Schedule H, Line 4i - Schedule of Assets (Held at End of Year) 2 (Details) - EBP 47-0914596 001 [Member]		12 Months Ended
Dec. 31, 2025 USD ($)	Dec. 31, 2025 USD ($)
*Common Stock of MainStreet Bancshares, Incorporated	$ 28,052,536	$ 28,052,536
Investment, Identifier [Axis]: CollectiveTrustFundsMember
*Common Stock of MainStreet Bancshares, Incorporated	$ 15,864,705	$ 15,864,705
Investment, Identifier [Axis]: EmployerSecurityCommonStockMember
EBP, Asset Held for Investment, Party-in-Interest [true false]	false	false
*Common Stock of MainStreet Bancshares, Incorporated	$ 7,836,449	$ 7,836,449
Investment, Identifier [Axis]: EmployerSecurityMember
*Common Stock of MainStreet Bancshares, Incorporated	$ 7,913,245	$ 7,913,245
Investment, Identifier [Axis]: EmployerSecurityPreferredStockMember
EBP, Asset Held for Investment, Party-in-Interest [true false]	true	true
*Common Stock of MainStreet Bancshares, Incorporated	$ 76,796	$ 76,796
Investment, Identifier [Axis]: MutualFundAmericanBalanceFundMember
*Common Stock of MainStreet Bancshares, Incorporated	411,234	411,234
Investment, Identifier [Axis]: MutualFundAmericanBeaconSmallCapValueFundMember
*Common Stock of MainStreet Bancshares, Incorporated	147,373	147,373
Investment, Identifier [Axis]: MutualFundAmericanCenturyMidCapValueFundMember
*Common Stock of MainStreet Bancshares, Incorporated	214,236	214,236
Investment, Identifier [Axis]: MutualFundAmericanCenturySmallCapValueFundMember
*Common Stock of MainStreet Bancshares, Incorporated	86,271	86,271
Investment, Identifier [Axis]: MutualFundAmericanFundsFundamentalInvestorsFundMember
*Common Stock of MainStreet Bancshares, Incorporated	90,860	90,860
Investment, Identifier [Axis]: MutualFundAmericanFundsMortgageFundMember
*Common Stock of MainStreet Bancshares, Incorporated	1,407	1,407
Investment, Identifier [Axis]: MutualFundAmericanMutualFundMember
*Common Stock of MainStreet Bancshares, Incorporated	62,685	62,685
Investment, Identifier [Axis]: MutualFundBlackRockGlobalAllocationFundMember
*Common Stock of MainStreet Bancshares, Incorporated	31,230	31,230
Investment, Identifier [Axis]: MutualFundCapitalWorldGrowthAndIncomeFundMember
*Common Stock of MainStreet Bancshares, Incorporated	98,147	98,147
Investment, Identifier [Axis]: MutualFundEUPACFundMember
*Common Stock of MainStreet Bancshares, Incorporated	206,818	206,818
Investment, Identifier [Axis]: MutualFundFidelity500IndexFundMember
*Common Stock of MainStreet Bancshares, Incorporated	162,831	162,831
Investment, Identifier [Axis]: MutualFundFidelityAdvisorsGrowthOpportunitiesFundMember
*Common Stock of MainStreet Bancshares, Incorporated	242,790	242,790
Investment, Identifier [Axis]: MutualFundFidelityInternationalIndexFundMember
*Common Stock of MainStreet Bancshares, Incorporated	14,578	14,578
Investment, Identifier [Axis]: MutualFundFidelityMidCapIndexFundMember
*Common Stock of MainStreet Bancshares, Incorporated	55,086	55,086
Investment, Identifier [Axis]: MutualFundFidelityUSBondIndexMember
*Common Stock of MainStreet Bancshares, Incorporated	12,887	12,887
Investment, Identifier [Axis]: MutualFundJPMorganLargeCapGrowthR7FundMember
*Common Stock of MainStreet Bancshares, Incorporated	782,754	782,754
Investment, Identifier [Axis]: MutualFundMember
*Common Stock of MainStreet Bancshares, Incorporated	3,660,340	3,660,340
Investment, Identifier [Axis]: MutualFundNewWorldFundIncMember
*Common Stock of MainStreet Bancshares, Incorporated	58,931	58,931
Investment, Identifier [Axis]: MutualFundNomuraDiversifiedIncomeFundMember
*Common Stock of MainStreet Bancshares, Incorporated	5,783	5,783
Investment, Identifier [Axis]: MutualFundPIMCODiversifiedIncomeInstitutionalFundMember
*Common Stock of MainStreet Bancshares, Incorporated	107,808	107,808
Investment, Identifier [Axis]: MutualFundPIMCOIncomeInstitutionalFundMember
*Common Stock of MainStreet Bancshares, Incorporated	25,087	25,087
Investment, Identifier [Axis]: MutualFundSmallcapWorldFundIncMember
*Common Stock of MainStreet Bancshares, Incorporated	117,249	117,249
Investment, Identifier [Axis]: MutualFundTheGrowthFundOfAmericaMember
*Common Stock of MainStreet Bancshares, Incorporated	411,298	411,298
Investment, Identifier [Axis]: MutualFundTheNewEconomyFundMember
*Common Stock of MainStreet Bancshares, Incorporated	121,280	121,280
Investment, Identifier [Axis]: MutualFundWashingtonMutualInvestorsFundMember
*Common Stock of MainStreet Bancshares, Incorporated	$ 191,717	$ 191,717
Investment, Identifier [Axis]: PSAPrincipalRealEstateSecuritiesSeparateAccountZMember
EBP, Asset Held for Investment, Party-in-Interest [true false]	true	true
*Common Stock of MainStreet Bancshares, Incorporated	$ 59,170	$ 59,170
Investment, Identifier [Axis]: PSAPrincipalSpectrumSecuritiesIncomeSeparateAccountZMember
EBP, Asset Held for Investment, Party-in-Interest [true false]	true	true
*Common Stock of MainStreet Bancshares, Incorporated	$ 42,591	$ 42,591
Investment, Identifier [Axis]: ParticipantLoansMember
EBP, Asset Held for Investment, Party-in-Interest [true false]	true	true
*Common Stock of MainStreet Bancshares, Incorporated	$ 378,555	$ 378,555
EBP, Asset Held for Investment, Participant Loan, Maturity Date		Dec. 31, 2051
Investment, Identifier [Axis]: ParticipantLoansMember \| Minimum [Member]
EBP, Asset Held for Investment, Participant Loan, Interest Rate	5.25%
Investment, Identifier [Axis]: ParticipantLoansMember \| Maximum [Member]
EBP, Asset Held for Investment, Participant Loan, Interest Rate	10.50%
Investment, Identifier [Axis]: PooledSeparateAccountsMember
*Common Stock of MainStreet Bancshares, Incorporated	$ 101,761	$ 101,761
Investment, Identifier [Axis]: PrincipalFixedIncomeGuaranteedOptionMember
EBP, Asset Held for Investment, Party-in-Interest [true false]	true	true
*Common Stock of MainStreet Bancshares, Incorporated	$ 133,930	$ 133,930
Investment, Identifier [Axis]: PrincipalLifeTimeHybrid2015CITZMember
EBP, Asset Held for Investment, Party-in-Interest [true false]	true	true
*Common Stock of MainStreet Bancshares, Incorporated	$ 793,289	$ 793,289
Investment, Identifier [Axis]: PrincipalLifeTimeHybrid2020CITZMember
EBP, Asset Held for Investment, Party-in-Interest [true false]	true	true
*Common Stock of MainStreet Bancshares, Incorporated	$ 854,055	$ 854,055
Investment, Identifier [Axis]: PrincipalLifeTimeHybrid2025CITZMember
EBP, Asset Held for Investment, Party-in-Interest [true false]	true	true
*Common Stock of MainStreet Bancshares, Incorporated	$ 1,399,875	$ 1,399,875
Investment, Identifier [Axis]: PrincipalLifeTimeHybrid2030CITZMember
EBP, Asset Held for Investment, Party-in-Interest [true false]	true	true
*Common Stock of MainStreet Bancshares, Incorporated	$ 2,809,099	$ 2,809,099
Investment, Identifier [Axis]: PrincipalLifeTimeHybrid2035CITZMember
EBP, Asset Held for Investment, Party-in-Interest [true false]	true	true
*Common Stock of MainStreet Bancshares, Incorporated	$ 2,170,557	$ 2,170,557
Investment, Identifier [Axis]: PrincipalLifeTimeHybrid2040CITZMember
EBP, Asset Held for Investment, Party-in-Interest [true false]	true	true
*Common Stock of MainStreet Bancshares, Incorporated	$ 1,803,956	$ 1,803,956
Investment, Identifier [Axis]: PrincipalLifeTimeHybrid2045CITZMember
EBP, Asset Held for Investment, Party-in-Interest [true false]	true	true
*Common Stock of MainStreet Bancshares, Incorporated	$ 2,380,955	$ 2,380,955
Investment, Identifier [Axis]: PrincipalLifeTimeHybrid2050CITZMember
EBP, Asset Held for Investment, Party-in-Interest [true false]	true	true
*Common Stock of MainStreet Bancshares, Incorporated	$ 1,679,236	$ 1,679,236
Investment, Identifier [Axis]: PrincipalLifeTimeHybrid2055CITZMember
EBP, Asset Held for Investment, Party-in-Interest [true false]	true	true
*Common Stock of MainStreet Bancshares, Incorporated	$ 1,065,624	$ 1,065,624
Investment, Identifier [Axis]: PrincipalLifeTimeHybrid2060CITZMember
EBP, Asset Held for Investment, Party-in-Interest [true false]	true	true
*Common Stock of MainStreet Bancshares, Incorporated	$ 461,239	$ 461,239
Investment, Identifier [Axis]: PrincipalLifeTimeHybrid2065CITZMember
EBP, Asset Held for Investment, Party-in-Interest [true false]	true	true
*Common Stock of MainStreet Bancshares, Incorporated	$ 130,428	$ 130,428
Investment, Identifier [Axis]: PrincipalLifeTimeHybrid2070CITZMember
EBP, Asset Held for Investment, Party-in-Interest [true false]	true	true
*Common Stock of MainStreet Bancshares, Incorporated	$ 7,818	$ 7,818
Investment, Identifier [Axis]: PrincipalLifeTimeHybridIncomeCITZMember
EBP, Asset Held for Investment, Party-in-Interest [true false]	true	true
*Common Stock of MainStreet Bancshares, Incorporated	$ 308,574	$ 308,574

Current value of investment, excluding plan interest in master trust, in schedule of asset held for investment of employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). Includes, but is not limited to, derivative, investment measured at net asset value per share as practical expedient, and insurance contract.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name Employee Retirement Income Security Act of 1974
-Number 2520
-Section 103
-Subsection 10
-Paragraph b
-Subparagraph (1)(i)(D)
-Publisher DOL-EBSA

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6A-05(a)(Schedule I))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477804/962-205-S99-1

+ Details

Name:	us-gaap-ebp_EmployeeBenefitPlanAssetHeldForInvestmentInvestmentExcludingPlanInterestInMasterTrustCurrentValue
Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Indicates (true false) whether asset held for investment of employee stock purchase, saving, or similar plan (employee benefit plan (EBP)) was transacted with party-in-interest.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6A-05(a)(Schedule I))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477804/962-205-S99-1

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Name Employee Retirement Income Security Act of 1974
-Number 2520
-Section 103
-Subsection 10
-Paragraph b
-Subparagraph (1)(i)(A)
-Publisher DOL-EBSA

+ Details

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Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:booleanItemType
Balance Type:	na
Period Type:	instant

- Definition

Interest rate on participant loan in schedule of asset held for investment of employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

+ References

+ Details

Name:	us-gaap-ebp_EmployeeBenefitPlanParticipantLoanInterestRate
Namespace Prefix:	us-gaap-ebp_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Maturity date of participant loan in schedule of asset held for investment of employee stock purchase, saving, or similar plan (employee benefit plan (EBP)), in YYYY-MM-DD format.

+ References

+ Details

Name:	us-gaap-ebp_EmployeeBenefitPlanParticipantLoanMaturityDate
Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration