Acquisitions and Divestitures (Details) - USD ($)		1 Months Ended		3 Months Ended	6 Months Ended	9 Months Ended
	Jul. 31, 2018	Nov. 30, 2018	Jul. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Mar. 31, 2018	Mar. 01, 2018	Dec. 31, 2017	Sep. 29, 2017
Business Acquisition [Line Items]
Capitalized Costs, Proved Properties				$ 2,400,000		$ 3,200,000	$ 2,400,000
Asset Retirement Obligation						4,800,000
Business Acquisition, Transaction Costs						500,000
Proceeds from sales of assets, net						1,700,000
Business Acquisition, Pro Forma Revenue							321,221,000
Business Acquisition, Pro Forma Income (Loss) from Continuing Operations, Net of Tax							$ 26,162,000
Business Acquisition, Pro Forma Earnings Per Share, Basic							$ 1.74
Business Acquisition, Pro Forma Earnings Per Share, Diluted							$ 1.71
Second Lien Facility						200,000,000		$ 200,000,000				$ 200,000,000
Working Interests Acquisition [Member] [Domain]
Business Acquisition [Line Items]
Cash Paid on Date of Acquisition						6,000,000
Hunt Acquisition [Member]
Business Acquisition [Line Items]
Application of working capital adjustments	$ 200,000		$ 200,000							$ 245,000
Capitalized Costs, Proved Properties										82,443,000
Asset Retirement Obligation										356,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net										96,978,000
Net Cash Paid on Date of Acquisition										82,955,000
Payments to Acquire Business						$ 86,000,000.0
Cash Paid on Date of Acquisition										84,400,000
Accumulated Costs, net of suspended revenues, for wells in which Hunt elected not to participate										13,778,000
Business Acquisition, Transaction Costs									$ 400,000	96,978,000	$ 100,000
Capitalized Costs, Unproved Properties										$ 16,339,000
Cash Received for Suspended Revenues Attributable to Acquired Properties			1,448,000
Mid-Continent Divestiture [Member]
Business Acquisition [Line Items]
Application of working capital adjustments	(1,300,000)		(1,300,000)
Asset Retirement Obligation	300,000		$ 300,000
Proceeds from sales of assets, net	$ 6,200,000				$ 6,000,000.0
Cash Paid to Buyer in Connection with Final Settlement		$ 500,000
Cash Paid for Suspended Revenues in Connection with FInal Settlement		$ 200,000
Pre-Tax Operating Income Attributable to Assets Sold				$ 200,000			$ (1,600,000)