Note 5 - Loans and the Allowance for Credit Losses - Amortized Cost of of the Modified Loans (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2024	Dec. 31, 2023
Modified	$ 83,317	$ 17,798
Loans Modified, Gross	$ 7,663,100	$ 7,474,275
Modified, percentage	1.09%	0.24%
Weighted Average Term Extension (Month)	142 months	216 months
Weighted Average Payment Reduction	$ 6	$ 0
Weighted Average Interest Rate Reduction	0.80%	1.90%
Weighted Average [Member]
Payment Deferral (Month)	3 months	6 months
Extended Maturity [Member]
Modified	$ 19,054	$ 243
Payment Deferral [Member]
Modified	126	10,283
Contractual Interest Rate Reduction [Member]
Modified	63,804	7,272
Principal Forgiveness [Member]
Modified	333	0
Commercial Portfolio Segment [Member]
Modified	18,100	10,317
Loans Modified, Gross	$ 1,532,730	$ 1,578,730
Modified, percentage	1.18%	0.65%
Weighted Average Term Extension (Month)	6 months	36 months
Weighted Average Payment Reduction	$ 6
Commercial Portfolio Segment [Member] \| Weighted Average [Member]
Payment Deferral (Month)	3 months	6 months
Commercial Portfolio Segment [Member] \| Extended Maturity [Member]
Modified	$ 17,641	$ 34
Commercial Portfolio Segment [Member] \| Payment Deferral [Member]
Modified	126	10,283
Commercial Portfolio Segment [Member] \| Contractual Interest Rate Reduction [Member]
Modified	0	0
Commercial Portfolio Segment [Member] \| Principal Forgiveness [Member]
Modified	333	0
Commercial Real Estate Portfolio Segment [Member]
Modified	63,804	7,481
Loans Modified, Gross	$ 5,880,679	$ 5,895,545
Modified, percentage	1.08%	0.13%
Weighted Average Term Extension (Month)		180 months
Weighted Average Payment Reduction		$ 0
Weighted Average Interest Rate Reduction	0.80%	1.90%
Commercial Real Estate Portfolio Segment [Member] \| Extended Maturity [Member]
Modified	$ 0	$ 209
Commercial Real Estate Portfolio Segment [Member] \| Payment Deferral [Member]
Modified	0	0
Commercial Real Estate Portfolio Segment [Member] \| Contractual Interest Rate Reduction [Member]
Modified	63,804	7,272
Commercial Real Estate Portfolio Segment [Member] \| Principal Forgiveness [Member]
Modified	0	$ 0
Residential Portfolio Segment [Member]
Modified	1,413
Loans Modified, Gross	$ 249,691
Modified, percentage	0.57%
Weighted Average Term Extension (Month)	136 months
Weighted Average Payment Reduction	$ 0
Residential Portfolio Segment [Member] \| Extended Maturity [Member]
Modified	1,413
Residential Portfolio Segment [Member] \| Payment Deferral [Member]
Modified	0
Residential Portfolio Segment [Member] \| Contractual Interest Rate Reduction [Member]
Modified	0
Residential Portfolio Segment [Member] \| Principal Forgiveness [Member]
Modified	$ 0

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Percentage of financing receivable modified during period for debtor experiencing financial difficulty to total financing receivables.

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