FAIR VALUE (Tables)	12 Months Ended
FAIR VALUE (Tables)	Dec. 31, 2024
FAIR VALUE [Abstract]
Assets and Liabilities Measured at Fair Value on Recurring Basis [Table Text Block]	Assets and liabilities measured at fair value on a recurring basis are summarized below as of December 31, 2024 and 2023: As of December 31, 2024 As of December 31, 2023 Fair Value Measurements Using Fair Value Measurements Using Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total (In thousands) Assets: Available-for-sale debt securities: U.S. Treasury securities $ 59,189 $ - $ - $ 59,189 $ 135,393 $ - $ - $ 135,393 Noncallable U.S. agencies debt securities - 533,296 - 533,296 - 433,437 - 433,437 Callable U.S. agencies debt securities - 1,307,035 - 1,307,035 - 1,874,960 - 1,874,960 MBS - 2,658,967 4,195 (1) 2,663,162 - 2,779,994 4,785 (1) 2,784,779 Puerto Rico government obligation - - 1,620 1,620 - - 1,415 1,415 Other investments - - 1,000 1,000 - - - - Equity securities 4,886 - - 4,886 4,893 - - 4,893 Derivative assets - 318 - 318 - 341 - 341 Liabilities: Derivative liabilities - 150 - 150 - 317 - 317 (1) Related to private label MBS.
Fair Value of Assets and Liabilities Measured on Recurring Basis [Table Text Block]	The table below presents a reconciliation of the beginning and ending balances of all assets measured at fair value on a recurring basis using significant unobservable inputs (Level 3) for the years ended December 31, 2024, 2023, and 2022: Available-for-Sale Debt Securities (1) Level 3 Instruments Only 2024 2023 2022 (In thousands) Beginning balance $ 6,200 $ 8,495 $ 11,084 Total gains (losses): Included in other comprehensive income (loss) (unrealized) 830 (750) (401) Included in earnings (unrealized) (2) 50 (20) 434 Purchases 1,000 - - Principal repayments and amortization (3) (1,265) (1,525) (2,622) Ending balance $ 6,815 $ 6,200 $ 8,495 (1) Amounts mostly related to private label MBS. (2) Changes in unrealized gains (losses) included in earnings were recognized within provision for credit losses - expense and relate to assets still held as of the reporting date. (3) For each of the years ended December 31, 2023 and 2022, includes a $ 0.5 million repayment of a matured debt security.
Fair Value Measurement Inputs and Valuation Techniques [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 December 31, 2024 and 2023: December 31, 2024 Fair Value Valuation Technique Unobservable Input Range Weighted Average Minimum Maximum (Dollars in thousands) Available-for-sale debt securities: Private label MBS $ 4,195 Discounted cash flows Discount rate 16.6% 16.6% 16.6% Prepayment rate 0.0% 5.7% 3.2% Projected cumulative loss rate 0.1% 10.1% 4.9% Puerto Rico government obligation $ 1,620 Discounted cash flows Discount rate 11.5% 11.5% 11.5% Projected cumulative loss rate 23.9% 23.9% 23.9% December 31, 2023 Fair Value Valuation Technique Unobservable Input Range Weighted Average Minimum Maximum (Dollars in thousands) Available-for-sale debt securities: Private label MBS $ 4,785 Discounted cash flows Discount rate 16.1% 16.1% 16.1% Prepayment rate 0.0% 6.9% 3.7% Projected cumulative loss rate 0.1% 10.9% 4.2% Puerto Rico government obligation $ 1,415 Discounted cash flows Discount rate 14.1% 14.1% 14.1% Projected cumulative loss rate 25.8% 25.8% 25.8%
Impairment or Valuation Adjustments were Recorded for Assets Recognized at Fair Value [Table Text Block]	For the years ended December 31, 2024, 2023, and 2022, the Corporation recorded losses or valuation adjustments for assets recognized at fair value on a non-recurring basis and still held at the respective reporting dates, as shown in the following table: Carrying value as of December 31, Related to losses recorded for the Year Ended December 31, 2024 2023 2022 2024 2023 2022 (In thousands) Level 3: Loans receivable (1) $ 16,296 $ 15,609 $ 11,437 $ (373) $ (1,839) $ (736) OREO (2) 1,471 3,218 5,461 (100) (416) (917) Premises and equipment (3) - - 1,242 - - (218) Level 2: Loans held for sale (4) $ 15,276 $ - $ 12,306 $ (78) $ - $ (106) (1) Consists mainly of collateral dependent commercial and construction loans. The Corporation generally measured losses based on the fair value of the collateral. The Corporation derived the fair values from external appraisals that took into consideration prices in observed transactions involving similar assets in similar locations but adjusted for specific characteristics and assumptions of the collateral (e.g., absorption rates), which are not market observable. The haircuts applied on appraisals for the year ended December 31, 2024 were 8 %, and for the year ended December 31, 2023 the haircuts ranged from 16 % to 20 %. There were no haircuts applied on appraisals for the year ended December 31, 2022. (2) The Corporation derived the fair values from appraisals that took into consideration prices in observed transactions involving similar assets in similar locations but adjusted for specific characteristics and assumptions of the properties (e.g., absorption rates and net operating income of income producing properties), which are not market observable. Losses were related to market valuation adjustments after the transfer of the loans to the OREO portfolio. The haircuts applied on appraisals ranged from 2 % to 44 % for the year ended December 31, 2024 and 1 % to 28 %, for the years ended December 31 , 2023 and 2022. (3) Relates to a banking facility reclassified to held-for-sale and measured at the fair value of the collateral. (4) The Corporation derived the fair value of these loans based on published secondary market prices of MBS with similar characteristics.
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis, Valuation Techniques [Table Text Block]	Qualitative information regarding the financial instruments measured at fair value on a non-recurring basis using significant unobservable inputs (Level 3) as of December 31, 2024 are as follows: December 31, 2024 Method Inputs Loans Income, Market, Comparable Sales, Discounted Cash Flows External appraised values; probability weighting of broker price opinions; management assumptions regarding market trends or other relevant factors OREO Income, Market, Comparable Sales, Discounted Cash Flows External appraised values; probability weighting of broker price opinions; management assumptions regarding market trends or other relevant factors Premises and equipment Market External appraised value
Estimated Fair Value and Carrying Value of Financial Instruments [Table Text Block]	The following tables present the carrying value, estimated fair value and estimated fair value level of the hierarchy of financial instruments as of December 31, 2024 and 2023: Total Carrying Amount in Statement of Financial Condition as of December 31, 2024 Fair Value Estimate as of December 31, 2024 Level 1 Level 2 Level 3 (In thousands) Assets: Cash and due from banks and money market investments (amortized cost) $ 1,159,415 $ 1,159,415 $ 1,159,415 $ - $ - Available-for-sale debt securities (fair value) 4,565,302 4,565,302 59,189 4,499,298 6,815 Held-to-maturity debt securities: Held-to-maturity debt securities (amortized cost) 317,786 Less: ACL on held-to-maturity debt securities (802) Held-to-maturity debt securities, net of ACL $ 316,984 308,040 - 212,432 95,608 Equity securities (amortized cost) 47,132 47,132 - 47,132 (1) - Other equity securities (fair value) 4,886 4,886 4,886 - - Loans held for sale (lower of cost or market) 15,276 15,276 - 15,276 - Loans held for investment: Loans held for investment (amortized cost) 12,746,556 Less: ACL for loans and finance leases (243,942) Loans held for investment, net of ACL $ 12,502,614 12,406,405 - - 12,406,405 MSRs (amortized cost) 25,019 43,046 - - 43,046 Derivative assets (fair value) (2) 318 318 - 318 - Liabilities: Deposits (amortized cost) $ 16,871,298 $ 16,872,963 $ - $ 16,872,963 $ - Long-term advances from the FHLB (amortized cost) 500,000 500,128 - 500,128 - Junior subordinated debentures (amortized cost) 61,700 61,752 - - 61,752 Derivative liabilities (fair value) (2) 150 150 - 150 - (1) Includes FHLB stock with a carrying value of $ 34.0 million, which is considered restricted. (2) Includes interest rate swap agreements and forward contracts. Total Carrying Amount in Statement of Financial Condition as of December 31, 2023 Fair Value Estimate as of December 31, 2023 Level 1 Level 2 Level 3 (In thousands) Assets: Cash and due from banks and money market investments (amortized cost) $ 663,164 $ 663,164 $ 663,164 $ - $ - Available-for-sale debt securities (fair value) 5,229,984 5,229,984 135,393 5,088,391 6,200 Held-to-maturity debt securities: Held-to-maturity debt securities (amortized cost) 354,178 Less: ACL on held-to-maturity debt securities (2,197) Held-to-maturity debt securities, net of ACL $ 351,981 346,132 - 235,239 110,893 Equity securities (amortized cost) 44,782 44,782 - 44,782 (1) - Other equity securities (fair value) 4,893 4,893 4,893 - - Loans held for sale (lower of cost or market) 7,368 7,476 - 7,476 - Loans held for investment: Loans held for investment (amortized cost) 12,185,483 Less: ACL for loans and finance leases (261,843) Loans held for investment, net of ACL $ 11,923,640 11,762,855 - - 11,762,855 MSRs (amortized cost) 26,941 45,244 - - 45,244 Derivative assets (fair value) (2) 341 341 - 341 - Liabilities: Deposits (amortized cost) $ 16,555,985 $ 16,565,435 $ - $ 16,565,435 $ - Long-term advances from the FHLB (amortized cost) 500,000 500,522 - 500,522 - Junior subordinated debentures (amortized cost) 161,700 159,999 - - 159,999 Derivative liabilities (fair value) (2) 317 317 - 317 - (1) Includes FHLB stock with a carrying value of $ 34.6 million, which is considered restricted. (2) Includes interest rate swap agreements, interest rate caps, forward contracts and interest rate lock commitments.

Tabular disclosure of the fair value measurement of assets using significant unobservable inputs (Level 3), a reconciliation of the beginning and ending balances, separately presenting changes during the period attributable to the following: (1) total gains or losses for the period (realized and unrealized), segregating those gains or losses included in earnings (or changes in net assets) and gains or losses recognized in other comprehensive income (loss), and a description of where those gains or losses included in earnings (or changes in net assets) are reported in the statement of income (or activities); (2) purchases, sales, issues, and settlements (each type disclosed separately); and (3) transfers in and transfers out of Level 3 (for example, transfers due to changes in the observability of significant inputs), by class of asset.