Note 11 - Stock-based Compensation - Summary of the Status of the Company's Stock Options (Details)	6 Months Ended
	Mar. 31, 2019 $ / shares shares
Outstanding (in shares) | shares	290,000
Outstanding, weighted average exercise price (in dollars per share) | $ / shares	$ 2.40
Granted (in shares) | shares	330,000
Granted, weighted average exercise price (in dollars per share) | $ / shares	$ 1.33
Exercised (in shares) | shares
Exercised, weighted average exercise price (in dollars per share) | $ / shares
Expired (in shares) | shares
Expired, weighted average exercise price (in dollars per share) | $ / shares
Forfeited (in shares) | shares
Forfeited, weighted average exercise price (in dollars per share) | $ / shares
Outstanding (in shares) | shares	620,000
Outstanding, weighted average exercise price (in dollars per share) | $ / shares	$ 1.83
Exercisable (in shares) | shares	426,667
Exercisable, weighted average exercise price (in dollars per share) | $ / shares	$ 2