Annual report pursuant to Section 13 and 15(d)

Income Taxes (Narrative) (Details)

v3.20.4
Income Taxes (Narrative) (Details) - USD ($)
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Income Taxes [Line Items]    
Deferred tax assets $ 126,252,000 $ 108,787,000
Valuation allowance 126,252,000 84,628,000
Interest or penalties accrued 0 0
Deferred tax assets   24,159,000
Uncertain tax positions $ 0 $ 0
Prior Production Sharing Contract, Through September 17, 2018 [Member]    
Income Taxes [Line Items]    
Entitled percent for consortium after initial royalty percentage 70.00%  
Production Sharing Contract, September 17, 2018 Through September 16, 2028 [Member]    
Income Taxes [Line Items]    
Entitled percent for consortium after initial royalty percentage 80.00%  
Production Sharing Contract, After September 16, 2028 [Member]    
Income Taxes [Line Items]    
Entitled percent for consortium after initial royalty percentage 70.00%  
Minimum [Member]    
Income Taxes [Line Items]    
Allocation of remaining profit production, government payments, percentage 50.00%  
Minimum [Member] | Domestic Country [Member]    
Income Taxes [Line Items]    
Foreign tax credit carryforward, expiration dates Dec. 31, 2035  
Minimum [Member] | Foreign Country [Member]    
Income Taxes [Line Items]    
Foreign tax credit carryforward, expiration dates Dec. 31, 2021  
Maximum [Member]    
Income Taxes [Line Items]    
Allocation of remaining profit production, government payments, percentage 60.00%  
Maximum [Member] | Domestic Country [Member]    
Income Taxes [Line Items]    
Foreign tax credit carryforward, expiration dates Dec. 31, 2037  
Maximum [Member] | Foreign Country [Member]    
Income Taxes [Line Items]    
Foreign tax credit carryforward, expiration dates Dec. 31, 2025