Revenue (Disaggregation of Revenue) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019
Disaggregation of Revenue [Line Items]
Total contracts with customers	$ 20,784,502	$ 25,329,046	$ 40,506,010	$ 46,793,254
Revenue reductions (TCJA)			0	(523,881)
Alternative Revenue Programs	1,653,229	(54,087)	1,717,174	(301,548)
Operating revenues	22,437,731	25,274,959	42,223,184	46,491,706
Natural Gas [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Total contracts with customers	12,892,659	15,397,504	25,177,242	28,410,332
Natural Gas [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Total contracts with customers	6,368,939	8,357,598	12,102,779	15,700,155
Natural Gas [Member] | Industrial and Transportation [Member]
Disaggregation of Revenue [Line Items]
Total contracts with customers	1,243,426	1,249,316	2,570,669	2,475,364
Other [Member]
Disaggregation of Revenue [Line Items]
Total contracts with customers	279,478	324,628	655,320	731,284
Gas Utility [Member]
Disaggregation of Revenue [Line Items]
Total contracts with customers	20,622,490	25,112,836	40,184,151	46,396,878
Revenue reductions (TCJA)			0	(523,881)
Alternative Revenue Programs	1,653,229	(54,087)	1,717,174	(301,548)
Operating revenues	22,275,719	25,058,749	41,901,325	46,095,330
Gas Utility [Member] | Natural Gas [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Total contracts with customers	12,892,659	15,397,504	25,177,242	28,410,332
Gas Utility [Member] | Natural Gas [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Total contracts with customers	6,368,939	8,357,598	12,102,779	15,700,155
Gas Utility [Member] | Natural Gas [Member] | Industrial and Transportation [Member]
Disaggregation of Revenue [Line Items]
Total contracts with customers	1,243,426	1,249,316	2,570,669	2,475,364
Gas Utility [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Total contracts with customers	117,466	108,418	333,461	334,908
Non Utility [Member]
Disaggregation of Revenue [Line Items]
Total contracts with customers	162,012	216,210	321,859	396,376
Revenue reductions (TCJA)			0	0
Alternative Revenue Programs	0	0	0	0
Operating revenues	162,012	216,210	321,859	396,376
Non Utility [Member] | Natural Gas [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Total contracts with customers	0	0	0	0
Non Utility [Member] | Natural Gas [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Total contracts with customers	0	0	0	0
Non Utility [Member] | Natural Gas [Member] | Industrial and Transportation [Member]
Disaggregation of Revenue [Line Items]
Total contracts with customers	0	0	0	0
Non Utility [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Total contracts with customers	$ 162,012	$ 216,210	$ 321,859	$ 396,376