FAIR VALUE (Tables)	3 Months Ended
FAIR VALUE (Tables)	Mar. 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 March 31,2024 and December 31, 2023: As of March 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: Debt securities available for sale: U.S. Treasury securities $ 116,068 $ - $ - $ 116,068 $ 135,393 $ - $ - $ 135,393 Noncallable U.S. agencies debt securities - 467,940 - 467,940 - 433,437 - 433,437 Callable U.S. agencies debt securities - 1,785,476 - 1,785,476 - 1,874,960 - 1,874,960 MBS - 2,671,420 4,724 (1) 2,676,144 - 2,779,994 4,785 (1) 2,784,779 Puerto Rico government obligation - - 1,551 1,551 - - 1,415 1,415 Equity securities 4,871 - - 4,871 4,893 - - 4,893 Derivative assets - 239 - 239 - 341 - 341 Liabilities: Derivative liabilities - 242 - 242 - 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 quarters ended March 31, 2024 and 2023: Quarter Ended March 31, 2024 2023 Level 3 Instruments Only Securities Available for Sale (1) Securities Available for Sale (1) (In thousands) Beginning balance $ 6,200 $ 8,495 Total gains (losses): Included in other comprehensive income (loss) (unrealized) 239 (162) Included in earnings (unrealized) (2) 69 9 Principal repayments and amortization (3) (233) (737) Ending balance $ 6,275 $ 7,605 (1) Amounts related to private label MBS and a Puerto Rico government obligation. (2) Changes in unrealized gains included in earnings were recognized within provision for credit losses - expense and relate to assets still held as of the reporting date. (3) For the quarter ended March 31, 2023 includes a $ 0.5 million repayment related to 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 March 31,2024 and December 31, 2023: March 31, 2024 Fair Value Valuation Technique Unobservable Input Range Weighted Average Minimum Maximum (Dollars in thousands) Available-for-sale debt securities: Private label MBS $ 4,724 Discounted cash flows Discount rate 16.4% 16.4% 16.4% Prepayment rate 0.0% 6.9% 3.7% Projected cumulative loss rate 0.2% 10.5% 3.8% Puerto Rico government obligation $ 1,551 Discounted cash flows Discount rate 13.0% 13.0% 13.0% Projected cumulative loss rate 21.3% 21.3% 21.3% 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 quarters ended March 31, 2024 and 2023, the Corporation recorded losses or valuation adjustments for assets recognized at fair value on a non-recurring basis and still held at March 31, 2024 and 2023, as shown in the following table: Carrying value as of March 31, Related to losses recorded for the Quarter Ended March 31, 2024 2023 2024 2023 (In thousands) Level 3: Loans receivable (1) $ 9,654 $ 3,486 $ (41) $ (60) OREO (2) 859 814 (163) (33) (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. There were no significant haircuts applied on appraisals for the quarters ended March 31, 2024 and 2023. (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 ranged from 2 % to 21 % for the quarter ended March 31, 2024 and from 10 % to 28 % for the quarter ended March 31, 2023.
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 March 31,2024 and December 31, 2023: Total Carrying Amount in Statement of Financial Condition as of March 31, 2024 Fair Value Estimate as of March 31, 2024 Level 1 Level 2 Level 3 (In thousands) Assets: Cash and due from banks and money market investments (amortized cost) $ 684,519 $ 684,519 $ 684,519 $ - $ - Available-for-sale debt securities (fair value) 5,047,179 5,047,179 116,068 4,924,836 6,275 Held-to-maturity debt securities: Held-to-maturity debt securities (amortized cost) 349,330 Less: ACL on held-to-maturity debt securities (1,235) Held-to-maturity debt securities, net of ACL $ 348,095 338,120 - 228,237 109,883 Equity securities (amortized cost) 46,519 46,519 - 46,519 (1) - Other equity securities (fair value) 4,871 4,871 4,871 - - Loans held for sale (lower of cost or market) 12,080 12,173 - 12,173 - Loans held for investment: Loans held for investment (amortized cost) 12,311,448 Less: ACL for loans and finance leases (263,592) Loans held for investment, net of ACL $ 12,047,856 11,953,468 - - 11,953,468 MSRs (amortized cost) 26,355 44,764 - - 44,764 Derivative assets (fair value) (2) 239 239 - 239 - Liabilities: Deposits (amortized cost) $ 16,545,511 $ 16,546,891 $ - $ 16,546,891 $ - Advances from the FHLB (amortized cost): Long-term 500,000 496,672 - 496,672 - Other long-term borrowings (amortized cost) 161,700 160,199 - - 160,199 Derivative liabilities (fair value) (2) 242 242 - 242 - (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, interest rate lock commitments, and forward loan sales commitments. 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.