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, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Numerator
Net income	$ 745	$ 3,023	$ 5,701	$ 6,104
Denominator
Basic weighted average common shares outstanding (in shares)	6,581,632	6,510,902	6,569,165	6,513,821
Dilutive effect of stock options (in shares)	32,000	52,000	79,000	115,000
Diluted weighted average common shares outstanding (in shares)	6,613,955	6,562,577	6,648,091	6,628,883
Basic net income per common share (in dollars per share)	$ 0.11	$ 0.46	$ 0.87	$ 0.94
Diluted net income per common share (in dollars per share)	$ 0.11	$ 0.46	$ 0.86	$ 0.92