Note 18 - Income Taxes - Reconciliation of Beginning and Ending Amounts of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Balance at beginning of year	$ 6,357	$ 4,609	$ 7,781
Additions based on tax positions taken in prior years	293	5	675
Additions based on tax positions taken in the current year	2,446	2,580	1,532
Reduction based on tax positions taken in prior years	(276)	(837)	(5,379)
Balance at end of year	$ 8,820	$ 6,357	$ 4,609