INVESTMENT SECURITIES - Allowance for credit losses to HTM securities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Allowance for credit losses:
Beginning balance	$ 71
Total ending allowance balance	71
Corporate bonds
Allowance for credit losses:
Beginning balance	71	$ 0
Provision for credit losses	0	0
Securities charged-off (recoveries)	0	0
Total ending allowance balance	71	71
Corporate bonds | Cumulative change in accounting principle
Allowance for credit losses:
Beginning balance		71
Mortgage-Backed Securities, Issued by Private Enterprises [Member]
Allowance for credit losses:
Beginning balance	0	0
Provision for credit losses	0	0
Securities charged-off (recoveries)	0	0
Total ending allowance balance	$ 0	0
Mortgage-Backed Securities, Issued by Private Enterprises [Member] | Cumulative change in accounting principle
Allowance for credit losses:
Beginning balance		$ 0