Note 12 - Net Income Per Share (Details) - Basic and Diluted Net Income Per Share - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Basic and Diluted Net Income Per Share [Abstract]
Net income (in Dollars)	$ 9,284	$ 9,889	$ 27,541	$ 26,100
Average shares outstanding	14,754	14,574	14,704	14,542
Dilutive securities	232	174	236	190
Average shares outstanding including dilutive securities including dilutive securities	14,986	14,748	14,940	14,732
Net income per share, basic (in Dollars per share)	$ 0.63	$ 0.68	$ 1.87	$ 1.79
Net income per share, diluted (in Dollars per share)	$ 0.62	$ 0.67	$ 1.84	$ 1.77