Note 10 - Income Taxes (Details Textual) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Income Tax Expense (Benefit)	$ 5,489	$ 5,252	$ 11,286	$ 10,358
Unrecognized Tax Benefits	$ 4,000		$ 4,000		$ 3,800
Effective Income Tax Rate Reconciliation, Percent	31.20%	32.90%	31.70%	32.70%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	35.00%		35.00%