Acquisitions and Divestitures - Narrative (Details) $ / shares in Units, $ in Thousands			3 Months Ended					9 Months Ended
	Feb. 26, 2021 USD ($) a well $ / shares shares	Dec. 20, 2019 USD ($) a well	Jun. 30, 2021 USD ($) $ / shares shares	Mar. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Jun. 30, 2020 USD ($)	Dec. 31, 2019 USD ($)	Jun. 30, 2021 USD ($) $ / shares shares	Jun. 30, 2020 USD ($)	Apr. 02, 2021 USD ($)	Mar. 10, 2021 USD ($)	Sep. 30, 2020 $ / shares shares
Business Acquisition [Line Items]
Common stock, par value (USD per Share) | $ / shares			$ 0.001					$ 0.001				$ 0.001
Reverse stock split				83.000
Common stock outstanding post merger (in Shares) | shares	17,800,000		18,021,521					18,021,521				0
Transaction costs			$ 321			$ 15		$ 3,534	$ 42
Loss on discontinued operations			(967)			$ 0		(19,573)	$ 0
Transaction costs			200	$ 2,200	$ 1,000
Kansas Properties
Business Acquisition [Line Items]
Consideration from discontinued operations										$ 3,500	$ 3,500
Consideration from discontinued operations, closing adjustments										$ 200
Pro Forma
Business Acquisition [Line Items]
Transaction costs							$ 3,400
Impairment of oil and gas properties					$ 900
Kansas Properties
Business Acquisition [Line Items]
Loss on discontinued operations			1,000					19,600
Kansas Properties | Oil
Business Acquisition [Line Items]
Number of net acres acquired | a	11,000
Number of wells acquired, producing | well	153
Number of wells acquired, shut-in | well	19
Number of wells acquired, temporarily abandoned | well	6
Number of wells acquired, active disposal | well	36
J. Cleo Thompson and James Cleo Thompson, Jr., L.P. | Natural gas
Business Acquisition [Line Items]
Number of net acres acquired | a		1,237
Number of wells acquired, producing | well		11
Number of wells acquired | well		17
Number of wells acquired, salt water disposal | well		6
Consideration transferred		$ 3,300
Riley Exploration
Business Acquisition [Line Items]
Total consideration	$ 26,392
Transaction costs								4,800
Transaction costs, success fees								1,750
Acquisition related costs, paid at closing			300					$ 300
Acquisition related costs, paid at closing, period								30 days
Loss of acquiree since acquisition date, actual								$ 115
Riley Exploration | General and Administrative Expense
Business Acquisition [Line Items]
Transaction costs			$ 300					$ 3,400
TGC
Business Acquisition [Line Items]
Common stock, par value (USD per Share) | $ / shares	$ 0.001
Stock conversion ratio	97.796467
Reverse stock split	0.083