Stock Option - Activity (Details) - USD ($)	3 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Options
Exercised	0
2012 Employee Stock Option Plan
Options
Granted	0	37,500
Exercised	0	(5,200)
Outstanding, end of period	521,580	555,380
Exercisable, end of period	258,328	183,852
Weighted average exercise price
Weighted average exercise price, beginning of year	$ 19.37
Granted (per share)		$ 26.94
Exercised (per share)		8.64
Weighted average exercise price, end of period	19.37	19.25
Exercisable, end of period, weighted average exercise price	$ 17.40	15.26
Additional disclosures
Weighted average fair value at grant date of options granted		$ 13.36
Total intrinsic value of options exercised		$ 107,000
Total intrinsic value of options outstanding	$ 1,763,000	5,684,000
Total intrinsic value of options exercisable	$ 1,358,000	$ 2,586,000
2012 Non-Employee Stock Option Plan
Options
Outstanding, beginning of year	20,400	20,400
Granted	0	0
Exercised	0	0
Outstanding, end of period	20,400	20,400
Exercisable, end of period	13,920	11,280
Weighted average exercise price
Weighted average exercise price, beginning of year	$ 14.39	$ 14.39
Exercised (per share)	0
Weighted average exercise price, end of period	14.39	14.39
Exercisable, end of period, weighted average exercise price	$ 10.99	$ 8.92
Additional disclosures
Total intrinsic value of options outstanding	$ 167,000	$ 300,000
Total intrinsic value of options exercisable	$ 159,000	$ 227,000
2018 Non-Employee Stock Option Plan
Options
Outstanding, beginning of year	75,000	89,000
Granted	0	0
Exercised	0	(6,300)
Outstanding, end of period	75,000	82,700
Exercisable, end of period	50,720	38,740
Weighted average exercise price
Weighted average exercise price, beginning of year	$ 14.83	$ 14.91
Exercised (per share)		14.41
Weighted average exercise price, end of period	14.83	14.95
Exercisable, end of period, weighted average exercise price	$ 12.87	$ 12.75
Additional disclosures
Total intrinsic value of options exercised		$ 99,000
Total intrinsic value of options outstanding	$ 570,000	1,169,000
Total intrinsic value of options exercisable	$ 480,000	$ 633,000
2020 Non-Employee Stock Option Plan
Options
Outstanding, beginning of year	56,900
Granted	0	25,000
Exercised	0	0
Outstanding, end of period	56,900	51,900
Exercisable, end of period	25,760	14,380
Weighted average exercise price
Weighted average exercise price, beginning of year	$ 23.35
Granted (per share)		$ 26.94
Weighted average exercise price, end of period	23.35	22.64
Exercisable, end of period, weighted average exercise price	$ 21.21	19.51
Additional disclosures
Weighted average fair value at grant date of options granted		$ 13.36
Total intrinsic value of options outstanding	$ 109,000	$ 334,000
Total intrinsic value of options exercisable	$ 87,000	$ 138,000
2022 Employee Stock Option Plan
Options
Outstanding, beginning of year	5,000
Granted	0
Forfeited/Lapsed	(5,000)
Exercised	0
Outstanding, end of period	0
Weighted average exercise price
Weighted average exercise price, beginning of year	$ 40.01
Forfeited/Lapsed (per share)	$ (40.01)