Document and Entity Information
| Document and Entity Information | Nov. 13, 2023 |
| Cover [Abstract] | |
| Amendment Flag | false |
| Entity Central Index Key | 0001544206 |
| Document Type | 8-K |
| Document Period End Date | Nov. 13, 2023 |
| Entity Registrant Name | Carlyle Secured Lending, Inc. |
| Entity Incorporation State Country Code | MD |
| Entity File Number | 814-00995 |
| Entity Tax Identification Number | 80-0789789 |
| Entity Address, Address Line One | One Vanderbilt Avenue |
| Entity Address, Address Line Two | Suite 3400 |
| Entity Address, City or Town | New York |
| Entity Address, State or Province | NY |
| Entity Address, Postal Zip Code | 10017 |
| City Area Code | (212) |
| Local Phone Number | 813-4900 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common stock, $0.01 per share |
| Trading Symbol | CGBD |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |