Note 15 - Share-based Compensation - Stock Options Outstanding (Details)	3 Months Ended
	Dec. 31, 2019 $ / shares shares
Number Outstanding (in shares) | shares	2,282,152
Weighted Average Remaining Contractual Life (Year)	3 years 215 days
Weighted Average Exercise Price, Outstanding (in dollars per share)	$ 2.17
Number Exercisable (in shares) | shares	1,539,220
Weighted Average Exercise Price, Exercisable (in dollars per share)	$ 1.97
Range One [Member]
Lower Exercise Price (in dollars per share)	1.31
Upper Exercise Price (in dollars per share)	$ 1.76
Number Outstanding (in shares) | shares	584,533
Weighted Average Remaining Contractual Life (Year)	2 years 332 days
Weighted Average Exercise Price, Outstanding (in dollars per share)	$ 1.65
Number Exercisable (in shares) | shares	531,220
Weighted Average Exercise Price, Exercisable (in dollars per share)	$ 1.65
Range Two [Member]
Lower Exercise Price (in dollars per share)	1.86
Upper Exercise Price (in dollars per share)	$ 1.86
Number Outstanding (in shares) | shares	130,142
Weighted Average Remaining Contractual Life (Year)	2 years 350 days
Weighted Average Exercise Price, Outstanding (in dollars per share)	$ 1.86
Number Exercisable (in shares) | shares	130,142
Weighted Average Exercise Price, Exercisable (in dollars per share)	$ 1.86
Range Three [Member]
Lower Exercise Price (in dollars per share)	1.99
Upper Exercise Price (in dollars per share)	$ 1.99
Number Outstanding (in shares) | shares	937,500
Weighted Average Remaining Contractual Life (Year)	3 years 211 days
Weighted Average Exercise Price, Outstanding (in dollars per share)	$ 1.99
Number Exercisable (in shares) | shares	562,500
Weighted Average Exercise Price, Exercisable (in dollars per share)	$ 1.99
Range Four [Member]
Lower Exercise Price (in dollars per share)	2.02
Upper Exercise Price (in dollars per share)	$ 3.40
Number Outstanding (in shares) | shares	629,977
Weighted Average Remaining Contractual Life (Year)	4 years 127 days
Weighted Average Exercise Price, Outstanding (in dollars per share)	$ 2.97
Number Exercisable (in shares) | shares	315,358
Weighted Average Exercise Price, Exercisable (in dollars per share)	$ 2.97