Note 10 - Equity Compensation - Stock Options (Details) - USD ($)	12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Outstanding, shares (in shares)	2,282,938
Outstanding, weighted average exercise price (in dollars per share)	$ 6.20
Outstanding, weighted average remaining contractual term (Year)	6 years 8 months 12 days	7 years 1 month 6 days
Outstanding, aggregate intrinsic value	$ 5,320,456	$ 2,731,949
Granted, shares (in shares)	318,406
Granted, weighted average exercise price (in dollars per share)	$ 6.86
Exercised, shares (in shares)	(139,367)
Exercised, weighted average exercise price (in dollars per share)	$ 7.38
Forfeited, shares (in shares)	(132,329)
Forfeited, weighted average exercise price (in dollars per share)	$ 8.84
Expired, shares (in shares)	(2,500)
Expired, weighted average exercise price (in dollars per share)	$ 7.29
Outstanding, shares (in shares)	2,327,148	2,282,938
Outstanding, weighted average exercise price (in dollars per share)	$ 6.07	$ 6.20
Exercisable, shares (in shares)	1,013,157
Exercisable, weighted average exercise price (in dollars per share)	$ 7.58
Exercisable, weighted average remaining contractual term (Year)	5 years
Exercisable, aggregate intrinsic value	$ 1,239,663
Vested and expected to vest at June 30, 2021 (in shares)	2,256,565
Vested and expected to vest, weighted average exercise price (in dollars per share)	$ 6.08
Vested and expected to vest, weighted average remaining contractual term (Year)	6 years 7 months 6 days
Vested and expected to vest, aggregate intrinsic value	$ 5,165,389