Note 15 - Fair Values of Financial Instruments (Details Textual)	12 Months Ended
Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	$ 458,000	$ 76,000
Impaired Financing Receivable, Related Allowance	60,000	5,000
Provision for Loan and Lease Losses, Total	3,247,000	715,000
Standby Letters of Credit	$ 493,000	548,000
Measurement Input, Discount Rate [Member]
Other Real Estate Owned, Measurement Input	0.1
Fair Value, Nonrecurring [Member]
Other Real Estate, Ending Balance	$ 9,000	88,000
Other Real Estate, Gross Amount	18,000	91,000
Other Real Estate, Disposals	9,000	3,000
Impaired Loans [Member]
Provision for Loan and Lease Losses, Total	81,000	63,000
Commercial Business [Member]
Impaired Financing Receivable, Unpaid Principal Balance, Total	14,000
Real Estate Loan [Member]
Impaired Financing Receivable, Unpaid Principal Balance, Total		67,000
Home Equity Loan [Member]
Impaired Financing Receivable, Unpaid Principal Balance, Total		4,000
Market and Income Approach Valuation Technique [Member]
Impaired Financing Receivable, Recorded Investment, Total		0
Commercial Real Estate Portfolio Segment [Member]
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	380,000
Impaired Financing Receivable, Related Allowance	40,000
Provision for Loan and Lease Losses, Total	2,250,000	(100,000)
Commercial Portfolio Segment [Member]
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	78,000
Impaired Financing Receivable, Related Allowance	20,000
Provision for Loan and Lease Losses, Total	134,000	$ 386,000
Collateral Pledged [Member] \| Commercial Real Estate Portfolio Segment [Member]
Impaired Financing Receivable, with Related Allowance, Fair Value	340,000
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	380,000
Impaired Financing Receivable, Related Allowance	40,000
Collateral Pledged [Member] \| Commercial Portfolio Segment [Member]
Impaired Financing Receivable, with Related Allowance, Fair Value	58,000
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	78,000
Impaired Financing Receivable, Related Allowance	$ 20,000

Fair value portion of impaired financing receivable with related allowance.

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Amount of allowance for credit losses related to recorded investment.

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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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Amount of expense related to estimated loss from loan and lease transactions.

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