Note 2 - Acquisition - Pro Forma Information (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Acquisition of MNB [Member]
Net interest income	$ 67,834	$ 67,977
Total noninterest income	15,698	15,714
Net income	$ 13,466	$ 29,888
Basic earnings per common share (in dollars per share)	$ 0.34	$ 0.79
Diluted earnings per common share (in dollars per share)	$ 0.34	$ 0.78
First National Security Company Acquisition [Member]
Net interest income		$ 49,218
Total noninterest income		12,785
Net income		$ 26,118
Basic earnings per common share (in dollars per share)		$ 0.80
Diluted earnings per common share (in dollars per share)		$ 0.79