Fair Value Measurements (Schedule of Fair Value of Financial Assets and Liabilities Measured on a Recurring Basis) (Details) - Estimate of Fair Value Measurement - USD ($)	Sep. 30, 2020	Sep. 30, 2019
Quoted Prices in Active Markets Level 1
Liabilities:
Total	$ 0	$ 0
Significant Other Observable  Inputs Level 2
Liabilities:
Total	0	0
Significant Unobservable Inputs Level 3
Liabilities:
Total	124,740,970	100,900,952
Fair Value, Recurring
Liabilities:
Natural gas purchases	470,755	397,757
Total	2,694,311	1,292,098
Fair Value, Recurring | Interest Rate Swap
Liabilities:
Interest rate swaps	2,223,556	894,341
Fair Value, Recurring | Quoted Prices in Active Markets Level 1
Liabilities:
Natural gas purchases	0	0
Total	0	0
Fair Value, Recurring | Quoted Prices in Active Markets Level 1 | Interest Rate Swap
Liabilities:
Interest rate swaps	0	0
Fair Value, Recurring | Significant Other Observable  Inputs Level 2
Liabilities:
Natural gas purchases	470,755	397,757
Total	2,694,311	1,292,098
Fair Value, Recurring | Significant Other Observable  Inputs Level 2 | Interest Rate Swap
Liabilities:
Interest rate swaps	2,223,556	894,341
Fair Value, Recurring | Significant Unobservable Inputs Level 3
Liabilities:
Natural gas purchases	0	0
Total	0	0
Fair Value, Recurring | Significant Unobservable Inputs Level 3 | Interest Rate Swap
Liabilities:
Interest rate swaps	$ 0	$ 0