Note 10 - Income Taxes (Details Textual) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	35.00%		35.00%
Income Tax Expense (Benefit)	$ 5,625	$ 4,952	$ 10,556	$ 9,401
Effective Income Tax Rate Reconciliation, Percent	32.50%	31.10%	32.30%	30.90%
Unrecognized Tax Benefits	$ 1,500		$ 1,500		$ 1,300
Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions			$ 200