Note 13 - Income Taxes - Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Unrecognized tax benefits at beginning of period	$ 3,306	$ 3,007	$ 2,389
Gross increases – tax positions in current year	1,512	651	1,188
Reductions due to lapse of statute of limitations	(509)	(352)	(570)
Unrecognized tax benefits at end of period	$ 4,309	$ 3,306	$ 3,007