Segment Information (Reconciliation of Segment Information to Consolidated) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019	Sep. 30, 2019
Segment Reporting Information [Line Items]
Operating revenues	$ 22,437,731	$ 25,274,959	$ 42,223,184	$ 46,491,706
Depreciation	1,988,216	1,905,475	3,976,721	3,810,950
Operating income (loss)	6,999,616	6,203,483	12,081,595	9,467,705
Equity in earnings	1,188,593	698,175	2,282,679	1,261,224
Interest expense	1,038,293	892,649	2,123,478	1,709,431
Income before income taxes	7,467,808	6,130,718	12,716,331	9,267,093
Total assets	270,588,176		270,588,176		$ 258,353,696
Operating Segments | Gas Utility
Segment Reporting Information [Line Items]
Operating revenues	22,275,719	25,058,749	41,901,325	46,095,330
Depreciation	1,988,216	1,905,475	3,976,721	3,810,950
Operating income (loss)	6,988,528	6,154,052	12,030,013	9,384,877
Equity in earnings	0	0	0	0
Interest expense	661,997	585,509	1,380,850	1,161,748
Income before income taxes	6,642,411	5,689,205	11,121,293	8,468,126
Total assets	201,148,338		201,148,338		195,969,019
Operating Segments | Investment In Affiliates
Segment Reporting Information [Line Items]
Operating revenues	0	0	0	0
Depreciation	0	0	0	0
Operating income (loss)	(69,526)	(39,394)	(108,117)	(73,281)
Equity in earnings	1,188,593	698,175	2,282,679	1,261,224
Interest expense	376,296	307,140	742,628	547,683
Income before income taxes	744,698	352,581	1,435,052	642,676
Total assets	52,637,208		52,637,208		47,429,368
Parent and Other
Segment Reporting Information [Line Items]
Operating revenues	162,012	216,210	321,859	396,376
Depreciation	0	0	0	0
Operating income (loss)	80,614	88,825	159,699	156,109
Equity in earnings	0	0	0	0
Interest expense	0	0	0	0
Income before income taxes	80,699	$ 88,932	159,986	$ 156,291
Total assets	$ 16,802,630		$ 16,802,630		$ 14,955,309