Note 2 - Revenue - Disaggregation of Revenue (Details) - USD ($)	3 Months Ended	9 Months Ended
Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Total contracts with customers	$ 16,608,768	$ 13,552,645	$ 79,911,728	$ 67,729,290
Alternative revenue programs	655,847	905,557	1,104,470	3,807,640
Revenue	17,264,615	14,458,202	81,016,198	71,536,930
Oil and Gas [Member] \| Residential [Member]
Total contracts with customers	8,677,898	7,333,332	47,091,604	40,001,039
Oil and Gas [Member] \| Commercial [Member]
Total contracts with customers	6,284,281	4,706,086	27,740,237	22,946,163
Oil and Gas [Member] \| Transportation and Interruptible [Member]
Total contracts with customers	1,472,948	1,317,890	4,454,693	4,047,151
Product and Service, Other [Member]
Total contracts with customers	173,641	195,337	625,194	734,937
Gas Utility [Member]
Total contracts with customers	16,583,703	13,525,822	79,834,220	67,647,924
Alternative revenue programs	655,847	905,557	1,104,470	3,807,640
Revenue	17,239,550	14,431,379	80,938,690	71,455,564
Gas Utility [Member] \| Oil and Gas [Member] \| Residential [Member]
Total contracts with customers	8,677,898	7,333,332	47,091,604	40,001,039
Gas Utility [Member] \| Oil and Gas [Member] \| Commercial [Member]
Total contracts with customers	6,284,281	4,706,086	27,740,237	22,946,163
Gas Utility [Member] \| Oil and Gas [Member] \| Transportation and Interruptible [Member]
Total contracts with customers	1,472,948	1,317,890	4,454,693	4,047,151
Gas Utility [Member] \| Product and Service, Other [Member]
Total contracts with customers	148,576	168,514	547,686	653,571
Non-utility [Member]
Total contracts with customers	25,065	26,823	77,508	81,366
Alternative revenue programs	0	0	0	0
Revenue	25,065	26,823	77,508	81,366
Non-utility [Member] \| Oil and Gas [Member] \| Residential [Member]
Total contracts with customers	0	0	0	0
Non-utility [Member] \| Oil and Gas [Member] \| Commercial [Member]
Total contracts with customers	0	0	0	0
Non-utility [Member] \| Oil and Gas [Member] \| Transportation and Interruptible [Member]
Total contracts with customers	0	0	0	0
Non-utility [Member] \| Product and Service, Other [Member]
Total contracts with customers	$ 25,065	$ 26,823	$ 77,508	$ 81,366