Note 7 - Income Taxes (Details Textual) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Income Tax Expense (Benefit), Total	$ 871	$ 1,280	$ 1,471	$ 2,150
Effective Income Tax Rate Reconciliation, Percent, Total	23.80%	25.10%	22.20%	25.50%
Effective Income Tax Rate Reconciliation, Change in GILTI, Percent	2.00%		2.00%
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Acquisition Cost, Percent		2.80%		1.70%