Note 12 - Income Taxes - Unrecognized Tax Benefits Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Balance	$ 25,407	$ 20,491	$ 16,272
Increase for tax position of prior year		1,589	1,474
Increase for tax position of current year	9,782	4,663	2,957
Decrease due to lapse of statute of limitation	(223)	(776)	(212)
Decrease due to settlement with tax authorities	(560)	(560)
Decrease for tax position of prior year	(907)
Balance	$ 33,499	$ 25,407	$ 20,491