INVESTMENT SECURITIES - Debt Securities, Held-to-Maturity, Credit Quality Indicator (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	$ 801,324	$ 991,937
Asset-backed securities
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	301,284	471,996
Agency-guaranteed residential mortgage-backed securities
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	6,750	6,880
Agency-guaranteed commercial mortgage-backed securities
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	1,708	1,770
Agency-guaranteed residential collateralized mortgage obligations
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	157,231	169,754
Agency-guaranteed commercial collateralized mortgage obligations
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	179,333	158,320
Private label collateralized mortgage obligations
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	155,018	$ 183,217
AAA
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	97,429
AAA \| Asset-backed securities
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	0
AAA \| Agency-guaranteed residential mortgage-backed securities
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	0
AAA \| Agency-guaranteed commercial mortgage-backed securities
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	0
AAA \| Agency-guaranteed residential collateralized mortgage obligations
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	0
AAA \| Agency-guaranteed commercial collateralized mortgage obligations
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	0
AAA \| Private label collateralized mortgage obligations
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	97,429
AA
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	9,355
AA \| Asset-backed securities
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	0
AA \| Agency-guaranteed residential mortgage-backed securities
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	0
AA \| Agency-guaranteed commercial mortgage-backed securities
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	0
AA \| Agency-guaranteed residential collateralized mortgage obligations
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	0
AA \| Agency-guaranteed commercial collateralized mortgage obligations
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	0
AA \| Private label collateralized mortgage obligations
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	9,355
Not Rated
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	694,540
Not Rated \| Asset-backed securities
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	301,284
Not Rated \| Agency-guaranteed residential mortgage-backed securities
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	6,750
Not Rated \| Agency-guaranteed commercial mortgage-backed securities
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	1,708
Not Rated \| Agency-guaranteed residential collateralized mortgage obligations
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	157,231
Not Rated \| Agency-guaranteed commercial collateralized mortgage obligations
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	179,333
Not Rated \| Private label collateralized mortgage obligations
Schedule of Held-to-Maturity Securities [Line Items]
Investment securities held to maturity	$ 48,234