Note 2 - Revenue - Disaggregation of Revenue (Details) - USD ($)	3 Months Ended	9 Months Ended
Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Total contracts with customers	$ 16,655,418	$ 16,608,768	$ 92,399,419	$ 79,911,728
Alternative revenue programs	449,975	655,847	423,451	1,104,470
Revenue	17,105,393	17,264,615	92,822,870	81,016,198
Oil and Gas [Member] \| Residential [Member]
Total contracts with customers	8,856,258	8,677,898	54,726,706	47,091,604
Oil and Gas [Member] \| Commercial [Member]
Total contracts with customers	6,148,948	6,284,281	32,469,898	27,740,237
Oil and Gas [Member] \| Transportation and Interruptible [Member]
Total contracts with customers	1,528,443	1,472,948	4,618,742	4,454,693
Product and Service, Other [Member]
Total contracts with customers	121,769	173,641	584,073	625,194
Gas Utility [Member]
Total contracts with customers	16,632,091	16,583,703	92,326,634	79,834,220
Alternative revenue programs	449,975	655,847	423,451	1,104,470
Revenue	17,082,066	17,239,550	92,750,085	80,938,690
Gas Utility [Member] \| Oil and Gas [Member] \| Residential [Member]
Total contracts with customers	8,856,258	8,677,898	54,726,706	47,091,604
Gas Utility [Member] \| Oil and Gas [Member] \| Commercial [Member]
Total contracts with customers	6,148,948	6,284,281	32,469,898	27,740,237
Gas Utility [Member] \| Oil and Gas [Member] \| Transportation and Interruptible [Member]
Total contracts with customers	1,528,443	1,472,948	4,618,742	4,454,693
Gas Utility [Member] \| Product and Service, Other [Member]
Total contracts with customers	98,442	148,576	511,288	547,686
Non-utility [Member]
Total contracts with customers	23,327	25,065	72,785	77,508
Alternative revenue programs	0	0	0	0
Revenue	23,327	25,065	72,785	77,508
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	$ 23,327	$ 25,065	$ 72,785	$ 77,508