BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES (Policies)	6 Months Ended
	Jun. 30, 2023
BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES [Abstract]
Principles of consolidation [Policy Text Block]	The Consolidated Financial Statements (unaudited) for the quarter and six-month period ended June 30, 2023 (the “unaudited consolidated financial statements”) of First BanCorp. (the “Corporation”) have been prepared in conformity with the accounting policies stated in the Corporation’s Audited Consolidated Financial Statements for the fiscal year ended December 31, 2022 (the “audited consolidated financial statements”) included in the 2022 Annual Report on Form 10-K, as updated by the information contained in this report. Certain information and note disclosures normally included in the financial statements prepared in accordance with generally accepted accounting principles in the United States of America (“GAAP”) have been condensed or omitted from these statements pursuant to the rules and regulations of the SEC and, accordingly, these financial statements should be read in conjunction with the audited consolidated financial statements, which are included in the 2022 Annual Report on Form 10-K. All adjustments (consisting only of normal recurring adjustments) that are, in the opinion of management, necessary for a fair presentation of the statement of financial position, results of operations and cash flows for the interim periods have been reflected. All significant intercompany accounts and transactions have been eliminated in consolidation.
Adoption of New Accounting Requirements And Recently Issued Accounting Standards Not Yet Effective or Not Yet Adopted [Policy Text Block]	Adoption of New Accounting Requirements ASU 2022-02, “Financial Instruments – Credit Losses (Topic 326): Troubled Debt Restructurings (“TDR”) and Vintage Disclosures” Effective January 1, 2023, the Corporation adopted ASU 2022-02, which removed the existing measurement and disclosure requirements for TDR loans, added additional disclosure requirements related to modifications provided to borrowers experiencing financial difficulty regardless of whether the modification is accounted for as a new loan, and amends the guidance on vintage disclosures to require disclosure of gross charge-offs by year of origination. Prior to adoption, a change in contractual terms of a loan where a borrower was experiencing financial difficulty and received a concession not available through other sources was required to be disclosed as a TDR, whereas now a borrower that is experiencing financial difficulty and there has been a direct change to the timing or amount of contractual cash flows in the form of principal forgiveness, interest rate reduction, an other-than-insignificant payment delay, a term extension, or any combination of these types of loan modifications in the current period needs to be disclosed. ASU 2022-02 did not amend the definition of financial difficulty. Modifications of receivables are within the scope of ASU 2022-02 if they are accounted for in accordance with Accounting Standards Codification (“ASC”) 310-20. As such, finance leases are not within the scope of ASU 2022-02. Such modifications are evaluated following the requirements in ASC 310-20 to determine whether they should be accounted for as a new loan or a continuation of the existing loan. ASU 2022-02 also eliminated the requirement to use a discounted cash flow method for TDRs for the determination of the ACL, and allows the option of a non-discounted cash flow portfolio-based approach for modified loans to borrowers experiencing financial difficulties. The Corporation elected to apply a non-discounted cash flow, portfolio-based ACL approach for modified loans to borrowers experiencing financial difficulties for all portfolios, using a modified retrospective transition method. The adoption resulted in a net increase to the ACL of approximately $ 2.1 million and a decrease to retained earnings of approximately $ 1.3 million, after tax, predominantly driven by residential mortgage loans. The amount of defined modifications given to borrowers experiencing financial difficulty is disclosed in Note 3 – Loans Held for Investment, along with the financial impact of those modifications. The Corporation was not impacted by the adoption of the following ASUs during 2023: ● ASU 2022-01, “Derivatives and Hedging (Topic 815): Fair Value Hedging – Portfolio Layer Method” ● ASU 2021-08, “Business Combinations (Topic 805): Accounting for Contract Assets and Contract Liabilities From Contracts With Customers” Recently Issued Accounting Standards Not Yet Effective or Not Yet Adopted Standard Description Effective Date Effect on the financial statements ASU 2023-02, "Investments - Equity Method and Joint Ventures (Topic 323): Accounting for Investments in Tax Credit Structures Using the Proportional Amortization Method" In March 2023, the FASB issued ASU 2023-02 which, among other things, allows tax equity investments, regardless of the tax credit program from which the income tax credits are received, to be accounted for using the proportional amortization method if certain conditions are met and requires specific disclosures of such investments. The election needs to be made on a tax-credit- program-by-tax-credit-program basis. January 1, 2024. Early adoption is permitted in any interim period. The Corporation does not expect to be impacted by the amendments of this ASU since it does not hold tax equity investments. ASU 2023-01, "Leases (Topic 842): Common Control Arrangements" In March 2023, the FASB issued ASU 2023-01 which, among other things, generally requires a lessee in a common-control lease arrangement to amortize leasehold improvements over the useful life regardless of the lease term, subject to certain exceptions. In addition, a lessee that no longer controls the use of the underlying asset will account for the transfer of the underlying asset as an adjustment to equity. January 1, 2024. Early adoption is permitted for both interim and annual financial statements that have not yet been made available for issuance. The Corporation does not expect to be materially impacted by the adoption of this ASU during the first quarter of 2024. For other issued accounting standards not yet effective or not yet adopted, see Note 1 – Nature of Business and Summary of Significant Accounting Policies, to the audited consolidated financial statements included in the 2022 Annual Report on Form 10-K.