Acquisitions and Divestitures - Additional Information (Detail) $ / shares in Units, $ in Thousands			1 Months Ended		3 Months Ended			9 Months Ended	12 Months Ended
	Jul. 31, 2018 USD ($)	Mar. 01, 2018 USD ($)	Jul. 31, 2018 USD ($)	Mar. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Dec. 31, 2017 USD ($) a	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($) $ / shares	Dec. 31, 2017 USD ($) a $ / shares	Sep. 29, 2017 a
Significant Acquisitions and Disposals
Capitalized Costs, Proved Properties						$ 2,400			$ 4,100	$ 3,700	$ 2,400
Second Lien Facility									200,000	200,000
Property, Plant and Equipment, Gross									1,488,334	1,121,860
Asset Retirement Obligation						$ 3,286			4,934	4,314	$ 3,286
Cash Received for Suspended Revenues Attributable to Acquired Properties		$ 355
Mid-Continent Divestiture [Member]
Significant Acquisitions and Disposals
Proceeds from Sale of Oil and Gas Property and Equipment	$ 6,200								6,000
Cash Paid to Buyer in Connection with Final Settlement									500
Cash Paid for Suspended Revenues in Connection with FInal Settlement									200
Asset Retirement Obligation									300
Working Capital Adjustments, Net	1,300		$ 1,300
Pre-Tax Operating Income Attributable to Assets Sold					$ (1,600)		$ (2,200)
Undeveloped Acreage [Member]
Significant Acquisitions and Disposals
Proceeds from Sale of Oil and Gas Property and Equipment									1,700
Working Interests Acquisition [Member] [Domain]
Significant Acquisitions and Disposals
Cash Paid on Date of Acquisition									6,500
Hunt Acquisition [Member]
Significant Acquisitions and Disposals
Capitalized Costs, Proved Properties		82,443
Area of Land | a						9,700					9,700
Other Payments to Acquire Businesses									86,000
Cash Paid on Date of Acquisition		83,000
Accumulated Costs, net of suspended revenues, for wells in which Hunt elected not to participate		13,778
Business Acquisition, Transaction Costs		96,978		$ 400		$ 100			500		$ 100
Capitalized Costs, Proved Properties		16,339
Asset Retirement Obligation		356
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net		96,978
Working Capital Adjustments, Net	$ (245)		(245)
Cash Received for Suspended Revenues Attributable to Acquired Properties			$ 1,448
Net Cash Paid on Date of Acquisition		82,955
Devon Acquisition [Member]
Significant Acquisitions and Disposals
Business Acquisition, Revenue Reported by Acquired Entity since Acquisition Date				400		9,000
Business Acquisition, Pro Forma Revenue										446,077	209,015
Capitalized Costs, Proved Properties		42,866
Acreage, Net | a												19,600
Other Payments to Acquire Businesses									205,000	199,800	200,900
Cash Paid on Date of Acquisition		199,796
Business Acquisition, Transaction Costs									$ 1,300
Capitalized Costs, Proved Properties		146,686
Property, Plant and Equipment, Gross		8,642
Asset Retirement Obligation		494
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net		197,345
Working Capital Adjustments, Net		(2,451)
Preliminary Purchase Price		$ 197,345
Business Acquisition, Pro Forma Income (Loss) from Continuing Operations, Net of Tax										$ 227,930	$ 30,861
Business Acquisition, Pro Forma Earnings Per Share, Basic | $ / shares										$ 15.14	$ 2.06
Business Acquisition, Pro Forma Earnings Per Share, Diluted | $ / shares										$ 14.91	$ 2.05
Cash Received for Suspended Revenues Attributable to Acquired Properties								$ 1,100
Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual				$ 200		$ 4,000