Note 3 - Allowance for Loan Losses, Nonperforming Assets and Impaired Loans - Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Balance	$ 7,925	$ 8,300	$ 8,300
Charge-offs	(139)	(143)	(819)
Recoveries	77	45	287
Provision for (recovery of) loan losses	(472)	59	157
Balance	7,391	8,261	7,925
Real Estate Construction Portfolio Segment[Member]
Balance	337	438	438
Charge-offs	0
Recoveries	0	0	0
Provision for (recovery of) loan losses	(42)	(61)	(101)
Balance	295	377	337
Consumer Real Estate Portfolio Segment [Member]
Balance	2,027	1,830	1,830
Charge-offs			(146)
Recoveries			1
Provision for (recovery of) loan losses	(98)	(84)	342
Balance	1,929	1,746	2,027
Commercial Real Estate Portfolio Segment [Member]
Balance	3,044	3,738	3,738
Charge-offs		(30)	(139)
Recoveries	12	12	131
Provision for (recovery of) loan losses	(266)	(103)	(686)
Balance	2,790	3,617	3,044
Commercial Non Real Estate Segment [Member]
Balance	1,072	1,063	1,063
Charge-offs			(82)
Recoveries	7	4	23
Provision for (recovery of) loan losses	(163)	75	68
Balance	916	1,142	1,072
Public Sector and IDA Portfolio Segment[Member]
Balance	419	330	330
Charge-offs	0	0	0
Recoveries	0	0	0
Provision for (recovery of) loan losses	13	87	89
Balance	432	417	419
Consumer Non Real Estate Portfolio Segment [Member]
Balance	707	644	644
Charge-offs	(139)	(113)	(452)
Recoveries	58	29	132
Provision for (recovery of) loan losses	54	56	383
Balance	680	616	707
Unallocated Financing Receivables [Member]
Balance	319	257	257
Charge-offs	0	0	0
Recoveries	0	0	0
Provision for (recovery of) loan losses	30	89	62
Balance	$ 349	$ 346	$ 319

Amount of recovery of financing receivables doubtful of collection that were previously charged off.

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Amount of direct write-downs of financing receivables charged against the allowance.

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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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