Note 15 - Stock-Based Compensation (Details) - Stock Option Plans - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Stock Option Plans [Abstract]
Outstanding, beginning	661,771	662,506	608,852
Outstanding, beginning	$ 13.89	$ 13.82	$ 13.27
Outstanding, ending	623,176	661,771	662,506
Outstanding, ending	$ 13.88	$ 13.89	$ 13.82
Exercisable, ending	405,832	420,429	419,735
Weighted average fair value per option of options granted during the period	$ 5.11	$ 5.68	$ 5.14
Granted	73,403	82,609	96,232
Granted	$ 17.63	$ 17.11	$ 15.68
Exercised	(79,638)	(23,659)	(41,258)
Exercised	$ 14.70	$ 10.22	$ 10.06
Forfeited	(32,360)	(59,685)	(1,320)
Forfeited	$ 20.69	$ 19.02	$ 10.53