Document And Entity Information
Due after ten years, fair value
Note To Financial Statement Details Textual
Significant Accounting Policies
Note 1 - Summary of Significant Accounting Policies
Due in one year or less, amortized cost
Note 2 - Business Combinations
Note 3 - Accumulated Other Comprehensive Loss
Due in one year or less, fair value
Note 4 - Securities
Due after one year through five years, fair value
Note 5 - Loans and Other Real Estate Owned ("OREO")
Due after five years through ten years, fair value
Note 6 - Allowance for Credit Losses
Note 7 - Premises and Equipment
Note 8 - Deposits
Note 9 - Borrowings and Subordinated Debt
Mortgage-Backed Security, Issued by US Government-Sponsored Enterprise [Member]
us-gaap_AvailableforsaleSecuritiesSoldAtPar
Debt Securities, Available-for-Sale, Sold at Par Value
Note 10 - Securities Sold Under Agreements to Repurchase
Unrealized holding gains (losses) on debt securities available-for-sale, net of income taxes of $871 and ($175), respectively
Note 11 - Benefits Plans
Note 12 - Income Taxes
Note 13 - Operating Lease Commitments and Contingencies
us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax
Reclassification adjustment for losses on available-for- sale securities included in net income, net of income taxes of $2 and $-0-, respectively
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax
Note 14 - Regulatory Matters
Note 15 - Commitments and Standby Letters of Credit
Note 16 - Parent Company Statements
Note 17 - Fair Value Measurements
Note 1 - Summary of Significant Accounting Policies - Core Deposit Intangible - Schedule of Finite-Lived Intangible Assets, Future Amortization Expense (Details)
Note 2 - Business Combinations - Schedule of Recognized Identified Assets Acquired and Liabilities Assumed (Details)
Note 2 - Business Combinations - Schedule of Loans (Details)
Note 2 - Business Combinations - Acquisition Accounting Adjustments (Details)
Note 3 - Accumulated Other Comprehensive Loss - Schedule of Accumulated Other Comprehensive Income (Loss) (Details)
Note 3 - Accumulated Other Comprehensive Loss - Schedule of Accumulated Other Comprehensive Income (Loss) (Details) (Parentheticals)
Automobile Loan [Member]
Note 4 - Securities - Amortized Cost and Fair Value of Available for Sale Securities (Details)
Note 4 - Securities - Contractual Maturities (Details)
Note 4 - Securities - Continuous Unrealized Loss Position (Details)
Note 4 - Securities - Summary of Gains and Losses (Details)
Note 5 - Loans and Other Real Estate Owned ("OREO") - Categories of Loans (Details)
Note 5 - Loans - Summary of Loan Activity for Related Parties (Details)
Debt securities available-for-sale, continuous loss position, more than 12 months, unrealized losses
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss
Note 5 - Loans and Other Real Estate Owned ("OREO") - Reconciliation of Purchase Price to Par Value (Details)
Note 5 - Loans and Other Real Estate Owned ("OREO") - Loans Acquired in Business Combinations (Details)
Debt securities available-for-sale, continuous loss position, unrealized losses
Note 6 - Allowance for Credit Losses - Credit Rating (Details)
US Treasury Securities [Member]
Note 6 - Allowance for Credit Losses - Past Due (Details)
Note 6 - Allowance for Credit Losses - Nonaccrual (Details)
Note 6 - Allowance for Credit Losses - Activity in Allowance for Credit Losses (Details)
Note 6 - Allowance for Credit Losses - Collateral Dependent Loans (Details)
Debt securities available-for-sale, continuous loss position, less than 12 months, unrealized losses
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss
Note 6 - Allowance for Credit Losses - Summary of Modified Loans (Details)
Note 6 - Allowance for Credit Losses - Allowance for Unfunded Commitments (Details)
Note 7 - Premises and Equipment - Classifications of Premises and Equipment (Details)
US Government Agencies Debt Securities [Member]
Note 8 - Deposits - Maturity of Time Deposits (Details)
US Government-sponsored Enterprises Debt Securities [Member]
Corporate Debt Securities [Member]
Note 9 - Borrowings and Subordinated Debt - Federal Home Loan Bank Advances (Details)
Note 10 - Securities Sold Under Agreements to Repurchase - Liabilities (Details)
Note 11 - Benefits Plans - Schedule of Employee Stock Ownership Plan (Details)
Note 12 - Income Taxes - Provision for Income Taxes (Details)
Note 12 - Income Taxes - Deferred Tax Assets and Liabilities (Details)
Other Comprehensive Income
Note 12 - Income Taxes - Reconciliation of Income Tax Rate (Details)
Note 13 - Operating Lease Commitments and Contingencies - Lease Costs (Details)
Note 13 - Operating Lease Commitments and Contingencies - Schedule of Future Lease Payments (Details)
Note 14 - Regulatory Matters - Capital Amounts and Ratios (Details)
Note 15 - Commitments and Standby Letters of Credit - Financial Instruments With Credit Risk (Details)
us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsNumberOfPositions
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions
Note 16 - Parent Company Statements - Condensed Balance Sheets (Details)
us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerNumberOfPositions
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions
Note 16 - Parent Company Statements - Condensed Income Statements (Details)
Note 16 - Parent Company Statements - Condensed Statements of Cash Flows (Details)
Note 17 - Fair Value Measurements - Fair Value on a Recurring Basis (Details)
Debt securities available-for-sale, continuous loss position, fair value
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax
Note 17 - Fair Value Measurements - Assets Measured on a Nonrecurring Basis (Details)
Note 17 - Fair Value Measurements - Quantitative Information (Details)
us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
Total Stockholders’ Equity Less Maximum Cash Obligations Related to ESOP Shares
Balance
Balance
Note 17 - Fair Value Measurements - Estimated Fair Values of Financial Instruments (Details)
Notes To Financial Statements
Notes To Financial Statements [Abstract]
Debt securities available-for-sale, continuous loss position, less than 12 months, fair value
Debt securities available-for-sale, continuous loss position, more than 12 months, fair value
Financial Instruments [Domain]
us-gaap_LoansAndLeasesReceivableRelatedPartiesProceeds
Repayments
Financial Instrument [Axis]
New loans
us-gaap_LoansAndLeasesReceivableImpairedCommitmentToLend
Financing Receivable, Modified, Commitment to Lend
Lessee, Operating Leases [Text Block]
us-gaap_PolicyTextBlockAbstract
Accounting Policies
Debt Securities, Available-for-Sale [Table]
Allowance for Credit Losses [Text Block]
Liabilities [Abstract]
Total Assets
us-gaap_Assets
Total Assets
Net deferred tax asset
Other assets
Other Assets
Restricted investments in bank stock, at cost
Restricted Investments
Business Description and Accounting Policies [Text Block]
us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization
Finite-Lived Intangible Assets, Accumulated Amortization
Core deposit intangible, net
Finite-Lived Intangible Assets, Net
Total
Financial Standby Letter of Credit [Member]
Commitments and Contingencies Disclosure [Text Block]
us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment
Less accumulated depreciation
Premises and equipment, net
Net
Premises and equipment, gross
Gross Amounts of Recognized Liabilities
Federal Reserve Bank Advances [Member]
Investment in subsidiary
us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures
Equity in undistributed earnings of subsidiary
us-gaap_IncomeLossFromEquityMethodInvestments
Equity in undistributed earnings of subsidiaries
Income tax (benefit)
Income Taxes
Total Provision
Short-Term Debt, Type [Axis]
Short-Term Debt, Type [Domain]
us-gaap_MortgageLoansInProcessOfForeclosureAmount
Mortgage Loans in Process of Foreclosure, Amount
Gain (Loss) on Securities [Table Text Block]
Operating expenses
us-gaap_OperatingExpenses
us-gaap_DefinedContributionPlanCostRecognized
Defined Contribution Plan, Cost
Pennsylvania shares tax
us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay
Interest-bearing demand deposits
Cash and cash equivalents
us-gaap_CashAndCashEquivalentsAtCarryingValue
Salaries and employee benefits
Cash and due from banks
Amendment Flag
City Area Code
Use of Estimates, Policy [Policy Text Block]
Other Restricted Stock [Member]
Related to other restricted stock.
New Accounting Pronouncements, Policy [Policy Text Block]
us-gaap_GainLossOnSaleOfPropertyPlantEquipment
(Gain) loss on disposition of premises and equipment
Gain on sale of other real estate owned
us-gaap_GainLossOnSalesOfLoansNet
Gain on sale of loans
Current Fiscal Year End Date
us-gaap_DebtSecuritiesAvailableForSaleRealizedGainLoss
Debt Securities, Available-for-Sale, Realized Gain (Loss)
Accrued interest receivable
Interest Receivable
Document Fiscal Period Focus
Loss on sale of securities
Realized loss on sale of securities
Document Fiscal Year Focus
Consolidation, Policy [Policy Text Block]
Add: Net realized gain (loss) recognized on marketable equity securities sold during the period
us-gaap_EquitySecuritiesFvNiRealizedGainLoss
Document Period End Date
Entity File Number
Entity Emerging Growth Company
us-gaap_TierOneLeverageCapitalRequiredToBeWellCapitalizedToAverageAssets
Banking Regulation, Tier 1 Leverage Capital Ratio, Well Capitalized, Minimum
Document Type
us-gaap_CapitalRequiredToBeWellCapitalizedToRiskWeightedAssets
Banking Regulation, Total Risk-Based Capital Ratio, Well Capitalized, Minimum
Entity Small Business
Entity Shell Company
Document Information [Line Items]
Document Information [Table]
Entity Public Float
Entity Filer Category
Entity Current Reporting Status
Entity Voluntary Filers
us-gaap_TierOneRiskBasedCapitalRequiredToBeWellCapitalizedToRiskWeightedAssets
Banking Regulation, Tier 1 Risk-Based Capital Ratio, Well Capitalized, Minimum
Merger-related expenses
Entity Well-known Seasoned Issuer
Tier 1 (Core) Capital to average total assets Bank, actual amount
Tier 1 (Core) Capital to average total assets Bank, to be well capitalized amount
Bank owned life insurance
Award Timing MNPI Disclosure [Text Block]
us-gaap_ConcentrationRiskPercentage1
Concentration Risk, Percentage
Statement of Comprehensive Income [Abstract]
ecd_AwardTmgMnpiCnsdrdFlag
Award Timing MNPI Considered [Flag]
Entity Tax Identification Number
Entity Central Index Key
Insider Trading Policies and Procedures [Line Items]
Entity Registrant Name
ecd_InsiderTrdPoliciesProcAdoptedFlag
Insider Trading Policies and Procedures Adopted [Flag]
Entity [Domain]
Customer Concentration Risk [Member]
Legal Entity [Axis]
Entity Address, Address Line One
us-gaap_FinancingReceivableAllowanceForCreditLosses
Financing Receivable, Allowance for Credit Loss
ecd_NonRule10b51ArrTrmntdFlag
Non-Rule 10b5-1 Arrangement Terminated [Flag]
Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table Text Block]
Amortization of core deposit intangible
Entity Address, City or Town
ecd_Rule10b51ArrTrmntdFlag
Rule 10b5-1 Arrangement Terminated [Flag]
ecd_Rule10b51ArrAdoptedFlag
Rule 10b5-1 Arrangement Adopted [Flag]
Entity Address, Postal Zip Code
us-gaap_OtherRealEstate
Other Real Estate
Regulatory Capital Requirements under Banking Regulations [Text Block]
Entity Address, State or Province
Concentration Risk Type [Axis]
ecd_NonRule10b51ArrAdoptedFlag
Non-Rule 10b5-1 Arrangement Adopted [Flag]
Concentration Risk Type [Domain]
Material Terms of Trading Arrangement [Text Block]
us-gaap_ForeclosedAssets
Repossessed Assets
Entity Common Stock, Shares Outstanding
Trading Arrangements, by Individual [Table]
Taxable Municipal Notes [Member]
Nontaxable Municipal Notes [Member]
Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]
Advertising expense
Advertising Expense
us-gaap_CashSurrenderValueOfLifeInsurance
Cash Surrender Value of Life Insurance
Professional fees
Investments [Domain]
Concentration Risk Benchmark [Axis]
Concentration Risk Benchmark [Domain]
Data processing fees
Investment Type [Axis]
Net occupancy and equipment expense
Local Phone Number
Gain on sale of premises
us-gaap_TableTextBlock
Notes Tables
us-gaap_FederalHomeLoanBankAdvancesMaturitiesSummaryAverageInterestRateThreeToFourYearsFromBalanceSheetDate
Year four, weighted average rate
us-gaap_FederalHomeLoanBankAdvancesMaturitiesSummaryAverageInterestRateOfAmountsDueWithinOneYearOfBalanceSheetDate
Year one, weighted average rate
us-gaap_FederalHomeLoanBankAdvancesMaturitiesSummaryAverageInterestRateOneToTwoYearsFromBalanceSheetDate
Year two, weighted average rate
us-gaap_FederalHomeLoanBankAdvancesMaturitiesSummaryAverageInterestRateTwoToThreeYearsFromBalanceSheetDate
Year three, weighted average rate
us-gaap_FederalHomeLoanBankAdvancesMaturitiesSummaryDueFromOneToTwoYearsOfBalanceSheetDate
Year two, amount
us-gaap_FederalHomeLoanBankAdvancesMaturitiesSummaryDueFromTwoToThreeYearsOfBalanceSheetDate
Year three, amount
us-gaap_FederalHomeLoanBankStock
Federal Home Loan Bank Stock
us-gaap_FederalHomeLoanBankAdvancesMaturitiesSummaryDueFromThreeToFourYearsOfBalanceSheetDate
Year four, amount
us-gaap_FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresMaximumAmountAvailable
Federal Home Loan Bank, Advances, General Debt Obligations, Maximum Amount Available
us-gaap_CashCashEquivalentsAndFederalFundsSold
Total cash and cash equivalents
Federal funds sold
us-gaap_DisclosureTextBlockAbstract
Notes to Financial Statements
us-gaap_InterestExpenseFederalHomeLoanBankAndFederalReserveBankAdvancesLongTerm
Federal Home Loan Bank advances
Defined Benefit Plan [Table]
Interest expense, other long term debt
us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive
Thereafter
us-gaap_DeferredCompensationArrangementWithIndividualCompensationExpense
Deferred Compensation Arrangement with Individual, Compensation Expense
us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo
2027
Deposits
us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree
2028
us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour
2029
us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive
2030
us-gaap_DeferredCompensationArrangementWithIndividualRecordedLiability
Deferred Compensation Arrangement with Individual, Recorded Liability
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]
Segment Reporting, Policy [Policy Text Block]
us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths
2026
us-gaap_DeferredCompensationArrangementWithIndividualMaximumContractualTerm1
Deferred Compensation Arrangement with Individual, Maximum Contractual Term (Year)
Business Combination [Policy Text Block]
us-gaap_FiniteLivedIntangibleAssetUsefulLife
Finite-Lived Intangible Asset, Useful Life (Year)
Earnings Per Share, Policy [Policy Text Block]
Total Income
us-gaap_Revenues
Comprehensive Income, Policy [Policy Text Block]
Intangible Asset, Finite-Lived [Table]
Income Tax, Policy [Policy Text Block]
Dividends
Interest and dividend income
us-gaap_InterestAndDividendIncomeOperating
Total Interest and Dividend Income
Interest-bearing deposits in banks and time deposits
Deferred Bonus and Profit Sharing Arrangements, Individual Contracts, Type of Deferred Compensation [Axis]
Deferred Bonus and Profit Sharing Arrangement, Individual Contract, Type of Deferred Compensation [Domain]
Deferred Compensation, Excluding Share-Based Payments and Retirement Benefits [Member]
us-gaap_InterestIncomeFederalFundsSold
Federal funds sold
us-gaap_FinancingReceivableExcludingAccruedInterestRevolvingWriteoff
Loans, revolving, write-off
us-gaap_FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYearWriteoff
Loans, originated three years before, write-off
us-gaap_FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYearWriteoff
Loans, originated four years before, write-off
Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount
Loans, originated prior, write-off
Loans, originated prior, write-off
us-gaap_FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYearWriteoff
Loans, originated two years before, write-off
Loans, originated current year, write-off
Loans, originated current year, write-off
Modified in Period, to Total Financing Receivables, Percentage
us-gaap_FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYearWriteoff
Loans, originated one years before, write-off
Securities:
us-gaap_TimeDepositMaturitiesYearFour
2029
us-gaap_TimeDepositMaturitiesYearFive
2030
Taxable
Tax-exempt
us-gaap_TimeDepositMaturitiesYearOne
2026
us-gaap_TimeDepositMaturitiesYearTwo
2027
us-gaap_TimeDepositMaturitiesYearThree
2028
Advertising Cost [Policy Text Block]
Time Deposit Maturities [Table Text Block]
Interest and fees on loans
Stockholders' Equity, Policy [Policy Text Block]
miff_FinancingReceivableNumberOfLoans
Number of loans
Number of loans.
us-gaap_DeferredTaxAssetsNet
Total
Interest and Dividend Income
us-gaap_DeferredTaxAssetsLiabilitiesNet
Net Deferred Tax Asset
Intangible Assets, Finite-Lived, Policy [Policy Text Block]
us-gaap_DeferredTaxAssetsOther
Other
us-gaap_DeferredIncomeTaxLiabilities
Total
miff_BusinessCombinationAcquiredReceivablesDiscountPremium
Purchase (Premium) Discount
The discount (premium) on the acquired receivables.
Other
us-gaap_NoninterestIncomeOtherOperatingIncome
us-gaap_NoninterestIncome
Total Noninterest Income
miff_BusinessCombinationAcquiredReceivablesDiscountForNoncreditFactors
Discount for non-credit factors
The discount amount for noncredit factors for the acquired receivables.
us-gaap_InterestBearingDomesticDepositBrokered
Interest-Bearing Domestic Deposit, Brokered
miff_BusinessCombinationAcquiredReceivablesPurchasePrice
Purchase Price
The purchase price of the acquired receivables.
us-gaap_DeferredTaxAssetsUnrealizedLossesOnAvailableforSaleSecuritiesGross
Deferred Tax Asset, Debt Securities, Available-for-Sale, Unrealized Loss
us-gaap_TimeDepositsAtOrAboveFDICInsuranceLimit
Time Deposits, at or Above FDIC Insurance Limit
Earnings on bank owned life insurance
Increase in cash surrender value of bank owned life insurance
Deposit Liabilities Disclosures [Text Block]
Deposit Liability [Table]
Noninterest Income
Provision for credit losses
us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss
Net Interest Income after provision for credit losses
Provision for credit losses
us-gaap_ProvisionForLoanLossesExpensed
Repurchase Agreement, Counterparty [Table]
Schedule of Repurchase Agreements [Table Text Block]
us-gaap_InterestIncomeExpenseNet
Net Interest Income
Construction in Progress [Member]
Allowance for credit losses
us-gaap_NumberOfOperatingSegments
Number of Operating Segments
Furniture and Fixtures [Member]
Deferred compensation
Income:
Building [Member]
Land [Member]
Property, Plant and Equipment, Policy [Policy Text Block]
Property, Plant and Equipment [Table]
Long-Lived Tangible Asset [Axis]
Long-Lived Tangible Asset [Domain]
Deposit Account [Member]
Mortgage Banking [Member]
Credit and Debit Card [Member]
us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations
Cash and Cash Equivalents, Beginning of Year
Cash and Cash Equivalents, End of Year
Assets [Abstract]
Deferred tax assets:
Net Increase in Cash and Cash Equivalents
us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect
Net increase (decrease) in cash and cash equivalents
Transfers and Servicing of Financial Assets, Servicing of Financial Assets, Policy [Policy Text Block]
Net Cash Used In Financing Activities
us-gaap_NetCashProvidedByUsedInFinancingActivities
Net Cash (Used In) Provided by Financing Activities
Director [Member]
Transfers and Servicing of Financial Assets, Transfers of Financial Assets, Policy [Policy Text Block]
Executive Officer [Member]
Other
Net Cash Provided By Operating Activities
us-gaap_NetCashProvidedByUsedInOperatingActivities
Net Cash Provided by Operating Activities
Net Cash Provided By Investing Activities
us-gaap_NetCashProvidedByUsedInInvestingActivities
Net Cash Provided By (Used in) Investing Activities
Core deposit intangible
Other Correspondent Banks [Member]
Represents other correspondent banks.
miff_NumberOfOffices
Number of Offices
The number of offices.
Deferred loan origination costs
miff_ImpairmentOfInvestmentsInFederalHomeLoanBankStock
Impairment of Investments in Federal Home Loan Bank Stock
Amount of impairment of investments in Federal Home Loan Bank stock.
Bank Owned Life Insurance [Policy Text Block]
Disclosure of accounting policy for bank owned life insurance.
Interest-bearing Time Deposits [Policy Text Block]
Disclosure of accounting policy for interest-bearing time deposits.
us-gaap_BankingRegulationCommonEquityTierOneRiskBasedCapitalRatioWellCapitalizedMinimum
Banking Regulation, Common Equity Tier 1 Risk-Based Capital Ratio, Well Capitalized, Minimum
Investment, Policy [Policy Text Block]
Premises and equipment
Deferred tax liabilities:
us-gaap_PaymentsOfDividendsCommonStock
Dividends paid on common stock
Dividends paid
srt_FinancingReceivableBeforeAllowanceForCreditLossToTotalPercent
Financing Receivable, before Allowance for Credit Loss, to Total, Percent
Other
us-gaap_OtherNoninterestExpense
us-gaap_NoninterestExpense
Total Noninterest Expense
Scenario [Domain]
Forecast [Member]
FDIC deposit insurance
us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense
Mortgage servicing rights (7)
This element represents the amount of any measurement period adjustment (as defined) realized during the reporting period to mortgage servicing rights acquired in connection with a business combination for which the initial accounting was incomplete.
Time Deposits (5)
This element represents the amount of any measurement period adjustment (as defined) realized during the reporting period to time deposits acquired in connection with a business combination for which the initial accounting was incomplete.
miff_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustment
Net impact to income before taxes
This element represents the amount of any measurement period adjustment (as defined) realized during the reporting period.
Leased building (8)
This element represents the amount of any measurement period adjustment (as defined) realized during the reporting period to lease acquired in connection with a business combination for which the initial accounting was incomplete.
Noninterest income, revenues
Title and Position [Domain]
Bargain Purchase Gain [Policy Text Block]
Disclosure for the accounting policy for bargain purchase gain.
Title and Position [Axis]
Scenario [Axis]
Noninterest Expense
miff_FinancingReceivableAcquiredUnamortizedPurchasePremiumDiscount
Financing Receivable Acquired, Unamortized Purchase Premium (Discount)
Amount of unamortized purchase premium (discount) on purchased financing receivable. Excludes financing receivable covered under loss sharing agreement.
New Directors and Executive Officers [Member]
Related to new directors and executive officers.
Loans Acquired in Business Combinations [Table Text Block]
Tabular disclosure of loans acquired in business combinations.
Collateral Held [Domain]
Collateral Pledged [Member]
Real Estate [Member]
Real Estate Loan [Member]
Unfunded Loan Commitment [Member]
Collateral Held [Axis]
Current tax expense
Class of Financing Receivable [Domain]
Home Equity Loan [Member]
Unallocated Financing Receivables [Member]
Commercial Real Estate Portfolio Segment [Member]
Class of Financing Receivable [Axis]
Financing Receivable Portfolio Segment [Domain]
miff_FinancingReceivableReviewedForLoanGradePercentageOfDollarVolume
Financing Receivable, Reviewed for Loan Grade, Percentage of Dollar Volume
Percentage of dollar volume of financing receivable reviewed for loan grade.
Commercial Portfolio Segment [Member]
miff_FinancingReceivableAnnuallyReviewedForLoanGradeMinimumAmount
Financing Receivable, Annually Reviewed for Loan Grade, Minimum Amount
The minimum amount of financing receivable that is reviewed annually for loan grade.
Income before income taxes
us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest
Income Before Income Taxes
Residential Portfolio Segment [Member]
miff_FinancingReceivableReviewedForLoanGradePastDuePeriod
Financing Receivable, Reviewed for Loan Grade, Past Due Period (Day)
Period of past due financing receivable reviewed for loan grade.
miff_FinancingReceivableReviewedForLoanGradeMinimumCommitment
Financing Receivable, Reviewed for Loan Grade, Minimum Commitment
The amount of minimum commitment of financing receivable that is reviewed for loan grade.
Other Comprehensive Income (Loss) before Reclassifications, Tax
Consumer Portfolio Segment [Member]
Financing Receivable Portfolio Segment [Axis]
us-gaap_DebtSecuritiesAvailableForSaleAccruedInterestAfterAllowanceForCreditLoss
Debt Securities, Available-for-Sale, Accrued Interest, after Allowance for Credit Loss
ICFR Auditor Attestation Flag
Comprehensive Income (Loss) Note [Text Block]
us-gaap_DebtSecuritiesAvailableForSaleAccruedInterestAfterAllowanceForCreditLossStatementOfFinancialPositionExtensibleList
Debt Securities, Available-for-Sale, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible Enumeration]
miff_FinancingReceivableModifiedInPeriodNumberOfLoans
Financing Receivable, Modified in Period, Number of Loans
The number of financing receivables modified during period for debtor experiencing financial difficulty.
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]
Mortgage Banking Activity [Policy Text Block]
Commercial, Agricultural and State and Political Relationships [Member]
Represents commercial, agricultural and state and political relationships.
Financing Receivable, Real Estate Acquired Through Foreclosure [Policy Text Block]
Income Tax Jurisdiction [Axis]
Income Tax Jurisdiction [Domain]
Gross loans, before fee
Loans, before fees
Loans, before fees
Domestic Tax Jurisdiction [Member]
Financing Receivable [Policy Text Block]
Recoveries
us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff
Loans, write-off
Charge-offs
us-gaap_RepaymentsOfFederalHomeLoanBankBorrowings
Repayment of Federal Home Loan Bank advances
Defined Benefit Plan [Text Block]
Initial provision
us-gaap_FinancingReceivableExcludingAccruedInterestPurchasedWithCreditDeteriorationAllowanceForCreditLossAtAcquisitionDate
Cash and Cash Equivalents, Policy [Policy Text Block]
Provisions (Credits)
Loans, nonaccrual
Nonaccrual, no allowance
Accounting Policies [Abstract]
Basis of Accounting, Policy [Policy Text Block]
Cash dividends declared, per share (in dollars per share)
Tier 1 (Core) Capital to average total assets Bank, actual
Banking Regulation, Community Bank Leverage Ratio, Actual
Ratio of Tier 1 capital to average assets as defined by regulatory framework.
Tier 1 (Core) Capital to average total assets Bank, ratio
Banking Regulation, Community Bank Leverage Ratio, Well Capitalized, Minimum
Ratio of minimum Tier 1 leverage capital to average assets categorized as well capitalized as defined by regulatory framework for prompt corrective action.
Condensed Financial Information of Parent Company Only Disclosure [Text Block]
Proceeds from Federal Home Loan Bank advances
Nonaccrual, with allowance
Amortized cost excluding accrued interest, of financing receivable on nonaccrual status with allowance for credit loss. Excludes net investment in lease.
Commercial Customers [Member]
Represents commercial customers.
Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block]
Financing Receivable, Collateral Dependent [Table Text Block]
Tabular disclosure of collateral dependent financing receivables.
Outstanding Principal Balance
The outstanding balance of purchased financing receivables.
Accounts and Financing Receivables [Table]
Initial provision, non-PCD
Amount, excluding accrued interest, of allowance for credit loss at acquisition date of financing receivable purchased with credit deterioration. Excludes net investment in lease.
Other Collateral [Member]
Represents other collateral.
Auditor Name
Securities Sold Under Agreements to Repurchase [Text Block]
The entire disclosure for securities sold under agreements to repurchase.
Auditor Firm ID
Auditor Location
us-gaap_SharePrice
Share Price (in dollars per share)
us-gaap_FinancingReceivableAccruedInterestAfterAllowanceForCreditLossStatementOfFinancialPositionExtensibleList
Financing Receivable, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible Enumeration]
us-gaap_FinancingReceivableAccruedInterestAfterAllowanceForCreditLoss
Financing Receivable, Accrued Interest, after Allowance for Credit Loss
miff_EffectiveIncomeTaxRateReconciliationNondeductibleInterestExpenseAmount
Nondeductible interest expense, amount
Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to nondeductible interest expenses.
Statement of Financial Position [Abstract]
us-gaap_WeightedAverageNumberOfSharesOutstandingBasic
Weighted Average Number of Shares Outstanding, Basic (in shares)
us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments
Other, net, percentage
us-gaap_FinancingReceivableRevolvingConvertedToTermLoan
Financing Receivable, Revolving, Converted to Term Loan
us-gaap_EffectiveIncomeTaxRateContinuingOperations
Applicable Income Taxes and Effective Rates, percentage
Less: net deferred loan fees
miff_EffectiveIncomeTaxRateReconciliationNondeductibleInterestExpensePercent
Nondeductible interest expense, percentage
Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to nondeductible interest expenses.
Business Combination [Axis]
Earnings Per Share - Basic and Diluted (in dollars per share)
miff_EffectiveIncomeTaxRateReconciliationBankOwnedLifeInsuranceIncomeAmount
Bank owned life insurance, amount
Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to bank owned life insurance income.
Credit Loss, Financial Instrument [Policy Text Block]
Business Combination [Domain]
miff_EffectiveIncomeTaxRateReconciliationBankOwnedLifeInsuranceIncomePercent
Bank owned life insurance, percentage
Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to bank owned life insurance income.
us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLoss
Debt Securities, Available-for-Sale, Allowance for Credit Loss
Profit-sharing Employer Contribution Component to the 401(k) Plan [Member]
Represents the profit-sharing employer contribution component to the 401(k) Plan.
Employee Stock Option Plan [Member]
Represents the Employee Stock Option Plan.
Statement of Cash Flows [Abstract]
Statement of Stockholders' Equity [Abstract]
us-gaap_EffectiveIncomeTaxRateReconciliationTaxExemptIncome
Tax-exempt interest, percentage
Section 401(k) Plan [Member]
Represents the Section 401(k) plan.
Increase (decrease) in repurchase agreements
us-gaap_IncreaseDecreaseInFederalFundsPurchased
Decrease in Federal Funds purchased
miff_DefinedContributionPlanMinimumAge
Defined Contribution Plan, Minimum Age
The minimum age of employee under the defined contribution plan.
miff_DefinedContributionPlanRequisiteServiceHours
Defined Contribution Plan, Requisite Service Hours
Minimum number of hours the employee is required to perform under the defined contribution plan.
miff_EmployeeStockOwnershipPlanRequisiteServicePeriod
Employee Stock Ownership Plan, Requisite Service Period (Year)
Minimum period the individual is required to perform services under the employee stock ownership plan, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.
miff_DefinedContributionPlanRequisiteServicePeriod
Defined Contribution Plan, Requisite Service Period (Year)
Minimum period the individual is required to perform services under the deferred contribution plan, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.
miff_EmployeeStockOwnershipPlanMinimumAge
Employee Stock Ownership Plan, Minimum Age
Minimum age an employee must be under the employee stock ownership plan.
Financing Receivable, Nonaccrual [Table Text Block]
miff_EmployeeStockOwnershipPlanRequisiteServiceHours
Employee Stock Ownership Plan, Requisite Service Hours
Minimum number of service hours the employee is required to perform under the employee stock ownership plan.
miff_DefinedContributionPlanPeriodOfServiceFullyVested
Defined Contribution Plan, Period of Service, Fully Vested (Year)
Period of service of individual for fully vested awards under the defined contribution plan.
miff_DefinedContributionPlanPeriodOfServiceVestingRatably
Defined Contribution Plan, Period of Service, Vesting Ratably (Year)
Period of service of individual for vesting ratably under the defined contribution plan.
miff_EmployeeStockOwnershipPlanPeriodOfServiceFullyVested
Employee Stock Ownership Plan, Period of Service, Fully Vested (Year)
Period of service of individual for awards to fully vest under the employee stock ownership plan.
miff_EmployeeStockOwnershipPlanPeriodOfServiceVestingRatably
Employee Stock Ownership Plan, Period of Service, Vesting Ratably (Year)
Period of service for awards to vest ratably under the employee stock ownership plan.
Mifflinburg Bancorp, Inc. shares to be issued (in shares)
Business Combination, Consideration Transferred, Equity Interest, Share Issued, Number of Shares (in shares)
Allowance for Unfunded Commitments [Table Text Block]
Tabular disclosure for allowance for unfunded commitments.
us-gaap_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentFinancialLiabilities
Subordinated debt (4)
Dividends from subsidiaries
miff_DividendsFromSubsidiary
The amount of dividends received from subsidiary.
us-gaap_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentConsiderationTransferred
Fair value of total consideration transferred
miff_SplitdollarLifeInsurancePoliciesInitialCashOutlay
Split-dollar Life Insurance Policies, Initial Cash Outlay
Amount of initial cash outlay of split-dollar life insurance policies.
Investments Classified by Contractual Maturity Date [Table Text Block]
Loans (1)
miff_DefinedBenefitPlanMinimumAge
Defined Benefit Plan, Minimum Age
Minimum age required under the defined benefit plan.
Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]
Schedule of Deferred Tax Assets and Liabilities [Table Text Block]
Buildings (2)
miff_DefinedBenefitPlanLiabilityMultiplierOfSalary
Defined Benefit Plan, Liability, Multiplier of Salary
The multiplier of salary of individual for liability under defined benefit plan.
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]
us-gaap_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentIntangibles
Intangibles
Increase in deposits
Unrealized Gain (Loss) on Investments [Table Text Block]
Schedule of Available-for-Sale Securities Reconciliation [Table Text Block]
Collateral Dependent, net, measurement input
Collateral Dependent, net, measurement input
Value of input used to measure financing receivable.
Accrued interest payable
miff_AccruedInterestPayableFairValueDisclosure
Fair value portion of accrued interest payable.
Valuation, Appraisal of Collateral Approach [Member]
Valuation approach reflecting appraisal of the collateral.
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis, Valuation Techniques [Table Text Block]
us-gaap_LoansAndLeasesReceivableRelatedParties
Beginning balance
Ending balance
Fair Value Measurements, Nonrecurring [Table Text Block]
miff_BusinessAcquisitionExchangeRatio
Business Acquisition, Exchange Ratio
The exchange ratio of shares in the business acquisition.
Fair Value, Assets Measured on Recurring Basis [Table Text Block]
Contractual Interest Rate Reduction [Member]
us-gaap_IncomeTaxReconciliationOtherAdjustments
Other, net, amount
Restricted investments in bank stock
miff_RestrictedInvestmentsInBankStockFairValueDisclosure
Fair value portion of restricted investments in bank stock.
Cash Flows From Financing Activities:
Accrued interest receivable
miff_AccruedInterestReceivableFairValueDisclosure
Fair value portion of accrued interest receivable.
Bargain Purchase Gain
Bargain purchase gain
Business Combination, Bargain Purchase, Gain Recognized, Amount
Bargain purchase gain
Bargain purchase gain
us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate
Provision at statutory rate, percentage
Interest-bearing time deposits
miff_InterestbearingTimeDepositInOtherFinancialInstitutionFairValueDisclosure
Fair value portion of interest-bearing time deposit in other financial institution.
Northumberland Bancorp [Member]
Represents Northumberland Bancorp.
miff_DebtSecuritiesAvailableforsaleExcludingAccruedInterestAmortizedCostSold
Debt Securities, Available-for-Sale, Excluding Accrued Interest, Amortized Cost, Sold
Amount, excluding accrued interest, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale) sold during the period.
us-gaap_BusinessCombinationAcquiredReceivablesGrossContractualAmount
Par value
us-gaap_BusinessCombinationAcquiredReceivablesEstimatedUncollectible
Discount for credit risk
us-gaap_IncomeTaxReconciliationTaxExemptIncome
Tax-exempt interest, amount
Fair value - initially reported
Total identifiable net assets, at fair value
us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
Pledged Status [Domain]
Pledged Status [Axis]
us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities
Total liabilities assumed
us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired
Cash acquired in the acquisition of NUBC, net of cash paid
us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostAllowanceForCreditLossExcludingAccruedInterest
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Excluding Accrued Interest
Operating lease liability
us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCapitalLeaseObligation
Class of Stock [Axis]
Class of Stock [Domain]
Net cash and cash equivalents acquired in business combination
us-gaap_CashAcquiredFromAcquisition
Cash payment
Payments to Acquire Businesses, Gross
Debt securities available-for-sale, amortized cost
Debt securities available-for-sale, amortized cost
Total identifiable assets acquired at fair value
us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets
us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLoss
Debt Securities, Available-for-Sale, Amortized Cost, Excluding Accrued Interest, after Allowance for Credit Loss
Financing Receivables, 30 to 89 Days Past Due [Member]
Financial asset more than 29 days past due but fewer than 90 days past due.
Deferred tax asset
us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxAssets
us-gaap_PaymentsForProceedsFromLoansReceivable
Net increase in loans
us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment
Property, Plant, and Equipment
Intangibles
us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill
us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate
Provision at statutory rate, amount
Debt securities available-for-sale
Debt securities available-for-sale, at fair value
Debt securities available-for-sale, fair value
Income Tax Disclosure [Text Block]
Cash and cash equivalents
us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents
Total purchase price assigned to shares issued
Accumulated Other Comprehensive Income (Loss) [Table]
Fair value of total consideration transferred
Business Combination, Consideration Transferred
Per share value assigned to shares issued (in dollars per share)
Business Combination, Price Per Share (in dollars per share)
Pass [Member]
Proceeds from sales
Proceeds from Sale of Debt Securities, Available-for-Sale
Internal Credit Assessment [Axis]
Proceeds from maturities of securities
Proceeds from paydowns, maturities and calls
Internal Credit Assessment [Domain]
Business Combination, Pro Forma Information, Nonrecurring Adjustment [Table Text Block]
Consumer, Other [Member]
Marketable equity securities
Marketable equity securities, at fair value
Equity Securities, FV-NI
us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt
Purchases
Retirement Plan Name [Axis]
Financial Asset, Past Due [Member]
us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest
Financing Receivable, Allowance for Credit Loss, Excluding Accrued Interest
Less: allowance for credit losses
Allowance for credit losses
Beginning balance
Commercial
Retirement Plan Name [Domain]
Financial Asset, Not Past Due [Member]
Postretirement Life Insurance [Member]
us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss
Loans, net
Postemployment Retirement Benefits [Member]
Retirement Plan Type [Axis]
Retirement Plan Type [Domain]
Loans
Total loans net of deferred loan fees
Proceeds from sale of premises and equipment
Supplemental Employee Retirement Plan [Member]
Business Combination, Recognized Asset Acquired and Liability Assumed [Table Text Block]
us-gaap_FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYear
Loans, originated four years before
Special Mention [Member]
us-gaap_FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYear
Loans, originated three years before
Substandard [Member]
us-gaap_FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYear
Loans, originated current year
Doubtful [Member]
us-gaap_FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYear
Loans, originated two years before
Unlikely to be Collected Financing Receivable [Member]
us-gaap_FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYear
Loans, originated prior
us-gaap_FinancingReceivableExcludingAccruedInterestRevolving
Loans, revolving
Purchase Price
Par Value
NUBC recorded value
Allowance
Discount for non-credit factors
us-gaap_FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYear
Loans, originated one years before
us-gaap_PaymentsToAcquirePropertyPlantAndEquipment
Purchases of premises and equipment
Purchase (Premium) Discount
Financing Receivable, Purchased with Credit Deterioration, Discount (Premium)
Discount for credit risk
Other real estate acquired in settlement of loans
Supplementary Disclosure of Noncash Transactions
us-gaap_IncomeTaxesPaidNet
Income Taxes Paid, Net
Net change in the unrealized gain (loss) recognized during the period on marketable equity securities
us-gaap_EquitySecuritiesFvNiUnrealizedGainLoss
Net marketable equity security (gains) losses
Net marketable equity security gains (losses)
Net marketable equity security (gains) losses
Net gain (loss) recognized in net income during the period on marketable equity securities still held at the reporting date
Net marketable equity security (gains) losses
Supplementary Cash Flows Information
Principal Forgiveness [Member]
Payment Deferral [Member]
Loan Restructuring Modification [Axis]
Loan Restructuring Modification [Domain]
us-gaap_OperatingLeaseExpense
Operating Lease, Expense
Extended Maturity [Member]
Customer Lists [Member]
us-gaap_DebtInstrumentVariableInterestRateTypeExtensibleEnumeration
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration]
Financing Receivable, Modified [Table Text Block]
Core Deposits [Member]
Financing Receivable, Modified [Table]
Finite-Lived Intangible Assets by Major Class [Axis]
Finite-Lived Intangible Assets, Major Class Name [Domain]
Effective Income Tax Rate Reconciliation [Table]
Federal Home Loan Bank advances
Total, amount
Net Income
Net Income
Net Income
Financing Receivable Credit Quality Indicators [Table Text Block]
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Past Due [Table Text Block]
Financial Asset, Aging [Axis]
Financial Asset, Aging [Domain]
Proceeds from sale of foreclosed real estate
Financing Receivables [Text Block]
Business Combination [Text Block]
Business Combination [Table]
Decrease of interest-bearing time deposits
Long-Term Debt, Type [Axis]
Long-Term Debt, Type [Domain]
us-gaap_PaymentsForProceedsFromFederalReserveBankStock
Increase (decrease) in restricted investments in bank stock
us-gaap_RelatedPartyDepositLiabilities
Related Party Deposit Liabilities
Other, net
us-gaap_OtherOperatingActivitiesCashFlowStatement
Cash Flows From Investing Activities:
us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet
Change in other assets and liabilities, net
Related Party Transaction [Table]
(Decrease) increase in accrued interest payable
Schedule of Related Party Transactions [Table Text Block]
Federal Home Loan Bank, Advances [Table Text Block]
Off Balance Sheet Credit Exposures [Member]
Represents the off balance sheet credit exposures.
Trust Assets and Income [Policy Text Block]
The accounting policy describing the trust assets and income.
us-gaap_DebtInstrumentRedemptionPricePercentage
Debt Instrument, Redemption Price, Percentage
us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax
Reclassification adjustment for losses on available-for- sale securities included in net income, income taxes
Income tax effect
Unrealized holding gains (losses) on debt securities available-for-sale, income taxes
miff_BusinessCombinationRecognizedLiabilityAssumedAdjustmentsToUnfundedCommitments
Reserve for unfunded commitments
The adjustments to the unfunded commitments assumed in the business combination
Reserve for unfunded commitments
Amount of unfunded commitment reserve assumed in business combination and recognized at acquisition date.
us-gaap_DebtInstrumentTerm
Debt Instrument, Term (Year)
miff_BusinessCombinationRecognizedLiabilityAssumedLiabilityAdjustments
Total liabilities assumed
The adjustments to the total liabilities assumed in the business combination.
miff_BusinessCombinationRecognizedAssetAcquiredDeferredTaxAssetAdjustments
Deferred tax asset
The adjustments to the deferred tax assets acquired in the business combination.
miff_BusinessCombinationRecognizedAssetAcquiredToLiabilityAssumedExcessLessAdjustments
Total identifiable net assets, at fair value
Adjustments to the amount of asset acquired in excess of (less than) liability assumed in business combination and recognized at acquisition date. Excludes goodwill.
miff_BusinessCombinationCashSettlementOfSharesPricePerShareAdjustedPrice
Business Combination, Cash Settlement of Shares, Price Per Share, Adjusted Price (in dollars per share)
The adjustment to the share price for the business acquisition.
miff_BusinessCombinationRecognizedLiabilityAssumedOtherLiabilityCurrentAndNoncurrentAdjustments
Other liabilities
The adjustments made to the other liabilities, current and non current, assumed in the business combination
miff_BusinessCombinationRecognizedAssetAcquiredLoansNetAdjustments
Loans, net of allowance
The adjustments to the loans, net acquired in the business combination.
miff_BusinessCombinationRecognizedAssetAcquiredLoanGrossAdjustments
Loans gross
The adjustments to the loans, gross acquired and recognized in the business combination.
Interest Expense
Adjustments
The adjustments to the amount at purchase price of financing receivable purchased with credit deterioration.
Subordinated Debt [Member]
Interest expense
us-gaap_InterestExpenseOperating
Total Interest Expense
Measurement period adjustments
Adjustments to fair value of receivable purchased without credit deterioration, acquired in business combination. Excludes purchased financial asset with credit deterioration.
miff_BusinessCombinationAcquiredReceivablesPurchasePriceAdjustments
Adjustments
Adjustments to the purchase price of the acquired receivables.
us-gaap_FinancingReceivableIndividuallyEvaluatedForImpairment
Loans Receivable, Individually Evaluated
miff_BankingRegulationTier1LeverageCapitalRatioWellCapitalizedGracePeriodMinimum
Banking Regulation, Tier 1 Leverage Capital Ratio, Well Capitalized, Grace Period, Minimum
Ratio of the grace period minimum Tier 1 risk-based capital to risk-weighted assets categorized as well capitalized as defined by regulatory framework for prompt corrective action.
us-gaap_FinancingReceivableCollectivelyEvaluatedForImpairment
Loans Receivable, Collectively Evaluated
us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1
Allowance for Credit Losses, Individually Evaluated
us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment
Allowance for Credit Losses, Collectively Evaluated
us-gaap_ComprehensiveIncomeNetOfTax
Total Comprehensive Income
Financial Asset Acquired and No Credit Deterioration [Member]
Total Expense
miff_ExpenseTotal
The total amount of expense, operating and nonoperating.
Credit Loss Status [Axis]
us-gaap_OffBalanceSheetCreditLossLiabilityCreditLossExpenseReversal
Provision for credit losses
Credit Loss Status [Domain]
miff_DeferredTaxAssetsCoreContractTermination
Core contract termination
Amount before allocation of valuation allowances of deferred tax asset attributable to core contract termination.
Financial Asset Acquired with Credit Deterioration [Member]
us-gaap_OffBalanceSheetCreditLossLiability
Off-Balance-Sheet, Credit Loss, Liability
Balance
Balance
Purchase accounting adjustments on premises
Amount of deferred tax liability attributable to purchase accounting adjustments on premises.
miff_DeferredTaxAssetsPurchaseAccountingAdjustmentsOnLoans
Purchase accounting adjustments on loans
Amount before allocation of valuation allowances of deferred tax asset attributable to purchase accounting adjustments on loans.
Common stock, outstanding (in shares)
Financing Receivable, Allowance for Credit Loss [Table Text Block]
Financing Receivable, Allowance for Credit Loss [Table]
miff_DeferredTaxAssetsPurchaseAdjustmentsOnSecurities
Purchase accounting adjustments on securities
Amount before allocation of valuation allowances of deferred tax asset attributable to purchase adjustments on securities.
miff_EffectiveTaxReconciliationBargainPurchaseGainAmount
Bargain purchase gain, amount
Amount of difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying domestic federal statutory income tax rates to pretax income (loss) from continuing operations, attributable to bargain purchase gain.
us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Debt Instrument, Basis Spread on Variable Rate
Bargain purchase gain, percentage
Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to bargain purchase gain.
us-gaap_DebtInstrumentInterestRateStatedPercentage
Debt Instrument, Interest Rate, Stated Percentage
Purchase accounting adjustments on deposits and borrowings
Amount of deferred tax liability attributable to purchase accounting adjustments on deposits and borrowings.
Purchase accounting adjustments on intangible assets
Amount of deferred tax liability attributable to purchase accounting adjustments for intangible assets other than goodwill.
us-gaap_DebtInstrumentInterestRateEffectivePercentage
Debt Instrument, Interest Rate, Effective Percentage
us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent
Weighted-average discount rate
Lease, Cost [Table Text Block]
ROU assets acquired in exchange for lease liabilities
miff_PaymentsToAcquireBusinessesGrossAdjustments
Payments to Acquire Businesses, Gross, Adjustments
Adjustments to the gross payments to acquire businesses.
us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1
Weighted-average remaining term (years) (Year)
us-gaap_DividendsCash
Cash dividends declared
us-gaap_DebtInstrumentFaceAmount
Debt Instrument, Face Amount
Interim Period, Costs Not Allocable [Domain]
Nature of Expense [Axis]
miff_BusinessCombinationRecognizedAssetAcquiredAssetAdjustments
Total identifiable assets acquired at fair value
The adjustment to the recognized asset acquired in the business combination.
SIFMA Municipal Swap Rate [Member]
us-gaap_IncreaseDecreaseInAccruedInterestReceivableNet
Decrease (increase) in accrued interest receivable
Other Borrowings [Member]
Represents the other borrowings.
Variable Rate [Domain]
Schedule of Long-Term Debt Instruments [Table]
us-gaap_TreasuryStockCommonValue
Treasury stock, at cost: 2025: 301,664 shares; 2024: 301,464 shares
us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)
us-gaap_PaymentsForOriginationAndPurchasesOfLoansHeldForSale
Origination of loans held for sale
NUBC Acquisition
Proceeds from loans sold
Secured Overnight Financing Rate (SOFR) [Member]
Total Liabilities and Stockholders’ Equity
us-gaap_LiabilitiesAndStockholdersEquity
Total Liabilities and Stockholders' Equity
Reported Value Measurement [Member]
Asset Pledged as Collateral [Member]
Retained earnings
Accumulated other comprehensive loss
Debt Disclosure [Text Block]
us-gaap_OperatingLeaseLiability
Operating Lease, Liability
us-gaap_OperatingLeaseLiabilityStatementOfFinancialPositionExtensibleList
Operating Lease, Liability, Statement of Financial Position [Extensible Enumeration]
us-gaap_OperatingLeaseRightOfUseAsset
Operating Lease, Right-of-Use Asset
us-gaap_OperatingLeaseRightOfUseAssetStatementOfFinancialPositionExtensibleList
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]
us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue
Total undiscounted cash flows
us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount
Discount on cash flows
Deferred income tax expense (benefit)
us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree
2028
Measurement Input Type [Axis]
us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour
2029
Measurement Input Type [Domain]
us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive
2030
Measurement Input, Appraised Value [Member]
us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive
Thereafter
Net Investment in Lease, before Allowance for Credit Loss
us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths
2026
Debt Securities, Available-for-Sale [Table Text Block]
us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo
2027
Valuation Approach and Technique [Axis]
Valuation Approach and Technique [Domain]
Lessee, Operating Lease, Liability, to be Paid, Maturity [Table Text Block]
us-gaap_PensionAndOtherPostretirementBenefitsExpenseReversalOfExpenseNoncash
Pension and Other Postretirement Benefits Expense (Reversal of Expense), Noncash
Amortization of subordinated debt
us-gaap_AmortizationOfDebtDiscountPremium
us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments
Net accretion of discounts and premiums on securities
Depreciation
Depreciation
Bank owned life insurance
us-gaap_CashSurrenderValueFairValueDisclosure
us-gaap_FinancialLiabilitiesFairValueDisclosure
Financial Liabilities Fair Value Disclosure
FHLB advances
us-gaap_FederalHomeLoanBankBorrowingsFairValueDisclosure
Cash and cash equivalents
us-gaap_CashAndCashEquivalentsFairValueDisclosure
Repurchase agreements
us-gaap_SecuritiesLoanedOrSoldUnderAgreementsToRepurchaseFairValueDisclosure
us-gaap_AssetsHeldInTrust
Asset, Held-in-Trust
Subordinated debt
us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisSubordinatedDebtObligations
Treasury stock, shares (in shares)
Fair Value, Nonrecurring [Member]
Common stock, par value $1.00 per share; authorized 5,000,000 shares; issued 3,706,725 (2025) and 2,160,000 (2024) shares; outstanding 3,405,061 and 1,858,536 shares as of December 31, 2025 and December 31, 2024, respectively.
Fair Value, Recurring and Nonrecurring [Table]
Measurement Frequency [Axis]
Adjustments to reconcile net income to net cash provided by operating activities:
Measurement Frequency [Domain]
Fair Value, Recurring [Member]
Common stock, authorized (in shares)
Loans [Member]
Common stock, issued (in shares)
Common stock, par value (in dollars per share)
Nondeductible merger expenses
Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to nondeductible merger related costs.
Nondeductible merger expenses, percent
Percentage of difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying domestic federal statutory income tax rate to pretax income (loss) from continuing operation, attributable to nondeductible expense for merger related cots.
Lessee, Lease, Description [Table]
Statistical Measurement [Domain]
Maximum [Member]
Minimum [Member]
Weighted Average [Member]
Product and Service [Axis]
Product and Service [Domain]
Statistical Measurement [Axis]
Interest paid
Income taxes paid
Property, Plant and Equipment Disclosure [Text Block]
Property, Plant and Equipment [Table Text Block]
Federal Home Loan Bank of Pittsburgh [Member]
Portion at Fair Value Measurement [Member]
Estimate of Fair Value Measurement [Member]
Securities, available for sale
miff_BusinessCombinationRecognizedAssetAcquiredAvailableForSaleSecurities
Amount of available for sale securities acquired in business combination and recognized at acquisition date.
Dissenter's Shares [Member]
Represents Dissenter's shares.
Loans gross
miff_BusinessCombinationRecognizedAssetAcquiredLoanGross
Business Combination, Recognized Asset Acquired, Loan Gross
Amount of loan gross acquired in business combination and recognized at acquisition date.
Loans held for sale
miff_BusinessCombinationRecognizedAssetAcquiredLoansHeldForSale
Amount of loans held for sale acquired in business combination and recognized at acquisition date.
Measurement Basis [Axis]
Dissenter's shares (1) (in shares)
Business Combination, Number of Rights Shares Exercised (in shares)
Number of rights shares exercised for business combination.
Federal Home Loan Bank Branch [Domain]
Fair Value, Inputs, Level 3 [Member]
Fair value of Dissenter's shares (in dollars per share)
Business Combination, Cash Settlement of Shares, Price Per Share (in dollars per share)
Per share price of cash settlement of shares under business combination.
Restricted investment in bank stock
miff_BusinessCombinationRecognizedAssetAcquiredRestrictedInvestmentInBankStock
Amount of restricted investment in bank stock acquired in business combination and recognized at acquisition date.
Fair Value Hierarchy and NAV [Domain]
Customer [Axis]
miff_PolicyTable
Accrued interest receivable
miff_BusinessCombinationRecognizedAssetAcquiredAccruedInterestRecievable
Amount of accrued interest receivable acquired in business combination and recognized at acquisition date.
Customer [Domain]
Operating lease right of use asset
miff_BusinessCombinationRecognizedAssetAcquiredOperatingLeaseRightOfUseAssets
Amount of right of use assets acquired in business combination and recognized at acquisition date. Excludes goodwill and financial asset.
Fair Value, Inputs, Level 1 [Member]
Federal Home Loan Bank Branch [Axis]
Fair Value, Inputs, Level 2 [Member]
miff_BusinessCombinationRecognizedAssetAcquiredLoansNet
Loans, net of allowance
Net amount of loans acquired in business combination and recognized at acquisition date.
miff_BusinessCombinationRecognizedAssetAcquiredAllowanceForCreditLossOnLoans
Allowance for credit losses
Amount of allowance for credit loss on loans acquired in business combination and recognized at acquisition date.
Bank owned life insurance
miff_BusinessCombinationRecognizedAssetAcquiredBankOwnedLifeInsurance
Amount of bank owned life insurance acquired in business combination and recognized at acquisition date.
Fair Value Hierarchy and NAV [Axis]
Other liabilities
miff_BusinessCombinationRecognizedLiabilityAssumedOtherLiabilityCurrentAndNoncurrent
Amount of liability assumed in business combination and recognized at acquisition date, classified as other.
Accrued interest payable
miff_BusinessCombinationRecognizedLiabilityAssumedAccruedInterestPayable
Amount of accrued interest payable assumed in business combination and recognized at acquisition date.
Premises [Member]
Represents premises.
miff_BusinessCombinationNumberOfLoansAcquired
Business Combination, Number of Loans Acquired
Number of loans acquired under business combination.
Deposits
miff_BusinessCombinationRecognizedLiabilityAssumedDepositLiabilities
Amount of deposits liabilities assumed in business combination and recognized at acquisition date.
Other assets
miff_BusinessCombinationRecognizedAssetAcquiredOtherAssetCurrentAndNoncurrent
Amount of asset acquired in business combination and recognized at acquisition date, classified as other.
Subordinated debt
miff_BusinessCombinationRecognizedLiabilityAssumedSubordinatedDebt
Amount of subordinated Debt assumed in business combination and recognized at acquisition date.
Borrowings
miff_BusinessCombinationRecognizedLiabilityAssumedBorrowings
Amount of current and noncurrent borrowings assumed in business combination and recognized at acquisition date.
miff_FinancingReceivablePercentageOfLoanPortfolio
Financing Receivable, Percentage of Loan Portfolio
Percentage of loan portfolio under financing receivable.
Purchased Financial Assets with Credit Deterioration [Table Text Block]
Tabular disclosure of purchased financial assets with credit deterioration.
miff_FinancingReceivableNumberOfLoansInProcessOfForeclosure
Financing Receivable, Number of Loans in Process of Foreclosure
Number of loans in process of foreclosure.
us-gaap_MinorityInterest
Less maximum cash obligation to ESOP shares
Less maximum cash obligation to ESOP shares
Furniture, Fixtures and Equipment [Member]
Represents furniture, fixtures and equipment.
N N B [Member]
Represents NNB.
Cash Flows From Operating Activities:
miff_GainsLossesOnSalesOfForeclosedRealEstate
(Gain) loss on sale of foreclosed real estate
The net gain (loss) resulting from sales and other disposals of foreclosed real estate.
Revenue [Policy Text Block]
miff_BusinessCombinationRecognizedAssetAcquiredLoansNetDiscountedValue
Business Combination, Recognized Asset Acquired, Loans, Net Discounted Value
Net discounted value of loans acquired under business combination.
Repayment of Federal Reserve Bank Borrowings
The cash flow from federal reserve bank borrowings.
Statement [Line Items]
Extended Maturity and Payment Deferral [Member]
Loan modification for extension of term of loan in which it must be paid and a temporary postponement of loan payments.
Trust and Investment [Member]
Represents Trust and Investment.
miff_DebtInstrumentVariableRateAverageDay
Debt Instrument, Variable Rate, Average Day
Average date to calculate variable rate under debt instrument.
Deposits Total [Member]
Relating to total deposits.
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Parent [Member]
Capital surplus
Increase in maximum cash obligation related to ESOP shares
The amount of maximum cash obligations related to ESOP shares that have been increased (decreased) during the reporting period.
No Customer [Member]
Relating to no customer.
miff_NetAccretionOfAcquisitionAccountingEstimate
Net accretion of acquisition accounting adjustments
Net amortization of accounting estimates
The net amount of accretion of acquisition accounting estimate.
Fair Value, off-Balance-Sheet Risk [Table]
Fractional Shares [Member]
Represents Fractional Shares.
AOCI Attributable to Parent [Member]
Financial instruments
Stockholders' Equity
Schedule of Fair Value, off-Balance-Sheet Risks [Table Text Block]
Fair value per share (in dollars per share)
Fair value per share of the shares allocated that are subject to a repurchase obligation.
Net loans
Collateral Dependent, net
Change related to ESOP shares
Value of shares committed to be released under an Employee Stock Ownership Plan (ESOP).
Fair Value Disclosures [Text Block]
Fair Value, by Balance Sheet Grouping [Table Text Block]
Interest-bearing time deposits
Redeemable Common Stock Held by ESOP
Redeemable Common Stock Held By Employee Stock Ownership Plan
Total Liabilities
us-gaap_Liabilities
Total Liabilities
Commitments and Contingencies
Other Liabilities
us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesCurrentAndNoncurrent
Liability, Defined Benefit Plan
Counterparty Name [Axis]
Counterparty Name [Domain]
Deferred tax liability
us-gaap_DeferredIncomeTaxLiabilitiesNet
Accrued interest payable
Parent Company [Member]
Consolidated Entities [Axis]
Consolidated Entities [Domain]
Condensed Cash Flow Statement [Table]
Condensed Balance Sheet Statement [Table]
Condensed Cash Flow Statement [Table Text Block]
Condensed Balance Sheet [Table Text Block]
Condensed Income Statement [Table Text Block]
Condensed Income Statement [Table]
Condensed Financial Statements [Table]
Noncontrolling Interest [Member]
Retained Earnings [Member]
Treasury Stock, Common [Member]
Deferred Rent Credit
Additional Paid-in Capital [Member]
Common Stock [Member]
Equity Components [Axis]
Equity Component [Domain]
Subordinated Debt, at fair value
Subordinated debt, net
Vehicles [Member]
Document Annual Report
Entity Incorporation, State or Country Code
us-gaap_DebtInstrumentCarryingAmount
Long-Term Debt, Gross
Document Transition Report
Document Financial Statement Error Correction [Flag]
Entity Interactive Data Current
Repurchase agreements
us-gaap_FederalHomeLoanBankAdvancesMaturitiesSummaryDueWithinOneYearOfBalanceSheetDate
Year one, amount
Deposits
us-gaap_DepositsFairValueDisclosure
Agricultural Sector [Member]
Industry Sector [Domain]
Industry Sector [Axis]
Statement [Table]
Income Statement [Abstract]
Other comprehensive loss
Other comprehensive income (loss)
us-gaap_ServicingLiability
Servicing Liability
us-gaap_SecuritiesSoldUnderAgreementsToRepurchaseFairValueOfCollateral
Securities Sold under Agreements to Repurchase, Fair Value of Collateral
Gross Amounts Not Offset in the Balance Sheets, Financial Instruments
us-gaap_Deposits
Total deposits
Gross Amounts Offset in the Balance Sheets
Gross Amounts Not Offset in the Balance Sheets, Cash Collateral Pledged
Net Amount
Interest-bearing deposits
Noninterest-bearing deposits
Accounting Standards Update and Change in Accounting Principle [Table]
us-gaap_TimeDeposits
Total
us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax
Net realized losses on available-for-sale debt securities
us-gaap_EmployeeStockOwnershipPlanESOPCashContributionsToESOP
Employee Stock Ownership Plan (ESOP), Cash Contributions to ESOP
Other Commitments [Table]
Maximum cash obligation
Shares held by the ESOP (in shares)
Employee Stock Ownership Plan (ESOP), Shares in ESOP (in shares)
Employee Stock Ownership Plan (ESOP) Name [Axis]
Employee Stock Ownership Plan (ESOP), Plan [Domain]
Commitments to Extend Credit [Member]
Employee Stock Ownership Plan (ESOP) Disclosures [Table Text Block]
Offsetting Assets [Table]
Total Stockholders’ Equity
us-gaap_StockholdersEquity
Total Stockholders' Equity
us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
Debt securities available-for-sale, gross unrealized losses
Debt securities available-for-sale, gross unrealized gains
Due after one year through five years, amortized cost
Due after five years through ten years, amortized cost
Due after ten years, amortized cost