Acquisitions and Divestitures - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions		1 Months Ended				3 Months Ended				4 Months Ended	12 Months Ended			15 Months Ended
	Apr. 24, 2013	Oct. 31, 2015	Sep. 30, 2015	Aug. 31, 2015	May. 31, 2015	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Jun. 30, 2013	Apr. 24, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Jul. 31, 2014
Significant Acquisitions and Disposals
Loss per share – basic and diluted													$ (2.27)
Total revenues													$ 457,811
Sale Leaseback Transaction, Deferred Gain, Current											$ 400
Sale Leaseback Transaction, Deferred Gain, Net											9,400
Business Combination, Consideration Transferred	$ 401,000									$ 401,000
Payments to Acquire Businesses, Net of Cash Acquired											0	$ 0	358,239
Fair value of the Shares issued to seller											0	0	42,300
(Gain) loss on sales of assets, net											(41,335)	(120,769)	266
Payments To Settle Obligations Assumed In Acquisition Net											0	(33,712)	22,455
Eagle Ford Shale, Lavaca County [Member]
Significant Acquisitions and Disposals
Payments to Acquire Oil and Gas Property						$ 34,900
Business Combination, Consideration Transferred, Liabilities Incurred						10,700
Payments to Acquire Businesses, Gross												45,600
Proceeds from Sale of Oil and Gas Property and Equipment		$ 12,500
Gain on sale of oil and gas property											9,500
East Texas [Member]
Significant Acquisitions and Disposals
Proceeds from Sale of Oil and Gas Property and Equipment				$ 73,000
Gain on sale of oil and gas property					$ 43,000
Disposal Group, Including Discontinued Operation, Property, Plant and Equipment					29,500
Disposal Group, Including Discontinued Operation, Assets					33,300
Disposal Group, Including Discontinued Operation, Asset Retirement Obligation					$ 3,800
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax											1,300	(27,500)	(22,200)
South Texas Oil Gathering Sys. Development Rights
Significant Acquisitions and Disposals
Proceeds from Sale of Intangible Assets						147,100
Gain (Loss) on Disposition of Assets						147,100
Sale Leaseback Transaction, Recognized Gain, Net						63,000
Amount of the deferred gain recognized in the current period			$ 8,400
Sale Leaseback Transaction, Deferred Gain, Current											2,200
Sale Leaseback Transaction, Deferred Gain, Net											73,600
Sale Leaseback Transaction, Deferred Gain, Gross												84,100
Selma Chalk, MS Assets
Significant Acquisitions and Disposals
Proceeds from Sale of Oil and Gas Property and Equipment						67,900
Impairment of property							$ 117,900				117,900
South Texas Natural Gas Gathering Assets
Significant Acquisitions and Disposals
Sale Leaseback Transaction, Recognized Gain, Net								$ 56,700
Amount of the deferred gain recognized in the current period											$ 400	400
Proceeds from Sale of Oil and Gas Property and Equipment								96,000
(Gain) loss on sales of assets, net								$ (67,300)
Non-core assets
Significant Acquisitions and Disposals
Proceeds from Sale of Oil and Gas Property and Equipment												2,900
Net Payments on Post Closing Adjustments from Property Sales in Prior Years												100
(Gain) loss on sales of assets, net												(200)
Gain (Loss) on Disposition of Property, Plant and Equipment due to Post-close Adjustment												(300)
EF Acquisition
Significant Acquisitions and Disposals
Payments to Acquire Businesses, Gross	380,000
Oil and gas properties - proved	267,688									267,688
Oil and gas properties - unproved	$ 119,709									$ 119,709
Issuance of common stock in acquisition (shares, in millions)	10
PVA common stock price	$ 4.23									$ 4.23
Preferential Purchase Right Settlement									$ 21,000
Fair value of receivables acquired	$ 107,345									$ 107,345
Other assets acquired	2,068									2,068
Fair value of assets acquired	496,810									496,810
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accounts Payable	94,771									94,771
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Other	1,500									1,500
Total liabilities assumed in acquisition	96,271									96,271
Business Combination, Acquisition Related Costs													2,600
Business Combination, Consideration Transferred	400,539									400,539
Payments to Acquire Businesses, Net of Cash Acquired	358,239
Fair value of the Shares issued to seller	42,300
Business Combination, Consideration Transferred	$ 400,539
Business Combination Purchase Price Adjustments										$ 19,000
Payments To Settle Obligations Assumed In Acquisition Net													$ 22,500
Disputed Contractual Adjustments, Settled in Arbitration						$ 35,100
Arbitration Settlement Interest														$ 1,300
Professional fees, post acquisition arbitration proceedings												$ 600