Note 3 - Loans - Age Analysis of Past Due Loans and Nonaccrual Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015
Commercial and Agricultural Portfolio Segment [Member] \| Commercial [Member] \| Financing Receivables, 30-89 Days Past Due [Member]
Accruing loans past due	$ 262	$ 491
Commercial and Agricultural Portfolio Segment [Member] \| Commercial [Member]
Accruing loans past due	262	491
Nonaccrual loans	646	577
Current loans	44,865	46,714
Loans	45,773	47,782	$ 48,759
Commercial and Agricultural Portfolio Segment [Member] \| Agricultural [Member] \| Financing Receivables, 30-89 Days Past Due [Member]
Accruing loans past due	67	71
Commercial and Agricultural Portfolio Segment [Member] \| Agricultural [Member]
Accruing loans past due	67	71
Nonaccrual loans	281	178
Current loans	26,199	18,944
Loans	26,547	19,193	27,373
Real Estate Portfolio Segment [Member] \| Commercial [Member] \| Financing Receivables, 30-89 Days Past Due [Member]
Accruing loans past due	261	6,031
Real Estate Portfolio Segment [Member] \| Commercial [Member]
Accruing loans past due	261	6,031
Nonaccrual loans	8,179	7,565
Current loans	340,952	332,666
Loans	349,392	346,262	347,703
Real Estate Portfolio Segment [Member] \| Commercial Construction [Member] \| Financing Receivables, 30-89 Days Past Due [Member]
Accruing loans past due	109	90
Real Estate Portfolio Segment [Member] \| Commercial Construction [Member]
Accruing loans past due	109	90
Nonaccrual loans	200	1,643
Current loans	33,415	38,374
Loans	33,724	40,107	43,589
Real Estate Portfolio Segment [Member] \| Residential Construction [Member]
Current loans	10,325	9,413
Loans	10,325	9,413	10,465
Real Estate Portfolio Segment [Member] \| Residential [Member] \| Financing Receivables, 30-89 Days Past Due [Member]
Accruing loans past due	3,069	3,683
Real Estate Portfolio Segment [Member] \| Residential [Member]
Accruing loans past due	3,069	3,683
Nonaccrual loans	3,520	3,164
Current loans	188,456	190,155
Loans	195,045	197,002	195,800
Real Estate Portfolio Segment [Member] \| Farmland [Member] \| Financing Receivables, 30-89 Days Past Due [Member]
Accruing loans past due	172	123
Real Estate Portfolio Segment [Member] \| Farmland [Member]
Accruing loans past due	172	123
Nonaccrual loans	919	1,103
Current loans	72,710	60,554
Loans	73,801	61,780	61,551
Consumer and Other Portfolio Segment [Member] \| Consumer [Member] \| Financing Receivables, 30-89 Days Past Due [Member]
Accruing loans past due	235	470
Consumer and Other Portfolio Segment [Member] \| Consumer [Member] \| Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Accruing loans past due	1	8
Consumer and Other Portfolio Segment [Member] \| Consumer [Member]
Accruing loans past due	236	478
Nonaccrual loans	241	178
Current loans	19,901	19,949
Loans	20,378	20,605	20,958
Consumer and Other Portfolio Segment [Member] \| Other [Member]
Current loans	21,132	16,492
Loans	21,132	16,492	8,006
Financing Receivables, 30-89 Days Past Due [Member]
Accruing loans past due	4,175	10,959
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Accruing loans past due	1	8
Accruing loans past due	4,176	10,967
Nonaccrual loans	13,986	14,408
Current loans	757,955	733,261
Loans	$ 776,117	$ 758,636	$ 764,204

Financing receivables that are current.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7A
-URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953401-111524

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- Definition

Recorded investment in financing receivables that are on nonaccrual status as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Recorded Investment
-URI http://asc.fasb.org/extlink&oid=65880944

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=66008989&loc=d3e5111-111524

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- Definition

Recorded Investment in financing receivables that are past due at the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Recorded Investment
-URI http://asc.fasb.org/extlink&oid=65880944

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7A
-URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953401-111524

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Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=65884687&loc=d3e4428-111522

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