Note 11 - Income Taxes (Details Textual) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Income Tax Expense (Benefit), Total	$ 4,709	$ 4,484	$ 13,391	$ 12,817
Effective Income Tax Rate Reconciliation, Percent, Total	21.90%	17.60%	21.60%	18.30%
Effective Income Tax Rate, Increase (Decrease), Percentage	4.30%		3.30%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent			21.00%
Unrecognized Tax Benefits, Ending Balance	$ 4,400		$ 4,400		$ 4,100