Annual report pursuant to Section 13 and 15(d)

Long-Term Debt - Additional Information (Detail)

v3.10.0.1
Long-Term Debt - Additional Information (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Oct. 26, 2018
Sep. 30, 2018
Sep. 12, 2016
Debt Disclosure [Line Items]          
Maximum borrowing capacity       $ 340,000  
Debt Issuance Costs, Line of Credit Arrangements, Gross $ 900 $ 1,700     $ 3,011
Write off of Deferred Debt Issuance Cost   800      
Required covenant, current ratio 1.00        
Interest Coverage Ratio, Maximum 3.00        
Second Lien Facility $ 200,000 200,000      
Proceeds from Debt, Net of Issuance Costs 187,800        
Debt Instrument, Unamortized Discount 4,000        
Unamortized Debt Issuance Expense $ 8,200        
Debt Instrument, Discounted Percentage 98.00%        
Revolving Credit Facility [Member]          
Debt Disclosure [Line Items]          
Maximum borrowing capacity     $ 450,000    
Line of Credit Facility, Interest Rate at Period End 5.9586%        
Required covenant, debt to EBITDAX ratio 3.50        
Revolving Credit Facility [Member] | Minimum          
Debt Disclosure [Line Items]          
Credit facility interest rate option one, applicable margin rate over Adjusted LIBOR 2.00%        
Revolving Credit Facility [Member] | Maximum          
Debt Disclosure [Line Items]          
Credit facility interest rate option one, applicable margin rate over Adjusted LIBOR 3.00%        
Credit facility interest rate option two, applicable margin rate 4.00%        
Revolving credit facility          
Debt Disclosure [Line Items]          
Letter of credit amount outstanding $ 400 $ 800      
Revolving credit facility | Letter of Credit          
Debt Disclosure [Line Items]          
Maximum borrowing capacity $ 5,000        
Letter of Credit          
Debt Disclosure [Line Items]          
Commitment fees for undrawn credit facility 0.50%        
Second Lien Facility [Member]          
Debt Disclosure [Line Items]          
Credit facility interest rate option one, applicable margin rate over Adjusted LIBOR 7.00%        
Credit facility interest rate option two, applicable margin rate 6.00%        
Second Lien Facility, Initial Interest Rate 8.34%        
Second Lien Facility, Effective Interest Rate 9.89%        
Interest Payable One [Member] | Revolving Credit Facility [Member]          
Debt Disclosure [Line Items]          
Debt Instrument, Interest Payable Period 1 month        
Interest Payable Two [Member] | Revolving Credit Facility [Member]          
Debt Disclosure [Line Items]          
Debt Instrument, Interest Payable Period 3 months        
Interest Payable Three [Member] | Revolving Credit Facility [Member]          
Debt Disclosure [Line Items]          
Debt Instrument, Interest Payable Period 6 months        
Year 2 [Member]          
Debt Disclosure [Line Items]          
Prepayment Premium 102.00%        
Prepayment Premium, Change in Control 102.00%        
Year 3 [Member]          
Debt Disclosure [Line Items]          
Prepayment Premium 101.00%        
Prepayment Premium, Change in Control 101.00%