Supplementary Information On Natural Gas, Oil And NGL Reserves (Summary of Net Quantities of Proved, Developed and Undeveloped Natural Gas Oil and NGL Reserves) (Details)	12 Months Ended
Sep. 30, 2022 Bcfe Mcf bbl	Sep. 30, 2021 Bcfe Mcf bbl	Sep. 30, 2020 Bcfe Mcf bbl
Reserve Quantities [Line Items]
Proved Natural Gas and Oil Reserves, Beginning Balance \| Bcfe	83.0	57.7	106.4
Revisions of previous estimates \| Bcfe	4.8	26.0	(45.9)
Acquisitions \| Bcfe	15.6	8.6	2.4
Divestitures \| Bcfe	(17.6)	(0.9)	(0.7)
Extensions, discoveries and other additions \| Bcfe	4.9	0.7	4.1
Production \| Bcfe	(9.6)	(9.1)	(8.6)
Proved Natural Gas and Oil Reserves, Ending Balance \| Bcfe	81.1	83.0	57.7
Natural Gas [Member]
Reserve Quantities [Line Items]
Proved Natural Gas and Oil Reserves, Beginning Balance \| Mcf	64,952,668	42,372,773	80,273,906
Revisions of previous estimates \| Mcf	2,405,959	21,930,522	(34,666,426)
Acquisitions \| Mcf	15,302,364	7,814,545	972,819
Divestitures \| Mcf	(16,624,066)	(820,122)	(60,966)
Extensions, discoveries and other additions \| Mcf	3,627,989	354,670	1,816,144
Production \| Mcf	(7,427,708)	(6,699,720)	(5,962,704)
Proved Natural Gas and Oil Reserves, Ending Balance \| Mcf	62,237,206	64,952,668	42,372,773
Oil [Member]
Reserve Quantities [Line Items]
Proved Natural Gas and Oil Reserves, Beginning Balance	1,504,840	1,333,657	2,380,090
Revisions of previous estimates	(13,498)	287,961	(1,094,923)
Acquisitions	29,987	91,198	156,133
Divestitures	(72,244)	(11,622)	(98,412)
Extensions, discoveries and other additions	132,227	28,125	260,555
Production	(198,535)	(224,479)	(269,786)
Proved Natural Gas and Oil Reserves, Ending Balance	1,382,777	1,504,840	1,333,657
NGL [Member]
Reserve Quantities [Line Items]
Proved Natural Gas and Oil Reserves, Beginning Balance	1,501,853	1,219,857	1,973,280
Revisions of previous estimates	409,597	389,825	(774,214)
Acquisitions	18,260	41,085	84,134
Divestitures	(83,931)	(4,174)	(13,201)
Extensions, discoveries and other additions	82,024	26,748	118,480
Production	(165,120)	(171,488)	(168,622)
Proved Natural Gas and Oil Reserves, Ending Balance	1,762,683	1,501,853	1,219,857

Energy measure of increase in quantity of proved reserve of oil and gas resulting from the extension of the proved acreage of previously discovered reservoir or discovery of new field with proved reserve or of new reservoir of proved reserve in old field, stated in a unit of energy. For example, but not limited to, barrel of oil equivalents (BOE) or one thousand cubic feet of natural gas equivalent (Mcfe).

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher SEC
-Name Form 20-F
-Section Item 18
-Subsection Instruction 2

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 235
-Section 50
-Paragraph 5
-Subparagraph (d)
-URI https://asc.fasb.org/extlink&oid=126939881&loc=d3e61831-109447

+ Details

Name:	srt_ProvedDevelopedAndUndevelopedReserveExtensionAndDiscoveryEnergy
Namespace Prefix:	srt_
Data Type:	dtr-types:energyItemType
Balance Type:	na
Period Type:	duration

- Definition

Energy measure of proved reserve of oil and gas, stated in a unit of energy. For example, but not limited to, barrel of oil equivalents (BOE) or one thousand cubic feet of natural gas equivalent (Mcfe).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher SEC
-Name Form 20-F
-Section Item 18
-Subsection Instruction 2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 235
-Section 50
-Paragraph 4
-URI https://asc.fasb.org/extlink&oid=126939881&loc=d3e61797-109447

+ Details

Name:	srt_ProvedDevelopedAndUndevelopedReserveNetEnergy
Namespace Prefix:	srt_
Data Type:	dtr-types:energyItemType
Balance Type:	na
Period Type:	instant

- Definition

Energy measure of decrease in quantity of proved reserve of oil and gas resulting from production, stated in a unit of energy. For example, but not limited to, barrel of oil equivalents (BOE) or one thousand cubic feet of natural gas equivalent (Mcfe).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher SEC
-Name Form 20-F
-Section Item 18
-Subsection Instruction 2

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 235
-Section 50
-Paragraph 5
-Subparagraph (e)
-URI https://asc.fasb.org/extlink&oid=126939881&loc=d3e61831-109447

+ Details

Name:	srt_ProvedDevelopedAndUndevelopedReserveProductionEnergy
Namespace Prefix:	srt_
Data Type:	dtr-types:energyItemType
Balance Type:	na
Period Type:	duration

- Definition

Energy measure of increase in quantity of proved reserve of oil and gas resulting from purchase of mineral in place, stated in a unit of energy. For example, but not limited to, barrel of oil equivalents (BOE) or one thousand cubic feet of natural gas equivalent (Mcfe).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher SEC
-Name Form 20-F
-Section Item 18
-Subsection Instruction 2

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 235
-Section 50
-Paragraph 5
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=126939881&loc=d3e61831-109447

+ Details

Name:	srt_ProvedDevelopedAndUndevelopedReservePurchaseOfMineralInPlaceEnergy
Namespace Prefix:	srt_
Data Type:	dtr-types:energyItemType
Balance Type:	na
Period Type:	duration

- Definition

Energy measure of increase (decrease) in quantity of proved reserve of oil and gas related to revision of a previous estimate resulting from new information, except for an increase in proved acreage, or change in economic factors, stated in a unit of energy. For example, but not limited to, barrel of oil equivalents (BOE) or one thousand cubic feet of natural gas equivalent (Mcfe).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher SEC
-Name Form 20-F
-Section Item 18
-Subsection Instruction 2

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 235
-Section 50
-Paragraph 5
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126939881&loc=d3e61831-109447

+ Details

Name:	srt_ProvedDevelopedAndUndevelopedReserveRevisionOfPreviousEstimateEnergy
Namespace Prefix:	srt_
Data Type:	dtr-types:energyItemType
Balance Type:	na
Period Type:	duration

- Definition

Additions to proved reserves that result from (1) extension of the proved acreage of previously discovered (old) reservoirs through additional drilling in periods after discovery and (2) discovery of new fields with proved reserves or of new reservoirs of proved reserves in old fields.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher SEC
-Name Form 20-F
-Section Item 18
-Subsection Instruction 2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 235
-Section 50
-Paragraph 5
-Subparagraph (d)
-URI https://asc.fasb.org/extlink&oid=126939881&loc=d3e61831-109447

+ Details

Name:	srt_ProvedDevelopedAndUndevelopedReservesExtensionsDiscoveriesAndAdditions
Namespace Prefix:	srt_
Data Type:	dtr-types:volumeItemType
Balance Type:	na
Period Type:	duration

- Definition

The net quantity of proved reserves as of the balance sheet date. Proved oil reserves are the estimated quantities of crude oil and natural gas liquids which geological and engineering data demonstrate with reasonable certainty to be recoverable.

+ References

+ Details

Name:	srt_ProvedDevelopedAndUndevelopedReservesNet
Namespace Prefix:	srt_
Data Type:	dtr-types:volumeItemType
Balance Type:	na
Period Type:	instant

- Definition

Production of proved reserves.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher SEC
-Name Form 20-F
-Section Item 18
-Subsection Instruction 2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 235
-Section 50
-Paragraph 5
-Subparagraph (e)
-URI https://asc.fasb.org/extlink&oid=126939881&loc=d3e61831-109447

+ Details

Name:	srt_ProvedDevelopedAndUndevelopedReservesProduction
Namespace Prefix:	srt_
Data Type:	dtr-types:volumeItemType
Balance Type:	na
Period Type:	duration

- Definition

Purchase of minerals in place.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher SEC
-Name Form 20-F
-Section Item 18
-Subsection Instruction 2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 235
-Section 50
-Paragraph 5
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=126939881&loc=d3e61831-109447

+ Details

Name:	srt_ProvedDevelopedAndUndevelopedReservesPurchasesOfMineralsInPlace
Namespace Prefix:	srt_
Data Type:	dtr-types:volumeItemType
Balance Type:	na
Period Type:	duration

- Definition

Revisions represent changes in previous estimates of proved reserves, either upward or downward, resulting from new information (except for an increase in proved acreage) normally obtained from development drilling and production history or resulting from change in economic factors.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher SEC
-Name Form 20-F
-Section Item 18
-Subsection Instruction 2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 235
-Section 50
-Paragraph 5
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126939881&loc=d3e61831-109447

+ Details

Name:	srt_ProvedDevelopedAndUndevelopedReservesRevisionsOfPreviousEstimatesIncreaseDecrease
Namespace Prefix:	srt_
Data Type:	dtr-types:volumeItemType
Balance Type:	na
Period Type:	duration

- Definition

Energy measure of decrease in quantity of proved reserve of oil and gas resulting from sale of mineral in place, stated in a unit of energy. For example, but not limited to, barrel of oil equivalents (BOE) or one thousand cubic feet of natural gas equivalent (Mcfe).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher SEC
-Name Form 20-F
-Section Item 18
-Subsection Instruction 2

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 235
-Section 50
-Paragraph 5
-Subparagraph (f)
-URI https://asc.fasb.org/extlink&oid=126939881&loc=d3e61831-109447

+ Details

Name:	srt_ProvedDevelopedAndUndevelopedReservesSaleOfMineralInPlaceEnergy
Namespace Prefix:	srt_
Data Type:	dtr-types:energyItemType
Balance Type:	na
Period Type:	duration

- Definition

Sales of minerals in place.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher SEC
-Name Form 20-F
-Section Item 18
-Subsection Instruction 2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 235
-Section 50
-Paragraph 5
-Subparagraph (f)
-URI https://asc.fasb.org/extlink&oid=126939881&loc=d3e61831-109447

+ Details

Name:	srt_ProvedDevelopedAndUndevelopedReservesSalesOfMineralsInPlace
Namespace Prefix:	srt_
Data Type:	dtr-types:volumeItemType
Balance Type:	na
Period Type:	duration

- Definition

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.

+ Details

Name:	srt_ReserveQuantitiesLineItems
Namespace Prefix:	srt_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	srt_ReserveQuantitiesByTypeOfReserveAxis=srt_NaturalGasReservesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ReserveQuantitiesByTypeOfReserveAxis=srt_OilReservesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ReserveQuantitiesByTypeOfReserveAxis=srt_NaturalGasLiquidsReservesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: