| N-2 | Dec. 13, 2023 USD ($) shares |
| Cover [Abstract] | |
| Entity Central Index Key | 0001278752 |
| Amendment Flag | false |
| Securities Act File Number | 814-00646 |
| Document Type | 8-K |
| Entity Registrant Name | MidCap Financial Investment Corporation |
| Entity Address, Address Line One | 9 West 57th Street |
| Entity Address, City or Town | New York |
| Entity Address, State or Province | NY |
| Entity Address, Postal Zip Code | 10019 |
| City Area Code | 212 |
| Local Phone Number | 515-3450 |
| Entity Emerging Growth Company | false |
| Capital Stock, Long-Term Debt, and Other Securities [Abstract] | |
| Long Term Debt [Table Text Block] | On December 13, 2023, MidCap Financial Investment Corporation (the “Company”) and U.S. Bank Trust Company, National Association (“Trustee”) entered into a Sixth Supplemental Indenture (the “Sixth Supplemental Indenture”) to the Indenture (the “Indenture”), dated as of October 9, 2012, between the Company and the Trustee. The Sixth Supplemental Indenture relates to |
| Long Term Debt, Title [Text Block] | 8.00% Notes due 2028 |
| Long Term Debt, Principal | $ | $ 86,250,000 |
| Long Term Debt, Structuring [Text Block] | On December 13, 2023, MidCap Financial Investment Corporation (the “Company”) and U.S. Bank Trust Company, National Association (“Trustee”) entered into a Sixth Supplemental Indenture (the “Sixth Supplemental Indenture”) to the Indenture (the “Indenture”), dated as of October 9, 2012, between the Company and the Trustee. The Sixth Supplemental Indenture relates to The Notes will mature on December 15, 2028. The Notes bear interest at a rate of 8.00% per year, commencing December 13, 2023. The Company will pay interest on the Notes on March 15, June 15, September 15 and December 15 of each year, beginning on March 15, 2024. The Notes may be redeemed in whole or in part at any time or from time to time at our option on or after December 15, 2025, at a redemption price of $25 per Note plus accrued and unpaid interest payments otherwise payable for the then-current quarterly interest period accrued to, but excluding, the date fixed for redemption. |
| Long Term Debt, Dividends and Covenants [Text Block] | The Indenture, as supplemented by the Sixth Supplemental Indenture, contains certain covenants including covenants requiring the Company to comply with Section 18(a)(1)(A) as modified by Section 61(a) of the Investment Company Act of 1940, as amended (the “1940 Act”), or any successor provisions, whether or not the Company continues to be subject to such provisions of the 1940 Act, but giving effect, in either case, to any exemptive relief granted to us by the U.S. Securities and Exchange Commission, and to provide financial information to the holders of the Notes and the Trustee if the Company should no longer be subject to the reporting requirements under the Securities Exchange Act of 1934. These covenants are subject to important limitations and exceptions that are described in the Indenture, as supplemented by the Sixth Supplemental Indenture. |
| Outstanding Security, Not Held [Shares] | shares | 80,000,000 |
