Note A - Basis of Presentation and Summary of Significant Accounting Policies - Calculation of Basic and Diluted Net Income Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Numerator
Net income	$ 2,504	$ 1,916	$ 7,607	$ 7,806
Denominator
Basic weighted average common shares outstanding (in shares)	6,003,036	6,200,712	6,167,539	6,296,408
Dilutive effect of stock options and restricted stock (in shares)	38,000	126,000	48,000	105,000
Diluted weighted average common shares outstanding (in shares)	6,041,424	6,326,777	6,216,422	6,401,021
Basic net income per common share (in dollars per share)	$ 0.42	$ 0.31	$ 1.23	$ 1.24
Diluted net income per common share (in dollars per share)	$ 0.41	$ 0.30	$ 1.22	$ 1.22