Note 5 - Loans and the Allowance for Credit Losses - Aging of Modified Loans (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2023 USD ($)
Commercial Portfolio Segment [Member]
Commercial	$ 44
Commercial Portfolio Segment [Member] | Financial Asset, Not Past Due [Member]
Commercial	44
Commercial Portfolio Segment [Member] | Financial Asset, 30 to 89 Days Past Due [Member]
Commercial	0
Commercial Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Commercial	0
Commercial Real Estate Portfolio Segment [Member]
Commercial	211
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, Not Past Due [Member]
Commercial	211
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, 30 to 89 Days Past Due [Member]
Commercial	0
Commercial Real Estate Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Commercial	$ 0