Note 11 - Earnings Per Share (Details) - Dilutive Effect of Stock Options and Awards (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Dilutive Effect of Stock Options and Awards [Abstract]
Net Income (in Dollars)	$ 11,553	$ 11,131	$ 31,267	$ 31,574
Weighted-average number of basic shares outstanding during the period	19,450	19,802	19,682	19,685
Dilutive effect of stock options, restricted stock and RSUs	263	363	387	403
Weighted-average number of diluted shares outstanding during the period	19,713	20,165	20,069	20,088
Basic earnings per share (in Dollars per share)	$ 0.59	$ 0.56	$ 1.59	$ 1.60
Diluted earnings per share (in Dollars per share)	$ 0.59	$ 0.55	$ 1.56	$ 1.57