| Document And Entity Information | Jan. 13, 2025 |
| Document Information [Line Items] | |
| Entity, Registrant Name | Magnolia Bancorp, Inc. |
| Document, Type | 8-K |
| Document, Period End Date | Jan. 13, 2025 |
| Entity, Incorporation, State or Country Code | LA |
| Entity, File Number | 333-281796 |
| Entity, Tax Identification Number | 99-2913448 |
| Entity, Address, Address Line One | 2900 Clearview Parkway |
| Entity, Address, City or Town | Metairie |
| Entity, Address, State or Province | LA |
| Entity, Address, Postal Zip Code | 70006 |
| City Area Code | 504 |
| Local Phone Number | 455-2444 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity, Emerging Growth Company | true |
| Entity, Ex Transition Period | false |
| Amendment Flag | false |
| Entity, Central Index Key | 0002033615 |
