Stock Options - Activity (Details) - USD ($)	12 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2022
2012 Employee Stock Option Plan
Options
Outstanding, beginning of year	521,580	523,080	214,080
Granted	0	37,500	338,000
Forfeited/Lapsed	(11,000)
Exercised	(147,544)	(39,000)	(29,000)
Outstanding, end of period	363,036	521,580	523,080
Exercisable, end of period	190,960	247,628	176,752
Weighted average exercise price
Weighted average exercise price, beginning of year	$ 19.37	$ 18.59	$ 9.59
Granted (per share)		26.94	23.17
Forfeited/Lapsed (per share)	(3.16)
Exercised (per share)	15.43	10.44	5.45
Weighted average exercise price, end of period	21.47	19.37	18.59
Exercisable, end of period, weighted average exercise price	$ 20.87	17.16	14.68
Additional disclosures
Weighted average fair value at grant date of options granted		$ 13.36	$ 12.16
Total intrinsic value of options exercised	$ 3,972,000	$ 822,000	$ 502,000
Total intrinsic value of options outstanding	11,067,000	7,968,000	1,916,000
Total intrinsic value of options exercisable	$ 5,936,000	$ 4,330,000	$ 1,218,000
2012 Non-Employee Stock Option Plan
Options
Outstanding, beginning of year	20,400	20,400	12,000
Granted	0	0	9,600
Exercised	0	0	(1,200)
Outstanding, end of period	20,400	20,400	20,400
Exercisable, end of period	16,560	13,920	11,280
Weighted average exercise price
Weighted average exercise price, beginning of year	$ 14.39	$ 14.39	$ 6.55
Granted (per share)			22.93
Forfeited/Lapsed (per share)			0
Exercised (per share)			4.35
Weighted average exercise price, end of period	14.39	14.39	14.39
Exercisable, end of period, weighted average exercise price	$ 12.41	$ 10.99	8.92
Additional disclosures
Weighted average fair value at grant date of options granted			$ 12.58
Total intrinsic value of options exercised			$ 19,000
Total intrinsic value of options outstanding	$ 766,000	$ 413,000	149,000
Total intrinsic value of options exercisable	$ 655,000	$ 329,000	$ 136,000
2018 Non-Employee Stock Option Plan
Options
Outstanding, beginning of year	75,000	89,000	70,100
Granted	0	0	23,500
Exercised	(6,100)	(14,000)	(4,600)
Outstanding, end of period	68,900	75,000	89,000
Exercisable, end of period	59,500	50,720	45,040
Weighted average exercise price
Weighted average exercise price, beginning of year	$ 14.83	$ 14.91	$ 11.93
Granted (per share)			22.93
Exercised (per share)	18.15	15.32	10.43
Weighted average exercise price, end of period	14.54	14.83	14.91
Exercisable, end of period, weighted average exercise price	$ 13.21	$ 12.87	12.98
Additional disclosures
Weighted average fair value at grant date of options granted			$ 12.58
Total intrinsic value of options exercised	$ 141,000	$ 209,000	$ 58,000
Total intrinsic value of options outstanding	2,578,000	1,486,000	561,000
Total intrinsic value of options exercisable	$ 2,305,000	$ 1,104,000	$ 354,000
2020 Non-Employee Stock Option Plan
Options
Outstanding, beginning of year	56,900	26,900	10,000
Granted	0	30,000	16,900
Exercised	0	0	0
Outstanding, end of period	56,900	56,900	26,900
Exercisable, end of period	30,140	18,760	7,380
Weighted average exercise price
Weighted average exercise price, beginning of year	$ 23.35	$ 18.64	$ 11.40
Granted (per share)		27.57	22.93
Weighted average exercise price, end of period	23.35	23.35	18.64
Exercisable, end of period, weighted average exercise price	$ 21.72	20.73	16.68
Additional disclosures
Weighted average fair value at grant date of options granted		$ 13.74	$ 12.58
Total intrinsic value of options outstanding	$ 1,627,000	$ 643,000	$ 92,000
Total intrinsic value of options exercisable	$ 911,000	$ 261,000	$ 37,000
2022 Employee Stock Option Plan
Options
Outstanding, beginning of year	5,000
Granted	130,000	5,000
Forfeited/Lapsed	(5,000)
Exercised		0
Outstanding, end of period	130,000	5,000
Exercisable, end of period	26,000	1,000
Weighted average exercise price
Weighted average exercise price, beginning of year	$ 40.01
Granted (per share)	41.38	$ 40.01
Forfeited/Lapsed (per share)	(40.01)
Weighted average exercise price, end of period	41.38	40.01
Exercisable, end of period, weighted average exercise price	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	$ 1,375,000
Total intrinsic value of options exercisable	$ 275,000