Note 4 - Allowance for Loan Losses - Segregated by Class of Loan (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2017	Mar. 31, 2016
Allowance for loan losses, beginning balance	$ 8,923	$ 8,604
Allowance for loan losses, charge-offs	(917)	(551)
Allowance for loan losses, recoveries	523	1,142
Provision for Loan Losses	335	354
Allowance for loan losses, ending balance	8,864	9,549
Commercial [Member] \| Commercial and Agricultural Portfolio Segment [Member]
Allowance for loan losses, beginning balance	456	855
Allowance for loan losses, charge-offs	(4)	(169)
Allowance for loan losses, recoveries	79	12
Provision for Loan Losses	(128)	(144)
Allowance for loan losses, ending balance	403	554
Commercial [Member] \| Real Estate Portfolio Segment [Member]
Allowance for loan losses, beginning balance	5,751	3,851
Allowance for loan losses, charge-offs	(852)	(248)
Allowance for loan losses, recoveries	247	168
Provision for Loan Losses	773	1,475
Allowance for loan losses, ending balance	5,919	5,246
Agricultural [Member] \| Commercial and Agricultural Portfolio Segment [Member]
Allowance for loan losses, beginning balance	168	203
Allowance for loan losses, charge-offs		(22)
Allowance for loan losses, recoveries	1	1
Provision for Loan Losses	20	10
Allowance for loan losses, ending balance	189	192
Commercial Construction [Member] \| Real Estate Portfolio Segment [Member]
Allowance for loan losses, beginning balance	323	691
Allowance for loan losses, charge-offs
Allowance for loan losses, recoveries	162	804
Provision for Loan Losses	(183)	(685)
Allowance for loan losses, ending balance	302	810
Residential Construction [Member] \| Real Estate Portfolio Segment [Member]
Allowance for loan losses, beginning balance	13	20
Allowance for loan losses, charge-offs
Allowance for loan losses, recoveries
Provision for Loan Losses	(3)
Allowance for loan losses, ending balance	10	20
Residential [Member] \| Real Estate Portfolio Segment [Member]
Allowance for loan losses, beginning balance	1,396	1,990
Allowance for loan losses, charge-offs	(15)	(63)
Allowance for loan losses, recoveries	15	14
Provision for Loan Losses	(160)	(136)
Allowance for loan losses, ending balance	1,236	1,805
Farmland [Member] \| Real Estate Portfolio Segment [Member]
Allowance for loan losses, beginning balance	722	912
Allowance for loan losses, charge-offs
Allowance for loan losses, recoveries		125
Provision for Loan Losses	(13)	(234)
Allowance for loan losses, ending balance	709	803
Consumer [Member] \| Consumer and Other Portfolio Segment [Member]
Allowance for loan losses, beginning balance	80	63
Allowance for loan losses, charge-offs	(46)	(49)
Allowance for loan losses, recoveries	19	15
Provision for Loan Losses	28	72
Allowance for loan losses, ending balance	81	101
Other [Member] \| Consumer and Other Portfolio Segment [Member]
Allowance for loan losses, beginning balance	14	19
Allowance for loan losses, charge-offs
Allowance for loan losses, recoveries		3
Provision for Loan Losses	1	(4)
Allowance for loan losses, ending balance	$ 15	$ 18

Amount of recovery of loans and lease receivables which had previously been fully or partially written-off as bad debts.

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Amount of loans and leases that have been written off from both loan receivables and allowance reserve for credit loss.

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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 of expense related to estimated loss from loan and lease transactions.

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