INVESTMENT SECURITIES - Schedule of Held To Maturity Credit Quality Indicator (Details) - USD ($) $ in Thousands	Sep. 30, 2026	Dec. 31, 2025
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Past due held-to-maturity debt securities	$ 925,727	$ 968,336
FNMA MBS
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Past due held-to-maturity debt securities	752,574	788,439
FNMA MBS \| A+ rated or higher
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Past due held-to-maturity debt securities	0	0
FNMA MBS \| Not rated
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Past due held-to-maturity debt securities	752,574	788,439
State and political subdivisions
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Past due held-to-maturity debt securities	173,153	179,897
State and political subdivisions \| A+ rated or higher
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Past due held-to-maturity debt securities	173,153	179,897
State and political subdivisions \| Not rated
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Past due held-to-maturity debt securities	$ 0	$ 0