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Summary of Significant Accounting Policies - Additional Information (Detail)
3 Months Ended 6 Months Ended
Jun. 30, 2017
USD ($)
Jun. 30, 2016
USD ($)
Jun. 30, 2017
USD ($)
Segment
Jun. 30, 2016
USD ($)
Dec. 31, 2016
USD ($)
Summary Of Significant Accounting Policies [Line Items]          
Accounts receivable $ 40,438,000   $ 40,438,000   $ 44,423,000
Capitalized interest expense 500,000 $ 300,000 900,000 $ 500,000  
Depreciation, depletion and amortization 25,152,000 20,949,000 $ 51,341,000 36,062,000  
Impairment of oil and gas properties       $ 17,665,000  
Asset retirement obligations credit adjusted discount rates     10.33% 10.33%  
Operating lease expiration year     2024    
Number of operating segment | Segment     1    
Oil and Gas Properties [Member]          
Summary Of Significant Accounting Policies [Line Items]          
Depreciation, depletion and amortization 24,600,000 20,400,000 $ 50,300,000 $ 35,000,000  
Other property and equipment [Member]          
Summary Of Significant Accounting Policies [Line Items]          
Depreciation 500,000 500,000 $ 1,000,000 1,000,000  
Other property and equipment [Member] | Minimum [Member]          
Summary Of Significant Accounting Policies [Line Items]          
Property and equipment, expected lives     5 years    
Other property and equipment [Member] | Maximum [Member]          
Summary Of Significant Accounting Policies [Line Items]          
Property and equipment, expected lives     40 years    
Proved Oil And Gas Properties [Member] | Utica Shale [Member]          
Summary Of Significant Accounting Policies [Line Items]          
Impairment of oil and gas properties 0 0 $ 0 17,700,000  
Unproved Oil And Gas Properties [Member]          
Summary Of Significant Accounting Policies [Line Items]          
Impairment of oil and gas properties 4,100,000 $ 9,400,000 8,300,000 $ 18,700,000  
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member]          
Summary Of Significant Accounting Policies [Line Items]          
Fair value of commodity derivative contracts (2,300,000)   (2,300,000)   (48,100,000)
Unbilled Revenues [Member]          
Summary Of Significant Accounting Policies [Line Items]          
Accounts receivable $ 38,800,000   $ 38,800,000   $ 41,400,000