Note 8 - Stock Based Compensation - Summary of Stock Option Activity (Details) - $ / shares	6 Months Ended	12 Months Ended
	Mar. 31, 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)	2 years 7 months 20 days	3 years 1 month 20 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)	$ 992.03	$ 989.72
Exercisable (in shares)	5,517
Exercisable, weighted average exercise price (in dollars per share)	$ 992.03
Exercisable (Year)	2 years 7 months 20 days