v3.10.0.1
Long-Term Debt - Additional Information (Detail)
3 Months Ended 6 Months Ended
Dec. 21, 2017
USD ($)
Dec. 20, 2017
Jun. 30, 2018
USD ($)
Jun. 30, 2018
USD ($)
May 01, 2018
USD ($)
Dec. 31, 2017
USD ($)
Line of Credit Facility [Line Items]            
Senior secured credit facility     $ 297,500,000 $ 297,500,000   $ 291,000,000
Senior Notes [Member]            
Line of Credit Facility [Line Items]            
Senior notes outstanding     85,200,000 85,200,000   85,200,000
Senior Secured Credit Facility [Member]            
Line of Credit Facility [Line Items]            
Senior secured credit facility, borrowing base     325,000,000 325,000,000    
Senior secured facility, maximum borrowing capacity     1,000,000,000 $ 1,000,000,000    
Maturity period of senior secured credit facility May 07, 2020 May 07, 2019   May 07, 2020    
Additional borrowing base, re-determination description       We, or the lenders, can each request one additional borrowing base redetermination each calendar year. Our semi-annual borrowing base redetermination was completed on May 1, 2018, and our borrowing base and aggregate lender commitments were reaffirmed at $325 million.    
Borrowing base re-determined completion date       May 01, 2018    
Borrowing base and aggregate lender commitments reaffirmed         $ 325,000,000  
Annual commitment fee of unused borrowings       0.50%    
Senior secured credit facility, interest rate description       Borrowings under the Credit Facility bore 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     $ 297,500,000 $ 297,500,000   291,000,000
Interest rate applicable of senior secured credit facility     5.80%      
Unused letters of credit outstanding     $ 300,000 $ 300,000   300,000
Production from liens covering the oil and gas properties       95.00%    
Required percentage of anticipated production to be hedged 50.00%          
Increase in applicable margin rates on borrowings 0.50%          
Debt issuance costs $ 1,000,000   $ 1,365,000 $ 1,365,000   $ 1,725,000
Consolidated interest coverage ratio     2.6 2.6    
Consolidated modified current ratio     1.6 1.6    
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 interest coverage ratio covenant (as defined in the Credit Facility) that requires us to maintain a ratio of consolidated EBITDAX (as defined in the Credit Facility) to cash Interest Expense (as defined in the Credit Facility) as of the last day of any fiscal quarter of not less than 1.25 to 1.0 (or 1.0 to 1.0 following the issuance of second lien indebtedness) through December 31, 2017, a ratio of not less than 1.5 to 1.0 through December 31, 2018, and a ratio of not less than 2.0 to 1.0 thereafter, and 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.    
Minimum interest coverage ratio, through December 31, 2018       1.75    
Minimum interest coverage ratio, through December 31, 2019       2.25    
Interest coverage ratio, thereafter       2.5    
Senior Secured Credit Facility [Member] | Covenants Agreements Two [Member]            
Line of Credit Facility [Line Items]            
Minimum current ratio       1.0    
Senior Secured Credit Facility [Member] | Minimum [Member]            
Line of Credit Facility [Line Items]            
Leverage ratio     1.0 1.0    
Senior Secured Credit Facility [Member] | Minimum [Member] | Prime Rate [Member]            
Line of Credit Facility [Line Items]            
Senior secured credit facility, marginal percentage       2.00%    
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       3.00%    
Senior Secured Credit Facility [Member] | Maximum [Member]            
Line of Credit Facility [Line Items]            
Leverage ratio     6.7 6.7    
Senior Secured Credit Facility [Member] | Maximum [Member] | Covenants Agreements Three [Member]            
Line of Credit Facility [Line Items]            
Leverage ratio, March 31, 2019       5.0    
Leverage ratio, through June 30, 2019       5.0    
Leverage ratio, September 30, 2019       4.75    
Leverage ratio, through December 31, 2019       4.75    
Leverage ratio, thereafter       4.0    
Senior Secured Credit Facility [Member] | Maximum [Member] | Prime Rate [Member]            
Line of Credit Facility [Line Items]            
Senior secured credit facility, marginal percentage       3.00%    
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       4.00%