Note L - Business Segments and Foreign Operations - Geographic Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Net Sales	$ 302,663	$ 240,733
Long-lived assets	75,016	59,317
Reportable Geographical Components [Member] | UNITED STATES
Net Sales	132,467	141,705
Long-lived assets	41,233	37,765
Reportable Geographical Components [Member] | NETHERLANDS
Net Sales	31,521	4,755
Long-lived assets	13,186
Reportable Geographical Components [Member] | CHINA
Net Sales	28,772	11,664
Reportable Geographical Components [Member] | BELGIUM
Long-lived assets	8,595	7,576
Reportable Geographical Components [Member] | ITALY
Net Sales	12,755	12,551
Long-lived assets	1,894	2,230
Reportable Geographical Components [Member] | SWITZERLAND
Long-lived assets	6,810	6,841
Reportable Geographical Components [Member] | AUSTRALIA
Net Sales	12,463	12,479
Reportable Geographical Components [Member] | CANADA
Net Sales	10,464	13,397
Reportable Geographical Components [Member] | Other Countries [Member]
Net Sales	74,221	44,182
Long-lived assets	$ 3,298	$ 4,905