Note 3 - Loans (Details) - Loan Portfolio by Credit Quality Indicator - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014
Commercial and Agricultural
Loans receivable	$ 764,204	$ 746,094	$ 743,281
Pass [Member]
Commercial and Agricultural
Loans receivable	712,731	686,072
Special Mention [Member]
Commercial and Agricultural
Loans receivable	19,450	27,139
Substandard [Member]
Commercial and Agricultural
Loans receivable	32,023	32,883
Commercial and Agricultural Portfolio Segment [Member] | Commercial [Member]
Commercial and Agricultural
Loans receivable	48,759	50,960	46,481
Commercial and Agricultural Portfolio Segment [Member] | Commercial [Member] | Pass [Member]
Commercial and Agricultural
Loans receivable	44,955	46,230
Commercial and Agricultural Portfolio Segment [Member] | Commercial [Member] | Special Mention [Member]
Commercial and Agricultural
Loans receivable	1,985	2,905
Commercial and Agricultural Portfolio Segment [Member] | Commercial [Member] | Substandard [Member]
Commercial and Agricultural
Loans receivable	1,819	1,825
Commercial and Agricultural Portfolio Segment [Member] | Agricultural [Member]
Commercial and Agricultural
Loans receivable	27,373	16,689	23,017
Commercial and Agricultural Portfolio Segment [Member] | Agricultural [Member] | Pass [Member]
Commercial and Agricultural
Loans receivable	27,150	16,504
Commercial and Agricultural Portfolio Segment [Member] | Agricultural [Member] | Special Mention [Member]
Commercial and Agricultural
Loans receivable	18	27
Commercial and Agricultural Portfolio Segment [Member] | Agricultural [Member] | Substandard [Member]
Commercial and Agricultural
Loans receivable	205	158
Real Estate Portfolio Segment [Member] | Commercial [Member]
Commercial and Agricultural
Loans receivable	347,703	332,231	327,498
Real Estate Portfolio Segment [Member] | Commercial [Member] | Pass [Member]
Commercial and Agricultural
Loans receivable	330,711	309,828
Real Estate Portfolio Segment [Member] | Commercial [Member] | Special Mention [Member]
Commercial and Agricultural
Loans receivable	6,529	11,220
Real Estate Portfolio Segment [Member] | Commercial [Member] | Substandard [Member]
Commercial and Agricultural
Loans receivable	10,463	11,183
Real Estate Portfolio Segment [Member] | Commercial Constuction [Member]
Commercial and Agricultural
Loans receivable	43,589	51,259	50,455
Real Estate Portfolio Segment [Member] | Commercial Constuction [Member] | Pass [Member]
Commercial and Agricultural
Loans receivable	38,819	45,063
Real Estate Portfolio Segment [Member] | Commercial Constuction [Member] | Special Mention [Member]
Commercial and Agricultural
Loans receivable	1,135	1,741
Real Estate Portfolio Segment [Member] | Commercial Constuction [Member] | Substandard [Member]
Commercial and Agricultural
Loans receivable	3,635	4,455
Real Estate Portfolio Segment [Member] | Residential Construction [Member]
Commercial and Agricultural
Loans receivable	10,465	11,221	9,700
Real Estate Portfolio Segment [Member] | Residential Construction [Member] | Pass [Member]
Commercial and Agricultural
Loans receivable	10,465	11,221
Real Estate Portfolio Segment [Member] | Residential Construction [Member] | Special Mention [Member]
Commercial and Agricultural
Loans receivable	0	0
Real Estate Portfolio Segment [Member] | Residential Construction [Member] | Substandard [Member]
Commercial and Agricultural
Loans receivable	0	0
Real Estate Portfolio Segment [Member] | Residential [Member]
Commercial and Agricultural
Loans receivable	195,800	203,753	204,313
Real Estate Portfolio Segment [Member] | Residential [Member] | Pass [Member]
Commercial and Agricultural
Loans receivable	175,906	180,550
Real Estate Portfolio Segment [Member] | Residential [Member] | Special Mention [Member]
Commercial and Agricultural
Loans receivable	8,764	10,582
Real Estate Portfolio Segment [Member] | Residential [Member] | Substandard [Member]
Commercial and Agricultural
Loans receivable	11,130	12,621
Real Estate Portfolio Segment [Member] | Farmland [Member]
Commercial and Agricultural
Loans receivable	61,551	49,951	50,401
Real Estate Portfolio Segment [Member] | Farmland [Member] | Pass [Member]
Commercial and Agricultural
Loans receivable	56,352	47,548
Real Estate Portfolio Segment [Member] | Farmland [Member] | Special Mention [Member]
Commercial and Agricultural
Loans receivable	821	415
Real Estate Portfolio Segment [Member] | Farmland [Member] | Substandard [Member]
Commercial and Agricultural
Loans receivable	4,378	1,988
Consumer and Other Portfolio Segment [Member] | Consumer [Member]
Commercial and Agricultural
Loans receivable	20,958	22,820	23,448
Consumer and Other Portfolio Segment [Member] | Consumer [Member] | Pass [Member]
Commercial and Agricultural
Loans receivable	20,394	22,115
Consumer and Other Portfolio Segment [Member] | Consumer [Member] | Special Mention [Member]
Commercial and Agricultural
Loans receivable	171	249
Consumer and Other Portfolio Segment [Member] | Consumer [Member] | Substandard [Member]
Commercial and Agricultural
Loans receivable	393	456
Consumer and Other Portfolio Segment [Member] | Other [Member]
Commercial and Agricultural
Loans receivable	8,006	7,210	$ 7,968
Consumer and Other Portfolio Segment [Member] | Other [Member] | Pass [Member]
Commercial and Agricultural
Loans receivable	7,979	7,013
Consumer and Other Portfolio Segment [Member] | Other [Member] | Special Mention [Member]
Commercial and Agricultural
Loans receivable	27	0
Consumer and Other Portfolio Segment [Member] | Other [Member] | Substandard [Member]
Commercial and Agricultural
Loans receivable	$ 0	$ 197