INVESTMENT SECURITIES (Narrative) (Details)	1 Months Ended				12 Months Ended
	Sep. 30, 2025 USD ($) security	Nov. 30, 2024 USD ($) security	Dec. 31, 2023 USD ($) security	Sep. 30, 2023 USD ($) security	Dec. 31, 2025 USD ($) security	Dec. 31, 2024 USD ($) security investment	Dec. 31, 2023 USD ($)
EQUITY
Investment securities classified from available-for-sale to held-to-maturity | investment						81
Cost basis of AFS securities sold		$ 106,500,000	$ 30,000,000.0			$ 762,700,000
Fair market value of AFS securities sold						673,200,000
Net unrealized loss from transfer of securities						89,500,000
Amortization of unrealized losses on investment securities transferred to held-to-maturity at fair value					$ 6,762,000	7,159,000	$ 7,440,000
Number of AFS securities sold | security	5	24	17
Amortized cost basis	$ 1,500,000
Realized loss on debt securities sold	$ 30,000
Debt securities available-for-sale, at fair value					748,212,000	737,658,000
Proceeds from sales of investment securities available-for-sale		$ 96,600,000	$ 28,100,000
Gross realized losses		9,900,000	1,900,000
Gross realized gains		0	0
Purchases of investment securities available-for-sale		$ 101,600,000	$ 28,300,000		50,592,000	253,580,000	47,393,000
Gain (loss) on sale of AFS securities				$ 100,000
Net loss on sales of investment securities					$ (30,000)	$ (9,934,000)	(2,074,000)
Number of AFS investment securities in an unrealized loss position | security					179	218
Number of HTM investment securities in an unrealized loss position | security					81	83
Common stock, value					$ 381,158,000	$ 404,494,000
Commercial - Non-government agencies
EQUITY
Cost basis of AFS securities sold				$ 1,500,000
Number of AFS securities sold | security				2
Debt securities available-for-sale, at fair value						9,927,000
Proceeds from sales of investment securities available-for-sale				$ 1,400,000
Collateralized Mortgage-Backed Securities | Asset Pledged as Collateral without Right
EQUITY
Debt securities available-for-sale, at fair value					736,700,000	756,000,000.0
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Noncontrolling Interest
EQUITY
Amortization of unrealized losses on investment securities transferred to held-to-maturity at fair value					$ (6,762,000)	$ (7,159,000)	$ (7,440,000)