Stock Options - Activity (Details) - USD ($)	3 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
2012 Employee Stock Option Plan
Options
Outstanding, beginning of year	363,036	521,580
Granted	0	0
Exercised	(2,000)	0
Outstanding, end of period	361,036	521,580
Exercisable, end of period	198,060	258,328
Weighted average exercise price
Weighted average exercise price, beginning of year	$ 21.47	$ 19.37
Exercised (per share)	26.94
Weighted average exercise price, end of period	21.44	19.37
Exercisable, end of period, weighted average exercise price	$ 20.97	$ 17.40
Additional disclosures
Total intrinsic value of options exercised	$ 35,000
Total intrinsic value of options outstanding	6,869,000	$ 1,763,000
Total intrinsic value of options exercisable	$ 3,860,000	$ 1,358,000
2012 Non-Employee Stock Option Plan
Options
Outstanding, beginning of year	20,400	20,400
Exercised	0	0
Outstanding, end of period	20,400	20,400
Exercisable, end of period	16,560	13,920
Weighted average exercise price
Weighted average exercise price, beginning of year	$ 14.39	$ 14.39
Weighted average exercise price, end of period	14.39	14.39
Exercisable, end of period, weighted average exercise price	$ 12.41	$ 10.99
Additional disclosures
Total intrinsic value of options outstanding	$ 532,000	$ 167,000
Total intrinsic value of options exercisable	$ 465,000	$ 159,000
2018 Non-Employee Stock Option Plan
Options
Outstanding, beginning of year	68,900	75,000
Granted	0	0
Forfeited/Lapsed	(4,000)
Exercised	0	0
Outstanding, end of period	64,900	75,000
Exercisable, end of period	59,500	50,720
Weighted average exercise price
Weighted average exercise price, beginning of year	$ 14.54	$ 14.83
Forfeited/Lapsed (per share)	22.93
Weighted average exercise price, end of period	14.02	14.83
Exercisable, end of period, weighted average exercise price	$ 13.21	$ 12.87
Additional disclosures
Total intrinsic value of options outstanding	$ 1,716,000	$ 570,000
Total intrinsic value of options exercisable	$ 1,621,000	$ 480,000
2020 Non-Employee Stock Option Plan
Options
Outstanding, beginning of year	56,900	56,900
Granted	0	0
Forfeited/Lapsed	(2,000)
Exercised	(3,000)	0
Outstanding, end of period	51,900	56,900
Exercisable, end of period	34,140	25,760
Weighted average exercise price
Weighted average exercise price, beginning of year	$ 23.35	$ 23.35
Forfeited/Lapsed (per share)	26.94
Exercised (per share)	26.94
Weighted average exercise price, end of period	23.00	23.35
Exercisable, end of period, weighted average exercise price	$ 21.42	$ 21.21
Additional disclosures
Total intrinsic value of options exercised	$ 32,000
Total intrinsic value of options outstanding	906,000	$ 109,000
Total intrinsic value of options exercisable	$ 650,000	$ 87,000
2022 Employee Stock Option Plan
Options
Outstanding, beginning of year		5,000
Granted	0	0
Forfeited/Lapsed		(5,000)
Exercised	0	0
Outstanding, end of period	130,000
Exercisable, end of period	26,000
Weighted average exercise price
Weighted average exercise price, beginning of year	$ 41.38	$ 40.01
Forfeited/Lapsed (per share)		$ 40.01
Weighted average exercise price, end of period	41.38
Exercisable, end of period, weighted average exercise price	$ 41.38
Additional disclosures
Total intrinsic value of options outstanding	$ 189,000
Total intrinsic value of options exercisable	$ 38,000