Note 5 - Loans and the Allowance for Credit Losses - Impairment Evaluation on Loans and Allowance for Credit Losses (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Individually analyzed, allowance for credit loss	$ 1,235	$ 941
Collectively evaluated, allowance for credit loss	81,238	80,616
Less: Allowance for credit losses - loans	82,685	81,974	$ 90,513	$ 78,773
Financing Receivable, Individually Evaluated for Credit Loss	56,497	69,963
Collectively evaluated	8,223,563	8,281,394
Gross loans	8,280,482	8,351,841
Financial Asset Acquired with Credit Deterioration [Member]
Less: Allowance for credit losses - loans	212	417
Gross loans	422	484
Commercial Portfolio Segment [Member]
Individually analyzed, allowance for credit loss	326	0
Collectively evaluated, allowance for credit loss	17,740	20,215
Less: Allowance for credit losses - loans	18,278	20,632	28,903	25,969
Financing Receivable, Individually Evaluated for Credit Loss	15,751	15,336
Collectively evaluated	1,516,557	1,562,910
Gross loans	1,532,730	1,578,730
Commercial Portfolio Segment [Member] \| Financial Asset Acquired with Credit Deterioration [Member]
Less: Allowance for credit losses - loans	212	417
Gross loans	422	484
Commercial Real Estate Portfolio Segment [Member]
Individually analyzed, allowance for credit loss	909	941
Collectively evaluated, allowance for credit loss	53,868	51,337
Less: Allowance for credit losses - loans	54,777	52,278	53,742	45,589
Financing Receivable, Individually Evaluated for Credit Loss	36,486	39,986
Collectively evaluated	5,844,193	5,855,559
Gross loans	5,880,679	5,895,545
Commercial Real Estate Portfolio Segment [Member] \| Financial Asset Acquired with Credit Deterioration [Member]
Less: Allowance for credit losses - loans	0	0
Gross loans	0	0
Commercial Construction Portfolio Segment [Member]
Individually analyzed, allowance for credit loss	0	0
Collectively evaluated, allowance for credit loss	5,064	4,739
Less: Allowance for credit losses - loans	5,064	4,739	3,718	3,580
Financing Receivable, Individually Evaluated for Credit Loss	2,204	8,700
Collectively evaluated	614,042	611,796
Gross loans	616,246	620,496
Commercial Construction Portfolio Segment [Member] \| Financial Asset Acquired with Credit Deterioration [Member]
Less: Allowance for credit losses - loans	0	0
Gross loans	0	0
Residential Portfolio Segment [Member]
Individually analyzed, allowance for credit loss	0	0
Collectively evaluated, allowance for credit loss	4,561	4,320
Less: Allowance for credit losses - loans	4,561	4,320	4,143	3,628
Financing Receivable, Individually Evaluated for Credit Loss	2,056	5,941
Collectively evaluated	247,635	250,100
Gross loans	249,691	256,041
Residential Portfolio Segment [Member] \| Financial Asset Acquired with Credit Deterioration [Member]
Less: Allowance for credit losses - loans	0	0
Gross loans	0	0
Consumer Portfolio Segment [Member]
Individually analyzed, allowance for credit loss	0	0
Collectively evaluated, allowance for credit loss	5	5
Less: Allowance for credit losses - loans	5	5	$ 7	$ 7
Financing Receivable, Individually Evaluated for Credit Loss	0	0
Collectively evaluated	1,136	1,029
Gross loans	1,136	1,029
Consumer Portfolio Segment [Member] \| Financial Asset Acquired with Credit Deterioration [Member]
Less: Allowance for credit losses - loans	0	0
Gross loans	$ 0	$ 0

Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

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