Note 4 - Loans and the Allowance for Credit Losses - Amortized Cost of of the Modified Loans (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($)
Modified	$ 17,798
Modified, percentage	0.21%
Modified, percentage	0.21%
Extended Maturity [Member]
Modified	$ 243
Payment Deferral [Member]
Modified	10,283
Contractual Interest Rate Reduction [Member]
Modified	7,272
Commercial Portfolio Segment [Member]
Modified	$ 10,317
Modified, percentage	0.65%
Modified, percentage	0.65%
Commercial Portfolio Segment [Member] | Extended Maturity [Member]
Modified	$ 34
Commercial Portfolio Segment [Member] | Payment Deferral [Member]
Modified	10,283
Commercial Portfolio Segment [Member] | Contractual Interest Rate Reduction [Member]
Modified	0
Commercial Real Estate Portfolio Segment [Member]
Modified	$ 7,481
Modified, percentage	0.13%
Modified, percentage	0.13%
Commercial Real Estate Portfolio Segment [Member] | Extended Maturity [Member]
Modified	$ 209
Commercial Real Estate Portfolio Segment [Member] | Payment Deferral [Member]
Modified	0
Commercial Real Estate Portfolio Segment [Member] | Contractual Interest Rate Reduction [Member]
Modified	$ 7,272