Note 2 - INVESTMENT SECURITIES - Amortized Cost and Fair Value of HTM and AFS Investment Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024	Mar. 31, 2024	Dec. 31, 2023
Securities HTM:
Securities HTM, Amortized cost	$ 874,294	$ 836,060
Securities HTM, Allowance for Credit (Losses)	(263)	(263)	$ (203)	$ (203)
Securities HTM, Gross Unrealized Gains	19,552	27,957
Securities HTM, Gross Unrealized (Losses)	(102,479)	(63,171)
Securities HTM, Fair Value	791,104	800,583
Securities AFS:
Securities AFS, Amortized Cost	317,770	331,337
Securities AFS, Gross Unrealized Gains	143	185
Securities AFS, Gross Unrealized (Losses)	(53,672)	(50,413)
Securities AFS, Fair Value	264,241	281,109
U.S. treasuries and govt. sponsored agency securities
Securities AFS:
Securities AFS, Amortized Cost	19,641	23,113
Securities AFS, Gross Unrealized Gains	7	7
Securities AFS, Gross Unrealized (Losses)	(2,161)	(2,529)
Securities AFS, Fair Value	17,487	20,591
Residential mortgage-backed and related securities
Securities AFS:
Securities AFS, Amortized Cost	47,841	55,641
Securities AFS, Gross Unrealized Gains	3	3
Securities AFS, Gross Unrealized (Losses)	(4,650)	(5,602)
Securities AFS, Fair Value	43,194	50,042
Municipal securities
Securities HTM:
Securities HTM, Amortized cost	845,226	806,992
Securities HTM, Allowance for Credit (Losses)	(254)	(254)	(202)	(202)
Securities HTM, Gross Unrealized Gains	15,157	23,292
Securities HTM, Gross Unrealized (Losses)	(102,476)	(63,164)
Securities HTM, Fair Value	757,653	766,866
Securities AFS:
Securities AFS, Amortized Cost	203,776	204,664
Securities AFS, Gross Unrealized (Losses)	(45,017)	(40,089)
Securities AFS, Fair Value	158,759	164,575
Asset-backed securities
Securities AFS:
Securities AFS, Amortized Cost	7,644	9,053
Securities AFS, Gross Unrealized Gains	121	171
Securities AFS, Gross Unrealized (Losses)	(1)
Securities AFS, Fair Value	7,764	9,224
Corporate securities
Securities HTM:
Securities HTM, Amortized cost	28,018	28,018
Securities HTM, Allowance for Credit (Losses)	(8)	(8)	$ (1)	(1)
Securities HTM, Gross Unrealized Gains	4,395	4,665
Securities HTM, Fair Value	32,405	32,675
Securities AFS:
Securities AFS, Amortized Cost	38,868	38,866
Securities AFS, Allowance for Credit (Losses)				$ (989)
Securities AFS, Gross Unrealized Gains	12	4
Securities AFS, Gross Unrealized (Losses)	(1,843)	(2,193)
Securities AFS, Fair Value	37,037	36,677
Other securities
Securities HTM:
Securities HTM, Amortized cost	1,050	1,050
Securities HTM, Allowance for Credit (Losses)	(1)	(1)
Securities HTM, Gross Unrealized (Losses)	(3)	(7)
Securities HTM, Fair Value	$ 1,046	$ 1,042

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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