Annual report pursuant to Section 13 and 15(d)

Segment Information (Segment Activity) (Details)

v3.20.1
Segment Information (Segment Activity) (Details) - USD ($)
$ in Thousands
 3 Months Ended 12 Months Ended
Dec. 31, 2019
Sep. 30, 2019
Jun. 30, 2019
Mar. 31, 2019
Dec. 31, 2018
Sep. 30, 2018
Jun. 30, 2018
Mar. 31, 2018
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Segment Reporting Information [Line Items]                      
Revenues-crude oil and natural gas sales $ 21,923 $ 17,603 $ 25,230 $ 19,765 $ 27,606 $ 25,266 $ 24,426 $ 27,645 $ 84,521 $ 104,943 $ 77,025
Depreciation, depletion and amortization                 7,083 5,596 6,457
Bad debt (recovery) expense and other                 (341) (77) 452
Gain on revision of asset retirement obligations                 (379) (3,325)  
Other operating income (expense), net                 (4,421) 365 (84)
Operating income (loss) $ 7,776 $ 1,501 $ 6,370 $ 5,546 $ 15,206 $ 17,320 $ 5,723 $ 13,038 21,193 51,287 19,951
Derivative instruments loss, net                 (446) 4,264 (1,032)
Interest income (expense), net                 733 (145) (1,414)
Other, net                 (438) 68 3,145
Income tax expense (benefit)                 23,890 (43,254) 10,378
Additions to crude oil and natural gas properties and equipment - accrual                 22,173 38,634 1,702
Gabon Segment [Member]                      
Segment Reporting Information [Line Items]                      
Revenues-crude oil and natural gas sales                     76,978
Depreciation, depletion and amortization                     6,196
Bad debt (recovery) expense and other                     452
Other operating income (expense), net                     (84)
Operating income (loss)                     28,488
Interest income (expense), net                     (1,414)
Other, net                     3,142
Income tax expense (benefit)                     11,638
Additions to crude oil and natural gas properties and equipment - accrual                     1,576
Equatorial Guinea Segment [Member]                      
Segment Reporting Information [Line Items]                      
Operating income (loss)                     (122)
Other, net                     15
Operating Segments [Member] | Gabon Segment [Member]                      
Segment Reporting Information [Line Items]                      
Revenues-crude oil and natural gas sales                 84,521 104,938  
Depreciation, depletion and amortization                 6,825 5,176  
Bad debt (recovery) expense and other                 (341) (77)  
Gain on revision of asset retirement obligations                 (379) (3,325)  
Other operating income (expense), net                 (4,456) 365  
Operating income (loss)                 35,049 61,930  
Interest income (expense), net                 5 (396)  
Other, net                 (230) 92  
Income tax expense (benefit)                 20,311 (26,670)  
Additions to crude oil and natural gas properties and equipment - accrual                 22,116 38,430  
Operating Segments [Member] | Equatorial Guinea Segment [Member]                      
Segment Reporting Information [Line Items]                      
Operating income (loss)                 (438) (470)  
Other, net                 (3) (4)  
Income tax expense (benefit)                 12    
Additions to crude oil and natural gas properties and equipment - accrual                   187  
Corporate and Other [Member]                      
Segment Reporting Information [Line Items]                      
Revenues-crude oil and natural gas sales                   5 47
Depreciation, depletion and amortization                 258 420 261
Other operating income (expense), net                 35    
Operating income (loss)                 (13,418) (10,173) (8,415)
Derivative instruments loss, net                 (446) 4,264 (1,032)
Interest income (expense), net                 728 251  
Other, net                 (205) (20) (12)
Income tax expense (benefit)                 3,567 (16,584) (1,260)
Additions to crude oil and natural gas properties and equipment - accrual                 $ 57 $ 17 $ 126