Note 17 - Stock-based Compensation - Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Stock-based compensation expense before income taxes	$ 2,473	$ 2,134	$ 2,016
Less: deferred tax benefit	(866)	(747)	(706)
Reduction of net income	$ 1,607	$ 1,387	$ 1,310