Condensed Consolidated Statements of Operations (Unaudited) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended
Sep. 30, 2017
Sep. 30, 2016
Sep. 30, 2017
Sep. 30, 2016
Net revenues        
Oil sales $ 87,286   $ 204,702  
Natural gas sales 12,852   33,226  
NGL sales 11,473   25,844  
Total net revenues 111,611   263,772  
Operating expenses        
Lease operating expenses 11,373   26,924  
Severance and ad valorem taxes 6,448   14,358  
Gathering, processing and transportation expenses 9,925   22,572  
Depreciation, depletion and amortization 42,387   102,847  
Impairment and abandonment expenses 0   (29)  
Exploration expense 1,622   4,092  
General and administrative expenses 13,311   36,017  
Total operating expenses 85,066   206,781  
Total operating income (loss) 26,545   56,991  
Other income (expense)        
Gain (loss) on sale of oil and natural gas properties (141)   7,216  
Interest expense (1,015)   (2,132)  
Net gain (loss) on derivative instruments (896)   5,392  
Other income 0   0  
Other income (expense) (2,052)   10,476  
Income (loss) before income taxes 24,493   67,467  
Income tax (expense) benefit (8,233)   (17,302)  
Net income (loss) 16,260   50,165  
Less: Net income attributable to noncontrolling interest 1,813   5,133  
Net income (loss) attributable to common shareholders $ 14,447   $ 45,032  
Income per share:        
Basic (USD per share) $ 0.06   $ 0.20  
Diluted (USD per share) $ 0.06   $ 0.19  
Predecessor        
Net revenues        
Oil sales   $ 23,388   $ 56,975
Natural gas sales   2,629   5,717
NGL sales   1,304   3,097
Total net revenues   27,321   65,789
Operating expenses        
Lease operating expenses   3,656   10,295
Severance and ad valorem taxes   1,432   3,523
Gathering, processing and transportation expenses   1,787   4,375
Depreciation, depletion and amortization   18,454   60,939
Impairment and abandonment expenses   1,649   2,546
Exploration expense   402   920
General and administrative expenses   4,848   9,735
Total operating expenses   32,228   92,333
Total operating income (loss)   (4,907)   (26,544)
Other income (expense)        
Gain (loss) on sale of oil and natural gas properties   15   11
Interest expense   (1,983)   (5,422)
Net gain (loss) on derivative instruments   1,741   (4,184)
Other income   0   6
Other income (expense)   (227)   (9,589)
Income (loss) before income taxes   (5,134)   (36,133)
Income tax (expense) benefit   0   406
Net income (loss)   (5,134)   (35,727)
Less: Net income attributable to noncontrolling interest   0   0
Net income (loss) attributable to common shareholders   $ (5,134)   $ (35,727)