| Document And Entity Information | 12 Months Ended |
| Dec. 31, 2024 | |
| Document Information [Line Items] | |
| Entity Central Index Key | 0001814390 |
| Document Type | N-CSR |
| Entity Registrant Name | Flat Rock Core Income Fund |
| Document Period End Date | Dec. 31, 2024 |
| Amendment Flag | false |
| N-2 | 12 Months Ended |
| Dec. 31, 2024 $ / shares shares | |
| Cover [Abstract] | |
| Entity Central Index Key | 0001814390 |
| Amendment Flag | false |
| Document Type | N-CSR |
| Entity Registrant Name | Flat Rock Core Income Fund |
| General Description of Registrant [Abstract] | |
| Investment Objectives and Practices [Text Block] | INVESTMENT OBJECTIVE Flat Rock Core Income Fund’s (the “Fund”) investment objective is the preservation of capital while generating current income from its debt investments and seeking to maximize the portfolio’s total return. |
| Risk Factors [Table Text Block] | 8. RISK FACTORS In the normal course of business, the Fund invests in financial instruments and enters into financial transactions where risk of potential loss exists due to such things as changes in the market (market risk) or failure or inability of the other party to a transaction to perform (credit and counterparty risk). See below for a detailed description of select principal risks. The following is not intended to be a comprehensive description of all of the potential risks associated with the Fund. The Fund’s prospectus provides a detailed discussion of the Fund’s risks. Credit Risk. Financial strength and solvency of an issuer are the primary factors influencing credit risk. The Fund could lose money if the issuer or guarantor of a debt security is unable or unwilling, or is perceived (whether by market participants, rating agencies, pricing services or otherwise) as unable or unwilling, to make timely principal and/or interest payments, or to otherwise honor its obligations. Companies in which the Fund invests could deteriorate as a result of, among other factors, an adverse development in their business, a change in the competitive environment or an economic downturn. As a result, companies that the Adviser may have expected to be stable may operate, or expect to operate, at a loss or have significant variations in operating results, may require substantial additional capital to support their operations or maintain their competitive position, or may otherwise have a weak financial condition or be experiencing financial distress. In addition, inadequacy of collateral or credit enhancement for a debt obligation may affect its credit risk. Although the Fund may invest in investments that the Adviser believes are secured by specific collateral, the value of which may exceed the principal amount of the investments at the time of initial investment, there can be no assurance that the liquidation of any such collateral would satisfy the borrower’s obligation in the event of non -payment respect to such investment, or that such collateral could be readily liquidated. In addition, in the event of bankruptcy of a borrower, the Fund could experience delays or limitations with respect to its ability to realize the benefits of the collateral securing an investment. Under certain circumstances, collateral securing an investment may be released without the consent of the Fund. Credit risk is typically greater for securities with ratings that are below investment grade (commonly referred to as “junk bonds”). Since the Fund can invest significantly in high -yield Senior Loans. -market -fraud -law CLO Risk. invest in equity and junior debt tranches of CLOs. The CLOs in which the Fund may invest may incur, or may have already incurred, debt that is senior to the Fund’s investment. CLOs also carry risks including, but not limited to, interest rate risk and credit risk. Investments in CLOs may be subject to certain tax provisions that could result in the Fund incurring tax or recognizing income prior to receiving cash distributions related to such income. CLOs that fail to comply with certain U.S. tax disclosure requirements may be subject to withholding requirements that could adversely affect cash flows and investment results. Any unrealized losses the Fund experiences with respect to its CLO investments may be an indication of future realized losses. Equity tranches are unrated and equity investors receive no principal payments, if any, until all debt obligations are paid. Middle Market Risk. -market -market -recognized Global Markets Risk: -governmental -Hamas Valuation Risk: -party -ask Interest Rate Risk: |
| NAV Per Share | $ / shares | $ 20.53 |
| Capital Stock, Long-Term Debt, and Other Securities [Abstract] | |
| Capital Stock [Table Text Block] | 10. MANDATORILY REDEEMABLE PREFERRED STOCK At December 31, 2024, the Fund had issued and outstanding 1,000 at the Fund’s option upon written notice. The Series B Term Preferred Shares are redeemable at $10,000 per share plus accrued and unpaid dividends (whether or not declared) exclusively at the Fund’s option. Debt issuance costs related to Series A Preferred Shares of $200,000 are deferred and amortized over the period the Series A Term Preferred Shares are outstanding. Debt issuance costs related to Series B Preferred Shares of $200,000 are deferred and amortized over the period the Series B Term Preferred Shares are outstanding. Series Mandatory Annual Shares Aggregate Unamortized Carrying Fair Value Series A September 15, 2026 4.00% 1,000 $ 10,000,000 $ 41,728 $ 9,958,272 $ 9,682,920 Series B March 15, 2025 4.50% 1,000 10,000,000 50,408 9,949,592 9,989,603 $ 20,000,000 $ 92,136 $ 19,907,864 $ 19,672,523 This fair value is based on Level 3 inputs under the fair value hierarchy. The following table summarizes the valuation techniques and significant unobservable inputs that are used to estimate the fair value for the Series A Term Preferred Shares and Series B Term Preferred Shares. The Series A Term Preferred Shares and Series B Term Preferred Shares are presented on the Statement of Assets and Liabilities at the aggregate liquidation preference, net of deferred financing costs. Assets Fair Value Valuation Unobservable Range/Weighted (1) Impact to (2) Series A Term Preferred Shares $ 9,682,920 Income Approach (Discounted Cash Flow Model) Discount Rates 5.95% – 6.50%/6.22% Decrease Series B Term Preferred Shares 9,989,603 Income Approach (Discounted Cash Flow Model) Discount Rates 5.95% – 6.50%/6.22% Decrease (1) Weighted averages are calculated based on fair value of investments. (2) he impact on fair value measurement of an increase in each unobservable input is in isolation. |
| Security Title [Text Block] | MANDATORILY REDEEMABLE PREFERRED STOCK |
| Security Dividends [Text Block] | Both the Series A and Series B Term Preferred Shares have a liquidation preference of $10,000 per share plus accrued and unpaid dividends (whether or not declared). |
| Security Liquidation Rights [Text Block] | The Series A Term Preferred Shares are entitled to a dividend at a rate of 4.00% per year based on the $10,000 liquidation preference before the common stock is entitled to receive any dividends. The Series B Term Preferred Shares are entitled to a dividend at a rate of 4.50% per year based on the $10,000 liquidation preference |
| Long Term Debt [Table Text Block] | 9. BORROWINGS The Fund maintains a $75 -owned As of December 31, 2024, the Fund had drawn down $41,583,286 from the Credit Facility and the maximum borrowing outstanding during the year was $61,625,518. The balance drawn from the Credit Facility is inclusive of $243,750 of upfront fees in addition to the principal balance. The Fund is charged an interest rate of 2.70% above the 1 -month |
| Outstanding Security, Title [Text Block] | Shares of beneficial interest outstanding |
| Outstanding Security, Held [Shares] | shares | 14,612,491 |
| Credit Risks [Member] | |
| General Description of Registrant [Abstract] | |
| Risk [Text Block] | Credit Risk. Financial strength and solvency of an issuer are the primary factors influencing credit risk. The Fund could lose money if the issuer or guarantor of a debt security is unable or unwilling, or is perceived (whether by market participants, rating agencies, pricing services or otherwise) as unable or unwilling, to make timely principal and/or interest payments, or to otherwise honor its obligations. Companies in which the Fund invests could deteriorate as a result of, among other factors, an adverse development in their business, a change in the competitive environment or an economic downturn. As a result, companies that the Adviser may have expected to be stable may operate, or expect to operate, at a loss or have significant variations in operating results, may require substantial additional capital to support their operations or maintain their competitive position, or may otherwise have a weak financial condition or be experiencing financial distress. In addition, inadequacy of collateral or credit enhancement for a debt obligation may affect its credit risk. Although the Fund may invest in investments that the Adviser believes are secured by specific collateral, the value of which may exceed the principal amount of the investments at the time of initial investment, there can be no assurance that the liquidation of any such collateral would satisfy the borrower’s obligation in the event of non -payment respect to such investment, or that such collateral could be readily liquidated. In addition, in the event of bankruptcy of a borrower, the Fund could experience delays or limitations with respect to its ability to realize the benefits of the collateral securing an investment. Under certain circumstances, collateral securing an investment may be released without the consent of the Fund. Credit risk is typically greater for securities with ratings that are below investment grade (commonly referred to as “junk bonds”). Since the Fund can invest significantly in high -yield |
| Senior Loans [Member] | |
| General Description of Registrant [Abstract] | |
| Risk [Text Block] | Senior Loans. -market -fraud -law |
| CLO Risk [Member] | |
| General Description of Registrant [Abstract] | |
| Risk [Text Block] | CLO Risk. invest in equity and junior debt tranches of CLOs. The CLOs in which the Fund may invest may incur, or may have already incurred, debt that is senior to the Fund’s investment. CLOs also carry risks including, but not limited to, interest rate risk and credit risk. Investments in CLOs may be subject to certain tax provisions that could result in the Fund incurring tax or recognizing income prior to receiving cash distributions related to such income. CLOs that fail to comply with certain U.S. tax disclosure requirements may be subject to withholding requirements that could adversely affect cash flows and investment results. Any unrealized losses the Fund experiences with respect to its CLO investments may be an indication of future realized losses. Equity tranches are unrated and equity investors receive no principal payments, if any, until all debt obligations are paid. |
| Middle Market Risk [Member] | |
| General Description of Registrant [Abstract] | |
| Risk [Text Block] | Middle Market Risk. -market -market -recognized |
| Global Markets Risk [Member] | |
| General Description of Registrant [Abstract] | |
| Risk [Text Block] | Global Markets Risk: -governmental -Hamas |
| Valuation Risk [Member] | |
| General Description of Registrant [Abstract] | |
| Risk [Text Block] | Valuation Risk: -party -ask |
| Interest Rate Risk [Member] | |
| General Description of Registrant [Abstract] | |
| Risk [Text Block] | Interest Rate Risk: |
