Common Stock Options (Schedule of Stock Option Activity) (Details) - USD ($)	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Number of Shares
Options outstanding, beginning balance (in shares)	68,492	100,000
Options granted (in shares)	13,000	0
Options exercised (in shares)	(29,992)	(31,508)
Options expired (in shares)	0	0
Options forfeited (in shares)	0	0
Options outstanding, ending balance (in shares)	51,500	68,492	100,000
Vested and exercisable at end of period (in shares)	51,500
Weighted- Average Exercise Price
Options outstanding, beginning balance (in usd per share)	$ 14.91	$ 14.34
Options granted (in usd per share)	27.87	0
Options exercised (in usd per share)	14.65	13.08
Options expired (in usd per share)	0	0
Options forfeited (in usd per share)	0	0
Options outstanding, ending balance (in usd per share)	18.34	$ 14.91	$ 14.34
Vested and exercisable at end of period (in usd per share)	$ 18.34
Options, Additional Disclosures
Weighted- Average Remaining Contractual Terms (years)	6 years 4 months 24 days	6 years 2 months 12 days	6 years 7 months 6 days
Weighted-Average Remaining Contractual Term, Vested and exercisable at end of period	6 years 4 months 24 days
Aggregate Intrinsic Value	$ 320,797	$ 981,170	$ 1,237,286
Aggregate Intrinsic Value, Vested and exercisable at end of period	$ 320,797
Weighted-average grant date option fair value (in usd per share)	$ 6.26	$ 0
Stock option expense	$ 81,380	$ 0
Intrinsic value of options exercised	411,638	456,002
Proceeds from exercise of stock options	$ 439,509	$ 412,179