Quarterly report pursuant to Section 13 or 15(d)

Income Taxes - Additional Information (Details)

v3.2.0.727
Income Taxes - Additional Information (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended 12 Months Ended
Jun. 30, 2015
Jun. 30, 2014
Jun. 30, 2015
Jun. 30, 2014
Dec. 31, 2014
Income Tax Expense (Benefit), Continuing Operations [Abstract]          
Income tax expense (benefit) $ (44,134) $ 5,273 $ (147,708) $ 11,921  
Ceiling test write-down $ 252,772 $ 0 $ 513,162 $ 0 $ 0
Effective tax rate 14.50% 34.90% 22.30% 36.20%  
Federal statutory income tax rate     35.00%    
Valuation allowance $ 62,900   $ 85,400    
Louisiana          
Income Tax Expense (Benefit), Continuing Operations [Abstract]          
Valuation allowance related to net operating losses $ 4,300   $ 4,300   $ 4,300
Minimum          
Income Tax Expense (Benefit), Continuing Operations [Abstract]          
Tax years under examination     2010    
Maximum          
Income Tax Expense (Benefit), Continuing Operations [Abstract]          
Tax years under examination     2014