Note 3 - Loans - Segregated by Class of Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016
Loans	$ 775,566	$ 754,283	$ 764,209
Commercial and Agricultural Portfolio Segment [Member] | Commercial [Member]
Loans	44,883	47,025	47,934
Commercial and Agricultural Portfolio Segment [Member] | Agricultural [Member]
Loans	21,810	17,080	24,307
Real Estate Portfolio Segment [Member] | Commercial [Member]
Loans	355,801	349,090	345,181
Real Estate Portfolio Segment [Member] | Commercial Construction [Member]
Loans	35,151	30,358	32,292
Real Estate Portfolio Segment [Member] | Residential Construction [Member]
Loans	9,230	11,830	9,141
Real Estate Portfolio Segment [Member] | Residential [Member]
Loans	200,572	195,580	196,140
Real Estate Portfolio Segment [Member] | Farmland [Member]
Loans	70,194	66,877	70,137
Consumer and Other Portfolio Segment [Member] | Consumer [Member]
Loans	19,134	19,695	19,936
Consumer and Other Portfolio Segment [Member] | Other [Member]
Loans	$ 18,791	$ 16,748	$ 19,141