| Document And Entity Information | 12 Months Ended |
| Dec. 31, 2023 | |
| Document Information [Line Items] | |
| Entity Registrant Name | FLAT ROCK OPPORTUNITY FUND |
| Document Type | N-CSR |
| Amendment Flag | false |
| Entity Central Index Key | 0001732078 |
| Document Period End Date | Dec. 31, 2023 |
| N-2 | 12 Months Ended |
| Dec. 31, 2023 $ / shares | |
| Cover [Abstract] | |
| Entity Central Index Key | 0001732078 |
| Amendment Flag | false |
| Document Type | N-CSR |
| Entity Registrant Name | FLAT ROCK OPPORTUNITY FUND |
| General Description of Registrant [Abstract] | |
| Investment Objectives and Practices [Text Block] | INVESTMENT OBJECTIVE Flat Rock Opportunity Fund's (the “Fund") investment objective is to generate current income and, as a secondary objective, long-term capital appreciation. |
| 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 list is not intended to be a comprehensive listing of all of the potential risks associated with the Fund. The Fund’s prospectus provides a detailed discussion of the Fund’s risks. CLO Risk: Between the closing date and the effective date of a CLO, the CLO collateral manager will generally expect to purchase additional collateral obligations for the CLO. During this period, the price and The failure by a CLO in which the Fund invests to satisfy financial covenants, including with respect to adequate collateralization and/or interest coverage tests, could lead to a reduction in the CLO’s payments to the Fund. In the event that a CLO fails certain tests, holders of CLO senior debt may be entitled to additional payments that would, in turn, reduce the payments the Fund would otherwise be entitled to receive. Separately, the Fund may incur expenses to the extent necessary to seek recovery upon default or to negotiate new terms, which may include the waiver of certain financial covenants, with a defaulting CLO or any other investment the Fund may make. If any of these occur, it could adversely affect the Fund’s operating results and cash flows. The Fund’s CLO investments are exposed to leveraged credit risk. If certain minimum collateral value ratios and/or interest coverage ratios are not met by a CLO, primarily due to senior secured loan defaults, then cash flow that otherwise would have been available to pay distributions to the Fund on its CLO investments may instead be used to redeem any senior notes or to purchase additional senior secured loans, until the ratios again exceed the minimum required levels or any senior notes are repaid in full. The Fund’s CLO investments and/or the underlying senior secured loans may prepay more quickly than expected, which could have an adverse impact on the Fund’s net assets. Liquidity Risk: Global Markets Risk: Credit Risk. 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 of scheduled interest or principal payments with 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 investments considered speculative in nature and unsecured investments, this risk may be substantial. The Fund’s right to payment and its security interest, if any, may be subordinated to the payment rights and security interests of more senior creditors. This risk may also be greater to the extent the Fund uses leverage or derivatives in connection with the management of the Fund. Changes in the actual or perceived creditworthiness of an issuer, or a downgrade or default affecting any of the Fund’s securities, could affect the Fund’s performance. Valuation Risk: Interest Rate Risk: |
| NAV Per Share | $ 19.21 |
| CLO Risk [Member] | |
| General Description of Registrant [Abstract] | |
| Risk [Text Block] | CLO Risk: Between the closing date and the effective date of a CLO, the CLO collateral manager will generally expect to purchase additional collateral obligations for the CLO. During this period, the price and The failure by a CLO in which the Fund invests to satisfy financial covenants, including with respect to adequate collateralization and/or interest coverage tests, could lead to a reduction in the CLO’s payments to the Fund. In the event that a CLO fails certain tests, holders of CLO senior debt may be entitled to additional payments that would, in turn, reduce the payments the Fund would otherwise be entitled to receive. Separately, the Fund may incur expenses to the extent necessary to seek recovery upon default or to negotiate new terms, which may include the waiver of certain financial covenants, with a defaulting CLO or any other investment the Fund may make. If any of these occur, it could adversely affect the Fund’s operating results and cash flows. The Fund’s CLO investments are exposed to leveraged credit risk. If certain minimum collateral value ratios and/or interest coverage ratios are not met by a CLO, primarily due to senior secured loan defaults, then cash flow that otherwise would have been available to pay distributions to the Fund on its CLO investments may instead be used to redeem any senior notes or to purchase additional senior secured loans, until the ratios again exceed the minimum required levels or any senior notes are repaid in full. The Fund’s CLO investments and/or the underlying senior secured loans may prepay more quickly than expected, which could have an adverse impact on the Fund’s net assets. |
| Liquidity Risk [Member] | |
| General Description of Registrant [Abstract] | |
| Risk [Text Block] | Liquidity Risk: |
| Global Markets Risk [Member] | |
| General Description of Registrant [Abstract] | |
| Risk [Text Block] | Global Markets Risk: |
| Credit Risk [Member] | |
| General Description of Registrant [Abstract] | |
| Risk [Text Block] | Credit Risk. 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 of scheduled interest or principal payments with 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 investments considered speculative in nature and unsecured investments, this risk may be substantial. The Fund’s right to payment and its security interest, if any, may be subordinated to the payment rights and security interests of more senior creditors. This risk may also be greater to the extent the Fund uses leverage or derivatives in connection with the management of the Fund. Changes in the actual or perceived creditworthiness of an issuer, or a downgrade or default affecting any of the Fund’s securities, could affect the Fund’s performance. |
| Valuation Risk [Member] | |
| General Description of Registrant [Abstract] | |
| Risk [Text Block] | Valuation Risk: |
| Interest Rate Risk [Member] | |
| General Description of Registrant [Abstract] | |
| Risk [Text Block] | Interest Rate Risk: |
