Note I - Income Taxes (Details Textual) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended	9 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Mar. 31, 2021	Mar. 31, 2020	Jun. 30, 2020
Effective Income Tax Rate Reconciliation, Percent, Total	19.30%	6.00%		10.50%	3.70%
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 2021
State and Local Jurisdiction [Member]
Open Tax Year				2017 2018 2019 2020 2021
Foreign Tax Authority [Member] | Swiss Federal Tax Administration (FTA) [Member]
Open Tax Year				2019 2020 2021