Condensed Consolidated Statements of Income - USD ($)	3 Months Ended		6 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
OPERATING REVENUES:
Operating revenues	$ 25,274,959	$ 24,917,973	$ 46,491,706	$ 43,674,024
OPERATING EXPENSES:
Operations and maintenance	3,714,084	3,488,889	7,236,083	6,716,633
General taxes	556,336	506,857	1,064,225	973,179
Depreciation and amortization	1,905,475	1,734,878	3,810,950	3,469,756
Total operating expenses	19,071,476	19,641,888	37,024,001	34,753,448
OPERATING INCOME	6,203,483	5,276,085	9,467,705	8,920,576
Equity in earnings of unconsolidated affiliate	698,175	191,513	1,261,224	340,324
Other income (expense), net	121,709	41,948	247,595	56,449
Interest expense	892,649	633,186	1,709,431	1,245,831
INCOME BEFORE INCOME TAXES	6,130,718	4,876,360	9,267,093	8,071,518
INCOME TAX EXPENSE	1,460,628	1,410,431	2,162,841	2,546,127
NET INCOME	$ 4,670,090	$ 3,465,929	$ 7,104,252	$ 5,525,391
BASIC EARNINGS PER COMMON SHARE (in dollars per share)	$ 0.58	$ 0.47	$ 0.89	$ 0.76
DILUTED EARNINGS PER COMMON SHARE (in dollars per share)	0.58	0.47	0.88	0.75
DIVIDENDS DECLARED PER COMMON SHARE (in dollars per share)	$ 0.165	$ 0.155	$ 0.33	$ 0.31
Gas Utility [Member]
OPERATING REVENUES:
Operating revenues	$ 25,058,749	$ 24,608,576	$ 46,095,330	$ 43,128,570
OPERATING EXPENSES:
Cost of gas and sales	12,771,338	13,743,277	24,677,797	23,304,683
Non Utility [Member]
OPERATING REVENUES:
Operating revenues	216,210	309,397	396,376	545,454
OPERATING EXPENSES:
Cost of gas and sales	$ 124,243	$ 167,987	$ 234,946	$ 289,197