Condensed Consolidated Statements of Income - USD ($)	3 Months Ended		6 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019
OPERATING REVENUES:
Operating revenues	$ 22,437,731	$ 25,274,959	$ 42,223,184	$ 46,491,706
OPERATING EXPENSES:
Operations and maintenance	4,110,149	3,714,084	8,027,619	7,236,083
General taxes	587,873	556,336	1,131,110	1,064,225
Depreciation and amortization	1,988,216	1,905,475	3,976,721	3,810,950
Total operating expenses	15,438,115	19,071,476	30,141,589	37,024,001
OPERATING INCOME	6,999,616	6,203,483	12,081,595	9,467,705
Equity in earnings of unconsolidated affiliate	1,188,593	698,175	2,282,679	1,261,224
Other income, net	317,892	121,709	475,535	247,595
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
INCOME TAX EXPENSE	1,787,492	1,460,628	3,029,079	2,162,841
NET INCOME	$ 5,680,316	$ 4,670,090	$ 9,687,252	$ 7,104,252
BASIC EARNINGS PER COMMON SHARE (in dollars per share)	$ 0.70	$ 0.58	$ 1.20	$ 0.89
DILUTED EARNINGS PER COMMON SHARE (in dollars per share)	0.70	0.58	1.19	0.88
DIVIDENDS DECLARED PER COMMON SHARE (in dollars per share)	$ 0.175	$ 0.165	$ 0.35	$ 0.33
Gas Utility [Member]
OPERATING REVENUES:
Operating revenues	$ 22,275,719	$ 25,058,749	$ 41,901,325	$ 46,095,330
OPERATING EXPENSES:
Cost of gas and sales	8,672,997	12,771,338	16,850,803	24,677,797
Non Utility [Member]
OPERATING REVENUES:
Operating revenues	162,012	216,210	321,859	396,376
OPERATING EXPENSES:
Cost of gas and sales	$ 78,880	$ 124,243	$ 155,336	$ 234,946