Note 10 - Earnings Per Share (Details) - Dilutive Effect of Stock Options and Awards (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Dilutive Effect of Stock Options and Awards [Abstract]
Net Income (in Dollars)	$ 9,716	$ 10,112
Weighted-average number of basic shares outstanding during the period	19,804	19,543
Dilutive effect of stock options, restricted stock and RSUs	473	332
Weighted-average number of diluted shares outstanding during the period	20,277	19,875
Basic earnings per share (in Dollars per share)	$ 0.49	$ 0.52
Diluted earnings per share (in Dollars per share)	$ 0.48	$ 0.51