Note 5 - Allowance for Loan Losses, Nonperforming Assets and Impaired Loans (Details Textual) $ in Thousands	12 Months Ended
Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Ratio of Allowance for Loan Losses to End of Period Loans, Excluding PPP Loans	1.16%
Mortgage Loans in Process of Foreclosure, Amount	$ 261
Interest and Fee Income, Loans and Leases, Total	$ 34,523	$ 33,869	$ 31,333
Threshold Period for Considering Loans as Special Mention or Classified (Day)	75 days
Financing Receivable, Modifications, Number of Contracts	0	1	13
Financing Receivable, Troubled Debt Restructuring, Subsequent Default, Number of Contracts	0
Number of Loan Modifications for COVID-19 Related Accommodations	388
Principal Balance of Loans with COVID-19 Related Accommodations	$ 182,829
Financing Receivable, Number of Principal and Interest Payment Deferrals	75
Financing Receivable, Principal and Interest Deferred Payments	$ 43,576
Financing Receivable, Number Deferrals in Modification	15
Financing Receivable, Deferred Payments in Modification	$ 38,935
Special Mention [Member]
Increase in Percentage of Allocation Loans Rated Special Mention	50.00%
Classified Excluding Impaired [Member]
Increase in Percentage of Allocation Loans Rated Classified	100.00%
Nonperforming Financial Instruments [Member]
Interest and Fee Income, Loans and Leases, Total	$ 0	$ 0	$ 0
Residential Portfolio Segment [Member]
Other Real Estate, Ending Balance	$ 110
Consumer Portfolio Segment [Member]
Financing Receivable, Troubled Debt Restructuring, Subsequent Default, Number of Contracts		7
Financing Receivable, Troubled Debt Restructuring		$ 263
Commercial Portfolio Segment [Member]
Financing Receivable, Number of Principal and Interest Payment Deferrals	17
Financing Receivable, Principal and Interest Deferred Payments	$ 39,402

The amount of deferred payments in modification under financing receivable.

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The number of deferrals in modification for financing receivable.

+ References

No definition available.

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Number of principal and interest payment deferrals on loans receivable related to loan modification programs offered to financial institution customers affected by COVID-19

+ References

No definition available.

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Deferred amounts of principal and interest payments on loans receivable related to loan modification programs offered to financial institution customers affected by COVID-19.

+ References

No definition available.

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- Definition

Increase in the percentage of allocation for loans rated classified.

+ References

No definition available.

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Increase in the percentage of allocation for loans rated special mention.

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Represents number of loan modifications for COVID-19 related accommodations.

+ References

No definition available.

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Represents principal balance of loans with COVID-19 related accommodations,

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No definition available.

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Represents ratio of allowance for loan losses, excluding PPP loans, to the end of period loans, net of unearned income and deferred fees.

+ References

No definition available.

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Represents the threshold period for considering loans as special mention or classified.

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Number of financing receivables that have been modified by troubled debt restructurings.

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Amount of financing receivable modified as troubled debt restructuring.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953676-111524

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-Topic 310
-SubTopic 40
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=121585226&loc=d3e18845-111554

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Number of financing receivable contracts modified as troubled debt restructuring within previous 12 months, with subsequent payment default.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953682-111524

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The aggregate interest and fee income generated by: (1) loans the Entity has positive intent and ability to hold for the foreseeable future, or until maturity or payoff, including commercial and consumer loans, whether domestic or foreign, which may consist of: (a) industrial and agricultural; (b) real estate; and (c) real estate construction loans; (d) trade financing; (e) lease financing; (f) home equity lines-of-credit; (g) automobile and other vehicle loans; and (h) credit card and other revolving-type loans and (2) loans and leases held-for-sale which may include mortgage loans, direct financing, and sales-type leases.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.1)
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Recorded investment of consumer mortgage loan receivables secured by residential real estate properties for which formal foreclosure proceedings are in process.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 35
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Carrying amount of other real estate not separately disclosed, including, but not limited to, real estate investments, real estate loans that qualify as investments in real estate, and premises that are no longer used in operations may also be included in real estate owned. This does not include real estate assets taken in settlement of troubled loans through surrender or foreclosure.

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