DEBT SECURITIES - Investment Securities Held to Maturity (Detail) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022	Dec. 31, 2021
Schedule Of Held To Maturity Securities [Line Items]
Held To Maturity Securities Amortized	$ 431,395	$ 437,537
Held to Maturity Gross Unrecognized gains	2,161	4,068
Held to Maturity Gross Unrecognized losses	13,804	14,490
Held to Maturity Fair value	419,752	427,115
Allowance for credit losses, Held-to-Maturity securities	$ 7,646	$ 8,286
Held to Maturity Weighted-average yield	5.04%	4.71%
Held to maturity accrued interest receivable excluded from estimate of credit losses	$ 3,700	$ 5,500
Residential MBS [Member]
Schedule Of Held To Maturity Securities [Line Items]
Held To Maturity Securities Amortized	161,587	166,739
Held to Maturity Gross Unrecognized gains	0	0
Held to Maturity Gross Unrecognized losses	5,497	7,156
Held to Maturity Fair value	156,090	159,583
Allowance for credit losses, Held-to-Maturity securities	$ 0	$ 0
Held to Maturity Weighted-average yield	3.81%	3.78%
Commercial MBS [Member]
Schedule Of Held To Maturity Securities [Line Items]
Held to Maturity Amortized Cost After 1 to 5 years	$ 9,576	$ 9,621
Held to Maturity Gross Unrecognized gains After 1 to 5 years	0	0
Held to Maturity Gross Unrecognized losses After 1 to 5 years	348	396
Held to Maturity Fair value After 1 to 5 years	9,228	9,225
Allowance for credit losses After 1 to 5 years	$ 0	$ 0
Held to Maturity Weighted-average yield After 1 to 5 years	3.48%	3.48%
Held to Maturity Amortized Cost After 10 years	$ 94,432	$ 95,467
Held to Maturity Gross Unrecognized gains After 10 years	0	0
Held to Maturity Gross Unrecognized losses After 10 years	4,541	4,169
Held to Maturity Fair value After 10 years	89,891	91,298
Allowance for credit losses After 10 years	$ 0	$ 0
Held to Maturity Weighted-average yield After 10 years	3.15%	3.15%
Held To Maturity Securities Amortized	$ 104,008	$ 105,088
Held to Maturity Gross Unrecognized gains	0	0
Held to Maturity Gross Unrecognized losses	4,889	4,565
Held to Maturity Fair value	99,119	100,523
Allowance for credit losses, Held-to-Maturity securities	$ 0	$ 0
Held to Maturity Weighted-average yield	3.18%	3.18%
MBS [Member]
Schedule Of Held To Maturity Securities [Line Items]
Held To Maturity Securities Amortized	$ 265,595	$ 271,827
Held to Maturity Gross Unrecognized gains	0	0
Held to Maturity Gross Unrecognized losses	10,386	11,721
Held to Maturity Fair value	255,209	260,106
Allowance for credit losses, Held-to-Maturity securities	$ 0	$ 0
Held to Maturity Weighted-average yield	3.56%	3.55%
Municipal Bonds [Member] | Puerto Rico [Member]
Schedule Of Held To Maturity Securities [Line Items]
Held to Maturity Amortized Due Withing One Year	$ 1,204	$ 1,202
Held to Maturity Gross Unrecognized gain Due Within One Year	0	0
Held to Maturity Gross Unrecognized losses Due Within One Year	10	15
Held to Maturity Fair value Due Within One Year	1,194	1,187
Allowance for credit losses Due within one year	$ 24	$ 2
Held to Maturity Weighted-average yield Due withing One Year	5.70%	5.20%
Held to Maturity Amortized Cost After 1 to 5 years	$ 42,633	$ 42,530
Held to Maturity Gross Unrecognized gains After 1 to 5 years	679	886
Held to Maturity Gross Unrecognized losses After 1 to 5 years	1,001	1,076
Held to Maturity Fair value After 1 to 5 years	42,311	42,340
Allowance for credit losses After 1 to 5 years	$ 659	$ 656
Held to Maturity Weighted-average yield After 1 to 5 years	6.74%	6.34%
Held to Maturity Amortized Cost After 5 to 10 years	$ 55,940	$ 55,956
Held to Maturity Gross Unrecognized gains After 5 to 10 years	1,482	3,182
Held to Maturity Gross Unrecognized losses After 5 to 10 years	603	360
Held to Maturity Fair value After 5 to 10 years	56,819	58,778
Allowance for credit losses After 5 to 10 years	$ 2,918	$ 3,243
Held to Maturity Weighted-average yield After 5 to 10 years	7.10%	6.29%
Held to Maturity Amortized Cost After 10 years	$ 66,023	$ 66,022
Held to Maturity Gross Unrecognized gains After 10 years	0	0
Held to Maturity Gross Unrecognized losses After 10 years	1,804	1,318
Held to Maturity Fair value After 10 years	64,219	64,704
Allowance for credit losses After 10 years	$ 4,045	$ 4,385
Held to Maturity Weighted-average yield After 10 years	8.12%	7.10%
Held To Maturity Securities Amortized	$ 165,800	$ 165,710
Held to Maturity Gross Unrecognized gains	2,161	4,068
Held to Maturity Gross Unrecognized losses	3,418	2,769
Held to Maturity Fair value	164,543	167,009
Allowance for credit losses, Held-to-Maturity securities	$ 7,646	$ 8,286	$ 12,324	$ 8,571
Held to Maturity Weighted-average yield	7.40%	6.62%
FHLMC [Member] | Residential MBS [Member]
Schedule Of Held To Maturity Securities [Line Items]
Held to Maturity Amortized Cost After 5 to 10 years	$ 20,129	$ 21,443
Held to Maturity Gross Unrecognized gains After 5 to 10 years	0	0
Held to Maturity Gross Unrecognized losses After 5 to 10 years	762	746
Held to Maturity Fair value After 5 to 10 years	19,367	20,697
Allowance for credit losses After 5 to 10 years	$ 0	$ 0
Held to Maturity Weighted-average yield After 5 to 10 years	3.03%	3.03%
Held to Maturity Amortized Cost After 10 years	$ 19,176	$ 19,362
Held to Maturity Gross Unrecognized gains After 10 years	0	0
Held to Maturity Gross Unrecognized losses After 10 years	596	888
Held to Maturity Fair value After 10 years	18,580	18,474
Allowance for credit losses After 10 years	$ 0	$ 0
Held to Maturity Weighted-average yield After 10 years	4.30%	4.21%
Held To Maturity Securities Amortized	$ 39,305	$ 40,805
Held to Maturity Gross Unrecognized gains	0	0
Held to Maturity Gross Unrecognized losses	1,358	1,634
Held to Maturity Fair value	37,947	39,171
Allowance for credit losses, Held-to-Maturity securities	$ 0	$ 0
Held to Maturity Weighted-average yield	3.65%	3.59%
GNMA [Member] | Residential MBS [Member]
Schedule Of Held To Maturity Securities [Line Items]
Held to Maturity Amortized Cost After 10 years	$ 18,502	$ 19,131
Held to Maturity Gross Unrecognized gains After 10 years	0	0
Held to Maturity Gross Unrecognized losses After 10 years	795	943
Held to Maturity Fair value After 10 years	17,707	18,188
Allowance for credit losses After 10 years	$ 0	$ 0
Held to Maturity Weighted-average yield After 10 years	3.31%	3.35%
FNMA [Member] | Residential MBS [Member]
Schedule Of Held To Maturity Securities [Line Items]
Held to Maturity Amortized Cost After 10 years	$ 71,258	$ 72,347
Held to Maturity Gross Unrecognized gains After 10 years	0	0
Held to Maturity Gross Unrecognized losses After 10 years	2,190	3,155
Held to Maturity Fair value After 10 years	69,068	69,192
Allowance for credit losses After 10 years	$ 0	$ 0
Held to Maturity Weighted-average yield After 10 years	4.16%	4.14%
Collateralized Mortgage Obligations [Member] | Residential MBS [Member]
Schedule Of Held To Maturity Securities [Line Items]
Held to Maturity Amortized Cost After 10 years	$ 32,522	$ 34,456
Held to Maturity Gross Unrecognized gains After 10 years	0	0
Held to Maturity Gross Unrecognized losses After 10 years	1,154	1,424
Held to Maturity Fair value After 10 years	31,368	33,032
Allowance for credit losses After 10 years	$ 0	$ 0
Held to Maturity Weighted-average yield After 10 years	3.49%	3.49%