Annual report pursuant to Section 13 and 15(d)

Segment Information (Segment Activity) (Detail)

v3.3.1.900
Segment Information (Segment Activity) (Detail) - USD ($)
$ in Thousands
 3 Months Ended 12 Months Ended
Dec. 31, 2015
Sep. 30, 2015
Jun. 30, 2015
Mar. 31, 2015
Dec. 31, 2014
Sep. 30, 2014
Jun. 30, 2014
Mar. 31, 2014
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Segment Reporting Information [Line Items]                      
Revenues-oil and natural gas sales $ 17,523 [1] $ 17,546 [1] $ 27,137 [1] $ 18,239 [1] $ 23,037 [1] $ 24,486 [1] $ 52,098 [1] $ 28,071 [1] $ 80,445 $ 127,691 $ 169,277
Depreciation, depletion and amortization                 33,010 20,086 16,929
Impairment of proved properties 52,100 18,000 5,800 5,400 98,300       81,322 98,341  
Bad debt expense and other   2,700     600 1,800     2,968 2,400 3,326
Operating income (loss) (75,124) $ (32,121) $ (1,030) $ (35,278) (94,270) $ 6,687 $ 33,828 $ (650) (143,553) (54,406) 77,225
Interest income (expense), net                 (1,325) 75 73
Income tax expense                 14,587 22,486 34,115
Additions to properties and equipment                 66,419 87,111 53,691
Long lived assets 33,373       108,124       33,373 108,124  
Total assets 123,958       248,849       123,958 248,849  
United States [Member]                      
Segment Reporting Information [Line Items]                      
Revenues-oil and natural gas sales                 498 1,369 1,891
Operating Segments [Member] | Gabon [Member]                      
Segment Reporting Information [Line Items]                      
Revenues-oil and natural gas sales                 79,947 126,322 167,386
Depreciation, depletion and amortization                 32,125 19,079 15,310
Impairment of proved properties                 78,080 98,341  
Bad debt expense and other                 2,968 2,400  
Operating income (loss)                 (87,243) (42,105) 98,795
Interest income (expense), net                 (1,144) 42 40
Income tax expense                 13,238 22,486 34,115
Additions to properties and equipment                 66,269 83,170 53,015
Long lived assets 21,329       76,247       21,329 76,247  
Total assets 98,858       192,957       98,858 192,957  
Operating Segments [Member] | Angola [Member]                      
Segment Reporting Information [Line Items]                      
Depreciation, depletion and amortization                 12 12 28
Bad debt expense and other                     3,326
Operating income (loss)                 (40,447) (3,798) (3,018)
Additions to properties and equipment                   3,117 629
Long lived assets 16       14,645       16 14,645  
Total assets 10,304       22,305       10,304 22,305  
Operating Segments [Member] | Equatorial Guinea [Member]                      
Segment Reporting Information [Line Items]                      
Operating income (loss)                 (1,342) (1,525) (768)
Long lived assets 10,000       10,000       10,000 10,000  
Total assets 10,200       10,197       10,200 10,197  
Operating Segments [Member] | United States [Member]                      
Segment Reporting Information [Line Items]                      
Revenues-oil and natural gas sales                 498 1,369 1,891
Depreciation, depletion and amortization                 633 901 1,528
Impairment of proved properties                 3,242    
Operating income (loss)                 (4,366) (119) (11,869)
Additions to properties and equipment                   8  
Long lived assets 1,234       6,359       1,234 6,359  
Total assets 1,470       6,611       1,470 6,611  
Corporate And Other [Member]                      
Segment Reporting Information [Line Items]                      
Depreciation, depletion and amortization                 240 94 63
Operating income (loss)                 (10,155) (6,859) (5,915)
Interest income (expense), net                 (181) 33 33
Income tax expense                 1,349    
Additions to properties and equipment                 150 816 $ 47
Long lived assets 794       873       794 873  
Total assets $ 3,126       $ 16,779       $ 3,126 $ 16,779  
[1] As discussed in Note 3 to the consolidated financial statements an error was identified the prepaid royalty account that caused previous periods to be misstated. Total revenues were corrected through an out of period adjustment in the fourth quarter of 2015 with reduction of $2.3 million, overstating operating loss and net loss by $2.3 million.