Stock Options - Activity (Details) - USD ($)	12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2019
2012 Employee Stock Option Plan
Options
Outstanding, beginning of year	235,680	145,000	114,400
Granted		141,880	58,000
Forfeited/Lapsed	(13,000)	(20,000)
Exercised	(8,600)	(31,200)	(27,400)
Outstanding, end of period	214,080	235,680	145,000
Exercisable, end of period	98,176	70,000	67,600
Weighted average exercise price
Weighted average exercise price, bgn	$ 9.42	$ 5.51	$ 3.55
Granted (per share)		12.25	8.30
Forfeited/Lapsed (per share)	6.91	9.92
Exercised (per share)	9.04	3.78	3.21
Weighted average exercise price, end	9.59	9.42	5.51
Exercisable, end of period, weighted average exercise price	$ 8.07	6.57	4.03
Additional disclosures
Weighted average fair value at grant date of options granted		$ 6.72	$ 4.58
Total intrinsic value of options exercised	$ 65,000	$ 278,000	$ 160,000
Total intrinsic value of options outstanding	1,840,000	696,000	1,353,000
Total intrinsic value of options exercisable	$ 993,000	$ 389,000	$ 731,000
2012 Non-Employee Stock Option Plan
Options
Outstanding, beginning of year	24,000	20,400	55,600
Granted		3,600
Forfeited/Lapsed	(9,600)		(3,600)
Exercised	(2,400)		(31,600)
Outstanding, end of period	12,000	24,000	20,400
Exercisable, end of period	6,240	11,520	6,000
Weighted average exercise price
Weighted average exercise price, bgn	$ 5.15	$ 4.00	$ 3.43
Granted (per share)		11.68	0
Forfeited/Lapsed (per share)	3.59		4.35
Exercised (per share)	4.35		2.96
Weighted average exercise price, end	6.55	5.15	4.00
Exercisable, end of period, weighted average exercise price	$ 6.04	4.18	$ 3.14
Additional disclosures
Weighted average fair value at grant date of options granted		$ 6.47
Total intrinsic value of options exercised	$ 31,000		$ 192,000
Total intrinsic value of options outstanding	140,000	$ 157,000	221,000
Total intrinsic value of options exercisable	$ 76,000	$ 87,000	$ 70,000
2018 Non-Employee Stock Option Plan
Options
Outstanding, beginning of year	96,800	30,400
Granted		66,400	40,000
Forfeited/Lapsed	(23,500)		(6,400)
Exercised	(3,200)		(3,200)
Outstanding, end of period	70,100	96,800	30,400
Exercisable, end of period	29,960	24,480	4,800
Weighted average exercise price
Weighted average exercise price, bgn	$ 11.74	$ 8.10
Granted (per share)		13.41	$ 8.10
Forfeited/Lapsed (per share)	11.68		8.10
Exercised (per share)	8.10		8.10
Weighted average exercise price, end	11.93	11.74	8.10
Exercisable, end of period, weighted average exercise price	$ 11.68	10.98	8.10
Additional disclosures
Weighted average fair value at grant date of options granted		$ 7.55	$ 5.12
Total intrinsic value of options exercised	$ 29,000		$ 24,000
Total intrinsic value of options outstanding	439,000	$ 110,000	205,000
Total intrinsic value of options exercisable	$ 195,000	$ 40,000	$ 32,000
2020 Non-Employee Stock Option Plan
Options
Granted	10,000	0
Exercised	0	0
Outstanding, end of period	10,000
Exercisable, end of period	2,000
Weighted average exercise price
Granted (per share)	$ 11.40
Weighted average exercise price, end	11.40
Exercisable, end of period, weighted average exercise price	11.40
Additional disclosures
Weighted average fair value at grant date of options granted	$ 6.10
Total intrinsic value of options outstanding	$ 68,000
Total intrinsic value of options exercisable	$ 14,000