Note 17 - Net Income (Loss) Per Share - Basic and Diluted Loss Per Share (Details) - USD ($)	3 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Net income	$ 620,327	$ 1,045,940
Basic income per share (in dollars per share)	$ 0.02	$ 0.03
Diluted income per share (in dollars per share)	$ 0.02	$ 0.03
Weighted average shares outstanding - basic (in shares)	32,977,765	32,896,021
Assumed exercise of dilutive options (in shares)	732,855	674,845
Weighted average shares outstanding - diluted (in shares)	33,710,620	33,570,866
Share-based Payment Arrangement, Option [Member]
Antidilutive securities (in shares)	708,727	991,750