Percentage points added to the reference rate to compute the variable rate on the debt instrument.

No definition available.

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Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22)(a)(1))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of the required periodic payments applied to principal.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-SubTopic 10
-Topic 210
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Indicates type of variable interest rate on debt instrument.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 470
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477734/942-470-50-3

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	enum2:enumerationSetItemType
Balance Type:	na
Period Type:	duration

- Definition

Fixed interest rate related to the interest rate derivative.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Details

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- Details

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- Details

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- Details

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Note 7 - Long-term Debt - Long-term Debt (Details) (Parentheticals) - USD ($)			1 Months Ended	12 Months Ended
	May 02, 2024	Mar. 06, 2024	Jul. 31, 2025	Sep. 30, 2024
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration]	Secured Overnight Financing Rate (SOFR) [Member]	Secured Overnight Financing Rate (SOFR) [Member]	Secured Overnight Financing Rate (SOFR) [Member]	Secured Overnight Financing Rate (SOFR) [Member]
Roanoke Gas Company [Member] \| Unsecured Senior Notes Payable, at 4.26%, Due on September 18, 2034 [Member]
Stated rate				4.26%
Roanoke Gas Company [Member] \| Unsecured Term Notes Payable, at 3.58%, Due on October 2, 2027 [Member] \| Unsecured Senior Notes Payable [Member]
Stated rate				3.58%
Roanoke Gas Company [Member] \| Unsecured Term Notes Payable, at 4.41 %, Due on March 28, 2031 [Member] \| Unsecured Senior Notes Payable [Member]
Stated rate				4.41%
Roanoke Gas Company [Member] \| Unsecured Term Notes Payable, at 3.60%, Due on December 6, 2029 [Member] \| Unsecured Senior Notes Payable [Member]
Stated rate				3.60%
Roanoke Gas Company [Member] \| Unsecured Term Note Payable, at 30-day SOFR Plus 1.20%, Due August 20, 2026 [Member] \| Unsecured Senior Notes Payable [Member]
Debt Instrument, Basis Spread on Variable Rate				1.20%
Derivative, Fixed Interest Rate				2.00%
Roanoke Gas Company [Member] \| Unsecured term note payable, at Term SOFR plus 1.00%, due October 1, 2028 [Member] \| Unsecured Senior Notes Payable [Member]
Debt Instrument, Basis Spread on Variable Rate				1.00%
Derivative, Fixed Interest Rate				2.49%
RGC Midstream LLC [Member] \| Unsecured term note payable at Term SOFR plus 1.55%, due December 31, 2025 [Member] \| Unsecured Senior Notes Payable [Member]
Debt Instrument, Basis Spread on Variable Rate				1.55%
RGC Midstream LLC [Member] \| Unsecured term note payable, at Daily Simple SOFR plus 1.26448%, due June 12, 2026[Member] \| Unsecured Senior Notes Payable [Member]
Debt Instrument, Basis Spread on Variable Rate				1.26448%
Derivative, Fixed Interest Rate				3.24%
RGC Midstream LLC [Member] \| Unsecured term note payable, at Daily Simple SOFR plus 1.26448%, due January 1, 2028 [Member] \| Unsecured Senior Notes Payable [Member]
Debt Instrument, Basis Spread on Variable Rate				1.26448%
Derivative, Fixed Interest Rate				2.443%
Debt Instrument, Periodic Payment				$ 400,000
RGC Midstream LLC [Member] \| Revolving Credit Facility, at Daily Simple SOFR plus 2.215%, due May 2, 2026 [Member \| Revolving Credit Facility [Member]
Debt Instrument, Basis Spread on Variable Rate				2.215%