jun. 20, 2026
Apr. 12, 2021
Feb. 25, 2021
Sep. 26, 2018
USD ($)
Sep. 30, 2020
USD ($)
item
Mar. 31, 2020
USD ($)
Dec. 31, 2021
USD ($)
item
Dec. 31, 2020
USD ($)
Dec. 31, 2019
USD ($)
Dec. 31, 2020
USD ($)
item
Apr. 30, 2021
Feb. 24, 2021
Sep. 17, 2018
USD ($)
Dec. 31, 2012
Property, Plant and Equipment [Line Items]                            
Reduction in VAT receivable             $ (1,593,000) $ (1,268,000) $ 275,000          
Deferred tax assets, basis difference in fixed assets             20,133,000 27,995,000   $ 27,995,000        
Impairment of proved crude oil and natural gas properties             0 30,625,000            
Property, net             $ 94,324,000 37,036,000   37,036,000        
Inventory adjustments               $ 900,000   $ 900,000        
Etame Marine Block [Member]                            
Property, Plant and Equipment [Line Items]                            
Impairment of proved crude oil and natural gas properties           $ 30,600,000                
Property, net           15,600,000                
Undeveloped acreage           2,300,000                
Undeveloped leasehold value           $ 11,500,000                
Etame Marine Block [Member] | Government Of Gabon [Member]                            
Property, Plant and Equipment [Line Items]                            
Working interest ownership, percentage             7.50%              
Etame Marine Block [Member] | VAALCO Gabon S.A. [Member]                            
Property, Plant and Equipment [Line Items]                            
Working interest ownership, percentage             63.575%              
Block P Offshore Equatorial Guinea [Member]                            
Property, Plant and Equipment [Line Items]                            
Working interest ownership, percentage               43.00%   43.00%       31.00%
Increase (decrease) in working interest ownership percentage   45.90%                        
Undeveloped acreage             $ 10,000,000.0              
Period of development             25 years              
Block P Offshore Equatorial Guinea [Member] | Crown Energy [Member]                            
Property, Plant and Equipment [Line Items]                            
Working interest ownership, percentage                     5.00%      
Scenario, Forecast [Member] | Etame Marine Block [Member] | Government Of Gabon [Member]                            
Property, Plant and Equipment [Line Items]                            
Working interest ownership, percentage 10.00%                          
Prior Production Sharing Contract, Through September 17, 2018 [Member]                            
Property, Plant and Equipment [Line Items]                            
Entitled percent for consortium after initial royalty percentage             70.00%              
Prior Production Sharing Contract, Through September 17, 2018 [Member] | Etame Marine Block [Member]                            
Property, Plant and Equipment [Line Items]                            
Number of exploitation areas | item             3              
Prior Production Sharing Contract, Through September 17, 2018 [Member] | Etame Marine Block [Member] | Consortium [Member]                            
Property, Plant and Equipment [Line Items]                            
Working interest ownership, percentage             7.50%              
Production Sharing Contract, September 17, 2018 Through September 16, 2028 [Member]                            
Property, Plant and Equipment [Line Items]                            
Other accrued liabilities             $ 4,600,000              
Deferred tax assets, basis difference in fixed assets             $ 18,600,000              
Estimated costs of technical studies         $ 500,000                  
Entitled percent for consortium after initial royalty percentage             80.00%              
Production Sharing Contract, September 17, 2018 Through September 16, 2028 [Member] | Consortium [Member]                            
Property, Plant and Equipment [Line Items]                            
Number of wells drilled | item                   2        
Number of wellbores drilled | item                   2        
Number of technical studies required | item         2                  
Estimated costs of technical studies         $ 1,500,000                  
Entitled percent for consortium after initial royalty percentage             80.00%              
Production Sharing Contract, September 17, 2018 Through September 16, 2028 [Member] | Signing Bonus [Member]                            
Property, Plant and Equipment [Line Items]                            
Payment of signing bonus, allocated to proved and unproved property       $ 11,800,000                    
Reduction in VAT receivable       8,400,000                    
Other accrued liabilities       1,700,000                    
Allocated to unproved leasehold cost             $ 6,700,000              
Production Sharing Contract, September 17, 2018 Through September 16, 2028 [Member] | Signing Bonus [Member] | Consortium [Member]                            
Property, Plant and Equipment [Line Items]                            
Payment of signing bonus, allocated to proved and unproved property       35,000,000.0                    
Reduction in VAT receivable       25,000,000.0                    
Other accrued liabilities       $ 5,000,000.0                    
Production Sharing Contract, September 17, 2018 Through September 16, 2028 [Member] | Tax Impact [Member]                            
Property, Plant and Equipment [Line Items]                            
Allocated to unproved leasehold cost             $ 7,100,000              
Production Sharing Contract, September 17, 2018 Through September 16, 2028 [Member] | Etame Marine Block [Member]                            
Property, Plant and Equipment [Line Items]                            
Number of exploitation areas | item             3              
Period of agreement for exploitation areas             10 years              
Production Sharing Contract, September 17, 2018 Through September 16, 2028 [Member] | Scenario, Forecast [Member] | Etame Marine Block [Member]                            
Property, Plant and Equipment [Line Items]                            
Increase (decrease) in working interest ownership percentage 1.60%                          
Production Sharing Contract, September 17, 2018 Through September 16, 2028 [Member] | Scenario, Forecast [Member] | Etame Marine Block [Member] | Government Of Gabon [Member]                            
Property, Plant and Equipment [Line Items]                            
Working interest ownership, percentage 10.00%                          
Increase (decrease) in working interest ownership percentage 2.50%                          
Production Sharing Contract, After September 16, 2028 [Member]                            
Property, Plant and Equipment [Line Items]                            
Entitled percent for consortium after initial royalty percentage             70.00%              
Production Sharing Contract, After September 16, 2028 [Member] | Consortium [Member]                            
Property, Plant and Equipment [Line Items]                            
Entitled percent for consortium after initial royalty percentage             70.00%              
Production Sharing Contract, After September 16, 2028 [Member] | Signing Bonus [Member]                            
Property, Plant and Equipment [Line Items]                            
Contractual obligation                         $ 21,800,000  
Production Sharing Contract, After September 16, 2028 [Member] | Signing Bonus [Member] | Consortium [Member]                            
Property, Plant and Equipment [Line Items]                            
Contractual obligation                         $ 65,000,000.0  
Production Sharing Contract, After September 16, 2028 [Member] | Etame Marine Block [Member]                            
Property, Plant and Equipment [Line Items]                            
Number of contract extension periods | item             2              
Production license agreement term extended by government             5 years              
Sasol Gabon S.A. [Member]                            
Property, Plant and Equipment [Line Items]                            
Undeveloped acreage             $ 2,200,000              
Undeveloped leasehold value             $ 13,700,000              
Sasol Gabon S.A. [Member] | Etame Marine Block [Member]                            
Property, Plant and Equipment [Line Items]                            
Working interest ownership, percentage     58.80%                 31.10%    
Increase (decrease) in working interest ownership percentage     27.80%                      
Atlas Petroleum [Member] | Block P Offshore Equatorial Guinea [Member]                            
Property, Plant and Equipment [Line Items]                            
Increase (decrease) in working interest ownership percentage               12.00%            
Potential payment               $ 3,100,000   $ 3,100,000