Note 11 - Other Stock Plans (Details Textual) - USD ($)	12 Months Ended
Sep. 30, 2025	Sep. 30, 2024
Maximum Amount Allowed For Dividend Reinvestment and Stock Purchase Plan	$ 100,000
Stock Issued During Period, Shares, Dividend Reinvestment Plan (in shares)	30,027	33,226
Stock Available for Issuance under Dividend Reinvestment Plan (in shares)	202,371
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares)	16,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Forfeitures in Period (in shares)		4,000
Restricted Stock [Member] \| Restricted Stock Plan for Outside Directors [Member]
Share Based Compensation by Share Based Payment Award, Maximum Allowed Percentage of Retainer Fee Paid Monthly in Common Stock	100.00%
Share Based Compensation by Share Based Payment Award, Percentage of Retainer Fee Paid Monthly in Common Stock	40.00%
Share Based Compensation by Share Based Payment Award, Minimum Shares Owned Requirement (in shares)	10,000
Shares Issued, Value, Share-Based Payment Arrangement, after Forfeiture	$ 331,030	$ 299,200
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeited in Period (in shares)	0	0
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares)	149,022
Restricted Stock [Member] \| RGC Resources Inc. Restricted Stock Plan [Member]
Shares Issued, Value, Share-Based Payment Arrangement, after Forfeiture	$ 673,057	$ 660,424
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares)	286,560
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount	$ 222,026	$ 285,683
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Forfeitures in Period (in shares)	0	0
Restricted Stock [Member] \| Stock Bonus Plan [Member]
Shares Issued, Value, Share-Based Payment Arrangement, after Forfeiture	$ 27,500	$ 24,841
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares)	1,766
Share-Based Compensation Arrangement by Share-Based Payment Award, Shares Issued in Period (in shares)	1,352	1,562

The maximum amount allowed for dividend reinvestment and stock purchase plan.

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The maximum allowed percentage of retainer fee paid monthly in common stock under share based payment arrangement.

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The minimum number of shares required to be owned under share based payment arrangement.

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The percentage of retainer fee paid monthly in common stock under share based payment arrangement.

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Number of shares available for issuance under dividend reinvestment plan.

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Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

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The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan.

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Number of shares issued under share-based payment arrangement.

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Number of shares issued during the period from a dividend reinvestment plan (DRIP). A dividend reinvestment plan allows the shareholders to reinvest dividends paid to them by the entity on new issues of stock by the entity.

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Value, after forfeiture, of shares issued under share-based payment arrangement. Excludes employee stock ownership plan (ESOP).

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