Note I - Income Taxes (Details Textual) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Effective Income Tax Rate Reconciliation, Percent, Total	20.80%	17.00%	7.20%	17.80%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent			21.00%
Effective Income Tax Rate Reconciliation, Global Intangible Low-taxed Income, Amount			$ 400
Income Tax Benefit Cares Act			300
Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Amount			400
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability			500
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	$ 0		$ 0
Domestic Tax Authority [Member]
Open Tax Year			2017 2018 2019 2020
State and Local Jurisdiction [Member]
Open Tax Year			2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
Foreign Tax Authority [Member] | Swiss Federal Tax Administration (FTA) [Member]
Open Tax Year			2019 2020