Note 16 - Share-based Compensation - Stock Options Outstanding (Details)	12 Months Ended
	Sep. 30, 2021 $ / shares shares
Number Outstanding (in shares) | shares	2,745,384
Weighted Average Remaining Contractual Life (Year)	3 years 9 months 29 days
Weighted Average Exercise Price, Outstanding (in dollars per share)	$ 3.02
Number Exercisable (in shares) | shares	1,541,176
Weighted Average Exercise Price, Exercisable (in dollars per share)	$ 2.24
Range One [Member]
Upper Exercise Price (in dollars per share)	$ 1.86
Number Outstanding (in shares) | shares	324,157
Weighted Average Remaining Contractual Life (Year)	2 years
Weighted Average Exercise Price, Outstanding (in dollars per share)	$ 1.64
Number Exercisable (in shares) | shares	324,157
Weighted Average Exercise Price, Exercisable (in dollars per share)	$ 1.64
Range Two [Member]
Upper Exercise Price (in dollars per share)	$ 1.99
Number Outstanding (in shares) | shares	937,500
Weighted Average Remaining Contractual Life (Year)	2 years 5 months 8 days
Weighted Average Exercise Price, Outstanding (in dollars per share)	$ 1.99
Number Exercisable (in shares) | shares	937,500
Weighted Average Exercise Price, Exercisable (in dollars per share)	$ 1.99
Range Three [Member]
Upper Exercise Price (in dollars per share)	$ 3.17
Number Outstanding (in shares) | shares	65,000
Weighted Average Remaining Contractual Life (Year)	4 months 13 days
Weighted Average Exercise Price, Outstanding (in dollars per share)	$ 2.48
Number Exercisable (in shares) | shares	65,000
Weighted Average Exercise Price, Exercisable (in dollars per share)	$ 2.48
Range Four [Member]
Upper Exercise Price (in dollars per share)	$ 3.40
Number Outstanding (in shares) | shares	1,133,727
Weighted Average Remaining Contractual Life (Year)	5 years 1 month 2 days
Weighted Average Exercise Price, Outstanding (in dollars per share)	$ 3.39
Number Exercisable (in shares) | shares	166,863
Weighted Average Exercise Price, Exercisable (in dollars per share)	$ 3.40
Range Five [Member]
Upper Exercise Price (in dollars per share)	$ 8.03
Number Outstanding (in shares) | shares	285,000
Weighted Average Remaining Contractual Life (Year)	6 years 3 months 18 days
Weighted Average Exercise Price, Outstanding (in dollars per share)	$ 6.66
Number Exercisable (in shares) | shares	47,656
Weighted Average Exercise Price, Exercisable (in dollars per share)	$ 6.87