Stock Options (Detail) - USD ($)	3 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
2012 Employee Stock Option Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding, beginning of year	57,200	70,600
Granted	4,000	0
Terminated/Lapsed	0	0
Exercised	(2,500)	(2,000)
Outstanding, end of period	58,700	68,600
Exercisable, end of period	27,900	41,700
Weighted average fair value at grant date of options granted	$ 5.67
Total intrinsic value of options exercised	$ 25,000	$ 6,000
Total intrinsic value of options outstanding	313,000	245,000
Total intrinsic value of options exercisable	$ 210,000	$ 148,000
Outstanding, beginning of year, weighted average exercise price	$ 7.09	$ 5.84
Granted, weighted average exercise price	15.30	0
Terminated/Lapsed, weighted average exercise price	0	0
Exercised, weighted average exercise price	6.31	6.31
Outstanding, end of period, weighted average exercise price	7.68	5.82
Exercisable, end of period, weighted average exercise price	$ 6.57	$ 5.86
2012 Non-Employee Stock Option Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding, beginning of year	27,800	14,200
Granted	0	0
Terminated/Lapsed	0	0
Exercised	0	0
Outstanding, end of period	27,800	14,200
Exercisable, end of period	13,800	10,200
Weighted average fair value at grant date of options granted
Total intrinsic value of options exercised
Total intrinsic value of options outstanding	225,000	67,000
Total intrinsic value of options exercisable	$ 129,000	$ 47,000
Outstanding, beginning of year, weighted average exercise price	$ 6.85	$ 4.69
Granted, weighted average exercise price	0	0
Terminated/Lapsed, weighted average exercise price	0	0
Exercised, weighted average exercise price	0	0
Outstanding, end of period, weighted average exercise price	6.85	4.69
Exercisable, end of period, weighted average exercise price	$ 5.61	$ 4.82
2002 Employee Stock Option Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding, beginning of year	0	5,000
Granted	0	0
Terminated/Lapsed	0	0
Exercised	0	(5,000)
Outstanding, end of period	0	0
Exercisable, end of period	0	0
Total intrinsic value of options exercised		$ 20,000
Total intrinsic value of options exercisable
Outstanding, beginning of year, weighted average exercise price	$ 0	$ 5.35
Granted, weighted average exercise price	0	0
Terminated/Lapsed, weighted average exercise price	0	0
Exercised, weighted average exercise price	0	5.35
Outstanding, end of period, weighted average exercise price	0	0
Exercisable, end of period, weighted average exercise price	$ 0	$ 0