Quarterly report pursuant to Section 13 or 15(d)

Commitments and Contingencies (Narrative) (Details)

v3.20.2
Commitments and Contingencies (Narrative) (Details)
$ in Thousands
 1 Months Ended 9 Months Ended
Aug. 31, 2020
USD ($)
km²
Jun. 30, 2020
USD ($)
Oct. 31, 2019
USD ($)
Sep. 30, 2020
USD ($)
item
Dec. 31, 2019
USD ($)
Sep. 30, 2019
USD ($)
Jul. 31, 2019
USD ($)
Commitments And Contingencies [Line Items]              
Abandonment funding       $ 11,885 $ 11,371 $ 11,112  
Etame Marine Block [Member]              
Commitments And Contingencies [Line Items]              
Estimated abandonment costs       19,200      
Abandonment funding       11,900      
Loss contingency       $ 4,400     $ 4,400
Payment of joint venture audit settlement   $ 800 $ 1,100        
Area of three-dimensional seismic data | km² 742            
Etame Marine Block [Member] | Minimum [Member]              
Commitments And Contingencies [Line Items]              
Expected time to complete acquisition of data 2 months            
Expected cost of data acquisition $ 4,000            
Etame Marine Block [Member] | Maximum [Member]              
Commitments And Contingencies [Line Items]              
Expected time to complete acquisition of data 3 months            
Expected cost of data acquisition $ 5,000            
FPSO Charter [Member]              
Commitments And Contingencies [Line Items]              
Number of extensions | item       2      
Period of charter       1 year      
Guarantee liability       $ 400 $ 400    
Percentage of share in charter payment       31.10%      
Share in charter payment, approximate annual amount       $ 9,700      
Full Charter Payment [Member]              
Commitments And Contingencies [Line Items]              
Contractual obligation       65,100      
Consortium [Member] | Etame Marine Block [Member]              
Commitments And Contingencies [Line Items]              
Estimated abandonment costs       61,800      
Abandonment funding       38,300      
Consortium [Member] | FPSO Charter [Member]              
Commitments And Contingencies [Line Items]              
Maximum exposure       $ 65,100