Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Policies (Narrative) (Details)

v3.20.1
Summary of Significant Accounting Policies (Narrative) (Details)
$ in Thousands, in Billions
 1 Months Ended 6 Months Ended 12 Months Ended
May 06, 2019
$ / bbl
bbl
Sep. 26, 2018
USD ($)
Sep. 17, 2018
USD ($)
Sep. 17, 2018
XAF ( )
Dec. 31, 2019
USD ($)
Dec. 31, 2019
USD ($)
Dec. 31, 2019
USD ($)
bbl
Dec. 31, 2018
USD ($)
$ / bbl
Dec. 31, 2017
USD ($)
Dec. 31, 2019
XAF ( )
/ $
Organization And Accounting Policies [Line Items]                    
Reduction in VAT receivable             $ 275 $ (777) $ (3,025)  
Exchange rate | / $                   585.7
Bad debt recovery (expense)             341 77 (452)  
Inventory adjustment             0   0  
Interest Costs Capitalized             0 0 0  
Asset retirement obligation, revision of estimate         $ (400)   $ (379) $ (6,527) 703  
Monthly royalty rate, based on production at the published price             13.00%      
Working interest of carried partner, percentage             7.50%      
Future working interest of carried partner percentage             10.00%      
Derivative cap price | $ / bbl               74.00    
Derivative floor price | $ / bbl               74.00    
Gain (loss) on foreign currency transactions             $ (200) $ (100) 500  
Barrels | bbl             274,870      
Cash received to settle derivatives             $ 2,400 700 200  
Restatement Adjustment [Member]                    
Organization And Accounting Policies [Line Items]                    
Accrued liabilities                 (2,600)  
Office Equipment [Member]                    
Organization And Accounting Policies [Line Items]                    
Estimated useful life             5 years      
Leasehold Improvements [Member] | Minimum [Member]                    
Organization And Accounting Policies [Line Items]                    
Estimated useful life             5 years      
Leasehold Improvements [Member] | Maximum [Member]                    
Organization And Accounting Policies [Line Items]                    
Estimated useful life             7 years      
Gabon [Member]                    
Organization And Accounting Policies [Line Items]                    
Receivable balance, gross |                   5.4
Receivable balance, net, noncurrent |                   1.8
Reduction in VAT receivable, gross amount   $ 25,000   14.1            
Reduction in VAT receivable   $ 8,400 $ 4,200 4.7            
Bad debt recovery (expense)             $ 300 100 $ (400)  
Inventory adjustment               400    
Asset retirement obligation, revision of estimate           $ 400        
Etame Field [Member]                    
Organization And Accounting Policies [Line Items]                    
Asset retirement obligation, revision of estimate           $ 600   $ (6,500)    
Commodity Contract, July 19 Through June 2020 [Member]                    
Organization And Accounting Policies [Line Items]                    
Derivative, average price per barrel | $ / bbl 66.70                  
Barrels | bbl 500,000