Note 16 - Income Taxes - Reconciliation of Beginning and Ending Balance of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Unrecognized benefit—beginning of period	$ 2,635	$ 2,365	$ 2,162
Gross increases—prior period tax positions		57
Gross increases—current period tax positions		213	203
Unrecognized benefit—end of period	$ 2,635	$ 2,635	$ 2,365