Note 2 - Revenue (Tables)

9 Months Ended

Jun. 30, 2026

Notes Tables

Disaggregation of Revenue [Table Text Block]

		Three Months Ended June 30, 2026												Three Months Ended June 30, 2025
		Gas utility				Non utility				Total operating revenues				Gas utility				Non utility				Total operating revenues
Natural Gas (Billed and Unbilled):
Residential		$	8,856,258			$	—			$	8,856,258			$	8,677,898			$	—			$	8,677,898
Commercial			6,148,948				—				6,148,948				6,284,281				—				6,284,281
Transportation and interruptible			1,528,443				—				1,528,443				1,472,948				—				1,472,948
Other			98,442				23,327				121,769				148,576				25,065				173,641
Total contracts with customers			16,632,091				23,327				16,655,418				16,583,703				25,065				16,608,768
Alternative revenue programs			449,975				—				449,975				655,847				—				655,847
Total operating revenues		$	17,082,066			$	23,327			$	17,105,393			$	17,239,550			$	25,065			$	17,264,615

		Nine Months Ended June 30, 2026												Nine Months Ended June 30, 2025
		Gas utility				Non utility				Total operating revenues				Gas utility				Non utility				Total operating revenues
Natural Gas (Billed and Unbilled):
Residential		$	54,726,706			$	—			$	54,726,706			$	47,091,604			$	—			$	47,091,604
Commercial			32,469,898				—				32,469,898				27,740,237				—				27,740,237
Transportation and interruptible			4,618,742				—				4,618,742				4,454,693				—				4,454,693
Other			511,288				72,785				584,073				547,686				77,508				625,194
Total contracts with customers			92,326,634				72,785				92,399,419				79,834,220				77,508				79,911,728
Alternative revenue programs			423,451				—				423,451				1,104,470				—				1,104,470
Total operating revenues		$	92,750,085			$	72,785			$	92,822,870			$	80,938,690			$	77,508			$	81,016,198

Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block]

		Current Assets								Current Liabilities
		Trade accounts receivable⁽¹⁾				Unbilled revenue⁽¹⁾				Customer credit balances				Customer deposits
Balance at September 30, 2025		$	3,354,154			$	1,373,512			$	1,891,161			$	1,537,311
Balance at June 30, 2026			4,971,493				1,329,228				1,097,450				1,962,431
Increase (decrease)		$	1,617,339			$	(44,284	)		$	(793,711	)		$	425,120