Note 4 - Loans and the Allowance for Loan Losses - Outstanding Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Loans	$ 573,446	$ 566,199
Deferred loan costs, net	3,399	3,257
Allowance for loan losses	(7,067)	(6,958)	$ (6,622)	$ (6,669)
Total net loans	569,778	562,498
Commercial Portfolio Segment [Member] \| Commercial Loans [Member]
Loans	42,707	49,563
Allowance for loan losses	(796)	(914)	(772)	(725)
Commercial Portfolio Segment [Member] \| Agricultural Loans [Member]
Loans	70,041	69,160
Allowance for loan losses	(542)	(538)	(494)	(623)
Commercial Portfolio Segment [Member] \| Real Estate Loan [Member]
Loans	282,533	271,710
Allowance for loan losses	(2,969)	(2,686)	(2,759)	(2,729)
Commercial Portfolio Segment [Member] \| Construction Loans [Member]
Loans	37,637	40,161
Allowance for loan losses	(641)	(758)	(791)	(783)
Residential Portfolio Segment [Member] \| Real Estate Loan [Member]
Loans	16,413	15,900
Allowance for loan losses	(195)	(214)	(212)	(231)
Residential Portfolio Segment [Member] \| Equity Lines of Credit [Member]
Loans	37,519	38,490
Allowance for loan losses	(450)	(464)	(510)	(533)
Consumer Portfolio Segment [Member] \| Automobile Loan [Member]
Loans	82,737	77,135
Allowance for loan losses	(1,384)	(1,289)	(977)	(946)
Consumer Portfolio Segment [Member] \| Other Loans [Member]
Loans	3,859	4,080
Allowance for loan losses	$ (90)	$ (95)	$ (107)	$ (99)

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.

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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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