INVESTMENT SECURITIES - Amortized cost and fair value of securities held-to-maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Debt Securities, Held-to-Maturity, Maturity [Abstract]
Amortized Cost	$ 72,374	$ 74,173
Gross Unrecognized Gains	8	9
Gross Unrecognized Losses	(7,474)	(7,565)
Fair Value	64,908	66,617
Allowance for Credit Losses	(71)	(71)
U.S. Treasury debt
Debt Securities, Held-to-Maturity, Maturity [Abstract]
Amortized Cost	258	253
Gross Unrecognized Gains	0	0
Gross Unrecognized Losses	(13)	(11)
Fair Value	245	242
Allowance for Credit Losses	0	0
Corporate bonds
Debt Securities, Held-to-Maturity, Maturity [Abstract]
Amortized Cost	23,672	23,687
Gross Unrecognized Gains	0	0
Gross Unrecognized Losses	(2,674)	(3,020)
Fair Value	20,998	20,667
Allowance for Credit Losses	(71)	(71)	$ (71)	$ 0
Government National Mortgage Association ("GNMA") mortgage-backed securities ("MBS") – residential
Debt Securities, Held-to-Maturity, Maturity [Abstract]
Amortized Cost	33,202	34,579
Gross Unrecognized Gains	0	0
Gross Unrecognized Losses	(3,559)	(3,410)
Fair Value	29,643	31,169
Allowance for Credit Losses	0	0
Federal National Mortgage Association ("FNMA") MBS – residential
Debt Securities, Held-to-Maturity, Maturity [Abstract]
Amortized Cost	5,886	6,035
Gross Unrecognized Gains	0	0
Gross Unrecognized Losses	(554)	(509)
Fair Value	5,332	5,526
Allowance for Credit Losses	0	0
Government collateralized mortgage obligations ("GMO") and MBS – commercial
Debt Securities, Held-to-Maturity, Maturity [Abstract]
Amortized Cost	5,625	5,836
Gross Unrecognized Gains	8	9
Gross Unrecognized Losses	(416)	(377)
Fair Value	5,217	5,468
Allowance for Credit Losses	0	0
Corporate collateralized mortgage obligations ("CMO") and MBS(1)
Debt Securities, Held-to-Maturity, Maturity [Abstract]
Amortized Cost	3,731	3,783
Gross Unrecognized Gains	0	0
Gross Unrecognized Losses	(258)	(238)
Fair Value	3,473	3,545
Allowance for Credit Losses	$ 0	$ 0	$ 0	$ 0