Annual report pursuant to Section 13 and 15(d)

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

v3.10.0.1
Segment Information (Long-lived Assets From Continuing Operations) (Details) - USD ($)
$ in Thousands
Dec. 31, 2018
Sep. 30, 2018
Dec. 31, 2017
Segment Reporting Information [Line Items]      
Total assets $ 166,312 $ 162,361 $ 79,633
Continuing Operations [Member]      
Segment Reporting Information [Line Items]      
Long lived assets 52,724   23,221
Total assets 163,022   76,797
Operating Segments | Continuing Operations [Member] | Gabon Segment [Member]      
Segment Reporting Information [Line Items]      
Long lived assets 42,195   12,638
Total assets 103,401   63,121
Operating Segments | Continuing Operations [Member] | Equatorial Guinea Segment [Member]      
Segment Reporting Information [Line Items]      
Long lived assets 10,187   10,000
Total assets 10,320   10,095
Corporate, Non-Segment | Continuing Operations [Member]      
Segment Reporting Information [Line Items]      
Long lived assets 342   583
Total assets $ 49,301   $ 3,581