Other Investments (Schedule of Other Investments) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Sep. 30, 2019
Other Assets:
Investment in unconsolidated affiliates	$ 54,856,710		$ 54,856,710		$ 47,375,459
Current Liabilities:
Capital contributions payable	2,427,398		2,427,398		5,024,824
Income Statement location:
Equity in earnings of unconsolidated affiliate	1,205,574	$ 777,193	3,488,253	$ 2,038,417
Undistributed earnings, net of income taxes, of MVP in retained earnings	5,857,553		5,857,553		3,267,176
Change in investment in unconsolidated affiliate [Abstract]
Cash investment			6,590,424	16,650,944
Change in accrued capital calls			(2,597,426)	(3,015,078)
Equity in earnings of unconsolidated affiliate	1,205,574	$ 777,193	3,488,253	2,038,417
Change in investment in unconsolidated affiliates			7,481,251	$ 15,674,283
MVP [Member]
Other Assets:
MVP	54,494,911		54,494,911		47,055,426
Current Liabilities:
Capital contributions payable	2,388,167		2,388,167		4,958,260
Southgate [Member]
Other Assets:
Southgate	361,799		361,799		320,033
Current Liabilities:
Capital contributions payable	$ 39,231		$ 39,231		$ 66,564