Note 10 - Effective Income Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Tax provision, at federal statutory income tax rate	$ 22,960	$ 17,177	$ 13,571
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	35.00%	35.00%	35.00%
State taxes, net of federal benefit	$ 2,654	$ 2,167	$ 1,706
State taxes, net of federal benefit	4.00%	4.40%	4.40%
Other, net	$ (2,234)	$ (940)	$ (543)
Other, net	(3.40%)	(1.90%)	(1.40%)
Income taxes	$ 23,380	$ 18,404	$ 14,734
Effective Income Tax Rate Reconciliation, Percent	35.60%	37.50%	38.00%