Note 1 - Basis of Presentation and Significant Accounting Policies - Summary of Status of Company's Non-vested Shares (Details)	6 Months Ended
	Mar. 31, 2022 $ / shares shares
Non-vested options (in shares) | shares	583,458
Weighted-Average Grant Date Fair Value, Non-vested Balance (in dollars per share) | $ / shares	$ 1.40
Options, Granted (in shares) | shares	851,250
Weighted-Average Grant Date Fair Value, Non-vested granted (in dollars per share) | $ / shares	$ 1.43
Non-vested options, vested (in shares) | shares	(272,900)
Weighted-Average Grant Date Fair Value, vested (in dollars per share) | $ / shares	$ 1.06
Non-vested options, forfeited (in shares) | shares	(26,009)
Weighted-Average Grant Date Fair Value, forfeited (in dollars per share) | $ / shares	$ 1.40
Non-vested options (in shares) | shares	1,135,799
Weighted-Average Grant Date Fair Value, Non-vested Balance (in dollars per share) | $ / shares	$ 1.50