Note 15 - Share-based Compensation - Stock Options Outstanding (Details)	3 Months Ended
	Dec. 31, 2023 $ / shares shares
Lower Exercise Price (in dollars per share)	$ 1.51
Upper Exercise Price (in dollars per share)	$ 8.03
Number Outstanding (in shares) | shares	3,766,772
Weighted Average Remaining Contractual Life (Year)	5 years 5 months 26 days
Weighted average exercise price, outstanding balance (in dollars per share)	$ 2.85
Number Exercisable (in shares) | shares	992,981
Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 3.48
Range One [Member]
Lower Exercise Price (in dollars per share)	1.51
Upper Exercise Price (in dollars per share)	$ 1.76
Number Outstanding (in shares) | shares	991,407
Weighted Average Remaining Contractual Life (Year)	6 years 3 months 14 days
Weighted average exercise price, outstanding balance (in dollars per share)	$ 1.71
Number Exercisable (in shares) | shares	104,157
Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 1.75
Range Two [Member]
Lower Exercise Price (in dollars per share)	2.64
Upper Exercise Price (in dollars per share)	$ 2.68
Number Outstanding (in shares) | shares	88,000
Weighted Average Remaining Contractual Life (Year)	6 years 7 months 6 days
Weighted average exercise price, outstanding balance (in dollars per share)	$ 2.67
Number Exercisable (in shares) | shares	0
Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 0
Range Three [Member]
Lower Exercise Price (in dollars per share)	2.69
Upper Exercise Price (in dollars per share)	$ 2.69
Number Outstanding (in shares) | shares	1,100,000
Weighted Average Remaining Contractual Life (Year)	5 years 9 months 7 days
Weighted average exercise price, outstanding balance (in dollars per share)	$ 2.69
Number Exercisable (in shares) | shares	125,000
Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 2.69
Range Four [Member]
Lower Exercise Price (in dollars per share)	3.09
Upper Exercise Price (in dollars per share)	$ 8.03
Number Outstanding (in shares) | shares	1,587,365
Weighted Average Remaining Contractual Life (Year)	4 years 9 months
Weighted average exercise price, outstanding balance (in dollars per share)	$ 3.69
Number Exercisable (in shares) | shares	763,824
Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 3.84