Note 5 - Loans and Allowance for Loan Losses (Details Textual)	3 Months Ended	12 Months Ended
Mar. 31, 2022 USD ($)	Mar. 31, 2021 USD ($)	Dec. 31, 2021 USD ($)
Financing Receivable Number Of Loans 90 Days Past Due And Still Accruing	$ 0		$ 0
Impaired Financing Receivable, Interest Income, Cash Basis Method	$ 0		$ 0
Number Of Loans Identified As Troubled Debt Restructurings	7		9
Financing Receivable, Troubled Debt Restructuring	$ 3,200,000		$ 3,400,000
Financing Receivable, Nonaccrual Troubled Debt Restructuring	1,600,000		1,700,000
Allowance for Credit Losses Reserve, Change In Method of Calculating Impairment	33,292,000	$ 30,795,000	32,912,000
Financing Receivable, Troubled Debt Restructuring, Commitment to Lend	$ 0		$ 0
Financing Receivable, Troubled Debt Restructuring, Subsequent Default, Number of Contracts	0		0
Financing Receivable, Modifications, Number of Contracts	0	0
Specific Reserve [Member]
Allowance for Credit Losses Reserve, Change In Method of Calculating Impairment	$ 26,000	$ 524,000	$ 30,000
Specific Reserve [Member] \| One Loan [Member]
Allowance for Credit Losses Reserve, Change In Method of Calculating Impairment	$ 2,000		$ 3,000

Allowance for credit losses reserve change in method of calculating impairment.

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- Definition

Financing receivable nonaccrual troubled debt restructuring.

+ References

No definition available.

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- Definition

Financing receivable number of loans 90 days past due and still accruing.

+ References

No definition available.

+ Details

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- Definition

Represents number of loans identified as troubled debt restructurings.

+ References

No definition available.

+ Details

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- Definition

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

+ References

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- Definition

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 https://asc.fasb.org/extlink&oid=123577603&loc=SL6953676-111524

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 4
-URI https://asc.fasb.org/extlink&oid=121585226&loc=d3e18845-111554

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- Definition

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 https://asc.fasb.org/extlink&oid=123577603&loc=SL6953682-111524

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- Definition

Amount of interest income recognized on a cash-basis method of accounting that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(3)
-URI https://asc.fasb.org/extlink&oid=123577603&loc=d3e5212-111524

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- Definition

Amount of unfunded portion of contractual agreement to lend funds to borrower for financing receivable modified as troubled debt restructuring.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=121585226&loc=d3e18794-111554

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