Stock Options - Activity (Details) - USD ($)	3 Months Ended		6 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2024	Dec. 31, 2023
2012 Employee Stock Option Plan
Options
Outstanding, beginning of year			363,036	521,580
Forfeited/Lapsed				(11,000)
Exercised	0	(31,600)	(2,000)	(31,600)
Outstanding, end of period	361,036	478,980	361,036	478,980
Exercisable, end of period	265,660	289,728	265,660	289,728
Weighted average exercise price
Weighted average exercise price, beginning of year			$ 21.47	$ 19.37
Forfeited/Lapsed (per share)				3.15
Exercised (per share)			26.94	22.13
Weighted average exercise price, end of period	$ 21.44	$ 19.56	21.44	19.56
Exercisable, end of period, weighted average exercise price	$ 21.36	$ 18.58	$ 21.36	$ 18.58
Additional disclosures
Total intrinsic value of options exercised			$ 35,000	$ 375,000
Total intrinsic value of options outstanding	$ 5,100,000	$ 7,034,000	5,100,000	7,034,000
Total intrinsic value of options exercisable	$ 3,772,000	$ 4,539,000	$ 3,772,000	$ 4,539,000
2012 Non-Employee Stock Option Plan
Options
Outstanding, beginning of year			20,400	20,400
Outstanding, end of period	20,400	20,400	20,400	20,400
Exercisable, end of period	18,480	15,840	18,480	15,840
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	14.39	14.39
Exercisable, end of period, weighted average exercise price	$ 13.5	$ 12.44	$ 13.5	$ 12.44
Additional disclosures
Total intrinsic value of options outstanding	$ 432,000	$ 405,000	$ 432,000	$ 405,000
Total intrinsic value of options exercisable	$ 408,000	$ 345,000	$ 408,000	$ 345,000
2018 Non-Employee Stock Option Plan
Options
Outstanding, beginning of year			68,900	75,000
Granted			0	0
Forfeited/Lapsed			(4,000)
Exercised		(1,600)	0	(1,600)
Outstanding, end of period	64,900	73,400	64,900	73,400
Exercisable, end of period	62,200	58,620	62,200	58,620
Weighted average exercise price
Weighted average exercise price, beginning of year			$ 14.54	$ 14.83
Forfeited/Lapsed (per share)			22.93
Exercised (per share)				15.27
Weighted average exercise price, end of period	$ 14.02	$ 14.82	14.02	14.82
Exercisable, end of period, weighted average exercise price	$ 13.63	$ 13.81	$ 13.63	$ 13.81
Additional disclosures
Total intrinsic value of options exercised				$ 28,000
Total intrinsic value of options outstanding	$ 1,398,000	$ 1,426,000	$ 1,398,000	1,426,000
Total intrinsic value of options exercisable	$ 1,364,000	$ 1,198,000	$ 1,364,000	$ 1,198,000
2020 Non-Employee Stock Option Plan
Options
Outstanding, beginning of year			56,900	56,900
Granted			0	0
Forfeited/Lapsed			(2,000)
Exercised	0	0	(3,000)	0
Outstanding, end of period	51,900	56,900	51,900	56,900
Exercisable, end of period	37,520	29,140	37,520	29,140
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	23.35
Exercisable, end of period, weighted average exercise price	$ 21.55	$ 21.41	$ 21.55	$ 21.41
Additional disclosures
Total intrinsic value of options exercised			$ 32,000
Total intrinsic value of options outstanding	$ 652,000	$ 620,000	652,000	$ 620,000
Total intrinsic value of options exercisable	$ 525,000	$ 374,000	$ 525,000	$ 374,000
2022 Employee Stock Option Plan
Options
Outstanding, beginning of year			130,000
Granted		10,000	0	10,000
Outstanding, end of period	130,000		130,000
Exercisable, end of period	28,000		28,000
Weighted average exercise price
Weighted average exercise price, beginning of year			$ 41.38
Weighted average exercise price, end of period	$ 41.38		41.38
Exercisable, end of period, weighted average exercise price	$ 39.96		$ 39.96
Additional disclosures
Total intrinsic value of options outstanding	$ 140,000		$ 140,000
Total intrinsic value of options exercisable	$ 56,000		$ 56,000