Note 3 - Allowance for Loan Losses, Nonperforming Assets and Impaired Loans - Restructurings By Class (Details) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019 USD ($)
Number of contracts	0	1	0	1
Pre-modification outstanding principal balance				$ 98
Post-modification outstanding principal balance				$ 98
Residential Portfolio Segment [Member] \| Equity Lines [Member]
Number of contracts				1
Pre-modification outstanding principal balance				$ 98
Post-modification outstanding principal balance				$ 98

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

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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Amount, after troubled debt restructuring, of modified financing receivable.

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Amount, before troubled debt restructuring, of financing receivable to be modified.

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