Document And Entity Information
Note To Financial Statement Details Textual
Statistical Measurement [Axis]
Significant Accounting Policies
Note 2 - Investment Securities
Income Tax Expense
ecd_NonRule10b51ArrTrmntdFlag
Non-Rule 10b5-1 Arrangement Terminated [Flag]
Note 3 - Loans Receivable
ecd_NonRule10b51ArrAdoptedFlag
Non-Rule 10b5-1 Arrangement Adopted [Flag]
Note 4 - Derivatives and Risk Management Activities
Trading Arrangements, by Individual [Table]
Note 5 - Fair Value Presentation
Material Terms of Trading Arrangement [Text Block]
Note 6 - Earnings Per Common Share
Note 7 - Accumulated Other Comprehensive Loss
Taxable Municipal Bonds [Member]
Financial Instrument [Axis]
Nontaxable Municipal Bonds [Member]
Note 2 - Investment Securities - Schedule of Available-for-sale Investment Securities (Details)
Note 2 - Investment Securities - Schedule of Held-to-maturity Investment Securities (Details)
us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss
Gross unrealized losses, held-to-maturity
Gross unrealized gains, held-to-maturity
Note 2 - Investment Securities - Schedule of Held-to-maturity Investment Securities with Credit Rating (Details)
us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
Gross unrealized losses, available-for-sale
Note 2 - Investment Securities - Schedule of Maturities of Securities (Details)
Minimum [Member]
Gross unrealized gains, available-for-sale
Note 2 - Investment Securities - Summary of Unrealized Loss Positions (Details)
Note 3 - Loans Receivable - Schedule of Loans Receivable (Details)
Statistical Measurement [Domain]
Note 3 - Loans Receivable - Segments of the Loan Portfolio by Aging Categories (Details)
Maximum [Member]
Note 3 - Loans Receivable - Summary of Activity in Allowance for Loan Losses (Details)
Note 3 - Loans Receivable - Summary of Nonaccrual Loans (Details)
Note 3 - Loans Receivable - Accrued Interest Receivable Written Off of Loans (Details)
Note 3 - Loans Receivable - Schedule of Collateral Dependent Loans (Details)
Note 3 - Loans Receivable - Summary of Modified Financing Receivables (Details)
Note 3 - Loans Receivable - Summary of Credit Quality Indicators (Details)
Note 3 - Loans Receivable - Off-balance Sheet Credit Exposure (Details)
Note 4 - Derivatives and Risk Management Activities - Summary of Derivative Instruments (Details)
Note 5 - Fair Value Presentation - Fair Value Measured on a Recurring Basis (Details)
Note 5 - Fair Value Presentation - Schedule of Assets Measured on Recurring Basis, Unobservable Input Reconciliation (Details)
Recoveries
Note 5 - Fair Value Presentation - Summary of Assets and Liabilities Measured on Nonrecurring Basis (Details)
Note 5 - Fair Value Presentation - Valuation Techniques for Assets and Liabilities Measured on Nonrecurring Basis (Details)
Note 5 - Fair Value Presentation - Carrying Amounts and Fair Values of Financial Instruments (Details)
Note 6 - Earnings Per Common Share - Calculation of Basic and Diluted Earnings Per Common Share (Details)
Note 7 - Accumulated Other Comprehensive Loss - Components of Accumulated Other Comprehensive Income (Details)
Notes To Financial Statements
Notes To Financial Statements [Abstract]
us-gaap_DebtSecuritiesAvailableForSaleRestricted
Debt Securities, Available-for-Sale, Restricted
Debt Securities, Available-for-Sale [Table]
Salaries and employee benefits
Financial Instruments [Domain]
Dividends on common stock, per share (in dollars per share)
us-gaap_IncreaseDecreaseInAccruedInterestReceivableNet
Accrued interest receivable and other receivables
us-gaap_PreferredStockDividendRatePercentage
Preferred Stock, Dividend Rate, Percentage
us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsNumberOfPositions
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions
us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerNumberOfPositions
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions
Due in one year or less, held-to-maturity, amortized cost
Segment Reporting [Text Block]
Due from one to five years, held-to-maturity, amortized cost
Available-for-sale, more than 12 months, fair value
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer
Available-for-sale, less than 12 months, fair value
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months
Adjustments to reconcile net income to net cash provided by operating activities:
Preferred stock, $1.00 par value, 2,000,000 shares authorized; 28,750 shares issued and outstanding at June 30, 2026 and December 31, 2025
us-gaap_Liabilities
Total Liabilities
Liabilities
Due from after five to ten years, held-to-maturity, amortized cost
Due after ten years, held-to-maturity, amortized cost
us-gaap_LiabilitiesAndStockholdersEquity
Total Liabilities and Stockholders’ Equity
Segment Reporting [Table]
Credit Rating, Standard & Poor's [Axis]
Federal Home Loan Bank of Atlanta [Member]
us-gaap_ShareBasedCompensation
Stock-based compensation expense
Administrative expenses
Change in:
Preferred Stock, Shares Issued (in shares)
Preferred Stock, Shares Outstanding (in shares)
Preferred Stock, Shares Outstanding, Ending Balance (in shares)
Preferred Stock, Shares Authorized (in shares)
Preferred Stock, Shares Authorized (in shares)
Portion at Fair Value Measurement [Member]
Reported Value Measurement [Member]
Fair Value, by Balance Sheet Grouping [Table]
Preferred Stock, Par or Stated Value Per Share (in dollars per share)
Preferred Stock, Par or Stated Value Per Share (in dollars per share)
us-gaap_DerivativeExcludedComponentGainRecognizedInEarnings
Derivative, Excluded Component, Gain, Recognized in Earnings
us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect
Decrease in Cash and Cash Equivalents
Furniture and equipment expenses
Cash and cash equivalents
us-gaap_CashAndCashEquivalentsFairValueDisclosure
Estimate of Fair Value Measurement [Member]
New Accounting Pronouncements, Policy [Policy Text Block]
us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations
Cash and Cash Equivalents, beginning of period
Cash and Cash Equivalents, end of period
US Government Agencies Debt Securities [Member]
Statement [Table]
Classified [Member]
Represents classified.
Time deposits
Fair Value, off-Balance-Sheet Risk [Table]
us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss
Available-for-sale, unrealized loss
Loans, net
Consumer secured loans
Consumer secured loans
us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition
Available-for-sale, fair value
Preferred Stocks [Member]
Represents preferred stock.
Derivative liability – interest rate swaps on loans
Derivative liabilities
Bank owned life insurance
us-gaap_CashSurrenderValueFairValueDisclosure
Financing Receivable, Allowance for Credit Loss [Table Text Block]
us-gaap_DepositLiabilitiesReclassifiedAsLoansReceivable1
Deposit Liabilities Reclassified as Loans Receivable
Multifamily [Member]
Financing Receivable, Past Due [Table Text Block]
us-gaap_EquitySecuritiesFvNiRestricted
Equity Securities, FV-NI, Restricted
Federal Reserve Bank [Member]
Represents info pertaining to Federal Reserve Bank.
Community Bankers Bank Stock [Member]
Represents information pertaining to Community Bankers bank stock
Financing Receivable Credit Quality Indicators [Table Text Block]
Gain on equity securities
Financing Receivable, Modified [Table Text Block]
Single Family [Member]
Collateralized Mortgage Obligations [Member]
Interest and fees on loans
Gain (Loss) on Securities [Table Text Block]
Assets
Measurement Frequency [Axis]
Statement [Line Items]
Fair Value Hierarchy and NAV [Axis]
Common stock, shares issued (in shares)
Common stock, shares outstanding (in shares)
Common stock, shares authorized (in shares)
Common Stock, Shares Authorized (in shares)
Maturities, called, refunded
us-gaap_ProceedsFromSaleAndMaturityOfHeldToMaturitySecurities
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]
Common stock, $4.00 par value, 15,000,000 shares authorized; issued and outstanding 7,117,438 shares (including 259,985 nonvested shares) at June 30, 2026 and 7,496,571 shares (including 244,964 nonvested shares) at December 31, 2025
us-gaap_AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization
Investment Program, Proportional Amortization Method, Applied, Amortization Expense
mnsb_NumberOfBuildingsDesignatedAsHeldForSale
Number of Buildings Designated as Held for Sale
Represents the number of buildings designated as held for sale.
us-gaap_AmortizationMethodQualifiedAffordableHousingProjectInvestments
Investment, Proportional Amortization Method, Elected, Amount
mnsb_NumberOfBuildingsInOneComplex
Number of Buildings in One Complex
Represents the number of buildings contained in one complex.
us-gaap_MortgageLoansInProcessOfForeclosureAmount
Mortgage Loans in Process of Foreclosure, Amount
us-gaap_PolicyTextBlockAbstract
Accounting Policies
Property Held-for-Sale, Measurement Input
Value of input used to measure property held for sale.
us-gaap_DisclosureTextBlockAbstract
Notes to Financial Statements
us-gaap_TableTextBlock
Notes Tables
Comprehensive Income (Loss) Note [Text Block]
Federal funds sold
us-gaap_ComprehensiveIncomeNetOfTax
Comprehensive Income
Maturities, sales, called, refunded
Amortization of right-of-use assets
Deposits
us-gaap_DepositsFairValueDisclosure
Property held for sale, at fair value
Asset, Held-for-Sale, Not Part of Disposal Group
us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue
December 31, 2025 fair value
June 30, 2026 fair value
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]
Proceeds from sale of loans
Amortized cost, available-for-sale
Total, available-for-sale, amortized cost
Subordinated debt, net
us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisSubordinatedDebtObligations
Proceeds from sale of premises and equipment
Investment securities held-to-maturity (HTM), at amortized cost, net of allowance for credit losses of $0 and $0, respectively
Criticized [Member]
Redemption of restricted investment in bank stock
Other comprehensive income (loss), net of tax expense (benefit):
Statement of Stockholders' Equity [Abstract]
Proceeds from sale of other real estate owned
Statement of Comprehensive Income [Abstract]
Loan Restructuring Modification [Axis]
Collateral pledges
us-gaap_DerivativeAssetFairValueOfCollateral
Loan Restructuring Modification [Domain]
Interest Rate Below Market Reduction [Member]
Statement of Cash Flows [Abstract]
Financing Receivable Portfolio Segment [Axis]
Financial Asset, Equal to or Greater than 30 Days Past Due [Member]
Financial asset equal to or greater than 30 days past due.
Other comprehensive income
Financing Receivable, Accrued Interest, Writeoff [Table Text Block]
Tabular disclosure of writeoff of accrued interest on financing receivable recognized by reversing interest income.
Stockholders’ Equity
Equity Components [Axis]
Nonaccrual, with allowance
Amortized cost of financing receivable on nonaccrual status with allowance for credit loss. Excludes net investment in lease.
Financing Receivable Portfolio Segment [Domain]
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis, Valuation Techniques [Table Text Block]
Equity Component [Domain]
Fair Value Measurements, Nonrecurring [Table Text Block]
Fair Value, Inputs, Level 2 [Member]
Fair Value, Inputs, Level 3 [Member]
AOCI Attributable to Parent [Member]
Fair Value, Inputs, Level 1 [Member]
Additional Paid-in Capital [Member]
Retained Earnings [Member]
Extended Maturity on Interest Only Payments [Member]
Represents extended maturity on interest only payments.
Collateral pledges
Subordinated Debt [Member]
Financial Asset, Aging [Axis]
Premises and equipment, net
Subordinated debt, net
Property held for sale
Financing Receivable, Nonaccrual [Table Text Block]
Financial Asset, Aging [Domain]
Provision For Credit Losses - Loans
Provision for credit losses, net
Financial Asset, 30 to 59 Days Past Due [Member]
Franchise tax
Franchise tax expense.
Stock-based compensation expense
mnsb_PolicyTable
Financial Asset, 60 to 89 Days Past Due [Member]
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Fair Value Disclosures [Text Block]
Fair Value, by Balance Sheet Grouping [Table Text Block]
Supplementary Disclosure of Cash Flow Information
Held-to-maturity, Amortized cost
Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss
Total, held-to-maturity, amortized cost
us-gaap_PaymentsToAcquireEquitySecuritiesFvNi
Purchases of equity securities
Allowance for Credit Losses [Text Block]
Collateral Held [Domain]
Collateral Held [Axis]
us-gaap_PaymentsToAcquireHeldToMaturitySecurities
Purchases
us-gaap_GainLossOnSaleOfPropertyPlantEquipment
Loss on disposal of premises and equipment
Total accumulated other comprehensive loss
Accumulated other comprehensive loss
us-gaap_FinancingReceivableDeferredIncome
Less: Unearned Fees, net
us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest
Income Before Income Taxes
Data processing
Organization, Consolidation and Presentation of Financial Statements Disclosure and Significant Accounting Policies [Text Block]
Gain on retirement of subordinated debt
Gain on retirement of subordinated debt
us-gaap_FinancingReceivableBeforeAllowanceForCreditLossAndFee
Total Gross Loans
Capital surplus
Use of Estimates, Policy [Policy Text Block]
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]
us-gaap_PaymentsToAcquirePropertyPlantAndEquipment
Purchase of premises and equipment, including property held for sale
Collateral Pledged [Member]
Collateralized Mortgage-Backed Securities [Member]
Debt Securities, Available-for-Sale, Unrealized Loss Position, Fair Value [Table]
us-gaap_NoninterestExpense
Total Non-Interest Expense
Non-Interest Expense
Amortized cost basis
Subordinated debt amortization expense
us-gaap_PaymentsToAcquireRestrictedInvestments
Purchases of restricted investment in bank stock
Financial Asset, Not Past Due [Member]
Vesting of restricted stock, net of stock surrendered
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Table Text Block]
Fair Value, Recurring and Nonrecurring [Table]
Allowance for credit losses on off-balance sheet credit exposure
Off-Balance-Sheet, Credit Loss, Liability
Balance
Balance
Tax effect
Unrealized loss on investment securities available-for-sale
Fair Value Measurement Inputs and Valuation Techniques [Table]
Class of Stock [Domain]
Real Estate Disclosure [Text Block]
Cash Flows from Operating Activities
Cash Flows from Investing Activities
us-gaap_NetCashProvidedByUsedInOperatingActivities
Net cash provided by operating activities
Cash Flows from Financing Activities
us-gaap_NetCashProvidedByUsedInInvestingActivities
Net cash (used in) provided by investing activities
Financing Receivable, Year One
us-gaap_NetCashProvidedByUsedInFinancingActivities
Net cash provided by (used in) financing activities
us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt
Purchases, available-for-sale securities
Payments, available-for-sale securities
us-gaap_LiabilitiesFairValueDisclosure
Total
Assets, fair value
Total
Financing Receivable, Revolving
Net increase (decrease) in interest-bearing demand, savings, NOW, money market and time deposits
Accounting Policies [Abstract]
Segments [Domain]
Allowance for credit losses
Debt Securities, Held-to-Maturity, Allowance for Credit Loss
Segments [Axis]
US States and Political Subdivisions Debt Securities [Member]
us-gaap_StockRepurchasedDuringPeriodValue
Common stock repurchased
Net (decrease) increase in non-interest bearing demand deposits
Measurement Input Type [Axis]
Income Statement [Abstract]
Provision for off-balance sheet credit losses, net
Measurement Input, Cost to Sell [Member]
us-gaap_NumberOfReportableSegments
Number of Reportable Segments
Deferred income tax expense (benefit)
Measurement Input, Discount Rate [Member]
Net income
Net income
Net Income
Net Income Available to Common Shareholders
Net income available to common shareholders
Financial Asset, Past Due [Member]
Real Estate [Table]
Consumer Loans [Member]
Information on consumer loans.
Measurement Input Type [Domain]
us-gaap_InterestIncomeExpenseNet
Net Interest Income
Accumulated Other Comprehensive Income (Loss) [Table]
us-gaap_DebtSecuritiesHeldToMaturityNonaccrual
Debt Securities, Held-to-Maturity, Nonaccrual
Depositary Shares [Member]
Represents depositary shares.
Other Real Estate Owned, Measurement Input
Accrued interest and other receivables
Amount of interest and other receivables.
Common stock, shares nonvested (in shares)
The number of nonvested shares of common stock.
Savings and NOW deposits
Amount of interest bearing deposits with no stated maturity, which may include passbook and statement savings accounts and money-market deposit accounts (MMDAs) and Amount of deposits in interest-bearing transaction accounts at banks or savings and loans, that are restricted in regard to ownership and can usually only be held by individuals, nonprofit entities and governments. Negotiable order of withdrawal accounts differ from money market demand accounts as they typically have higher reserve requirements and no limit on the number of checks that can be written.
Nonaccrual, no allowance
Occupancy expenses
Other operating expenses
FDIC insurance
Outside services
Amount of noninterest expense for outside services.
Interest on savings and NOW deposits
Interest expense incurred on all NOW and savings deposits.
Bank owned life insurance income
Income from bank owned life insurance
us-gaap_NoninterestIncome
Total Non-Interest Income
Non-Interest Income
us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLoss
Debt Securities, Available-for-Sale, Allowance for Credit Loss
Measurement Basis [Axis]
Loss on sale of other real estate owned
Loss on sale of other real estate owned
Financing Receivable, Collateral Dependent Loans [Table Text Block]
Tabular disclosure of collateral dependent loans.
Other non-interest income
mnsb_FinancingReceivableAccruedInterestRecovery
Financing Receivable, Accrued Interest, Recovery
Amount of recovery of accrued interest on financing receivable recognized by reversing interest income.
Fair Value Hierarchy and NAV [Domain]
Off-Balance-Sheet Credit Exposure [Table Text Block]
Tabular disclosure of activity in the allowance for credit losses for off-balance sheet credit exposure.
Transfers from loans to other real estate owned
Measurement Frequency [Domain]
Statement of Financial Position [Abstract]
Unsecured [Member]
Information pertaining to unsecured consumer loans.
us-gaap_RepaymentsOfSubordinatedDebt
Net decrease in subordinated debt
Change in fair value (1)
Cash paid during the period for income taxes
Series A Fixed-rate Non-cumulative Perpetual Preferred Stock [Member]
Represents Series A Fixed-Rate Non-Cumulative Perpetual Preferred Stock.
mnsb_DepositarySharesFractionalInterestInPreferredStockDenominator
Depositary Shares, Fractional Interest in Preferred Stock, Denominator
The denominator of the fractional interest in preferred stock for depositary shares.
us-gaap_DividendsCommonStock
Dividends on common stock
us-gaap_DividendsPreferredStock
Dividends on preferred stock
Advertising and marketing
Unsecured, Non Real Estate [Member]
Represents unsecured non real estate.
Commercial and Industrial [Member]
Represents commercial and industrial.
Other real estate owned expenses
Other assets
Fair Value, Nonrecurring [Member]
Construction and Land Development [Member]
Represents construction and land development.
Fair Value, Recurring [Member]
us-gaap_PaymentsForRepurchaseOfCommonStock
Repurchases of common stock
us-gaap_IncreaseDecreaseInOtherOperatingAssets
Other assets
Document Type
Non-owner Occupied [Member]
Represents non-owner occupied.
Financing Receivable, Year Two
Financing Receivable, Year Three
Document Information [Line Items]
Document Quarterly Report
Document Information [Table]
Farmland [Member]
Represents farmland.
Owner-occupied [Member]
Represents owner-occupied.
us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment
Weighted Average Number of Shares Outstanding, Diluted, Adjustment (in shares)
Entity Interactive Data Current
Bank owned life insurance
Financing Receivable Prior
Document Transition Report
Financing Receivable, Year Four
Financing Receivable, Year Five
Earnings per common share:
Weighted average number of common shares issued, basic and diluted (in shares)
us-gaap_WeightedAverageNumberOfSharesOutstandingBasic
Loans, net of allowance for credit losses of $19,306 and $19,308, respectively
Net Loans
Derivative Instrument [Axis]
Basic and diluted earnings per common share (in dollars per share)
Basic (in dollars per share)
Earnings Per Share, Basic, by Common Class, Including Two-Class Method [Table]
Interest-bearing demand deposits
Debt Securities, Available-for-Sale [Table Text Block]
Collaborative Arrangement and Arrangement Other than Collaborative [Table]
us-gaap_Deposits
Total deposits
Matched Interest Rate Swap With Counterparty [Member]
Represents the matched interest rate swap with counterparty.
Money market deposits
Non-interest bearing demand deposits
Matched Interest Rate Swap with Borrower [Member]
Represents the matched interest rate swap with borrower.
Depreciation, amortization, and accretion, net
Document Fiscal Period Focus
Document Fiscal Year Focus
Accrued interest receivable
mnsb_AccruedInterestReceivableFairValueDisclosure
Fair value portion of accrued interest receivable.
Amendment Flag
Accrued interest payable
mnsb_InterestPayableFairValueDisclosure
Fair value portion of interest payable.
Common Stock [Member]
Financing Receivable, Past Due [Table]
us-gaap_IncreaseDecreaseInOtherOperatingLiabilities
Other liabilities
Document Period End Date
Restricted securities
Restricted securities, at amortized cost
Building [Member]
Legal Entity [Axis]
Residential Portfolio Segment [Member]
us-gaap_InterestAndDividendIncomeOperating
Total Interest Income
Consumer Portfolio Segment [Member]
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Table]
Commercial Portfolio Segment [Member]
Entity File Number
Net unrealized gain on securities available-for-sale
Entity Tax Identification Number
Supplemental Noncash Disclosures
us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss
Available-for-sale, less than 12 months, unrealized loss
Entity [Domain]
us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss
Available-for-sale, more than 12 months, unrealized loss
Entity Central Index Key
Allowance for credit loss
Less: Allowance for Credit Losses - Loans
Beginning Balance
Ending Balance
Entity Registrant Name
Current period gross write-offs, total
Charge-offs
Entity Current Reporting Status
Entity Incorporation, State or Country Code
Pass [Member]
Current Fiscal Year End Date
mnsb_AmortizationMethodQualifiedNewMarketTaxCreditInvestments
Amortization Method Qualified New Market Tax Credit Investments
The amount of investment related to new market tax credits using proportional amortization method.
Entity Filer Category
Dividends on preferred stock, per share (in dollars per share)
Entity Shell Company
Entity Emerging Growth Company
Notional amount
Entity Small Business
Positions
Valuation Approach and Technique [Axis]
Core Banking Segment [Member]
Represents core banking.
Derivative asset – interest rate swap on loans
Derivative assets
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]
Preferred Stock Dividends
Preferred stock dividends
Interest Expense
Interest-bearing deposits at other financial institutions
Derivative Instruments and Hedging Activities Disclosure [Text Block]
Valuation Approach and Technique [Domain]
Valuation, Market Approach [Member]
Held-to-maturity
mnsb_HeldtomaturitySecuritiesFairValueDisclosure
Fair value of investment in debt security measured at amortized cost (held-to-maturity).
Secured [Member]
Represents secured.
Entity Address, State or Province
Entity Address, City or Town
Interest on time deposits
Retained earnings
us-gaap_InterestExpenseOperating
Total Interest Expense
Entity Address, Address Line One
City Area Code
Due from one to five years, available-for-sale, amortized cost
us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation
Repurchase of common stock for tax withholding on stock-based compensation
Due from after five to ten years, available-for-sale, amortized cost
Local Phone Number
Due in one year or less, available-for-sale, amortized cost
Consumer secured loans, measurement input
Measurement input for loans receivable.
Entity Address, Postal Zip Code
Interest on money market deposits
Derivative [Table]
Interest on interest-bearing demand deposits
Preferred Stock [Member]
Title of 12(b) Security
Security Exchange Name
Due from after five to ten years, available-for-sale, fair value
Trading Symbol
Due after ten years, available-for-sale, fair value
Due in one year or less, available-for-sale, fair value
Due from one to five years, available-for-sale, fair value
Due after ten years, available-for-sale, amortized cost
Class of Stock [Axis]
Other real estate owned
The fair value portion of other real estate owned.
Available-for-sale
Investment securities available-for-sale (AFS), at fair value
Fair value, available-for-sale
Total, available-for-sale, fair value
mnsb_NetIncreaseDecreaseInLoanPortfolio
Net change in loan portfolio
The net amount of (increase) decrease in loan portfolio.
Class of Financing Receivable [Axis]
Interest on federal funds purchased
Class of Financing Receivable [Domain]
Entity Common Stock, Shares Outstanding
Earnings Per Share [Text Block]
Low Income Housing Tax Credits [Member]
Represents information pertaining to low income housing tax credits.
mnsb_NonmarketableEquitySecurities
Non-Marketable Equity Securities
Nonmarketable equity securities.
Unrealized losses on available for sale securities arising during the period, tax benefit
Financing Receivable, Credit Quality Indicator [Table]
Nonaccrual
Unrealized gain (loss) on available for sale securities arising during the period (net of tax expense (benefit), $122 and ($27), respectively, for the three months ended June 30, and $75 and $74, respectively for the six months ended June 30).
Internal Credit Assessment [Axis]
Debt Securities, Held-to-Maturity [Table]
Debt Securities, Held-to-Maturity [Table Text Block]
us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss
Net Interest Income After Provision For Credit Losses
Fair value, held-to-maturity
Total, held-to-maturity, fair value
Interest on subordinated debt
Long-Lived Assets Held-for-Sale, Name [Domain]
Investments Classified by Contractual Maturity Date [Table Text Block]
Interest on interest-bearing deposits at other financial institutions
Interest on federal funds sold
Internal Credit Assessment [Domain]
Due from after five to ten years, held-to-maturity, fair value
Common stock, par value (in dollars per share)
Common Stock, Par or Stated Value Per Share (in dollars per share)
Due after ten years, held-to-maturity, fair value
Taxable securities
Due in one year or less, held-to-maturity, fair value
Due from one to five years, held-to-maturity, fair value
Other liabilities
Basis of Accounting, Policy [Policy Text Block]
Tax-exempt securities
Derivative Contract [Domain]
Cash and due from banks
us-gaap_CashCashEquivalentsAndFederalFundsSold
Cash and cash equivalents
us-gaap_Assets
Total Assets
Financing Receivable, Nonaccrual [Table]
Other
Long-Lived Asset, Held-for-Sale, Type [Axis]
Mortgage-backed securities
U.S. government agencies
us-gaap_FinancingReceivableExcludingAccruedInterestModifiedPeriod
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount
% of Total Loan Type
Collateral dependent loans
Total Gross Loans
Diluted (in dollars per share)
Investment [Text Block]
us-gaap_FinancingReceivableExcludingAccruedInterestModifiedSubsequentDefault
Financing Receivable, Excluding Accrued Interest, Modified, Subsequent Default
Debt Securities, Trading, and Equity Securities, FV-NI [Table]
Interest and dividends on investment securities
Other real estate owned, net
Current period gross write-offs, year two
Current period gross write-offs, year three
Current period gross write-offs, current
Current period gross write-offs, year one
Construction [Member]
Schedule of Derivative Instruments [Table Text Block]
External Credit Rating, Standard & Poor's [Domain]
Standard & Poor's, AAA Rating [Member]
Term increase (Month)
Accounts and Financing Receivables [Table]
Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block]
Current period gross write-offs, revolving
mnsb_FinancingReceivableAccruedInterestWriteoffNetOfRecoveries
Financing Receivable, Accrued Interest Writeoff, Net of Recoveries
Represents the amount of accrued interest write off net of recoveries on financing receivables during the period.
Current period gross write-offs, revolving converted to term
Consolidation, Policy [Policy Text Block]
Current period gross write-offs, year four
Current period gross write-offs, prior
mnsb_NumberOfMortgageLoansInProcessOfForeclosure
Number of Mortgage Loans in Process of Foreclosure
Represents number of consumer mortgage loan receivables secured by residential real estate properties for which formal foreclosure proceedings are in process.
Cash paid during the period for interest
Interest Rate Swap [Member]
mnsb_AmortizationMethodQualifiedNewMarketTaxCreditInvestmentsAmortization
Amortization Method Qualified New Market Tax Credit Investments Amortization
The amount of amortization related to the new market tax credit investments.
Extended Maturity and Interest Rate Reduction [Member]
us-gaap_StockholdersEquity
Total Stockholders’ Equity
Balance
Balance
Municipal Bonds [Member]
us-gaap_PaymentsOfDividendsCommonStock
Cash dividends paid on common stock
Accrued Interest, Writeoff
us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock
Cash dividends paid on preferred stock
ecd_Rule10b51ArrTrmntdFlag
Rule 10b5-1 Arrangement Terminated [Flag]
Deposit account service charges
ecd_Rule10b51ArrAdoptedFlag
Rule 10b5-1 Arrangement Adopted [Flag]
Financing Receivable, revolving converted to term