v3.3.1.900
Long-Term Debt - Additional Information (Detail) - USD ($)
3 Months Ended 12 Months Ended
Dec. 15, 2015
Dec. 31, 2015
Sep. 30, 2015
Dec. 31, 2015
Dec. 31, 2013
Dec. 31, 2014
Line of Credit Facility [Line Items]            
Senior notes, net   $ 225,839,000   $ 225,839,000   $ 244,239,000
Proceeds from issuance of senior notes         $ 242,824,000  
Gain on extinguishment of debt   9,080,000 $ 1,483,000 10,563,000    
Semi-annual interest payment amount $ 8,600,000          
Senior Notes [Member]            
Line of Credit Facility [Line Items]            
Senior notes, net   225,839,000   $ 225,839,000   244,239,000
Senior Notes [Member] | 7% Senior Notes Originated June 11, 2013 [Member]            
Line of Credit Facility [Line Items]            
Senior Notes maturity date       Jun. 15, 2021    
Senior notes, net   $ 250,000,000   $ 250,000,000    
Stated interest rate   7.00%   7.00%    
Debt instrument payment of interest       Semi-annually on June 15 and December 15.    
Proceeds from issuance of senior notes       $ 243,000,000    
Repurchased price of senior notes       8,800,000    
Repurchased senior notes face value   $ 19,700,000   19,700,000    
Gain on extinguishment of debt       $ 10,600,000    
Senior Notes [Member] | 7% Senior Notes Originated June 11, 2013 [Member] | Debt Instrument, Redemption, Period One [Member]            
Line of Credit Facility [Line Items]            
Debt instrument redemption description       Before June 15, 2016, we may redeem up to 35% of the Senior Notes at a redemption price of 107% of the principal amount, plus accrued and unpaid interest to the redemption date, with the proceeds of certain equity offerings.    
Debt instrument, redemption percentage       35.00%    
Debt instrument, redemption of principal amount percentage       107.00%    
Senior Notes [Member] | 7% Senior Notes Originated June 11, 2013 [Member] | Debt Instrument, Redemption, Period Two [Member]            
Line of Credit Facility [Line Items]            
Debt instrument redemption description       Before June 15, 2016, we may redeem some or all of the Notes for cash at a redemption price equal to 100% of their principal amount plus an applicable make-whole premium and accrued and unpaid interest to the redemption date.    
Debt instrument, redemption of principal amount percentage       100.00%    
Senior Secured Credit Facility [Member]            
Line of Credit Facility [Line Items]            
Maturity period of senior secured credit facility       May 07, 2019    
Senior secured credit facility, borrowing base   450,000,000   $ 450,000,000    
Aggregate lender commitments   450,000,000   450,000,000    
Senior secured facility, maximum borrowing capacity   1,000,000,000   $ 1,000,000,000    
Senior secured credit facility, interest rate description       Borrowings under the Credit Facility bear interest based on the agent bank's prime rate plus an applicable margin ranging from 0.50% to 1.50%, or the sum of the LIBOR rate plus an applicable margin ranging from 1.50% to 2.50%. In addition, we pay an annual commitment fee ranging from 0.375% to 0.50% of unused borrowings available    
Senior secured credit facility   273,000,000   $ 273,000,000   150,000,000
Interest rate applicable of senior secured credit facility       2.20%    
Unused letters of credit outstanding   $ 300,000   $ 300,000   $ 300,000
Production from liens covering the oil and gas properties       80.00%    
Minimum current ratio       1.0    
Interest coverage ratio       2.5    
Outstanding equity interests ownership percentage   50.00%   50.00%    
Senior Secured Credit Facility [Member] | Covenants Agreements One [Member]            
Line of Credit Facility [Line Items]            
Covenant description       A consolidated modified current ratio covenant (as defined in the Credit Facility) that requires us to maintain a ratio of not less than 1.0 to 1.0 as of the last day of any fiscal quarter    
Senior Secured Credit Facility [Member] | Covenants Agreements Two [Member]            
Line of Credit Facility [Line Items]            
Covenant description       A consolidated interest coverage ratio covenant (as defined in the Credit Facility) that requires us to maintain a ratio of consolidated EBITDAX to interest of not less than 2.5 to 1.0 as of the last day of any fiscal quarter.    
Senior Secured Credit Facility [Member] | Minimum [Member]            
Line of Credit Facility [Line Items]            
Annual commitment fee of unused borrowings       0.375%    
Senior Secured Credit Facility [Member] | Minimum [Member] | Prime Rate [Member]            
Line of Credit Facility [Line Items]            
Senior secured credit facility, marginal percentage       0.50%    
Senior Secured Credit Facility [Member] | Minimum [Member] | London Interbank Offered Rate (LIBOR) [Member]            
Line of Credit Facility [Line Items]            
Senior secured credit facility, marginal percentage       1.50%    
Senior Secured Credit Facility [Member] | Maximum [Member]            
Line of Credit Facility [Line Items]            
Annual commitment fee of unused borrowings       0.50%    
Senior Secured Credit Facility [Member] | Maximum [Member] | Prime Rate [Member]            
Line of Credit Facility [Line Items]            
Senior secured credit facility, marginal percentage       1.50%    
Senior Secured Credit Facility [Member] | Maximum [Member] | London Interbank Offered Rate (LIBOR) [Member]            
Line of Credit Facility [Line Items]            
Senior secured credit facility, marginal percentage       2.50%