Note 6 - Loans and the Allowance for Credit Losses - Impairment Evaluation on Loans and Allowance for Credit Losses (Details) - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024	Mar. 31, 2024	Dec. 31, 2023
Individually analyzed, allowance for credit loss	$ 356	$ 1,235
Collectively evaluated, allowance for credit loss	81,874	81,238
Less: Allowance for credit losses - loans	82,403	82,685	$ 82,869	$ 81,974
Individually analyzed, gross loans	48,953	56,497
Collectively evaluated, gross loans	8,156,977	8,223,563
Gross loans	8,206,343	8,280,482
Financial Asset Acquired with Credit Deterioration [Member]
Less: Allowance for credit losses - loans	173	212
Gross loans	413	422
Commercial Portfolio Segment [Member]
Individually analyzed, allowance for credit loss	323	326
Collectively evaluated, allowance for credit loss	17,535	17,740
Less: Allowance for credit losses - loans	18,031	18,278	20,735	20,632
Individually analyzed, gross loans	15,599	15,751
Collectively evaluated, gross loans	1,476,908	1,516,557
Gross loans	1,492,920	1,532,730
Commercial Portfolio Segment [Member] \| Financial Asset Acquired with Credit Deterioration [Member]
Less: Allowance for credit losses - loans	173	212
Gross loans	413	422
Commercial Real Estate Portfolio Segment [Member]
Individually analyzed, allowance for credit loss	33	909
Collectively evaluated, allowance for credit loss	54,553	53,868
Less: Allowance for credit losses - loans	54,586	54,777	52,794	52,278
Individually analyzed, gross loans	29,109	36,486
Collectively evaluated, gross loans	5,808,562	5,844,193
Gross loans	5,837,671	5,880,679
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	5,030	5,064
Less: Allowance for credit losses - loans	5,030	5,064	5,011	4,739
Individually analyzed, gross loans	2,204	2,204
Collectively evaluated, gross loans	615,389	614,042
Gross loans	617,593	616,246
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	4,752	4,561
Less: Allowance for credit losses - loans	4,752	4,561	4,326	4,320
Individually analyzed, gross loans	2,041	2,056
Collectively evaluated, gross loans	254,514	247,635
Gross loans	256,555	249,691
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	4	5
Less: Allowance for credit losses - loans	4	5	$ 3	$ 5
Individually analyzed, gross loans	0	0
Collectively evaluated, gross loans	1,604	1,136
Gross loans	1,604	1,136
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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