DEBT SECURITIES (Tables)	12 Months Ended
DEBT SECURITIES (Tables)	Dec. 31, 2024
Other Than Temporary Impairment Credit Losses Recognized In Earnings [Line Items]
ACL on Available-for-Sale Debt Securities [Table Text Block]	Year Ended December 31, 2024 Private label MBS Puerto Rico Government Obligations Total (In thousands) Beginning balance $ 116 $ 395 $ 511 Provision for credit losses - (benefit) - (50) (50) Net recoveries 60 - 60 ACL on available-for-sale debt securities $ 176 $ 345 $ 521 Year Ended December 31, 2023 Private label MBS Puerto Rico Government Obligations Total (In thousands) Beginning balance $ 83 $ 375 $ 458 Provision for credit losses - expense - 20 20 Net recoveries 33 - 33 ACL on available-for-sale debt securities $ 116 $ 395 $ 511 Year Ended December 31, 2022 Private label MBS Puerto Rico Government Obligations Total (In thousands) Beginning balance $ 797 $ 308 $ 1,105 Provision for credit losses - (benefit) expense (501) 67 (434) Net charge-offs (213) - (213) ACL on available-for-sale debt securities $ 83 $ 375 $ 458
ACL on Held-to-Maturity Debt Securities [Table Text Block]	Puerto Rico Municipal Bonds Year Ended December 31, 2024 2023 2022 (In thousands) Beginning Balance $ 2,197 $ 8,286 $ 8,571 Provision for credit losses - (benefit) (1,395) (6,089) (285) ACL on held-to-maturity debt securities $ 802 $ 2,197 $ 8,286
Available-for-Sale Securities [Member]
Other Than Temporary Impairment Credit Losses Recognized In Earnings [Line Items]
Investments Classified by Contractual Maturity Date [Table Text Block]	December 31, 2024 Amortized cost (1) Gross Unrealized ACL Fair Value (2) Weighted- Gains Losses average yield% (Dollars in thousands) U.S. Treasury securities: Due within one year $ 59,992 $ - $ 803 $ - $ 59,189 0.75 U.S. GSEs obligations: Due within one year 1,090,678 - 22,826 - 1,067,852 0.79 After 1 to 5 years 817,835 39 53,195 - 764,679 0.96 After 10 years 7,835 - 35 - 7,800 4.73 Puerto Rico government obligation: After 10 years (3) 2,951 - 986 345 1,620 - United States and Puerto Rico government obligations 1,979,291 39 77,845 345 1,901,140 0.87 MBS: Residential MBS: FHLMC certificates: After 1 to 5 years 14,477 - 460 - 14,017 2.14 After 5 to 10 years 122,548 - 9,977 - 112,571 1.52 After 10 years 936,531 25 168,691 - 767,865 1.51 1,073,556 25 179,128 - 894,453 1.52 GNMA certificates: Due within one year 881 - 6 - 875 2.68 After 1 to 5 years 8,025 - 350 - 7,675 0.71 After 5 to 10 years 67,181 - 6,125 - 61,056 1.86 After 10 years 142,330 16 22,041 - 120,305 2.78 218,417 16 28,522 - 189,911 2.42 FNMA certificates: After 1 to 5 years 21,921 - 689 - 21,232 2.13 After 5 to 10 years 244,966 - 18,874 - 226,092 1.74 After 10 years 979,366 16 159,560 - 819,822 1.51 1,246,253 16 179,123 - 1,067,146 1.56 Collateralized mortgage obligations (“CMOs”) issued or guaranteed by the FHLMC, FNMA, and GNMA: After 10 years 377,812 74 52,338 - 325,548 2.88 Private label: After 5 to 10 years 4,886 - 1,430 57 3,399 6.69 After 10 years 1,200 - 285 119 796 6.32 6,086 - 1,715 176 4,195 6.62 Total Residential MBS 2,922,124 131 440,826 176 2,481,253 1.79 Commercial MBS: After 1 to 5 years 33,835 13 2,286 - 31,562 2.59 After 5 to 10 years 10,621 - 1,653 - 8,968 1.67 After 10 years 178,537 - 37,158 - 141,379 2.06 Total Commercial MBS 222,993 13 41,097 - 181,909 2.12 Total MBS 3,145,117 144 481,923 176 2,663,162 1.82 Other: Due within one year 1,000 - - - 1,000 2.32 Total available-for-sale debt securities $ 5,125,408 $ 183 $ 559,768 $ 521 $ 4,565,302 1.45 (1) Excludes accrued interest receivable on available-for-sale debt securities that totaled $ 9.6 million as of December 31, 2024 reported as part of accrued interest receivable on loans and investment securities in the consolidated statements of financial condition, and excluded from the estimate of credit losses. (2) Includes $ 466.1 million (amortized cost - $ 533.7 million) that was pledged at the FHLB as collateral for borrowings and letters of credit as well as $ 3.0 billion (amortized cost - $ 3.3 billion) pledged as collateral for the uninsured portion of government deposits. The secured parties are not permitted to sell or repledge the collateral. (3) Consists of a residential pass-through MBS issued by the PRHFA that is collateralized by certain second mortgages originated under a program launched by the Puerto Rico government in 2010 and is in nonaccrual status based on the delinquency status of the underlying second mortgage loans collateral. December 31, 2023 Amortized cost (1) Gross Unrealized ACL Fair value (2) Weighted- Gains Losses average yield% (Dollars in thousands) U.S. Treasury securities: Due within one year $ 80,314 $ - $ 2,144 $ - $ 78,170 0.66 After 1 to 5 years 60,239 - 3,016 - 57,223 0.75 U.S. GSEs’ obligations: Due within one year 542,847 - 15,832 - 527,015 0.77 After 1 to 5 years 1,899,620 49 135,347 - 1,764,322 0.86 After 5 to 10 years 8,850 - 687 - 8,163 2.64 After 10 years 8,891 8 2 - 8,897 5.49 Puerto Rico government obligation: After 10 years (3) 3,156 - 1,346 395 1,415 - United States and Puerto Rico government obligations 2,603,917 57 158,374 395 2,445,205 0.85 MBS: Residential MBS: FHLMC certificates: After 1 to 5 years 19,561 - 868 - 18,693 2.06 After 5 to 10 years 153,308 - 12,721 - 140,587 1.55 After 10 years 991,060 15 161,197 - 829,878 1.41 1,163,929 15 174,786 - 989,158 1.44 GNMA certificates: Due within one year 254 - 3 - 251 3.27 After 1 to 5 years 16,882 - 872 - 16,010 1.19 After 5 to 10 years 27,916 8 2,247 - 25,677 1.62 After 10 years 206,254 87 22,786 - 183,555 2.57 251,306 95 25,908 - 225,493 2.38 FNMA certificates: After 1 to 5 years 32,489 - 1,423 - 31,066 2.11 After 5 to 10 years 293,492 - 23,146 - 270,346 1.70 After 10 years 1,047,298 83 156,344 - 891,037 1.37 1,373,279 83 180,913 - 1,192,449 1.46 CMOs issued or guaranteed by the FHLMC, FNMA, and GNMA: After 10 years 273,539 - 52,263 - 221,276 1.54 Private label: After 10 years 7,086 - 2,185 116 4,785 7.66 Total Residential MBS 3,069,139 193 436,055 116 2,633,161 1.55 Commercial MBS: After 1 to 5 years 45,022 - 6,898 - 38,124 2.17 After 5 to 10 years 22,386 - 2,685 - 19,701 2.16 After 10 years 122,830 - 29,037 - 93,793 1.36 Total Commercial MBS 190,238 - 38,620 - 151,618 1.64 Total MBS 3,259,377 193 474,675 116 2,784,779 1.55 Total available-for-sale debt securities $ 5,863,294 $ 250 $ 633,049 $ 511 $ 5,229,984 1.24 (1) Excludes accrued interest receivable on available-for-sale debt securities that totaled $ 10.6 million as of December 31, 2023 reported as part of accrued interest receivable on loans and investment securities in the consolidated statements of financial condition, and excluded from the estimate of credit losses. (2) Includes $ 477.9 million (amortized cost - $ 527.2 million) that was pledged at the FHLB as collateral for borrowings and letters of credit as well as $ 2.8 billion (amortized cost - $ 3.2 billion) pledged as collateral for the uninsured portion of government deposits. The secured parties are not permitted to sell or repledge the collateral. (3) Consists of a residential pass-through MBS issued by the PRHFA that is collateralized by certain second mortgages originated under a program launched by the Puerto Rico government in 2010 and is in nonaccrual status based on the delinquency status of the underlying second mortgage loans collateral.
Investments Fair Value and Gross Unrealized Losses [Table Text Block]	As of December 31, 2024 Less than 12 months 12 months or more Total Unrealized Unrealized Unrealized Fair Value Losses Fair Value Losses Fair Value Losses (In thousands) U.S. Treasury and U.S. GSEs’ obligations $ 8,005 $ 35 $ 1,886,046 $ 76,824 $ 1,894,051 $ 76,859 Puerto Rico government obligation - - 1,620 986 (1) 1,620 986 MBS: Residential MBS: FHLMC 36,224 85 857,492 179,043 893,716 179,128 GNMA 22,281 508 166,470 28,014 188,751 28,522 FNMA 53,325 132 1,012,331 178,991 1,065,656 179,123 CMOs issued or guaranteed by the FHLMC, FNMA, and GNMA 52,778 248 187,772 52,090 240,550 52,338 Private label - - 4,195 1,715 (1) 4,195 1,715 Commercial MBS 44,831 823 131,152 40,274 175,983 41,097 $ 217,444 $ 1,831 $ 4,247,078 $ 557,937 $ 4,464,522 $ 559,768 (1) Unrealized losses do not include the credit loss component recorded as part of the ACL. As of December 31, 2024, the PRHFA bond and private label MBS had an ACL of $ 0.3 million and $ 0.2 million, respectively. As of December 31, 2023 Less than 12 months 12 months or more Total Unrealized Unrealized Unrealized Fair Value Losses Fair Value Losses Fair Value Losses (In thousands) U.S. Treasury and U.S. GSEs’ obligations $ 2,544 $ 2 $ 2,428,784 $ 157,026 $ 2,431,328 $ 157,028 Puerto Rico government obligation - - 1,415 1,346 (1) 1,415 1,346 MBS: Residential MBS: FHLMC 9 - 988,092 174,786 988,101 174,786 GNMA 12,257 100 202,390 25,808 214,647 25,908 FNMA - - 1,183,275 180,913 1,183,275 180,913 CMOs issued or guaranteed by the FHLMC, FNMA, and GNMA - - 221,276 52,263 221,276 52,263 Private label - - 4,785 2,185 (1) 4,785 2,185 Commercial MBS 11,370 18 140,248 38,602 151,618 38,620 $ 26,180 $ 120 $ 5,170,265 $ 632,929 $ 5,196,445 $ 633,049 (1) Unrealized losses do not include the credit loss component recorded as part of the ACL. As of December 31, 2023, the PRHFA bond and private label MBS had an ACL of $ 0.4 million and $ 0.1 million, respectively.
Held-to-Maturity Securities [Member]
Other Than Temporary Impairment Credit Losses Recognized In Earnings [Line Items]
Investments Classified by Contractual Maturity Date [Table Text Block]	December 31, 2024 Amortized cost (1) (2) Gross Unrecognized Fair value Weighted- Gains Losses ACL average yield% (Dollars in thousands) Puerto Rico municipal bonds: Due within one year $ 2,214 $ 134 $ 6 $ 2,342 $ 6 5.07 After 1 to 5 years 61,289 2,724 438 63,575 433 7.33 After 5 to 10 years 13,184 811 205 13,790 127 5.79 After 10 years 15,755 146 - 15,901 236 8.07 Total Puerto Rico municipal bonds 92,442 3,815 649 95,608 802 7.18 MBS: Residential MBS: FHLMC certificates: After 5 to 10 years 12,112 - 353 11,759 - 3.03 After 10 years 16,936 - 1,142 15,794 - 4.30 29,048 - 1,495 27,553 - 3.77 GNMA certificates: After 10 years 13,472 - 842 12,630 - 3.29 FNMA certificates: After 10 years 61,233 - 3,786 57,447 - 4.19 CMOs issued or guaranteed by FHLMC, FNMA, and GNMA: After 10 years 25,566 - 1,321 24,245 - 3.49 Total Residential MBS 129,319 - 7,444 121,875 - 3.86 Commercial MBS: After 1 to 5 years 9,258 - 151 9,107 - 3.48 After 10 years 86,767 - 5,317 81,450 - 3.92 Total Commercial MBS 96,025 - 5,468 90,557 - 3.88 Total MBS 225,344 - 12,912 212,432 - 3.87 Total held-to-maturity debt securities $ 317,786 $ 3,815 $ 13,561 $ 308,040 $ 802 4.83 (1) Excludes accrued interest receivable on held-to-maturity debt securities that totaled $ 4.1 million as of December 31, 2024 reported as part of accrued interest receivable on loans and investment securities in the consolidated statements of financial condition, and excluded from the estimate of credit losses. (2) Includes $ 198.6 million (fair value - $ 192.4 million) that serves as collateral for the uninsured portion of government deposits. The secured parties are not permitted to sell or repledge the collateral. December 31, 2023 Amortized cost (1) (2) Gross Unrecognized Fair value Weighted- Gains Losses ACL average yield% (Dollars in thousands) Puerto Rico municipal bonds: Due within one year $ 3,165 $ 8 $ 38 $ 3,135 $ 50 9.30 After 1 to 5 years 51,230 994 710 51,514 1,266 7.78 After 5 to 10 years 36,050 3,540 210 39,380 604 7.13 After 10 years 16,595 269 - 16,864 277 8.87 Total Puerto Rico municipal bonds 107,040 4,811 958 110,893 2,197 7.78 MBS: Residential MBS: FHLMC certificates: After 5 to 10 years 16,469 - 556 15,913 - 3.03 After 10 years 18,324 - 714 17,610 - 4.32 34,793 - 1,270 33,523 - 3.71 GNMA certificates: After 10 years 16,265 - 789 15,476 - 3.32 FNMA certificates: After 10 years 67,271 - 2,486 64,785 - 4.18 CMOs issued or guaranteed by FHLMC, FNMA, and GNMA: After 10 years 28,139 - 1,274 26,865 - 3.49 Total Residential MBS 146,468 - 5,819 140,649 - 3.84 Commercial MBS: After 1 to 5 years 9,444 - 297 9,147 - 3.48 After 10 years 91,226 - 5,783 85,443 - 3.15 Total Commercial MBS 100,670 - 6,080 94,590 - 3.18 Total MBS 247,138 - 11,899 235,239 - 3.57 Total held-to-maturity debt securities $ 354,178 $ 4,811 $ 12,857 $ 346,132 $ 2,197 4.84 (1) Excludes accrued interest receivable on held-to-maturity debt securities that totaled $ 4.8 million as of December 31, 2023 reported as part of accrued interest receivable on loans and investment securities in the consolidated statements of financial condition, and excluded from the estimate of credit losses. (2) Includes $ 126.6 million (fair value - $ 125.9 million) that serves as collateral for the uninsured portion of government deposits. The secured parties are not permitted to sell or repledge the collateral.
Investments Fair Value and Gross Unrealized Losses [Table Text Block]	As of December 31, 2024 Less than 12 months 12 months or more Total Unrecognized Unrecognized Unrecognized Fair Value Losses Fair Value Losses Fair Value Losses (In thousands) Puerto Rico municipal bonds $ - $ - $ 20,071 $ 649 $ 20,071 $ 649 MBS: Residential MBS: FHLMC certificates - - 27,553 1,495 27,553 1,495 GNMA certificates - - 12,630 842 12,630 842 FNMA certificates - - 57,447 3,786 57,447 3,786 CMOs issued or guaranteed by FHLMC, FNMA, and GNMA - - 24,245 1,321 24,245 1,321 Commercial MBS - - 90,557 5,468 90,557 5,468 Total held-to-maturity debt securities $ - $ - $ 232,503 $ 13,561 $ 232,503 $ 13,561 As of December 31, 2023 Less than 12 months 12 months or more Total Unrecognized Unrecognized Unrecognized Fair Value Losses Fair Value Losses Fair Value Losses (In thousands) Puerto Rico municipal bonds $ - $ - $ 34,682 $ 958 $ 34,682 $ 958 MBS: Residential MBS: FHLMC certificates - - 33,523 1,270 33,523 1,270 GNMA certificates - - 15,476 789 15,476 789 FNMA certificates - - 64,785 2,486 64,785 2,486 CMOs issued or guaranteed by FHLMC, FNMA, and GNMA - - 26,865 1,274 26,865 1,274 Commercial MBS - - 94,590 6,080 94,590 6,080 Total held-to-maturity debt securities $ - $ - $ 269,921 $ 12,857 $ 269,921 $ 12,857