Summary of Significant Accounting Policies - Additional Information 1 (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2017 USD ($) a	Sep. 30, 2016 USD ($)	Sep. 30, 2017 USD ($) a Well	Sep. 30, 2016 USD ($)
Operations And Summary Of Significant Accounting Policies [Line Items]
JV acreage cost reimbursement working interest per well	25.00%		25.00%
Bossier shale JV wells gross wells | Well			4
Working interest for JV acreage and infrastructure			50.00%
Proceeds received to meet or exceed JV production targets			$ 400,000
Proceeds to be received per JV drilled well			80,000
Proceeds from sale of oil and gas properties	$ 1,500,000		1,500,000	$ 2,100,000
Loss on sale of oil and gas properties	(1,000,000)		(1,000,000)	(1,600,000)
Impairment of oil and gas properties		$ 113,000		24,573,000
Impairment of unproved oil and natural gas properties		76,400,000		84,100,000
Cash flow hedges derivative instruments	0		0
Commodity Derivatives | Natural Gas Properties
Operations And Summary Of Significant Accounting Policies [Line Items]
Gain on derivative financial instruments	$ 1,400,000	0	$ 14,600,000	700,000
Oil and Gas Properties Impairment related to Assets Held For Sale
Operations And Summary Of Significant Accounting Policies [Line Items]
Impairment of oil and gas properties				20,800,000
Oil and Gas Properties Impairment excluding Assets Held For Sale
Operations And Summary Of Significant Accounting Policies [Line Items]
Impairment of oil and gas properties		$ 100,000		$ 24,600,000
Caddo Parish Louisiana
Operations And Summary Of Significant Accounting Policies [Line Items]
Joint venture approximate net acreage | a	7,000		7,000
Harrison County Texas
Operations And Summary Of Significant Accounting Policies [Line Items]
Joint venture approximate net acreage | a	5,700		5,700
Proceeds to be received for acreage and infrastructure			$ 1,400,000
Sabine Parish Louisiana
Operations And Summary Of Significant Accounting Policies [Line Items]
Proceeds to be received for acreage and infrastructure			$ 1,100,000