Note 1 - Nature of Operations and Summary of Significant Accounting Policies (Details) - Earnings Per Share (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Earnings Per Share [Abstract]
Net Income (in Dollars)	$ 35,688	$ 23,231	$ 27,684
Average common shares outstanding	16,879	16,339	16,909
Average common share stock options outstanding	43	13	2
Average diluted common shares	16,922	16,352	16,911
Basic earnings per share (in Dollars per share)	$ 2.11	$ 1.42	$ 1.64
Diluted earnings per share (in Dollars per share)	$ 2.11	$ 1.42	$ 1.64