Note 5 - Allowance for Loan Losses (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, beginning of period	$ 7,554	$ 8,001	$ 8,925
Provision for (credit to) loan losses	30	200	400
Charge-offs	(404)	(787)	(1,613)
Recoveries	214	140	289
Allowance for loan losses, end of period	7,394	7,554	8,001
Commercial Portfolio Segment [Member] \| Commercial and Industrial [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, beginning of period	1,521	1,892	2,044
Provision for (credit to) loan losses	41	(353)	(202)
Charge-offs	(140)	(56)	(17)
Recoveries	37	38	67
Allowance for loan losses, end of period	1,459	1,521	1,892
Commercial Portfolio Segment [Member] \| Construction Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, beginning of period	286	297	439
Provision for (credit to) loan losses	163	(11)	(142)
Charge-offs	0	0	0
Recoveries	0	0	0
Allowance for loan losses, end of period	449	286	297
Commercial Portfolio Segment [Member] \| Secured by Commercial Real Estate [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, beginning of period	2,411	2,700	2,898
Provision for (credit to) loan losses	227	(214)	(131)
Charge-offs	0	(84)	(70)
Recoveries	8	9	3
Allowance for loan losses, end of period	2,646	2,411	2,700
Commercial Portfolio Segment [Member] \| Secured by Residential Real Estate [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, beginning of period	1,812	1,630	1,632
Provision for (credit to) loan losses	(44)	687	1,019
Charge-offs	(120)	(531)	(1,069)
Recoveries	112	26	48
Allowance for loan losses, end of period	1,760	1,812	1,630
State and Political Subdivisions Portfolio Segment [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, beginning of period	222	221	186
Provision for (credit to) loan losses	(99)	1	35
Charge-offs	0	0	0
Recoveries	0	0	0
Allowance for loan losses, end of period	123	222	221
Loans to Depository Institutions Portfolio Segment [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, beginning of period		0	4
Provision for (credit to) loan losses			(4)
Charge-offs			0
Recoveries			0
Allowance for loan losses, end of period			0
Finance Leases Portfolio Segment [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, beginning of period	164	93	103
Provision for (credit to) loan losses	(121)	76	15
Charge-offs	(52)	(21)	(39)
Recoveries	9	16	14
Allowance for loan losses, end of period	0	164	93
Retail Portfolio Segment [Member] \| Consumer Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, beginning of period	76	85	64
Provision for (credit to) loan losses	60	57	142
Charge-offs	(92)	(95)	(167)
Recoveries	32	29	46
Allowance for loan losses, end of period	76	76	85
Retail Portfolio Segment [Member] \| Family Residential Mortgages [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, beginning of period	350	312	303
Provision for (credit to) loan losses	16	38	103
Charge-offs	0	0	(95)
Recoveries	0	0	1
Allowance for loan losses, end of period	366	350	312
Retail Portfolio Segment [Member] \| Home Equity Loans and Lines [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, beginning of period	428	453	583
Provision for (credit to) loan losses	(91)	(47)	(84)
Charge-offs	0	0	(156)
Recoveries	16	22	110
Allowance for loan losses, end of period	353	428	453
Unallocated Financing Receivables [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, beginning of period	284	318	669
Provision for (credit to) loan losses	(122)	(34)	(351)
Charge-offs	0	0	0
Recoveries	0	0	0
Allowance for loan losses, end of period	$ 162	$ 284	$ 318

Provision credit for loan and lease losses.

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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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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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