Note 12 - Income Taxes (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Undistributed Earnings of Foreign Subsidiaries	$ 46,200	$ 27,700
Unrecognized Tax Benefits, Ending Balance	41,521	33,499	$ 25,407	$ 20,491
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	31,500	24,300
Unrecognized Tax Benefits, Interest on Income Taxes Accrued	3,300	2,400
Domestic Tax Authority [Member]
Operating Loss Carryforwards, Total		0
Domestic Tax Authority [Member] | Research Tax Credit Carryforward [Member]
Tax Credit Carryforward, Amount	1,500
State and Local Jurisdiction [Member]
Operating Loss Carryforwards, Total	20,000
State and Local Jurisdiction [Member] | Research Tax Credit Carryforward [Member]
Tax Credit Carryforward, Amount	33,400
Foreign Tax Authority [Member]
Operating Loss Carryforwards, Total	34,100
Bermuda Subsidiary [Member]
Foreign Earnings Repatriated	$ 70,000	$ 30,000	$ 75,000