Note O - Income Taxes (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Undistributed Earnings of Foreign Subsidiaries	$ 1,729	$ 6,208
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	918	938
Unrecognized Tax Benefits, Income Tax Penalties Accrued	185	$ 148
Domestic Tax Authority [Member]
Operating Loss Carryforwards, Subject to Expiration	7,655
Operating Loss Carryforwards, Not Subject to Expiration	7,655
Tax Credit Carryforward, Amount	$ 9,410
Open Tax Year	2017 2018 2019 2020
State and Local Jurisdiction [Member]
Operating Loss Carryforwards, Subject to Expiration	$ 23,132
Tax Credit Carryforward, Amount	$ 975
State and Local Jurisdiction [Member] | Wisconsin Department of Revenue [Member]
Open Tax Year	2010 2011 2012 2013
Foreign Tax Authority [Member]
Open Tax Year	2016 2017 2018 2019 2020