Note 3 - Loans - Segregated by Class of Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016
Loans	$ 760,341	$ 754,283	$ 754,261
Commercial and Agricultural Portfolio Segment [Member] | Commercial [Member]
Loans	44,925	47,025	45,115
Commercial and Agricultural Portfolio Segment [Member] | Agricultural [Member]
Loans	19,306	17,080	18,562
Real Estate Portfolio Segment [Member] | Commercial [Member]
Loans	359,143	349,090	347,372
Real Estate Portfolio Segment [Member] | Commercial Construction [Member]
Loans	30,540	30,358	35,970
Real Estate Portfolio Segment [Member] | Residential Construction [Member]
Loans	9,367	11,830	9,849
Real Estate Portfolio Segment [Member] | Residential [Member]
Loans	195,282	195,580	195,679
Real Estate Portfolio Segment [Member] | Farmland [Member]
Loans	64,870	66,877	66,285
Consumer and Other Portfolio Segment [Member] | Consumer [Member]
Loans	19,188	19,695	19,661
Consumer and Other Portfolio Segment [Member] | Other [Member]
Loans	$ 17,720	$ 16,748	$ 15,768