Note 10 - Financial Instrument Commitments (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
Jun. 30, 2021	Dec. 31, 2020
Commitments And Contingencies Disclosure [Line Items]
Commitments to extend credit and unused lines of credit	$ 361,498	$ 319,104
Commitments to Extend Credit [Member]
Commitments And Contingencies Disclosure [Line Items]
Commitments to extend credit and unused lines of credit	338,841	296,537
Standby Letters of Credit [Member]
Commitments And Contingencies Disclosure [Line Items]
Commitments to extend credit and unused lines of credit	$ 22,657	$ 22,567

Maximum amount of loss due to credit risk that, based on the gross fair value of the financial instrument, the entity would incur if parties to the financial instruments that make up the concentration failed completely to perform according to the terms of the contracts and the collateral or other security, if any, for the amount due proved to be of no value to the entity.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121572278&loc=d3e13537-108611

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