| Document and Entity Information | Jun. 11, 2024 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Jun. 11, 2024 |
| Entity File Number | 001-37747 |
| Entity Registrant Name | MEDALLION FINANCIAL CORP. |
| Entity Central Index Key | 0001000209 |
| Entity Incorporation, State or Country Code | DE |
| Entity Tax Identification Number | 04-3291176 |
| Entity Address, Address Line One | 437 Madison Avenue |
| Entity Address, Address Line Two | 38th Floor |
| Entity Address, City or Town | New York |
| Entity Address, State or Province | NY |
| Entity Address, Postal Zip Code | 10022 |
| City Area Code | 212 |
| Local Phone Number | 328-2100 |
| Title of 12(b) Security | Common Stock, par value $0.01 per share |
| Trading Symbol | MFIN |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
