Note 5 - Loans and the Allowance for Credit Losses - Aging of Modified Loans (Details) - Commercial Portfolio Segment [Member] - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2024	Mar. 31, 2023
Modified	$ 126	$ 63
Financial Asset, Not Past Due [Member]
Modified	126	63
Financial Asset, 30 to 89 Days Past Due [Member]
Modified	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Modified	$ 0	$ 0

Amortized cost of financing receivable modified during period for debtor experiencing financial difficulty.

Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 33
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-33

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 12A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481933/310-10-55-12A

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 42
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-42

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration