Note 5 - Employee Benefit Plan (Details Textual) - USD ($)	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Defined Contribution Plan, Employer Discretionary Contribution Amount	$ 914,942	$ 838,946
First Level of Matching [Member]
Defined Contribution Plan, Employer Matching Contribution, Percent of Match	100.00%
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay	3.00%
Second Level Of Matching [Member]
Defined Contribution Plan, Employer Matching Contribution, Percent of Match	50.00%
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay	3.00%