DEBT SECURITIES - ACL for Debt Securities Available-for-Sale (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale, Allowance for Credit Loss [Line Items]
Beginning Balance	$ 458
Ending Balance	511	$ 458
Residential MBS [Member]
Debt Securities, Available-for-sale, Allowance for Credit Loss [Line Items]
Beginning Balance	83
Ending Balance	116	83
Puerto Rico government obligations [Member]
Debt Securities, Available-for-sale, Allowance for Credit Loss [Line Items]
Beginning Balance	400
Ending Balance	400	400
Available-for-sale Securities [Member]
Debt Securities, Available-for-sale, Allowance for Credit Loss [Line Items]
Beginning Balance	458	1,105	$ 1,310
Provision for credit losses - expense (benefit)	20	(434)	(136)
Net charge-offs	33	(213)	(69)
Ending Balance	511	458	1,105
Available-for-sale Securities [Member] | Residential MBS [Member] | Private label [Member]
Debt Securities, Available-for-sale, Allowance for Credit Loss [Line Items]
Beginning Balance	83	797	1,002
Provision for credit losses - expense (benefit)	0	(501)	(136)
Net charge-offs	33	(213)	(69)
Ending Balance	116	83	797
Available-for-sale Securities [Member] | Puerto Rico government obligations [Member]
Debt Securities, Available-for-sale, Allowance for Credit Loss [Line Items]
Beginning Balance	375	308	308
Provision for credit losses - expense (benefit)	20	67	0
Net charge-offs	0	0	0
Ending Balance	$ 395	$ 375	$ 308