Discontinued Operations and Assets Held for Sale - Statement of Operations (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
	Mar. 01, 2021	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Apr. 02, 2021	Mar. 10, 2021
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss from discontinued operations before income taxes		$ (882)	$ 0	$ (19,513)	$ 0
Income tax expense		(85)	0	(60)	0
Loss on discontinued operations		(967)	$ 0	(19,573)	$ 0
Kansas Properties
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Consideration from discontinued operations						$ 3,500	$ 3,500
Kansas Properties | Discontinued Operations, Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Consideration from discontinued operations							$ 3,500
Closing costs	$ 200
Total revenues		0		0
Lease operating expenses		0		115
Goodwill impairment		0		18,516
Total expenses		0		18,631
Other expense		882		882
Loss from discontinued operations before income taxes		(882)		(19,513)
Income tax expense		(85)		(60)
Loss on discontinued operations		(967)		(19,573)
Kansas Properties | Discontinued Operations, Disposed of by Sale | Oil and natural gas sales, net
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total revenues		$ 0		$ 0