Note 7 - Fair Value (Details Textual)	3 Months Ended	12 Months Ended
Mar. 31, 2020 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2019 USD ($)
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	$ 270,000	$ 141,000	$ 76,000
Impaired Financing Receivable, Related Allowance	26,000	70,000	5,000
Provision for Loan and Lease Losses, Total	$ 792,000	180,000
Measurement Input, Discount Rate [Member]
Other Real Estate Owned, Measurement Input	0.1
Fair Value, Nonrecurring [Member]
Provision for Loan and Lease Losses, Total	$ 0	21,000
Other Real Estate, Ending Balance	0		88,000
Other Real Estate, Gross Amount			91,000
Other Real Estate, Disposals			3,000
Impaired Loans [Member]
Provision for Loan and Lease Losses, Total	24,000	63,000
Real Estate Loan [Member]
Impaired Financing Receivable, Unpaid Principal Balance, Total	70,000		67,000
Home Equity Loan [Member]
Impaired Financing Receivable, Unpaid Principal Balance, Total	4,000		4,000
Commercial Real Estate Portfolio Segment [Member]
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	150,000
Impaired Financing Receivable, Related Allowance	19,000
Provision for Loan and Lease Losses, Total	606,000	(73,000)
Commercial Portfolio Segment [Member]
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	45,000	63,000
Impaired Financing Receivable, Related Allowance	5,000	63,000
Provision for Loan and Lease Losses, Total	45,000	$ 206,000
Collateral Pledged [Member]
Impaired Financing Receivable, with Related Allowance, Fair Value			$ 0
Collateral Pledged [Member] \| Commercial Real Estate Portfolio Segment [Member]
Impaired Financing Receivable, with Related Allowance, Fair Value	131,000
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	150,000
Impaired Financing Receivable, Related Allowance	19,000
Collateral Pledged [Member] \| Commercial Portfolio Segment [Member]
Impaired Financing Receivable, with Related Allowance, Fair Value	40,000
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	45,000
Impaired Financing Receivable, Related Allowance	$ 5,000

Fair value portion of impaired financing receivable with related allowance.

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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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+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Amount of expense related to estimated loss from loan and lease transactions.

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