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NOTE 2 - INVESTMENT SECURITIES - Amortized Cost and Fair Value of HTM and AFS Investment Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2026	Mar. 31, 2026	Dec. 31, 2025	Jun. 30, 2025	Mar. 31, 2025	Dec. 31, 2024
Securities HTM:
Pledged securities held to maturity, at amortized cost	$ 991,452		$ 948,676
Securities HTM, Amortized Cost	991,734		948,958
Securities HTM, Allowance for Credit (Losses)	(282)	$ (282)	(282)	$ (263)	$ (263)	$ (263)
Securities HTM, Gross Unrealized Gains	26,705		26,062
Securities HTM, Gross Unrealized (Losses)	(144,969)		(117,075)
Securities HTM, Fair Value	873,188		857,663
Securities AFS:
Securities AFS, Amortized Cost	338,193		326,752
Securities AFS, Gross Unrealized Gains	593		424
Securities AFS, Gross Unrealized (Losses)	(44,797)		(47,399)
Securities AFS, Fair Value	293,989		279,777
U.S. treasuries and govt. sponsored agency securities
Securities AFS:
Securities AFS, Amortized Cost	15,725		17,775
Securities AFS, Gross Unrealized Gains	2		4
Securities AFS, Gross Unrealized (Losses)	(1,799)		(1,755)
Securities AFS, Fair Value	13,928		16,024
Residential mortgage-backed and related securities
Securities AFS:
Securities AFS, Amortized Cost	93,014		72,951
Securities AFS, Gross Unrealized Gains	375		151
Securities AFS, Gross Unrealized (Losses)	(4,874)		(4,247)
Securities AFS, Fair Value	88,515		68,855
Municipal securities
Securities HTM:
Securities HTM, Amortized Cost	960,475		918,189
Securities HTM, Allowance for Credit (Losses)	(272)	(272)	(272)	(254)	(254)	(254)
Securities HTM, Gross Unrealized Gains	25,085		23,402
Securities HTM, Gross Unrealized (Losses)	(144,967)		(117,074)
Securities HTM, Fair Value	840,321		824,245
Securities AFS:
Securities AFS, Amortized Cost	203,187		203,613
Securities AFS, Gross Unrealized Gains	13		27
Securities AFS, Gross Unrealized (Losses)	(37,619)		(40,555)
Securities AFS, Fair Value	165,581		163,085
Asset-backed securities
Securities AFS:
Securities AFS, Amortized Cost	3,685		4,345
Securities AFS, Gross Unrealized Gains	84		94
Securities AFS, Fair Value	3,769		4,439
Corporate securities
Securities HTM:
Securities HTM, Amortized Cost	30,209		29,719
Securities HTM, Allowance for Credit (Losses)	(9)	(9)	(9)	(8)	(8)	(8)
Securities HTM, Gross Unrealized Gains	1,620		2,660
Securities HTM, Fair Value	31,820		32,370
Securities AFS:
Securities AFS, Amortized Cost	22,582		28,068
Securities AFS, Gross Unrealized Gains	119		148
Securities AFS, Gross Unrealized (Losses)	(505)		(842)
Securities AFS, Fair Value	22,196		27,374
Other securities
Securities HTM:
Securities HTM, Amortized Cost	1,050		1,050
Securities HTM, Allowance for Credit (Losses)	(1)	$ (1)	(1)	$ (1)	$ (1)	$ (1)
Securities HTM, Gross Unrealized (Losses)	(2)		(1)
Securities HTM, Fair Value	$ 1,047		$ 1,048