Note 10 - Income Taxes (Details Textual) - USD ($) $ in Millions	9 Months Ended
Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Unrecognized Tax Benefits, Ending Balance	$ 27.6		$ 28.5
Liability for Uncertainty in Income Taxes, Current			2.4
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense, Total	0.5	$ 0.4
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued, Total	$ 4.7		$ 5.2
Domestic Tax Authority [Member] \| Internal Revenue Service (IRS) [Member]
Open Tax Year	2017 2018 2019 2020
State and Local Jurisdiction [Member]
Open Tax Year	2014 2015 2016 2017 2018 2019 2020
Foreign Tax Authority [Member] \| Asia [Member]
Open Tax Year	2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
Foreign Tax Authority [Member] \| Europe [Member]
Open Tax Year	2012 2013 2014 2015 2016 2017 2018 2019 2020

Amount recognized for uncertainty in income taxes classified as current.

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Tax year that remains open to examination under enacted tax laws, in YYYY format.

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