Quarterly report pursuant to Section 13 or 15(d)

Segment Information (Details)

v2.4.0.6
Segment Information (Details) (USD $)
In Thousands, unless otherwise specified
3 Months Ended 6 Months Ended
Jun. 30, 2012
Jun. 30, 2011
Jun. 30, 2012
Jun. 30, 2011
Dec. 31, 2011
Segment activity          
Revenues $ 58,818 $ 58,547 $ 104,104 $ 105,319  
Income (loss) from operations 38,632 42,512 68,739 73,853  
Total Assets 290,126   290,126   275,015
Corporate and Other [Member]
         
Segment activity          
Income (loss) from operations (2,149) (2,656) (4,939) (5,359)  
Total Assets 45,413   45,413   45,986
Gabon [Member]
         
Segment activity          
Revenues 57,886 58,531 102,613 105,267  
Income (loss) from operations 45,258 46,057 79,605 81,058  
Total Assets 184,568   184,568   185,341
Angola [Member]
         
Segment activity          
Income (loss) from operations (585) (476) (1,199) (931)  
Total Assets 21,503   21,503   21,452
North Sea [Member]
         
Segment activity          
Income (loss) from operations (49) (72) (122) (198)  
Total Assets             
USA [Member]
         
Segment activity          
Revenues 932 16 1,491 52  
Income (loss) from operations (3,843) (341) (4,606) (717)  
Total Assets $ 38,642   $ 38,642   $ (22,236)