Commitments and Contingencies (Narrative) (Details)	1 Months Ended	12 Months Ended
	Jul. 31, 2020	Sep. 30, 2020 USD ($) $ / dekatherm Bcf	Sep. 30, 2019 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Asset management contract term	1 year
Minimum energy volume required (in dth) | Bcf		1.3
Franchise agreement term		20 years
Franchise fee annual increase		3.00%
Franchise fee, total cost through end of agreement | $		$ 2,294,588
Minimum
Product Information [Line Items]
Purchase price per energy volume (in usd per dth) | $ / dekatherm		2.17
Maximum
Product Information [Line Items]
Purchase price per energy volume (in usd per dth) | $ / dekatherm		2.62
Natural Gas Pipeline and Storage Capacity
Product Information [Line Items]
Cost of sales | $		$ 21,881,000	$ 30,317,000