Note 10 - Earnings Per Share - Dilutive Effect of Stock Options and Awards (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Net Income	$ 9,174	$ 9,998	$ 17,074	$ 19,714
Weighted-average number of basic shares outstanding during the period (in shares)	19,475	19,795	19,462	19,799
Dilutive effect of stock options, restricted stock and RSUs (in shares)	231	287	343	414
Weighted-average number of diluted shares outstanding during the period (in shares)	19,706	20,082	19,805	20,213
Basic earnings per share (in dollars per share)	$ 0.47	$ 0.51	$ 0.88	$ 1
Diluted earnings per share (in dollars per share)	$ 0.47	$ 0.50	$ 0.86	$ 0.98