Quarterly report pursuant to Section 13 or 15(d)

Revenue (Narrative) (Details)

v3.19.3
Revenue (Narrative) (Details) - USD ($)
$ in Thousands
 9 Months Ended
Sep. 30, 2019
Sep. 30, 2018
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 $ 7,347 $ 9,385  
Future working interest of carried partner percentage 10.00%    
Foreign taxes payable attributable to sharing obligation $ 3,200   $ 3,300
Minimum      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]      
Lifting period, time to complete 1 day    
Maximum      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]      
Lifting period, time to complete 2 days