DEBT SECURITIES (Tables)	6 Months Ended
DEBT SECURITIES (Tables)	Jun. 30, 2023
Other Than Temporary Impairment Credit Losses Recognized In Earnings [Line Items]
Debt Securities, Available-for-sale, Allowance for Credit Loss [Table Text Block]	Quarter Ended June 30, 2023 Six-Month Period Ended June 30, 2023 Private label MBS Puerto Rico Government Obligations Total Private label MBS Puerto Rico Government Obligations Total (In thousands) Beginning balance $ 83 $ 366 $ 449 $ 83 $ 375 $ 458 Provision for credit losses - benefit - (16) (16) - (25) (25) ACL on available-for-sale debt securities $ 83 $ 350 $ 433 $ 83 $ 350 $ 433 Quarter Ended June 30, 2022 Six-Month Period Ended June 30, 2022 Private label MBS Puerto Rico Government Obligations Total Private label MBS Puerto Rico Government Obligations Total (In thousands) Beginning balance $ 403 $ 308 $ 711 $ 797 $ 308 $ 1,105 Provision for credit losses - (benefit) expense (113) 78 (35) (501) 78 (423) Net charge-offs - - - (6) - (6) ACL on available-for-sale debt securities $ 290 $ 386 $ 676 $ 290 $ 386 $ 676
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Table Text Block]	Puerto Rico Municipal Bonds Quarter Ended Six-Month Period Ended June 30, 2023 June 30, 2023 (In thousands) Beginning Balance $ 7,646 $ 8,286 Provision for credit losses - expense 755 115 ACL on held-to-maturity debt securities $ 8,401 $ 8,401 Puerto Rico Municipal Bonds Quarter Ended Six-Month Period Ended June 30, 2022 June 30, 2022 (In thousands) Beginning Balance $ 12,324 $ 8,571 Provision for credit losses - (benefit) expense (3,439) 314 ACL on held-to-maturity debt securities $ 8,885 $ 8,885
Significant Assumptions in Valuation of Private Label MBS [Table Text Block]	The tables below present quantitative information for significant assets measured at fair value on a recurring basis using significant unobservable inputs (Level 3) as of June 30, 2023 and December 31, 2022: June 30, 2023 Fair Value Valuation Technique Unobservable Input Range Weighted Average Minimum Maximum (Dollars in thousands) Available-for-sale debt securities: Private label MBS $ 5,246 Discounted cash flows Discount rate 16.7% 16.7% 16.7% Prepayment rate 1.2% 12.0% 8.9% Projected cumulative loss rate 0.2% 15.5% 5.6% Puerto Rico government obligations $ 2,111 Discounted cash flows Discount rate 13.4% 13.4% 13.4% Projected cumulative loss rate 18.5% 18.5% 18.5% December 31, 2022 Fair Value Valuation Technique Unobservable Input Range Weighted Average Minimum Maximum (Dollars in thousands) Available-for-sale debt securities: Private label MBS $ 5,794 Discounted cash flows Discount rate 16.2% 16.2% 16.2% Prepayment rate 1.5% 15.2% 11.8% Projected cumulative loss rate 0.3% 15.6% 5.6% Puerto Rico government obligations $ 2,201 Discounted cash flows Discount rate 12.9% 12.9% 12.9% Projected cumulative loss rate 19.3% 19.3% 19.3%
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]	The amortized cost, gross unrecognized gains and losses, estimated fair value, ACL, weighted-average yield and contractual maturities of held-to-maturity debt securities as of June 30, 2023 and December 31, 2022 were as follows June 30, 2023 Amortized cost (1) Gross Unrecognized Fair value Weighted- Gains Losses ACL average yield% (Dollars in thousands) Puerto Rico municipal bonds: Due within one year $ 1,205 $ - $ 29 $ 1,176 $ 26 5.90 After 1 to 5 years 42,736 661 1,360 42,037 689 6.93 After 5 to 10 years 56,160 2,733 446 58,447 3,209 7.44 After 10 years 66,023 - 2,023 64,000 4,477 8.54 Total Puerto Rico municipal bonds 166,124 3,394 3,858 165,660 8,401 7.74 MBS: Residential MBS: FHLMC certificates: After 5 to 10 years 18,836 - 1,203 17,633 - 3.03 After 10 years 18,936 - 906 18,030 - 4.33 37,772 - 2,109 35,663 - 3.68 GNMA certificates: After 10 years 17,765 - 1,046 16,719 - 3.35 FNMA certificates: After 10 years 69,956 - 3,161 66,795 - 4.17 CMOs issued or guaranteed by FHLMC, FNMA, and GNMA After 10 years 30,197 - 1,658 28,539 - 3.49 Total Residential MBS 155,690 - 7,974 147,716 - 3.83 Commercial MBS: After 1 to 5 years 9,533 - 479 9,054 - 3.48 After 10 years 93,379 - 5,628 87,751 - 3.15 Total Commercial MBS 102,912 - 6,107 96,805 - 3.18 Total MBS 258,602 - 14,081 244,521 - 3.57 Total held-to-maturity debt securities $ 424,726 $ 3,394 $ 17,939 $ 410,181 $ 8,401 5.20 (1) Excludes accrued interest receivable on held-to-maturity debt securities that totaled $ 6.8 million as of June 30, 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. December 31, 2022 Amortized cost (1) Gross Unrecognized Fair value Weighted- Gains Losses ACL average yield% (Dollars in thousands) Puerto Rico municipal bonds: Due within one year $ 1,202 $ - $ 15 $ 1,187 $ 2 5.20 After 1 to 5 years 42,530 886 1,076 42,340 656 6.34 After 5 to 10 years 55,956 3,182 360 58,778 3,243 6.29 After 10 years 66,022 - 1,318 64,704 4,385 7.10 Total held-to-maturity debt securities 165,710 4,068 2,769 167,009 8,286 6.62 MBS: Residential MBS: FHLMC certificates: After 5 to 10 years 21,443 - 746 20,697 - 3.03 After 10 years 19,362 - 888 18,474 - 4.21 40,805 - 1,634 39,171 - 3.59 GNMA certificates: After 10 years 19,131 - 943 18,188 - 3.35 FNMA certificates: After 10 years 72,347 - 3,155 69,192 - 4.14 CMOs issued or guaranteed by FHLMC, FNMA, and GNMA After 10 years 34,456 - 1,424 33,032 - 3.49 Total Residential MBS 166,739 - 7,156 159,583 - 3.78 Commercial MBS: After 1 to 5 years 9,621 - 396 9,225 - 3.48 After 10 years 95,467 - 4,169 91,298 - 3.15 Total Commercial MBS 105,088 - 4,565 100,523 - 3.18 Total MBS 271,827 - 11,721 260,106 - 3.55 Total held-to-maturity debt securities $ 437,537 $ 4,068 $ 14,490 $ 427,115 $ 8,286 4.71 (1) Excludes accrued interest receivable on held-to-maturity debt securities that totaled $ 5.5 million as of December 31, 2022 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.
Schedule of Unrealized Loss on Investments [Table Text Block]	The following tables present the Corporation’s held-to-maturity debt securities’ fair value and gross unrecognized losses, aggregated by category and length of time that individual securities had been in a continuous unrecognized loss position, as of June 30, 2023 and December 31, 2022, including debt securities for which an ACL was recorded: As of June 30, 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 $ - $ - $ 107,673 $ 3,858 $ 107,673 $ 3,858 MBS: Residential MBS: FHLMC certificates 35,663 2,109 - - 35,663 2,109 GNMA certificates 16,719 1,046 - - 16,719 1,046 FNMA certificates 66,795 3,161 - - 66,795 3,161 CMOs issued or guaranteed by FHLMC, FNMA, and GNMA 28,539 1,658 - - 28,539 1,658 Commercial MBS 9,054 479 87,751 5,628 96,805 6,107 Total held-to-maturity debt securities $ 156,770 $ 8,453 $ 195,424 $ 9,486 $ 352,194 $ 17,939 As of December 31, 2022 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 $ - $ - $ 98,797 $ 2,769 $ 98,797 $ 2,769 MBS: Residential MBS: FHLMC certificates 39,171 1,634 - - 39,171 1,634 GNMA certificates 18,188 943 - - 18,188 943 FNMA certificates 69,192 3,155 - - 69,192 3,155 CMOs issued or guaranteed by FHLMC, FNMA, and GNMA 33,032 1,424 - - 33,032 1,424 Commercial MBS 100,523 4,565 - - 100,523 4,565 Total held-to-maturity debt securities $ 260,106 $ 11,721 $ 98,797 $ 2,769 $ 358,903 $ 14,490
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]	The amortized cost, gross unrealized gains and losses, ACL, estimated fair value, and weighted-average yield of available-for-sale debt securities by contractual maturities as of June 30, 2023 were as follows: June 30, 2023 Amortized cost (1) Gross ACL Fair value Unrealized Weighted- Gains Losses average yield% (Dollars in thousands) U.S. Treasury securities: Due within one year $ 27,671 $ - $ 705 $ - $ 26,966 0.61 After 1 to 5 years 120,787 - 8,084 - 112,703 0.69 U.S. government-sponsored entities (“GSEs”) obligations: Due within one year 224,161 - 5,089 - 219,072 0.42 After 1 to 5 years 2,344,874 56 209,839 - 2,135,091 0.85 After 5 to 10 years 11,267 4 871 - 10,400 3.16 After 10 years 10,844 22 1 - 10,865 5.38 Puerto Rico government obligations: After 10 years (2) 3,254 - 794 349 2,111 - United States and Puerto Rico government obligations 2,742,858 82 225,383 349 2,517,208 0.83 Mortgage-backed securities (“MBS”): Residential MBS: Freddie Mac (“FHLMC”) certificates: After 1 to 5 years 20,047 - 1,191 - 18,856 1.97 After 5 to 10 years 171,682 - 17,242 - 154,440 1.58 After 10 years 1,038,513 - 180,505 - 858,008 1.41 1,230,242 - 198,938 - 1,031,304 1.44 Ginnie Mae (“GNMA”) certificates: Due within one year 1 - - - 1 2.53 After 1 to 5 years 20,426 - 1,257 - 19,169 1.25 After 5 to 10 years 32,172 - 2,952 - 29,220 1.70 After 10 years 219,768 7 26,660 - 193,115 2.63 272,367 7 30,869 - 241,505 2.42 Fannie Mae (“FNMA”) certificates: After 1 to 5 years 22,434 - 1,399 - 21,035 1.72 After 5 to 10 years 338,605 - 31,862 - 306,743 1.75 After 10 years 1,102,263 38 178,364 - 923,937 1.37 1,463,302 38 211,625 - 1,251,715 1.46 Collateralized mortgage obligations (“CMOs”) issued or guaranteed by the FHLMC, FNMA, and GNMA: After 10 years 288,194 - 58,267 - 229,927 1.48 Private label: After 10 years 7,498 - 2,168 84 5,246 7.61 Total Residential MBS 3,261,603 45 501,867 84 2,759,697 1.55 Commercial MBS: After 1 to 5 years 44,311 - 7,308 - 37,003 2.15 After 5 to 10 years 25,656 - 3,430 - 22,226 2.13 After 10 years 125,202 - 27,967 - 97,235 1.40 Total Commercial MBS 195,169 - 38,705 - 156,464 1.67 Total MBS 3,456,772 45 540,572 84 2,916,161 1.56 Total available-for-sale debt securities $ 6,199,630 $ 127 $ 765,955 $ 433 $ 5,433,369 1.23 (1) Excludes accrued interest receivable on available-for-sale debt securities that totaled $ 10.7 million as of June 30, 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) Consists of a residential pass-through MBS issued by the Puerto Rico Housing Finance Authority (“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, 2022 Amortized cost (1) Gross ACL Fair value Unrealized Weighted- Gains Losses average yield% (Dollars in thousands) U.S. Treasury securities: Due within one year $ 7,493 $ - $ 309 $ - $ 7,184 0.22 After 1 to 5 years 141,366 - 9,675 - 131,691 0.70 U.S. GSEs’ obligations: Due within one year 129,018 - 4,036 - 124,982 0.32 After 1 to 5 years 2,395,273 22 227,724 - 2,167,571 0.83 After 5 to 10 years 56,251 13 7,670 - 48,594 1.54 After 10 years 12,170 36 - - 12,206 4.62 Puerto Rico government obligations: After 10 years (2) 3,331 - 755 375 2,201 - United States and Puerto Rico government obligations 2,744,902 71 250,169 375 2,494,429 0.83 MBS: Residential MBS: FHLMC certificates: After 1 to 5 years 4,235 - 169 - 4,066 2.33 After 5 to 10 years 201,072 - 18,709 - 182,363 1.55 After 10 years 1,092,289 - 186,558 - 905,731 1.38 1,297,596 - 205,436 - 1,092,160 1.41 GNMA certificates: Due within one year 5 - - - 5 1.73 After 1 to 5 years 15,508 - 622 - 14,886 2.00 After 5 to 10 years 45,322 1 3,809 - 41,514 1.31 After 10 years 232,632 51 27,169 - 205,514 2.47 293,467 52 31,600 - 261,919 2.27 FNMA certificates: After 1 to 5 years 9,685 - 521 - 9,164 1.76 After 5 to 10 years 358,346 - 31,620 - 326,726 1.68 After 10 years 1,186,635 124 186,757 - 1,000,002 1.38 1,554,666 124 218,898 - 1,335,892 1.45 CMOs issued or guaranteed by the FHLMC, FNMA, and GNMA: After 10 years 302,232 - 56,539 - 245,693 1.44 Private label: After 10 years 7,903 - 2,026 83 5,794 6.83 Total Residential MBS 3,455,864 176 514,499 83 2,941,458 1.52 Commercial MBS: After 1 to 5 years 30,578 - 4,463 - 26,115 2.43 After 5 to 10 years 44,889 - 5,603 - 39,286 1.89 After 10 years 121,464 - 23,732 - 97,732 1.23 Total Commercial MBS 196,931 - 33,798 - 163,133 1.56 Total MBS 3,652,795 176 548,297 83 3,104,591 1.52 Other Due within one year 500 - - - 500 0.84 Total available-for-sale debt securities $ 6,398,197 $ 247 $ 798,466 458 $ 5,599,520 1.22 (1) Excludes accrued interest receivable on available-for-sale debt securities that totaled $ 11.1 million as of December 31, 2022 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) 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.
Schedule of Unrealized Loss on Investments [Table Text Block]	The following tables present the fair value and gross unrealized losses of the Corporation’s available-for-sale debt securities, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position, as of June 30, 2023 and December 31, 2022. The tables also include debt securities for which an ACL was recorded. As of June 30, 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 $ 2,887 $ 4 $ 2,496,214 $ 224,585 $ 2,499,101 $ 224,589 Puerto Rico government obligations - - 2,111 794 (1) 2,111 794 MBS: Residential MBS: FHLMC 19,638 959 1,011,666 197,979 1,031,304 198,938 GNMA 50,543 1,335 189,454 29,534 239,997 30,869 FNMA 42,650 2,361 1,204,127 209,264 1,246,777 211,625 CMOs issued or guaranteed by the FHLMC, FNMA, and GNMA 378 10 229,549 58,257 229,927 58,267 Private label - - 5,246 2,168 (1) 5,246 2,168 Commercial MBS 15,403 370 141,061 38,335 156,464 38,705 $ 131,499 $ 5,039 $ 5,279,428 $ 760,916 $ 5,410,927 $ 765,955 (1) Unrealized losses do not include the credit loss component recorded as part of the ACL. As of June 30, 2023, the PRHFA bond and private label MBS had an ACL of $ 0.4 million and $ 0.1 million, respectively. As of December 31, 2022 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 $ 298,313 $ 18,057 $ 2,174,724 $ 231,357 $ 2,473,037 $ 249,414 Puerto Rico government obligations - - 2,201 755 (1) 2,201 755 MBS: Residential MBS: FHLMC 260,524 45,424 831,637 160,012 1,092,161 205,436 GNMA 74,829 3,433 179,854 28,167 254,683 31,600 FNMA 405,977 49,479 920,200 169,419 1,326,177 218,898 CMOs issued or guaranteed by the FHLMC, FNMA, and GNMA 45,370 6,735 200,323 49,804 245,693 56,539 Private label - - 5,794 2,026 (1) 5,794 2,026 Commercial MBS 30,179 2,215 132,953 31,583 163,132 33,798 $ 1,115,192 $ 125,343 $ 4,447,686 $ 673,123 $ 5,562,878 $ 798,466 (1) Unrealized losses do not include the credit loss component recorded as part of the ACL. As of December 31, 2022, the PRHFA bond and private label MBS had an ACL of $ 0.4 million and $ 0.1 million, respectively.