Note K - Business Segments and Foreign Operations - Geographic Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Net sales	$ 295,127	$ 276,960
Long-lived assets	77,402	54,594
Reportable Geographical Components [Member] | UNITED STATES
Net sales	79,823	98,108
Long-lived assets	39,475	31,628
Reportable Geographical Components [Member] | NETHERLANDS
Net sales	46,162	33,845
Long-lived assets	10,270	10,396
Reportable Geographical Components [Member] | CHINA
Net sales	45,527	29,996
Reportable Geographical Components [Member] | FINLAND
Long-lived assets	14,362	0
Reportable Geographical Components [Member] | AUSTRALIA
Net sales	17,790	22,339
Reportable Geographical Components [Member] | BELGIUM
Long-lived assets	5,746	6,160
Reportable Geographical Components [Member] | ITALY
Net sales	16,814	19,671
Long-lived assets	1,356	1,372
Reportable Geographical Components [Member] | Other Countries [Member]
Net sales	89,011	73,001
Long-lived assets	5,100	4,419
Reportable Geographical Components [Member] | SWITZERLAND
Long-lived assets	$ 1,093	$ 619