Note 8 - Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, beginning of period	$ 9,164	$ 8,192	$ 8,834	$ 7,841
Provision for (credit to) loan losses	550	568	925	943
Charge-offs	(271)	(139)	(426)	(232)
Recoveries	51	24	161	93
Allowance for loan losses, end of period	9,494	8,645	9,494	8,645
Commercial Portfolio Segment [Member] \| Commercial and Industrial [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, beginning of period	3,302	2,840	3,092	2,711
Provision for (credit to) loan losses	844	177	1,036	284
Charge-offs	(207)	0	(207)	0
Recoveries	8	10	26	32
Allowance for loan losses, end of period	3,947	3,027	3,947	3,027
Commercial Portfolio Segment [Member] \| Construction Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, beginning of period	675	573	551	563
Provision for (credit to) loan losses	(87)	21	37	31
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Allowance for loan losses, end of period	588	594	588	594
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	2,913	2,710	2,824	2,410
Provision for (credit to) loan losses	(60)	293	29	591
Charge-offs	0	0	0	0
Recoveries	8	0	8	2
Allowance for loan losses, end of period	2,861	3,003	2,861	3,003
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	722	781	754	816
Provision for (credit to) loan losses	(9)	157	(68)	102
Charge-offs	(15)	(77)	(51)	(77)
Recoveries	16	2	79	22
Allowance for loan losses, end of period	714	863	714	863
State and Political Subdivisions Portfolio Segment [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, beginning of period	201	190	153	114
Provision for (credit to) loan losses	45	70	93	146
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Allowance for loan losses, end of period	246	260	246	260
Retail Portfolio Segment [Member] \| Consumer Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, beginning of period	188	67	164	57
Provision for (credit to) loan losses	46	9	154	48
Charge-offs	(49)	(21)	(151)	(70)
Recoveries	16	5	34	25
Allowance for loan losses, end of period	201	60	201	60
Retail Portfolio Segment [Member] \| Family Residential Mortgages [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, beginning of period	433	509	497	444
Provision for (credit to) loan losses	(15)	(47)	(79)	18
Charge-offs	0	(1)	0	(1)
Recoveries	0	0	0	0
Allowance for loan losses, end of period	418	461	418	461
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	294	311	338	357
Provision for (credit to) loan losses	21	40	(17)	33
Charge-offs	0	(40)	(17)	(84)
Recoveries	3	7	14	12
Allowance for loan losses, end of period	318	318	318	318
Unallocated Financing Receivables [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, beginning of period	436	211	461	369
Provision for (credit to) loan losses	(235)	(152)	(260)	(310)
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Allowance for loan losses, end of period	$ 201	$ 59	$ 201	$ 59

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
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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://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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