Note 3 - Loans (Details) - Age Analysis of Past Due Loans and Nonaccrual Loans - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014
Commercial and Agricultural
Accruing loans past due	$ 7,230	$ 9,708
Nonaccrual loans	14,120	18,334
Current loans	738,728	718,052
Loans receivable	760,078	746,094	$ 735,763
Financing Receivables, 30-89 Days Past Due [Member]
Commercial and Agricultural
Accruing loans past due	7,222	9,701
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Commercial and Agricultural
Accruing loans past due	8	7
Commercial and Agricultural Portfolio Segment [Member] | Commercial [Member]
Commercial and Agricultural
Accruing loans past due	423	872
Nonaccrual loans	739	405
Current loans	51,344	49,683
Loans receivable	52,506	50,960	41,840
Commercial and Agricultural Portfolio Segment [Member] | Commercial [Member] | Financing Receivables, 30-89 Days Past Due [Member]
Commercial and Agricultural
Accruing loans past due	423	872
Commercial and Agricultural Portfolio Segment [Member] | Commercial [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Commercial and Agricultural
Accruing loans past due	0	0
Commercial and Agricultural Portfolio Segment [Member] | Agricultural [Member]
Commercial and Agricultural
Accruing loans past due	99	0
Nonaccrual loans	162	45
Current loans	23,758	16,644
Loans receivable	24,019	16,689	18,568
Commercial and Agricultural Portfolio Segment [Member] | Agricultural [Member] | Financing Receivables, 30-89 Days Past Due [Member]
Commercial and Agricultural
Accruing loans past due	99	0
Commercial and Agricultural Portfolio Segment [Member] | Agricultural [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Commercial and Agricultural
Accruing loans past due	0	0
Real Estate Portfolio Segment [Member] | Commercial [Member]
Commercial and Agricultural
Accruing loans past due	1,379	2,309
Nonaccrual loans	4,905	5,325
Current loans	334,883	324,597
Loans receivable	341,167	332,231	332,895
Real Estate Portfolio Segment [Member] | Commercial [Member] | Financing Receivables, 30-89 Days Past Due [Member]
Commercial and Agricultural
Accruing loans past due	1,379	2,309
Real Estate Portfolio Segment [Member] | Commercial [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Commercial and Agricultural
Accruing loans past due	0	0
Real Estate Portfolio Segment [Member] | Commercial Constuction [Member]
Commercial and Agricultural
Accruing loans past due	84	142
Nonaccrual loans	3,152	3,251
Current loans	43,463	47,866
Loans receivable	46,699	51,259	50,180
Real Estate Portfolio Segment [Member] | Commercial Constuction [Member] | Financing Receivables, 30-89 Days Past Due [Member]
Commercial and Agricultural
Accruing loans past due	84	142
Real Estate Portfolio Segment [Member] | Commercial Constuction [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Commercial and Agricultural
Accruing loans past due	0	0
Real Estate Portfolio Segment [Member] | Residential Construction [Member]
Commercial and Agricultural
Accruing loans past due	255	0
Nonaccrual loans	0	0
Current loans	11,072	11,221
Loans receivable	11,327	11,221	10,875
Real Estate Portfolio Segment [Member] | Residential Construction [Member] | Financing Receivables, 30-89 Days Past Due [Member]
Commercial and Agricultural
Accruing loans past due	255	0
Real Estate Portfolio Segment [Member] | Residential Construction [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Commercial and Agricultural
Accruing loans past due	0	0
Real Estate Portfolio Segment [Member] | Residential [Member]
Commercial and Agricultural
Accruing loans past due	4,098	5,783
Nonaccrual loans	3,516	7,462
Current loans	195,191	190,508
Loans receivable	202,805	203,753	201,513
Real Estate Portfolio Segment [Member] | Residential [Member] | Financing Receivables, 30-89 Days Past Due [Member]
Commercial and Agricultural
Accruing loans past due	4,098	5,783
Real Estate Portfolio Segment [Member] | Residential [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Commercial and Agricultural
Accruing loans past due	0	0
Real Estate Portfolio Segment [Member] | Farmland [Member]
Commercial and Agricultural
Accruing loans past due	468	282
Nonaccrual loans	1,442	1,449
Current loans	52,225	48,220
Loans receivable	54,135	49,951	49,175
Real Estate Portfolio Segment [Member] | Farmland [Member] | Financing Receivables, 30-89 Days Past Due [Member]
Commercial and Agricultural
Accruing loans past due	468	282
Real Estate Portfolio Segment [Member] | Farmland [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Commercial and Agricultural
Accruing loans past due	0	0
Consumer and Other Portfolio Segment [Member] | Consumer [Member]
Commercial and Agricultural
Accruing loans past due	424	320
Nonaccrual loans	204	202
Current loans	20,743	22,298
Loans receivable	21,371	22,820	23,548
Consumer and Other Portfolio Segment [Member] | Consumer [Member] | Financing Receivables, 30-89 Days Past Due [Member]
Commercial and Agricultural
Accruing loans past due	416	313
Consumer and Other Portfolio Segment [Member] | Consumer [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Commercial and Agricultural
Accruing loans past due	8	7
Consumer and Other Portfolio Segment [Member] | Other [Member]
Commercial and Agricultural
Accruing loans past due	0	0
Nonaccrual loans	0	195
Current loans	6,049	7,015
Loans receivable	6,049	7,210	$ 7,169
Consumer and Other Portfolio Segment [Member] | Other [Member] | Financing Receivables, 30-89 Days Past Due [Member]
Commercial and Agricultural
Accruing loans past due	0	0
Consumer and Other Portfolio Segment [Member] | Other [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Commercial and Agricultural
Accruing loans past due	$ 0	$ 0