INVESTMENT SECURITIES - Schedule of Held To Maturity Credit Quality Indicator (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Past due held-to-maturity debt securities	$ 1,049,815	$ 1,058,565
FNMA MBS
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Past due held-to-maturity debt securities	864,584	872,653
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	864,584	872,653
State and political subdivisions
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Past due held-to-maturity debt securities	185,231	185,912
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	185,231	185,912
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