DEBT SECURITIES - ACL for Debt Securities Available-for-Sale (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Debt Securities, Available-for-sale, Allowance for Credit Loss [Line Items]
Beginning Balance	$ 433	$ 676	$ 458	$ 1,105
Provision for credit losses - expense (benefit)	32	(12)	7	(435)
Net charge-offs			0	6
Ending Balance	465	664	465	664
Residential MBS [Member]
Debt Securities, Available-for-sale, Allowance for Credit Loss [Line Items]
Beginning Balance			83
Ending Balance	83		83
Residential MBS [Member] | Private label [Member]
Debt Securities, Available-for-sale, Allowance for Credit Loss [Line Items]
Beginning Balance	83	290	83	797
Provision for credit losses - expense (benefit)	0	0	0	(501)
Net charge-offs			0	6
Ending Balance	83	290	83	290
Puerto Rico government obligations [Member]
Debt Securities, Available-for-sale, Allowance for Credit Loss [Line Items]
Beginning Balance	350	386	375	308
Provision for credit losses - expense (benefit)	32	(12)	7	66
Net charge-offs			0	0
Ending Balance	$ 382	$ 374	$ 382	$ 374