Annual report pursuant to Section 13 and 15(d)

Revenue (Narrative) (Details)

v3.20.1
Revenue (Narrative) (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]    
Initial crude oil sales and purchase agreement period 1 year  
Interval period, between lifting 30 days  
Monthly royalty rate, based on production at the published price 13.00%  
Working interest of carried partner, percentage 7.50%  
Income taxes paid in-kind with crude oil $ 7,268 $ 9,385
Future working interest of carried partner percentage 10.00%  
Foreign taxes payable attributable to sharing obligation $ 5,700  
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