Quarterly report pursuant to Section 13 or 15(d)

Segment Information (Long-lived Assets from Continuing Operations) (Details)

v3.19.2
Segment Information (Long-lived Assets from Continuing Operations) (Details) - USD ($)
$ in Thousands
Jun. 30, 2019
Dec. 31, 2018
Segment Reporting Information [Line Items]    
Total assets $ 202,067 $ 166,312
Continuing Operations [Member]    
Segment Reporting Information [Line Items]    
Long lived assets 51,869 52,724
Total assets 202,067 163,022
Operating Segments | Gabon Segment [Member] | Continuing Operations [Member]    
Segment Reporting Information [Line Items]    
Long lived assets 41,455 42,195
Total assets 137,660 103,401
Operating Segments | Equatorial Guinea Segment [Member] | Continuing Operations [Member]    
Segment Reporting Information [Line Items]    
Long lived assets 10,000 10,187
Total assets 10,083 10,320
Corporate and Other | Continuing Operations [Member]    
Segment Reporting Information [Line Items]    
Long lived assets 414 342
Total assets $ 54,324 $ 49,301