Note 8 - Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, beginning of period	$ 9,887	$ 8,834
Provision for (credit to) loan losses	500	225
Charge-offs	(92)	(82)
Recoveries	39	38
Allowance for loan losses, end of period	10,334	9,015
Commercial Portfolio Segment [Member] \| Commercial and Industrial [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, beginning of period	4,689	3,092
Provision for (credit to) loan losses	(41)	(16)
Charge-offs	0	0
Recoveries	9	7
Allowance for loan losses, end of period	4,657	3,083
Commercial Portfolio Segment [Member] \| Construction Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, beginning of period	590	551
Provision for (credit to) loan losses	(304)	51
Charge-offs	0	0
Recoveries	0	0
Allowance for loan losses, end of period	286	602
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	2,519	2,824
Provision for (credit to) loan losses	767	5
Charge-offs	0	0
Recoveries	0	0
Allowance for loan losses, end of period	3,286	2,829
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	629	754
Provision for (credit to) loan losses	(40)	(1)
Charge-offs	0	(31)
Recoveries	19	21
Allowance for loan losses, end of period	608	743
State and Political Subdivisions Portfolio Segment [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, beginning of period	115	153
Provision for (credit to) loan losses	19	37
Charge-offs	0	0
Recoveries	0	0
Allowance for loan losses, end of period	134	190
Retail Portfolio Segment [Member] \| Consumer Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, beginning of period	230	164
Provision for (credit to) loan losses	130	28
Charge-offs	(92)	(35)
Recoveries	10	9
Allowance for loan losses, end of period	278	166
Retail Portfolio Segment [Member] \| Family Residential Mortgages [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, beginning of period	549	497
Provision for (credit to) loan losses	111	3
Charge-offs	0	0
Recoveries	0	0
Allowance for loan losses, end of period	660	500
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	310	338
Provision for (credit to) loan losses	22	18
Charge-offs	0	(16)
Recoveries	1	1
Allowance for loan losses, end of period	333	341
Unallocated Financing Receivables [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, beginning of period	256	461
Provision for (credit to) loan losses	(164)	100
Charge-offs	0	0
Recoveries	0	0
Allowance for loan losses, end of period	$ 92	$ 561

Provision for (credit to) loan and lease losses.

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- Definition

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

+ References

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- Definition

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(3)
-URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953423-111524

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-Section S99
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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.

+ References

No definition available.

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- Definition

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://fasb.org/us-gaap/role/ref/legacyRef
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-SubTopic 210
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-URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953423-111524

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-Publisher FASB
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-URI http://asc.fasb.org/extlink&oid=27010918&loc=d3e74567-122707

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