| Cover | Dec. 18, 2023 |
| Document Information [Line Items] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Dec. 18, 2023 |
| Entity Registrant Name | Prospect Floating Rate and Alternative Income Fund, Inc. |
| Entity Tax Identification Number | 45-2460782 |
| Entity Address, City or Town | New York |
| Entity Address, State or Province | NY |
| Entity Address, Address Line Two | 42nd Floor |
| Entity Address, Postal Zip Code | 10016 |
| City Area Code | (212) |
| Local Phone Number | 448-0702 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Central Index Key | 0001521945 |
| Entity Incorporation, State or Country Code | MD |
| Securities Act File Number | 814-00908 |
| Entity Address, Address Line One | 10 East 40th Street |
| Entity Emerging Growth Company | false |
