Stock Options - Activity (Details) - USD ($)	12 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2023
2012 Employee Stock Option Plan
Options
Outstanding, beginning of year	363,036	521,580	523,080
Granted		0	37,500
Forfeited/Lapsed		(11,000)
Exercised	(2,000)	(147,544)	(39,000)
Outstanding, end of period	361,036	363,036	521,580
Exercisable, end of period	277,636	190,960	247,628
Weighted average exercise price
Weighted average exercise price, beginning of year	$ 21.47	$ 19.37	$ 18.59
Forfeited/Lapsed (per share)		(3.16)
Exercised (per share)	(26.94)	(15.43)	(10.44)
Weighted average exercise price, end of period	21.44	21.47	19.37
Exercisable, end of period, weighted average exercise price	$ 20.87	$ 20.87	17.16
Additional disclosures
Weighted average fair value at grant date of options granted			$ 13.36
Total intrinsic value of options exercised	$ 35,000	$ 3,972,000	$ 822,000
Total intrinsic value of options outstanding	2,980,000	11,067,000	7,968,000
Total intrinsic value of options exercisable	$ 2,448,000	$ 5,936,000	$ 4,330,000
2012 Non-Employee Stock Option Plan
Options
Outstanding, beginning of year	20,400	20,400	20,400
Exercised	0	0	0
Outstanding, end of period	20,400	20,400	20,400
Exercisable, end of period	18,480	16,560	13,920
Weighted average exercise price
Weighted average exercise price, beginning of year	$ 14.39	$ 14.39	$ 14.39
Forfeited/Lapsed (per share)			0
Exercised (per share)			0
Weighted average exercise price, end of period	14.39	14.39	14.39
Exercisable, end of period, weighted average exercise price	$ 13.5	$ 12.41	$ 10.99
Additional disclosures
Total intrinsic value of options outstanding	$ 312,000	$ 766,000	$ 413,000
Total intrinsic value of options exercisable	$ 299,000	$ 655,000	$ 329,000
2018 Non-Employee Stock Option Plan
Options
Outstanding, beginning of year	68,900	75,000	89,000
Forfeited/Lapsed	(4,000)
Exercised	0	(6,100)	(14,000)
Outstanding, end of period	64,900	68,900	75,000
Exercisable, end of period	62,200	59,500	50,720
Weighted average exercise price
Weighted average exercise price, beginning of year	$ 14.54	$ 14.83	$ 14.91
Forfeited/Lapsed (per share)	(22.93)
Exercised (per share)		(18.15)	(15.32)
Weighted average exercise price, end of period	14.02	14.54	14.83
Exercisable, end of period, weighted average exercise price	$ 13.63	$ 13.21	$ 12.87
Additional disclosures
Total intrinsic value of options exercised		$ 141,000	$ 209,000
Total intrinsic value of options outstanding	$ 1,017,000	2,578,000	1,486,000
Total intrinsic value of options exercisable	$ 999,000	$ 2,305,000	$ 1,104,000
2020 Non-Employee Stock Option Plan
Options
Outstanding, beginning of year	56,900	56,900
Granted		0	30,000
Forfeited/Lapsed	(2,000)
Exercised	(3,000)	0	0
Outstanding, end of period	51,900	56,900	56,900
Exercisable, end of period	38,520	30,140
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	23.35	$ 23.35
Exercisable, end of period, weighted average exercise price	$ 21.79	$ 21.72
Additional disclosures
Total intrinsic value of options exercised	$ 32,000
Total intrinsic value of options outstanding	352,000	$ 1,627,000
Total intrinsic value of options exercisable	$ 307,000	$ 911,000
2022 Employee Stock Option Plan
Options
Outstanding, beginning of year	130,000	5,000
Granted	0	130,000	5,000
Forfeited/Lapsed		(5,000)
Exercised	0	0	0
Outstanding, end of period	130,000	130,000	5,000
Exercisable, end of period	52,000	26,000	1,000
Weighted average exercise price
Weighted average exercise price, beginning of year	$ 41.38	$ 40.01
Granted (per share)		41.38	$ 40.01
Forfeited/Lapsed (per share)		(40.01)
Weighted average exercise price, end of period	41.38	41.38	40.01
Exercisable, end of period, weighted average exercise price	$ 41.38	41.38	40.01
Additional disclosures
Weighted average fair value at grant date of options granted		$ 21.29	$ 19.77
Total intrinsic value of options outstanding	$ 81,000	$ 1,375,000
Total intrinsic value of options exercisable	$ 32,000	$ 275,000