Supplemental Information on Oil and Natural Gas Operations (Unaudited) - Costs Incurred for Property Acquisition, Exploration and Development (Details) - USD ($) $ in Thousands	12 Months Ended
Sep. 30, 2021	Sep. 30, 2020
Acquisition of properties
Proved	$ 74	$ 1,187
Unproved	1,562	5,331
Exploration costs	7,993	8,039
Development costs	59,948	43,684
Total costs incurred	$ 69,577	$ 58,241

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Costs incurred, including capitalized costs and costs charged to expense, associated with the acquisition of oil and gas properties that have proved reserves.

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Costs incurred, including capitalized costs and costs charged to expense, associated with the acquisition of oil and gas properties that have unproved reserves.

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Development costs incurred, including capitalized costs and costs charged to expense, in oil and gas activities.

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Exploration costs incurred, including capitalized costs and costs charged to expense, in oil and gas activities.

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Amount of costs incurred related to oil and gas property acquisition, exploration and development activities, including capitalized costs and costs charged to expense.

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