DEBT SECURITIES - Investment Securities Held to Maturity (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Schedule Of Held To Maturity Securities [Line Items]
Held To Maturity Securities Amortized	$ 354,178	$ 437,537
Held to Maturity Gross Unrecognized gains	4,811	4,068
Held to Maturity Gross Unrecognized losses	12,857	14,490
Held to Maturity Fair value	346,132	427,115
Allowance for credit losses, Held-to-Maturity securities	$ 2,197	$ 8,286
Held to Maturity Weighted-average yield	4.84%	4.71%
Accrued interest receivable on loans and investments	$ 77,716	$ 69,730
Held-to-maturity Securities [Member]
Schedule Of Held To Maturity Securities [Line Items]
Accrued interest receivable on loans and investments	4,800	5,500
Municipal Bonds [Member]
Schedule Of Held To Maturity Securities [Line Items]
Held to Maturity Amortized Due Withing One Year	3,165	1,202
Held to Maturity Gross Unrecognized gain Due Within One Year	8	0
Held to Maturity Gross Unrecognized losses Due Within One Year	38	15
Held to Maturity Fair value Due Within One Year	3,135	1,187
Allowance for credit losses Due within one year	$ 50	$ 2
Held to Maturity Weighted-average yield Due withing One Year	9.30%	5.20%
Held to Maturity Amortized Cost After 1 to 5 years	$ 51,230	$ 42,530
Held to Maturity Gross Unrecognized gains After 1 to 5 years	994	886
Held to Maturity Gross Unrecognized losses After 1 to 5 years	710	1,076
Held to Maturity Fair value After 1 to 5 years	51,514	42,340
Allowance for credit losses After 1 to 5 years	$ 1,266	$ 656
Held to Maturity Weighted-average yield After 1 to 5 years	7.78%	6.34%
Held to Maturity Amortized Cost After 5 to 10 years	$ 36,050	$ 55,956
Held to Maturity Gross Unrecognized gains After 5 to 10 years	3,540	3,182
Held to Maturity Gross Unrecognized losses After 5 to 10 years	210	360
Held to Maturity Fair value After 5 to 10 years	39,380	58,778
Allowance for credit losses After 5 to 10 years	$ 604	$ 3,243
Held to Maturity Weighted-average yield After 5 to 10 years	7.13%	6.29%
Held to Maturity Amortized Cost After 10 years	$ 16,595	$ 66,022
Held to Maturity Gross Unrecognized gains After 10 years	269	0
Held to Maturity Gross Unrecognized losses After 10 years	0	1,318
Held to Maturity Fair value After 10 years	16,864	64,704
Allowance for credit losses After 10 years	$ 277	$ 4,385
Held to Maturity Weighted-average yield After 10 years	8.87%	7.10%
Held To Maturity Securities Amortized	$ 107,040	$ 165,710
Held to Maturity Gross Unrecognized gains	4,811	4,068
Held to Maturity Gross Unrecognized losses	958	2,769
Held to Maturity Fair value	110,893	167,009
Allowance for credit losses, Held-to-Maturity securities	$ 2,197	$ 8,286
Held to Maturity Weighted-average yield	7.78%	6.62%
Residential MBS [Member]
Schedule Of Held To Maturity Securities [Line Items]
Held To Maturity Securities Amortized	$ 146,468	$ 166,739
Held to Maturity Gross Unrecognized gains	0	0
Held to Maturity Gross Unrecognized losses	5,819	7,156
Held to Maturity Fair value	140,649	159,583
Allowance for credit losses, Held-to-Maturity securities	$ 0	$ 0
Held to Maturity Weighted-average yield	3.84%	3.78%
Commercial MBS [Member]
Schedule Of Held To Maturity Securities [Line Items]
Held to Maturity Amortized Cost After 1 to 5 years	$ 9,444	$ 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	297	396
Held to Maturity Fair value After 1 to 5 years	9,147	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	$ 91,226	$ 95,467
Held to Maturity Gross Unrecognized gains After 10 years	0	0
Held to Maturity Gross Unrecognized losses After 10 years	5,783	4,169
Held to Maturity Fair value After 10 years	85,443	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	$ 100,670	$ 105,088
Held to Maturity Gross Unrecognized gains	0	0
Held to Maturity Gross Unrecognized losses	6,080	4,565
Held to Maturity Fair value	94,590	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	$ 247,138	$ 271,827
Held to Maturity Gross Unrecognized gains	0	0
Held to Maturity Gross Unrecognized losses	11,899	11,721
Held to Maturity Fair value	235,239	260,106
Allowance for credit losses, Held-to-Maturity securities	$ 0	$ 0
Held to Maturity Weighted-average yield	3.57%	3.55%
Unisured Portion Of Government Deposits [Member] | Asset Pledged as Collateral [Member]
Schedule Of Held To Maturity Securities [Line Items]
Held To Maturity Securities Amortized	$ 126,600	$ 190,100
Held to Maturity Fair value	125,900	189,400
Puerto Rico [Member] | Municipal Bonds [Member]
Schedule Of Held To Maturity Securities [Line Items]
Allowance for credit losses, Held-to-Maturity securities	2,197	8,286	$ 8,571	$ 8,845
FHLMC [Member] | Residential MBS [Member]
Schedule Of Held To Maturity Securities [Line Items]
Held to Maturity Amortized Cost After 5 to 10 years	16,469	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	556	746
Held to Maturity Fair value After 5 to 10 years	15,913	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	$ 18,324	$ 19,362
Held to Maturity Gross Unrecognized gains After 10 years	0	0
Held to Maturity Gross Unrecognized losses After 10 years	714	888
Held to Maturity Fair value After 10 years	17,610	18,474
Allowance for credit losses After 10 years	$ 0	$ 0
Held to Maturity Weighted-average yield After 10 years	4.32%	4.21%
Held To Maturity Securities Amortized	$ 34,793	$ 40,805
Held to Maturity Gross Unrecognized gains	0	0
Held to Maturity Gross Unrecognized losses	1,270	1,634
Held to Maturity Fair value	33,523	39,171
Allowance for credit losses, Held-to-Maturity securities	$ 0	$ 0
Held to Maturity Weighted-average yield	3.71%	3.59%
GNMA [Member] | Residential MBS [Member]
Schedule Of Held To Maturity Securities [Line Items]
Held to Maturity Amortized Cost After 10 years	$ 16,265	$ 19,131
Held to Maturity Gross Unrecognized gains After 10 years	0	0
Held to Maturity Gross Unrecognized losses After 10 years	789	943
Held to Maturity Fair value After 10 years	15,476	18,188
Allowance for credit losses After 10 years	$ 0	$ 0
Held to Maturity Weighted-average yield After 10 years	3.32%	3.35%
FNMA [Member] | Residential MBS [Member]
Schedule Of Held To Maturity Securities [Line Items]
Held to Maturity Amortized Cost After 10 years	$ 67,271	$ 72,347
Held to Maturity Gross Unrecognized gains After 10 years	0	0
Held to Maturity Gross Unrecognized losses After 10 years	2,486	3,155
Held to Maturity Fair value After 10 years	64,785	69,192
Allowance for credit losses After 10 years	$ 0	$ 0
Held to Maturity Weighted-average yield After 10 years	4.18%	4.14%
CMOs issued or guaranteed by the FHLMC, FNMA, and GNMA: [Member] | Residential MBS [Member]
Schedule Of Held To Maturity Securities [Line Items]
Held to Maturity Amortized Cost After 10 years	$ 28,139	$ 34,456
Held to Maturity Gross Unrecognized gains After 10 years	0	0
Held to Maturity Gross Unrecognized losses After 10 years	1,274	1,424
Held to Maturity Fair value After 10 years	26,865	33,032
Allowance for credit losses After 10 years	$ 0	$ 0
Held to Maturity Weighted-average yield After 10 years	3.49%	3.49%