Note 9 - Stock Based Compensation - Summary of Stock Option Activity (Details) - $ / shares	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
Outstanding (in shares)	5,531
Outstanding, weighted average exercise price (in dollars per share)	$ 989.72
Outstanding, weighted average remaining contractual term (Year)	3 years 1 month 20 days	3 years 7 months 24 days
Granted (in shares)	0
Granted, weighted average exercise price (in dollars per share)	$ 0
Exercised (in shares)	0
Exercised, weighted average exercise price (in dollars per share)	$ 0
Forfeited (in shares)	(14)
Forfeited, weighted average exercise price (in dollars per share)	$ 82.8
Outstanding (in shares)	(5,517)	(5,531)
Outstanding, weighted average exercise price (in dollars per share)	$ 991.71	$ 989.72
Exercisable (in shares)	5,517
Exercisable, weighted average exercise price (in dollars per share)	$ 991.71
Exercisable (Year)	3 years 1 month 20 days