FAIR VALUE (Tables)	12 Months Ended
FAIR VALUE (Tables)	Dec. 31, 2023
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, 2023 and 2022: As of December 31, 2023 As of December 31, 2022 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: Debt securities available for sale: U.S. Treasury securities $ 135,393 $ - $ - $ 135,393 $ 138,875 $ - $ - $ 138,875 Noncallable U.S. agencies debt securities - 433,437 - 433,437 - 389,787 - 389,787 Callable U.S. agencies debt securities - 1,874,960 - 1,874,960 - 1,963,566 - 1,963,566 MBS - 2,779,994 4,785 (1) 2,784,779 - 3,098,797 5,794 (1) 3,104,591 Puerto Rico government obligations - - 1,415 1,415 - - 2,201 2,201 Other investments - - - - - - 500 500 Equity securities 4,893 - - 4,893 4,861 - - 4,861 Derivative assets - 341 - 341 - 633 - 633 Liabilities: Derivative liabilities - 317 - 317 - 476 - 476 (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, 2023, 2022, and 2021: Securities Available for Sale (1) Level 3 Instruments Only 2023 2022 2021 (In thousands) Beginning balance $ 8,495 $ 11,084 $ 11,977 Total (losses) gains: Included in other comprehensive income (loss) (unrealized) (750) (401) 1,281 Included in earnings (unrealized) (2) (20) 434 136 Purchases - - 1,000 Other (3) (1,525) (2,622) (3,310) Ending balance $ 6,200 $ 8,495 $ 11,084 (1) Amounts mostly related to private label MBS. (2) Changes in unrealized gains included in earnings were recognized within provision for credit losses - expense (benefit) and relate to assets still held as of the reporting date. (3) Mainly includes principal repayments.
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, 2023 and 2022: 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 obligations $ 1,415 Discounted cash flows Discount rate 14.1% 14.1% 14.1% Projected cumulative loss rate 25.8% 25.8% 25.8% 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%
Impairment or Valuation Adjustments were Recorded for Assets Recognized at Fair Value [Table Text Block]	As of December 31, 2023, the Corporation recorded losses or valuation adjustments for assets recognized at fair value on a non- recurring basis and still held at December 31, 2023, as shown in the following table: Carrying value as of December 31, Related to losses recorded for the Year Ended December 31, 2023 2022 2021 2023 2022 2021 (In thousands) Level 3: Loans receivable (1) $ 15,609 $ 11,437 $ 31,534 $ (1,839) $ (736) $ (5,466) OREO (2) 3,218 5,461 9,126 (416) (917) (48) Premises and equipment (3) - 1,242 - - (218) - Level 2: Loans held for sale (4) $ - $ 12,306 $ - $ - $ (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 ranged from 16 % to 20 %. (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 1 % to 28 %. (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 fair value measurements for Level 3 financial instruments as of December 31, 2023 are as follows: December 31, 2023 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, 2023 and 2022: 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 $ - Advances from the FHLB (amortized cost): Long-term 500,000 500,522 - 500,522 - Other long-term borrowings (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. Total Carrying Amount in Statement of Financial Condition as of December 31, 2022 Fair Value Estimate as of December 31, 2022 Level 1 Level 2 Level 3 (In thousands) Assets: Cash and due from banks and money market investments (amortized cost) $ 480,505 $ 480,505 $ 480,505 $ - $ - Available-for-sale debt securities (fair value) 5,599,520 5,599,520 138,875 5,452,150 8,495 Held-to-maturity debt securities: Held-to-maturity debt securities (amortized cost) 437,537 Less: ACL on held-to-maturity debt securities (8,286) Held-to-maturity debt securities, net of ACL $ 429,251 427,115 - 260,106 167,009 Equity securities (amortized cost) 50,428 50,428 - 50,428 (1) - Other equity securities (fair value) 4,861 4,861 4,861 - - Loans held for sale (lower of cost or market) 12,306 12,306 - 12,306 - Loans held for investment: Loans held for investment (amortized cost) 11,552,825 Less: ACL for loans and finance leases (260,464) Loans held for investment, net of ACL $ 11,292,361 11,106,809 - - 11,106,809 MSRs (amortized cost) 29,037 44,710 - - 44,710 Derivative assets (fair value) (2) 633 633 - 633 - Liabilities: Deposits (amortized cost) $ 16,143,467 $ 16,139,937 $ - $ 16,139,937 $ - Short-term securities sold under agreements to repurchase (amortized cost) 75,133 75,230 - 75,230 - Advances from the FHLB (amortized cost) Short-term 475,000 474,731 - 474,731 - Long-term 200,000 199,865 - 199,865 - Other long-term borrowings (amortized cost) 183,762 187,246 - - 187,246 Derivative liabilities (fair value) (2) 476 476 - 476 - (1) Includes FHLB stock with a carrying value of $ 42.9 million, which is considered restricted. (2) Includes interest rate swap agreements, interest rate caps, forward contracts, interest rate lock commitments, and forward loan sales commitments.