Note 7 - Income Taxes (Details Textual) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Deferred Tax Assets, Valuation Allowance, Total		$ 2,200		$ 2,200
Income Tax Expense (Benefit), Total	$ 8,776	$ 3,052	$ 1,927	$ 8,926
Unrecognized Tax Benefits, Ending Balance	400		400
Foreign Tax Authority [Member]
Deferred Tax Assets, Valuation Allowance, Total	$ 7,700		$ 7,700
Open Tax Year			2016 2017 2018 2019 2020 2021
Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
Open Tax Year			2017 2018 2019 2020 2021