Note 10 - Earnings Per Share - Dilutive Effect of Stock Options and Awards (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Net Income	$ 11,545	$ 11,553	$ 28,619	$ 31,267
Weighted-average number of basic shares outstanding during the period (in shares)	19,316	19,450	19,413	19,682
Dilutive effect of stock options and RSUs (in shares)	240	263	330	387
Weighted-average number of diluted shares outstanding during the period (in shares)	19,556	19,713	19,743	20,069
Basic earnings per share (in dollars per share)	$ 0.60	$ 0.59	$ 1.47	$ 1.59
Diluted earnings per share (in dollars per share)	$ 0.59	$ 0.59	$ 1.45	$ 1.56