Note 8 - Earnings Per Share (Details) - Dilutive effect of stock options, restricted stock, and RSU awards for each period (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Dilutive effect of stock options, restricted stock, and RSU awards for each period [Abstract]
Net Income (in Dollars)	$ 10,331	$ 10,346	$ 20,443	$ 19,283
Weighted-average number of basic shares outstanding during the period	19,706	19,774	19,625	19,771
Dilutive effect of stock options, restricted stock and RSUs	290	197	368	290
Weighted-average number of diluted shares outstanding during the period	19,996	19,971	19,993	20,061
Basic earnings per share (in Dollars per share)	$ 0.52	$ 0.52	$ 1.04	$ 0.98
Diluted earnings per share (in Dollars per share)	$ 0.52	$ 0.52	$ 1.02	$ 0.96