Stock Option - Activity (Details) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2022	Dec. 31, 2021	Jun. 30, 2022
Options
Exercised	(2,000)
2012 Employee Stock Option Plan
Options
Outstanding, beginning of year			523,080	214,080	214,080
Granted	0	338,000	37,500	338,000
Exercised	(2,000)	(23,000)	(7,200)	(28,000)
Outstanding, end of period	553,380	524,080	553,380	524,080	523,080
Exercisable, end of period	262,252	160,576	262,252	160,576
Weighted average exercise price
Weighted average exercise price, beginning of year			$ 18.59	$ 9.59	$ 9.59
Granted (per share)			26.94	23.17
Exercised (per share)			7.07	5.54
Weighted average exercise price, end of period	$ 18.90	$ 18.56	18.90	18.56	$ 18.59
Exercisable, end of period, weighted average exercise price	$ 16.88	$ 15.06	16.88	15.06
Additional disclosures
Weighted average fair value at grant date of options granted			$ 13.36	$ 12.16
Total intrinsic value of options exercised			$ 159,000	$ 485,000
Total intrinsic value of options outstanding	$ 4,746,000	$ 3,367,000	4,746,000	3,367,000
Total intrinsic value of options exercisable	$ 2,779,000	$ 1,595,000	$ 2,779,000	$ 1,595,000
2012 Non-Employee Stock Option Plan
Options
Outstanding, beginning of year			20,400	12,000	12,000
Granted	0	9,600	0	9,600
Exercised	0	0	0	0
Outstanding, end of period	20,400	21,600	20,400	21,600	20,400
Exercisable, end of period	13,200	11,760	13,200	11,760
Weighted average exercise price
Weighted average exercise price, beginning of year			$ 14.39	$ 6.55	$ 6.55
Granted (per share)				22.93
Exercised (per share)			0
Weighted average exercise price, end of period	$ 14.39	$ 13.83	14.39	13.83	$ 14.39
Exercisable, end of period, weighted average exercise price	$ 10.95	$ 8.28	$ 10.95	8.28
Additional disclosures
Weighted average fair value at grant date of options granted				$ 12.58
Total intrinsic value of options outstanding	$ 267,000	$ 241,000	$ 267,000	$ 241,000
Total intrinsic value of options exercisable	$ 218,000	$ 197,000	$ 218,000	$ 197,000
2018 Non-Employee Stock Option Plan
Options
Outstanding, beginning of year			89,000	70,100	70,100
Granted	0	23,500	0	23,500
Exercised	(3,600)	(3,000)	(9,900)	(3,000)
Outstanding, end of period	79,100	90,600	79,100	90,600	89,000
Exercisable, end of period	49,440	41,260	49,440	41,260
Weighted average exercise price
Weighted average exercise price, beginning of year			$ 14.91	$ 11.93	$ 11.93
Granted (per share)				22.93
Exercised (per share)			16.27	11.68
Weighted average exercise price, end of period	$ 14.74	$ 14.79	14.74	14.79	$ 14.91
Exercisable, end of period, weighted average exercise price	$ 13.02	$ 12.96	$ 13.02	12.96
Additional disclosures
Weighted average fair value at grant date of options granted				$ 12.58
Total intrinsic value of options exercised			$ 124,000	$ 39,000
Total intrinsic value of options outstanding	$ 1,008,000	$ 924,000	1,008,000	924,000
Total intrinsic value of options exercisable	$ 715,000	$ 496,000	$ 715,000	$ 496,000
2020 Non-Employee Stock Option Plan
Options
Outstanding, beginning of year			26,900	10,000	10,000
Granted	0	16,900	25,000	16,900
Exercised	0	0	0	0
Outstanding, end of period	51,900	26,900	51,900	26,900	26,900
Exercisable, end of period	17,760	7,380	17,760	7,380
Weighted average exercise price
Weighted average exercise price, beginning of year			$ 18.64	$ 11.40	$ 11.40
Granted (per share)			26.94	22.93
Weighted average exercise price, end of period	$ 22.64	$ 18.64	22.64	18.64	$ 18.64
Exercisable, end of period, weighted average exercise price	$ 20.16	$ 16.68	20.16	16.68
Additional disclosures
Weighted average fair value at grant date of options granted			$ 13.36	$ 12.58
Total intrinsic value of options outstanding	$ 251,000	$ 171,000	$ 251,000	$ 171,000
Total intrinsic value of options exercisable	$ 130,000	$ 61,000	$ 130,000	$ 61,000