Revenue (Disaggregation of Revenue) (Details) - USD ($)	3 Months Ended								12 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue [Line Items]
Total contracts with customers									$ 61,754,371	$ 67,641,080
Revenue reductions (TCJA)										(523,881)
Alternative Revenue Programs									1,321,020	385,445
Revenues	$ 9,780,289	$ 11,071,918	$ 22,437,731	$ 19,785,453	$ 9,851,869	$ 11,682,950	$ 25,274,959	$ 21,216,747	63,075,391	68,026,525
Natural gas | Residential customers
Disaggregation of Revenue [Line Items]
Total contracts with customers									37,022,219	39,519,618
Natural gas | Commercial customers
Disaggregation of Revenue [Line Items]
Total contracts with customers									18,387,674	22,562,265
Natural gas | Industrial and transportation customers
Disaggregation of Revenue [Line Items]
Total contracts with customers									5,188,069	4,770,657
Other
Disaggregation of Revenue [Line Items]
Total contracts with customers									1,156,409	1,312,421
Gas Utility
Disaggregation of Revenue [Line Items]
Total contracts with customers									61,087,905	66,920,815
Revenue reductions (TCJA)										(523,881)
Alternative Revenue Programs									1,321,020	385,445
Revenues									62,408,925	67,306,260
Gas Utility | Natural gas | Residential customers
Disaggregation of Revenue [Line Items]
Total contracts with customers									37,022,219	39,519,618
Gas Utility | Natural gas | Commercial customers
Disaggregation of Revenue [Line Items]
Total contracts with customers									18,387,674	22,562,265
Gas Utility | Natural gas | Industrial and transportation customers
Disaggregation of Revenue [Line Items]
Total contracts with customers									5,188,069	4,770,657
Gas Utility | Other
Disaggregation of Revenue [Line Items]
Total contracts with customers									489,943	592,156
Non Utility
Disaggregation of Revenue [Line Items]
Total contracts with customers									666,466	720,265
Revenue reductions (TCJA)										0
Alternative Revenue Programs									0	0
Revenues									666,466	720,265
Non Utility | Natural gas | Residential customers
Disaggregation of Revenue [Line Items]
Total contracts with customers									0	0
Non Utility | Natural gas | Commercial customers
Disaggregation of Revenue [Line Items]
Total contracts with customers									0	0
Non Utility | Natural gas | Industrial and transportation customers
Disaggregation of Revenue [Line Items]
Total contracts with customers									0	0
Non Utility | Other
Disaggregation of Revenue [Line Items]
Total contracts with customers									$ 666,466	$ 720,265