Note 18 - Income Taxes - Reconciliation of Beginning and Ending Amounts of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Balance at beginning of year	$ 8,820	$ 6,357	$ 4,609
Additions based on tax positions taken in prior years	104	293	5
Additions based on tax positions taken in the current year	2,314	2,446	2,580
Reduction based on tax positions taken in prior years	(615)	(276)	(837)
Balance at end of year	$ 10,623	$ 8,820	$ 6,357