Note 2 - Income Tax Expense (Details Textual) - USD ($)	9 Months Ended
Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Unrecognized Tax Benefits, Ending Balance	$ 787,000		$ 820,000
Income Taxes Paid, Net, Total	$ 7,500,000	$ 3,700,000
Domestic Tax Authority [Member] \| Internal Revenue Service (IRS) [Member]
Open Tax Year	2017 2018 2019 2020
Foreign Tax Authority [Member]
Open Tax Year	2014 2015 2016 2017 2018 2019 2020

The amount of cash paid during the current period to foreign, federal, state, and local authorities as taxes on income, net of any cash received during the current period as refunds for the overpayment of taxes.

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

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Amount of unrecognized tax benefits.

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