v3.25.2
Document And Entity Information
Jul. 22, 2025
Document Information [Line Items]  
Entity, Registrant Name MainStreet Bancshares, Inc.
Document, Type 8-K
Document, Period End Date Jul. 22, 2025
Entity, Incorporation, State or Country Code VA
Entity, File Number 001-38817
Entity, Tax Identification Number 81-2871064
Entity, Address, Address Line One 10089 Fairfax Boulevard
Entity, Address, City or Town Fairfax
Entity, Address, State or Province VA
Entity, Address, Postal Zip Code 22030
City Area Code 703
Local Phone Number 481-4567
Written Communications false
Soliciting Material false
Pre-commencement Tender Offer false
Pre-commencement Issuer Tender Offer false
Entity, Emerging Growth Company false
Amendment Flag false
Entity, Central Index Key 0001693577
CommonStock Custom [Member]  
Document Information [Line Items]  
Title of 12(b) Security Common Stock
Trading Symbol MNSB
Security Exchange Name NASDAQ
DepositarySharesEachRepresentingA140thInterestInAShareOf750SeriesAFixedrateNoncumulativePerpetualPreferredStock Custom [Member]  
Document Information [Line Items]  
Title of 12(b) Security Depositary Shares (each representing a 1/40th interest in a share of 7.50% Series A Fixed-Rate Non-Cumulative Perpetual Preferred Stock
Trading Symbol MNSBP
Security Exchange Name NASDAQ