Note 4 - Loans and the Allowance for Loan Losses - Outstanding Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015
Loans	$ 476,091		$ 461,123
Deferred loan costs, net	2,182		2,006
Allowance for loan losses	(6,855)	$ (6,743)	(6,549)	$ (6,430)	$ (6,198)	$ (6,078)
Loans, net	471,418		456,580
Commercial Portfolio Segment [Member] \| Commercial Loans [Member]
Loans	39,394		41,293
Allowance for loan losses	(705)	(788)	(655)	(835)	(637)	(639)
Commercial Portfolio Segment [Member] \| Agricultural Loans [Member]
Loans	54,974		51,103
Allowance for loan losses	(514)	(473)	(466)	(416)	(311)	(294)
Commercial Portfolio Segment [Member] \| Real Estate Loan [Member]
Loans	236,791		226,136
Allowance for loan losses	(2,812)	(2,919)	(2,740)	(2,465)	(2,762)	(2,525)
Commercial Portfolio Segment [Member] \| Construction Loans [Member]
Loans	24,819		21,904
Allowance for loan losses	(1,071)	(838)	(927)	(883)	(800)	(874)
Residential Portfolio Segment [Member] \| Real Estate Loan [Member]
Loans	18,952		21,283
Allowance for loan losses	(252)	(268)	(280)	(322)	(318)	(341)
Residential Portfolio Segment [Member] \| Home Equity Loan [Member]
Loans	42,211		42,338
Consumer Portfolio Segment [Member] \| Automobile Loan [Member]
Loans	55,255		53,553
Allowance for loan losses	(845)	(806)	(815)	(841)	(763)	(784)
Consumer Portfolio Segment [Member] \| Other Loans [Member]
Loans	3,695		3,513
Allowance for loan losses	$ (95)	$ (90)	$ (91)	$ (95)	$ (83)	$ (93)

Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Section 50
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-Subparagraph (g)
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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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.

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Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements and loans held for sale.

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Amount of deferred fees paid by borrowers and unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of loans that are being amortized into income as an adjustment to yield. Excludes amounts for loans and leases covered under loss sharing agreements.

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