| Document and Entity Information | Jun. 14, 2023 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Jun. 14, 2023 |
| Entity File Number | 814-00821 |
| Entity Registrant Name | FRANKLIN BSP LENDING CORPORATION |
| Entity Central Index Key | 0001490927 |
| Entity Incorporation, State or Country Code | MD |
| Entity Tax Identification Number | 27-2614444 |
| Entity Address, Address Line One | 9 West 57th Street, Suite 4920 |
| 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 | 588-6770 |
| Entity Emerging Growth Company | false |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
