Note 1 - Basis of Presentation and Significant Accounting Policies - Summary of Status of Company's Non-vested Shares (Details)	3 Months Ended
	Dec. 31, 2020 $ / shares shares
Non-vested options (in shares) | shares	339,897
Weighted-Average Grant Date Fair Value, Non-vested Balance (in dollars per share) | $ / shares	$ 0.60
Options, Granted (in shares) | shares	489,250
Weighted-Average Grant Date Fair Value, Non-vested granted (in dollars per share) | $ / shares	$ 1.55
Non-vested options, vested (in shares) | shares	(141,336)
Weighted-Average Grant Date Fair Value, vested (in dollars per share) | $ / shares	$ 0.78
Non-vested options, forfeited (in shares) | shares	(8,745)
Weighted-Average Grant Date Fair Value, forfeited (in dollars per share) | $ / shares	$ 0.58
Non-vested options (in shares) | shares	679,066
Weighted-Average Grant Date Fair Value, Non-vested Balance (in dollars per share) | $ / shares	$ 1.33