Oil and Natural Gas Properties - Narrative (Details) $ in Thousands	12 Months Ended
Sep. 30, 2021 USD ($) well	Sep. 30, 2020 USD ($) well
Capitalized Costs Relating to Oil and Gas Producing Activities, by Geographic Area [Line Items]
Number of exploratory drilled \| well	1	2
Exploratory well costs	$ 3,700	$ 7,100
Number of developed wells completed \| well	1
Proved properties, transfer in	$ 3,400
Depletion and amortization	25,200	20,800
Exploration costs	9,566	9,923
Oil and gas lease expirations	$ 9,347	$ 7,902
Minimum
Capitalized Costs Relating to Oil and Gas Producing Activities, by Geographic Area [Line Items]
Capitalized exploratory well costs capitalized period	1 year
Maximum
Capitalized Costs Relating to Oil and Gas Producing Activities, by Geographic Area [Line Items]
Capitalized exploratory well costs capitalized period	2 years

Capitalized Exploratory Well Costs, Capitalized Period

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- Definition

Capitalized Exploratory Well Costs, Transfer In To Proved Oil and Gas Property, Successful Effort Method

+ References

No definition available.

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- Definition

Number of development oil and gas wells capable of producing either oil or gas in sufficient quantity to justify completion as oil or gas well.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher SEC
-Name Regulation S-K (SK)
-Number 229
-Section 1205
-Paragraph (a)
-Subparagraph (2)

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Number of exploratory oil and gas wells capable of producing either oil or gas in sufficient quantity to justify completion as oil or gas well.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher SEC
-Name Regulation S-K (SK)
-Number 229
-Section 1205
-Paragraph (a)
-Subparagraph (1)

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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The amount of capitalized exploratory well costs that is pending the determination of proved reserves. This does not include amounts that were capitalized and subsequently expensed in the same annual period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 235
-Section 50
-Paragraph 1B
-Subparagraph (a)
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- Definition

The noncash expense charged against earnings to recognize the consumption of oil and gas reserves that are part of an entities' assets.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3602-108585

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Exploration expenses (including prospecting) related to oil and gas producing entities and would be included in operating expenses of that entity. Costs incurred in identifying areas that may warrant examination and in examining specific areas that are considered to have prospects of containing oil and gas reserves, including costs of drilling exploratory wells and exploratory-type stratigraphic test wells. Exploration costs may be incurred both before acquiring the related property (sometimes referred to in part as prospecting costs) and after acquiring the property. Principal types of exploration costs, which include depreciation and applicable operating costs of support equipment and facilities and other costs of exploration activities, are: (i) Costs of topographical, geographical and geophysical studies, rights of access to properties to conduct those studies, and salaries and other expenses of geologists, geophysical crews, and others conducting those studies. Collectively, these are sometimes referred to as geological and geophysical or "G&G" costs. (ii) Costs of carrying and retaining undeveloped properties, such as delay rentals, ad valorem taxes on properties, legal costs for title defense, and the maintenance of land and lease records. (iii) Dry hole contributions and bottom hole contributions. (iv) Costs of drilling and equipping exploratory wells. (v) Costs of drilling exploratory-type stratigraphic test wells.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 235
-Section 50
-Paragraph 23
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=123377692&loc=d3e62136-109447

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The expense charged against earnings to eliminate the capitalized costs of projects that have been terminated during the reporting period, which is added back to net income when calculating cash provided by (used in) operations using the indirect method.

+ References

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