Note 8 - Dilutive Effect of Stock Options and Awards (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Net Income	$ 10,583	$ 9,174	$ 20,474	$ 17,074
Weighted-average number of basic shares outstanding during the period (in shares)	19,008	19,475	19,001	19,462
Dilutive effect of stock options and RSUs (in shares)	285	231	319	343
Weighted-average number of diluted shares outstanding during the period (in shares)	19,293	19,706	19,320	19,805
Basic earnings per share (in dollars per share)	$ 0.56	$ 0.47	$ 1.08	$ 0.88
Diluted earnings per share (in dollars per share)	$ 0.55	$ 0.47	$ 1.06	$ 0.86

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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