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
	Sep. 30, 2017	Sep. 30, 2016
Numerator
Net income	$ 1,434	$ 2,490
Denominator
Basic weighted average common shares outstanding (in shares)	6,606,518	6,558,395
Dilutive effect of stock options (in shares)	224,000	89,000
Diluted weighted average common shares outstanding (in shares)	6,831,230	6,646,963
Basic net income per common share (in dollars per share)	$ 0.22	$ 0.38
Diluted net income per common share (in dollars per share)	$ 0.21	$ 0.37