Note 1 - Basis of Presentation and Significant Accounting Policies - Fair Value Assumptions for Stock Options Granted (Details)	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Expected dividend yield	0.00%	0.00%
Minimum [Member]
Expected life (years) (Year)	4 years 10 months 24 days	4 years 3 months 18 days
Risk-free interest rate	1.07%	0.33%
Expected volatility	64.83%	65.00%
Expected forfeiture rate	14.65%	14.18%
Expected exercise factor	2.02%	1.20%
Maximum [Member]
Expected life (years) (Year)	5 years 3 months 18 days	5 years 3 months 18 days
Risk-free interest rate	3.03%	0.59%
Expected volatility	67.21%	83.29%
Expected forfeiture rate	20.00%	16.41%
Expected exercise factor	2.03%	1.87%