Document And Entity Information Beyond ten years, fair value us-gaap_DerivativeNotionalAmount Derivative, Notional Amount Note To Financial Statement Details Textual Significant Accounting Policies Note 2 - Securities Within one year, amortized cost Note 3 - Loans Note 4 - Other Real Estate Owned Within one year, fair value Note 5 - Deposits One to five years, fair value Risk Participation Agreement [Member] Type of off-balance-sheet transaction in which a bank sells its exposure to a contingent obligation. Note 6 - Advances From the Federal Home Loan Bank Five to ten years, fair value Note 8 - Fair Values Measurement Note 9 - Income Taxes Residential Mortgage Backed Securities [Member] lmst_CommonEquityTierOneRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssets Common Equity Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets The minimum Tier One Common Equity ratio (Total Tier One Common Equity divided by risk weighted assets) required for capital adequacy purposes under the regulatory framework for prompt corrective action. Note 10 - Stock Plans and Stock Based Compensation Income Tax Disclosure [Text Block] Note 11 - Earnings Per Share Note 12 - Regulatory Capital Matters Collateralized Debt Obligations [Member] Note 13 - Off Balance Sheet Risks, Commitments, and Contingent Liabilities Note 2 - Securities - Amortized Cost, Gross Unrealized Gains or Losses, and Fair Value of Investment Securities (Details) Note 2 - Securities - Sales and Calls of Securities (Details) Schedule of Maturities of Long-term Debt [Table Text Block] Note 2 - Securities - Amortized Cost and Fair Value of Debt Investment Securities Portfolio by Contractual Maturity (Details) Note 2 - Securities - Securities With Unrealized Losses (Details) Note 3 - Loans - Loans (Details) Note 3 - Loans - Activity in Allowance for Loan Losses by Portfolio Segment (Details) Note 3 - Loans - Balance in Allowance for Loan Losses and Recorded Investment in Loans by Portfolio Segment and Bases on Impairment Method (Details) Note 3 - Loans - Loans Individually Evaluated for Impairment by Class of Loans (Details) Note 3 - Loans - Types of Troubled Debt Restructuring Loan Modification by Portfolio Segment (Details) Note 3 - Loans - Recorded Investment in Nonaccrual and Loans Past Due 90 Days and Still on Accrual by Class of Loan (Details) Note 3 - Loans - Aging of Recorded Investment in Past Due Loans (Details) US States and Political Subdivisions Debt Securities [Member] Note 3 - Loans - Risk Category of Loans by Class of Loans (Details) Note 4 - Other Real Estate Owned - Major Categories of OREO (Details) Share-based Payment Arrangement, Nonvested Award, Cost [Table Text Block] Note 4 - Other Real Estate Owned - Activity Relating to Other Real Estate Owned (Details) Note 4 - Other Real Estate Owned - Expenses Related to Other Real Estate Owned (Details) Note 5 - Deposits - Deposit Balances by Category (Details) Note 5 - Deposits - Maturities of Time Deposits (Details) Note 6 - Advances From the Federal Home Loan Bank - Advances From the Federal Home Loan Bank (Details) Collateralized Loan Obligations [Member] Granted, weighted average grant price (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Note 6 - Advances From the Federal Home Loan Bank - Advances From the Federal Home Loan Bank (Details) (Parentheticals) Pass [Member] us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss Available for sale, unrealized loss, 12 months or more Note 6 - Advances From the Federal Home Loan Bank - Principal Payments on Advances From the Federal Home Loan Bank (Details) Proceeds us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss Available for sale, unrealized loss Vested, weighted average grant price (in dollars per share) Forfeited, weighted average grant price (in dollars per share) Note 8 - Fair Values Measurement - Financial Assets Measured at the Fair Value on Recurring and Non-recurring Basis (Details) Note 8 - Fair Values Measurement - Qualitative Information About Level Three Fair Value Measurements for Financial Instruments Measured at Fair Value on Non-recurring Basis (Details) us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue Outstanding, weighted average grant price (in dollars per share) Outstanding, weighted average grant price (in dollars per share) Note 8 - Fair Values Measurement - Carrying Amount and Estimated Fair Values of Financial Instruments (Details) us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod Forfeited (in shares) Note 9 - Income Taxes - Deferred Tax Assets and Liabilities (Details) Note 10 - Stock Plans and Stock Based Compensation - Unvested Share Activity (Details) us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber Outstanding, beginning (in shares) Outstanding, ending (in shares) Note 10 - Stock Plans and Stock Based Compensation - Unrecognized Stock Based Compensation Expense Related to Unvested Shares (Details) us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss Available for sale, unrealized loss, less than 12 months Schedule of Nonvested Share Activity [Table Text Block] Note 11 - Earnings Per Share - Basic and Diluted Loss Per Share (Details) Internal Credit Assessment [Axis] lmst_FirstPriorityPledgePercentOfIssuedAndOutstandingStock First Priority Pledge, Percent of Issued and Outstanding Stock The amount of issued and outstanding stock of the company which secures a loan in a first priority pledge. Note 12 - Regulatory Capital Matters - Ratios and Amounts of Common Equity, Capital, and Total Capital to Risk-adjusted Assets (Details) Internal Credit Assessment [Domain] Maturities and prepayments of available for sale securities Note 13 - Off Balance Sheet Risks, Commitments, and Contingent Liabilities - Contractual Amounts of Financial Instruments With Off Balance Sheet Risk (Details) Granted (in shares) Corporate Debt Securities [Member] us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod Vested (in shares) Notes To Financial Statements Notes To Financial Statements [Abstract] lmst_DebtInstrumentFixedRateForFirstFiveYears Debt Instrument, Fixed Rate for First Five Years The contractual interest rate for the first five years after issuance of funds under the debt agreement US Treasury and Government [Member] us-gaap_OtherComprehensiveIncomeLossBeforeTax Net unrealized gain (loss) recognized in comprehensive income Ten Year Subordinated Debt Note, Issued July 23, 2019 [Member] Represents the ten year subordinated debt note, issued July 23, 2019 us-gaap_OtherComprehensiveIncomeLossTax Tax effect Net change in accumulated other comprehensive income, net of taxes Other comprehensive income (loss) Available for sale, fair value Available for sale, fair value, less than 12 months Available for sale, fair value, 12 months or more us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt Purchases of available for sale securities Financial Instruments [Domain] Net change in accrued interest payable and other liabilities The increase (decrease) during the reporting period in the total amount of accrued interest payable and other liabilities. lmst_IncreaseDecreaseInAccruedInterestReceivableAndOtherAssets Net change in accrued interest receivable and other assets The increase (decrease) during the reporting period in the total amount of accrued interest receivables and other assets. Financial Instrument [Axis] us-gaap_LoansAndLeasesReceivableImpairedCommitmentToLend Financing Receivable, Troubled Debt Restructuring, Commitment to Lend Agency mortgage-backed: residential, fair value lmst_EarningsPerShareBasicAndDilutedEstablishmentOfNetDeferredTaxAsset Earnings Per Share, Basic and Diluted, Establishment of Net Deferred Tax Asset The amount of benefit per basic and diluted share resulting from the establishment of a net deferred tax asset. Agency mortgage-backed: residential, amortized cost us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number, Ending Balance Loans, Notes, Trade and Other Receivables Disclosure [Text Block] lmst_ContributionToTierOneCapital Contribution to Tier One Capital The amount of contributions made to Tier 1 Capital as defined in the regulations. lmst_IncomeTaxExpenseBenefitFromNOLPerShare Income Tax Expense (Benefit) From NOL, Per Share Represents the amount per share of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to net operating loss carryforwards. Proceeds from sale of premises and equipment lmst_IncomeTaxExpenseBenefitFromNOL Income Tax Expense (Benefit) From NOL Represents the amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to net operating loss carryforwards. Credit Facility [Axis] Credit Facility [Domain] Initial recognition of right-of-use lease assets Represents the value of right-of-use assets recognized in noncash transactions us-gaap_PolicyTextBlockAbstract Accounting Policies Special Mention [Member] Substandard [Member] Doubtful [Member] us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant Add: Dilutive effects of assumed exercises of common stock warrants (in shares) us-gaap_PaymentsToAcquirePropertyPlantAndEquipment Purchases of premises and equipment, net Transfer from loans to other real estate Supplemental non-cash disclosure: lmst_LesseeOperatingLeaseLiabilityNotYetCommenced Lessee, Operating Lease, Liability, Not yet Commenced Represents the amount of the liability for operating leases not yet commenced. us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1 Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Troubled debt restructuring lmst_LesseeOperatingLeaseLeasesNotYetCommenced Lessee, Operating Lease, Leases Not yet Commenced Represents the amount of leases entered into, but not yet commenced. lmst_LesseeOperatingLeaseRightOfUseAssetNotYetCommenced Lessee, Operating Lease, Right-of-Use Asset, Not yet Commenced Represents the amount of the right-of-use asset for operating leases not yet commenced. us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1 Financing Receivable, Troubled Debt Restructuring, Subsequent Default, Number of Contracts us-gaap_Assets Total assets Supplemental cash flow information: us-gaap_LongTermDebtFairValue Senior Debt Weighted average common shares including unvested common shares outstanding (in shares) Plan Name [Axis] us-gaap_FinancingReceivableModificationsNumberOfContracts2 Financing Receivable, Modifications, Number of Contracts Plan Name [Domain] Loan Restructuring Modification [Axis] Loan Restructuring Modification [Domain] Net income available to common shareholders, basic and diluted Impaired Financing Receivables [Table Text Block] us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense Share-based Payment Arrangement, Expense, Tax Benefit Financing Receivable, Troubled Debt Restructuring [Table Text Block] Deposit account related expense Amount of noninterest expense on deposits. us-gaap_DeferredIncomeTaxAssetsNet Deferred taxes, net Share-based Payment Arrangement [Text Block] Earnings allocated to unvested shares Real estate acquired Award Type [Domain] Reclassification of disproportionate tax effect due to change in federal tax rate The amount of reclassification of tax effect from accumulated other comprehensive income. Federal Home Loan Bank advances Basis of Presentation and Significant Accounting Policies [Text Block] Net income Net income Award Type [Axis] Financial Instrument Performance Status [Axis] Financial Instrument Performance Status [Domain] Performing Financial Instruments [Member] Nonperforming Financial Instruments [Member] Standby Letters of Credit [Member] Loans Past Due 90 Days and Over Still Accruing Kentucky Municipalities [Member] Information pertaining to Kentucky municipalities. Kentucky Department of Revenue [Member] Information pertaining to Kentucky Department of Revenue. Financing Receivable Credit Quality Indicators [Table Text Block] Past due Warrant [Member] Nonaccrual Financial Asset, 30 to 59 Days Past Due [Member] Antidilutive Securities [Axis] Financial Asset, 60 to 89 Days Past Due [Member] Antidilutive Securities, Name [Domain] Financial Asset, Equal to or Greater than 90 Days Past Due [Member] Financing Receivable, Past Due [Table Text Block] Financial Asset, Period Past Due [Axis] Financial Asset, Period Past Due [Domain] Proceeds from sale of other real estate owned Commitments and Contingencies Disclosure [Text Block] Premises and equipment, net Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] us-gaap_FederalHomeLoanBankAdvancesWeightedAverageInterestRate Federal Home Loan Bank, Advances, Weighted Average Interest Rate Proceeds from mandatory redemptions of FHLB stock Derivative Instrument [Axis] Derivative Contract [Domain] Cash flows from investing activities Securities available for sale Debt Securities, Available-for-sale, Total Total, fair value Earnings Per Share [Text Block] lmst_JuniorSubordinatedDebtFairValueDisclosure Junior subordinated debentures Fair value of junior subordinated debt obligations. us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments Income before income taxes Income tax expense Other real estate owned, gross us-gaap_MortgageLoansInProcessOfForeclosureAmount Mortgage Loans in Process of Foreclosure, Amount us-gaap_OtherRealEstateDisposals Proceeds from sales of properties lmst_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedIntrinsicValue1 Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other Than Options, Nonvested Intrinsic Value1 The fair value of non-vested equity-based payment instruments, excluding stock (or unit) options, issued as of the balance sheet date. us-gaap_DebtInstrumentTerm Debt Instrument, Term lmst_SharebasedCompensationArrangementBySharebasedPaymentAwardExpectedFutureCompensationYearFour 2022 The expected future compensation expense related to unvested shares in year four. Interest bearing deposits in banks us-gaap_CashAndCashEquivalentsAtCarryingValue Beginning cash and cash equivalents Ending cash and cash equivalents us-gaap_RealEstateOwnedValuationAllowanceAmountsApplied Real Estate Owned, Valuation Allowance, Amounts Applied Salaries and employee benefits Cash and due from banks us-gaap_AllocatedShareBasedCompensationExpense Share-based Payment Arrangement, Expense Valuation adjustment write-downs Valuation adjustment write-downs Loans individually evaluated for impairment Loans collectively evaluated for impairment Real Estate Owned [Text Block] Individually evaluated for impairment Collectively evaluated for impairment Amendment Flag Impaired loans, measurement input Impaired Loans, Measurement Input Value of input used to measure impaired loans. Recoveries us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs Loans charged off us-gaap_ComprehensiveIncomeNetOfTax Comprehensive income Use of Estimates, Policy [Policy Text Block] New Accounting Pronouncements, Policy [Policy Text Block] us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardForfeitures Forfeited unvested stock Measurement Input, Estimated Discount for Cost to Sell [Member] Measurement input using estimated discounts for cost to sell. Reclassification, Policy [Policy Text Block] us-gaap_DebtInstrumentPeriodicPaymentPrincipal Debt Instrument, Periodic Payment, Principal us-gaap_GainLossOnSaleOfPropertyPlantEquipment Net gain on sales of premises and equipment us-gaap_SharesOutstanding Balances (in shares) Balances (in shares) Common stock, shares outstanding (in shares) Financing Receivable, Allowance for Credit Loss [Table Text Block] Net gain on sales Net gain on sales of other real estate owned Current Fiscal Year End Date us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 Debt Instrument, Basis Spread on Variable Rate Impaired loans, fair value Fair value portion of impaired loans. us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent Operating Lease, Weighted Average Discount Rate, Percent Document Fiscal Period Focus us-gaap_OperatingLeaseCost Operating Lease, Cost Net loss on sales and calls of investment securities Net realized loss on sales and calls of investment securities Document Fiscal Year Focus Document Period End Date Tier 1 capital (to average assets), actual ratio Tier 1 capital (to average assets), for capital adequacy purposes, ratio Entity Emerging Growth Company us-gaap_DebtInstrumentFaceAmount Debt Instrument, Face Amount Tier 1 capital (to average assets), for minimum requirements to be well capitalized, ratio Document Type Total risk-based capital to risk-weighted assets, for minimum requirements to be well capitalized, ratio Measurement Input, Discount Rate or Cap Rate [Member] Measurement input using interest rate to determine present value of future cash flows or using ratio of net operating income produced by asset to its capital cost. Entity Small Business Entity Shell Company us-gaap_CollateralizedAgreements Collateralized Agreements, Total Commercial Real Estate Property [Member Information pertaining to commercial real estate property. Document Information [Line Items] Document Information [Table] Total risk-based capital to risk-weighted assets, actual ratio Other real estate owned, fair value Fair value portion of other real estate owned. Total risk-based capital to risk-weighted assets, for capital adequacy purposes, ratio Capital Required for Capital Adequacy to Risk Weighted Assets Entity Filer Category Debt Instrument [Axis] Tier I capital to risk-weighted assets, actual ratio Entity Current Reporting Status Debt Instrument, Name [Domain] Tier I capital to risk-weighted assets, for capital adequacy purposes, ratio Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets Tier I capital to risk-weighted assets, for minimum requirements to be well capitalized, ratio London Interbank Offered Rate (LIBOR) [Member] Total risk-based capital to risk-weighted assets, actual amount Total risk-based capital to risk-weighted assets, for capital adequacy purposes, amount Total risk-based capital to risk-weighted assets, for minimum requirements to be well capitalized, amount Variable Rate [Domain] Net write-down of other real estate owned Bank owned life insurance Tier 1 capital (to average assets), actual amount Tier 1 capital (to average assets), for capital adequacy purposes, amount Variable Rate [Axis] Tier 1 capital (to average assets), for minimum requirements to be well capitalized, amount Stock-based compensation expense Schedule of Real Estate Properties [Table Text Block] Statement of Comprehensive Income [Abstract] Net write-down on premises held for sale Entity Central Index Key Tier I capital to risk-weighted assets, actual amount Entity Registrant Name Tier I capital to risk-weighted assets, for capital adequacy purposes, amount Tier I capital to risk-weighted assets, for minimum requirements to be well capitalized, amount Entity [Domain] Legal Entity [Axis] Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table Text Block] us-gaap_FinancingReceivableAllowanceForCreditLosses Balance Balance Regulatory Capital Requirements under Banking Regulations [Text Block] Other real-estate Other real estate owned OREO OREO us-gaap_StockRedeemedOrCalledDuringPeriodValue Redemption and retirement of preferred shares us-gaap_StockRedeemedOrCalledDuringPeriodShares Redemption and retirement of preferred shares (in shares) Entity Common Stock, Shares Outstanding (in shares) lmst_InterestExpenseSeniorDebt Senior debt Amount of interest expense on senior debt. Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] us-gaap_OtherForeclosedAssets Other Repossessed Assets Marketable Securities [Table Text Block] Loans, net of allowance of $8,904 and $8,880, respectively Loans, net Gross loans Total ending loans balance Professional fees Loans, allowance Less: Allowance for loan losses Total ending allowance balance Long-term Debt [Text Block] Marketing expense Trading Symbol Data processing expense Deferred compensation Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from deferred compensation. Deferred loan costs Amount of deferred tax liability attributable to taxable temporary differences from deferred loan costs. us-gaap_TableTextBlock Notes Tables us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardForfeited Forfeited unvested stock (in shares) Proceeds from sales of loans held for sale us-gaap_FederalHomeLoanBankAdvancesMaturitiesSummaryDueInRollingYearThree Year 3 us-gaap_FederalHomeLoanBankAdvancesMaturitiesSummaryDueInRollingYearFour Year 4 us-gaap_FederalHomeLoanBankAdvancesMaturitiesSummaryDueInRollingYearFive Year 5 us-gaap_FederalHomeLoanBankAdvancesMaturitiesSummaryDueAfterRollingYearFive Thereafter Risk Level, A Rated [Member] "A" rated risk level determined by a financial institution which provides risk ratings (Standard & Poor's, Moody's, Fitch, etc.) Risk Level, AA Rated [Member] "AA" rated risk level determined by a financial institution which provides risk ratings (Standard & Poor's, Moody's, Fitch, etc.) us-gaap_FederalHomeLoanBankAdvancesMaturitiesSummaryDueInNextRollingTwelveMonths Year 1 us-gaap_FederalHomeLoanBankAdvancesMaturitiesSummaryDueInRollingYearTwo Year 2 Other real estate owned, measurement input Risk Level, Subject to Downgrade [Member] Risk level determined to be "subject to downgrade" by a financial institution which provides risk ratings (Standard & Poor's, Moody's, Fitch, etc.) Federal Home Loan Bank stock Risk Level, Below A Rated [Member] Below "A" rated risk level determined by a financial institution which provides risk ratings (Standard & Poor's, Moody's, Fitch, etc.) Issuance of stock (in shares) us-gaap_FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresAmountOfAvailableUnusedFunds Federal Home Loan Bank, Advances, General Debt Obligations, Amount of Available, Unused Funds us-gaap_FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresRepaymentAndPenalties Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Repayment and Penalties us-gaap_LiabilitiesAndStockholdersEquity Total liabilities and stockholders’ equity us-gaap_FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresCollateralPledged1 Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Collateral Pledged Reported Value Measurement [Member] us-gaap_CashCashEquivalentsAndFederalFundsSold Cash and cash equivalents Issuance of stock Retained deficit Accumulated other comprehensive loss Measurement Input, Comparability Adjustment [Member] Measurement Input, Discount Rate [Member] Premises held for sale us-gaap_InterestExpense us-gaap_DisclosureTextBlockAbstract Notes to Financial Statements Federal Home Loan Bank Advances, Disclosure [Text Block] Schedule of Federal Home Loan Bank, Advances, by Branch of FHLB Bank [Table Text Block] us-gaap_OperatingLeaseLiability Operating Lease, Liability, Total Junior subordinated debentures us-gaap_InterestExpenseJuniorSubordinatedDebentures Subordinated capital note us-gaap_InterestExpenseSubordinatedNotesAndDebentures us-gaap_OperatingLeaseRightOfUseAsset Operating Lease, Right-of-Use Asset us-gaap_DeferredIncomeTaxExpenseBenefit Deferred taxes, net Measurement Input Type [Axis] Measurement Input Type [Domain] Deposits us-gaap_InterestExpenseDeposits Valuation Approach and Technique [Axis] Valuation Approach and Technique [Domain] Valuation, Income Approach [Member] Stock-based compensation expense us-gaap_ShareBasedCompensation Interest expense 2018 Omnibus Equity Compensation Plan [Member] And equity incentive plan created in 2018. us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments Net amortization on securities us-gaap_InterestAndDividendIncomeOperating Other real estate owned expense Total Represents the total amount of other real estate owned expense. Depreciation and amortization us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation Stock issued for share-based awards, net of withholdings to satisfy employee tax obligations upon award (in shares) Stock issued for share-based awards, net of withholdings to satisfy employee tax obligations upon award lmst_CapitalConservationBuffer Capital Conservation Buffer The capital conservation buffer that must be maintained by the bank, above certain other regulatory capital requirements. us-gaap_FederalHomeLoanBankBorrowingsFairValueDisclosure Federal Home Loan Bank advances lmst_CapitalConservationBufferAnnualPhasein Capital Conservation Buffer, Annual Phase-In The annual phase-in percentage of the capital conservation buffer that requires the bank to hold capital above certain regulatory requirements. us-gaap_CashAndCashEquivalentsFairValueDisclosure Cash and cash equivalents us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisSubordinatedDebtObligations Subordinated capital note Year 4 Year 5 Thereafter Taxable securities Tax exempt securities Year 1 Year 2 Year 3 Fair Value, Nonrecurring [Member] Common stock, no par, 39,000,000 shares authorized, 6,251,582 and 6,242,720 voting, and 1,220,000 and 1,220,000 non-voting issued and outstanding, respectively us-gaap_GainLossOnSaleOfLoansAndLeases Net gain on sales of loans held for sale Senior Notes [Member] Adjustments to reconcile net income to net cash from operating activities Measurement Frequency [Axis] Measurement Frequency [Domain] Loans, including fees Fair Value, Recurring [Member] Common stock, shares authorized (in shares) Common stock, shares issued (in shares) Common stock, no par (in dollars per share) lmst_DebtInstrumentFinancialCovenantsNonPerformingAssetsToTotalAssetsPercentageMinimum Debt Instrument, Financial Covenants, Non-performing Assets to Total Assets, Percentage, Minimum The minimum percentage of non-performing assets to total assets that are required to maintain pursuant to the debt agreement. Statistical Measurement [Domain] Maximum [Member] lmst_DebtInstrumentFinancialConvenantsMinimumCashOnHand Debt Instrument, Financial Convenants, Minimum Cash on Hand The minimum cash that is required to hold on hand pursuant to the debt agreement. Minimum [Member] lmst_DebtInstrumentFinancialConvenantsMinimumRiskBasedCapitalToRiskWeightedAssets Debt Instrument, Financial Convenants, Minimum Risk Based Capital to Risk Weighted Assets The minimum risk based capital to risk weighted assets ratio that are required to maintain pursuant to the debt agreement. Weighted Average [Member] Ownership [Domain] Product and Service [Axis] Product and Service [Domain] Limestone Bank [Member] Limestone Bank. Statistical Measurement [Axis] Interest income Gross gains This item represents the gross profit realized on the sale of debt or equity securities. Ownership [Axis] Gross losses This item represents the gross loss realized on the sale of debt or equity securities. us-gaap_DeferredTaxAssetsLiabilitiesNet Net deferred tax asset Interest paid Other us-gaap_DeferredTaxAssetsGross Certificates of deposit us-gaap_DeferredIncomeTaxLiabilities Portion at Fair Value Measurement [Member] [Default] Interest checking Estimate of Fair Value Measurement [Member] Other us-gaap_NoninterestIncomeOtherOperatingIncome Non-interest income revenue Revenue from Contract with Customer, Including Assessed Tax Net assets from acquisitions Measurement Basis [Axis] Net unrealized loss on securities Fair Value, Inputs, Level 3 [Member] us-gaap_TimeDepositsAtOrAboveFDICInsuranceLimit Time Deposits, at or Above FDIC Insurance Limit Fair Value Hierarchy and NAV [Domain] Income from bank owned life insurance Deposit Liabilities Disclosures [Text Block] Fair Value, Inputs, Level 1 [Member] Fair Value, Inputs, Level 2 [Member] Non-interest income us-gaap_DeferredTaxAssetsStateTaxes Deferred Tax Assets, State Taxes Fair Value Hierarchy and NAV [Axis] us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss Net interest income after provision for loan losses Provision (negative provision) for loan losses Accrued expenses Premises and Equipment [Member] Premises and equipment used in the normal conduct of business. us-gaap_InterestIncomeExpenseNet Net interest income Cash flows from operating activities Allowance for loan losses Statement [Line Items] Additional paid-in capital Accrued interest receivable and other assets Financial Instrument off Balance Sheet Risk, Amount AOCI Attributable to Parent [Member] Stockholders’ equity us-gaap_InvestmentInFederalHomeLoanBankStockFairValueDisclosure Federal Home Loan Bank stock Voting Common Stock [Member] Related to voting common stock. Schedule of Fair Value, Off-balance Sheet Risks [Table Text Block] Federal Home Loan Bank advances lmst_InterestExpenseFederalHomeLoanBankAndFederalReserveBankAdvances Interest expense incurred during the reporting period on borrowings associated with Federal Home Loan Bank and Federal Reserve Bank advances. Alternative minimum tax credit carry-forward Deferred Tax Assets, Tax Credit Carryforwards, Alternative Minimum Tax Federal funds sold and other The aggregate interest income earned from (1) the lending of excess federal funds to other commercial banks, (2) securities purchased under agreements to resell, (3) interest-bearing balances with other financial institutions, and (4) FHLB stock. New market tax credit carry-forward us-gaap_LoansReceivableFairValueDisclosure Loans, net Deposit Account [Member] Net operating loss carry-forward State franchise and deposit tax Represents the state franchise and deposit tax. Occupancy and equipment Amount of net occupancy expense that may include items, such as depreciation of facilities and equipment, lease expenses, property taxes and property and casualty insurance expense and equipment expense including depreciation, repairs, rentals, and service contract costs. This item also includes equipment purchases which do not qualify for capitalization in accordance with the entity's accounting policy. This item may also include furniture expenses. Litigation and loan collection expense Fees charged for services from professionals for collecting loan payments from customers who have defaulted on their loans. Fair Value Disclosures [Text Block] Fair Value, by Balance Sheet Grouping [Table Text Block] Debit Card [Member] Deferred tax assets: lmst_StateFranchiseTaxPercent State Franchise Tax, Percent Represents the franchise tax rate, assessed as a percentage of average capital. Assets lmst_PaymentsForProceedsFromLoanOriginationsAndPrincipalCollections Loan originations and payments, net The net cash outflow or inflow related to a loan origination (the process when securing a mortgage for a piece of real property), lease origination, and principal collections. us-gaap_Liabilities Total liabilities us-gaap_NetCashProvidedByUsedInFinancingActivities Net cash from financing activities Commitments and contingent liabilities (Note 13) us-gaap_NetCashProvidedByUsedInOperatingActivities Net cash from operating activities Other us-gaap_DeferredTaxLiabilitiesOther us-gaap_NetCashProvidedByUsedInInvestingActivities Net cash from investing activities us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease Net change in cash and cash equivalents Accounting Standards Update 2016-02 [Member] Subsidiaries [Member] FHLB stock dividends us-gaap_DeferredTaxLiabilitiesInvestments Net unrealized gain on securities Consolidated Entities [Axis] Consolidated Entities [Domain] Type of Adoption [Domain] Allowance for loan losses allocated, with an allowance recorded Impaired Financing Receivable, Related Allowance us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation Common shares withheld for taxes Fixed assets us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment Adjustments for New Accounting Pronouncements [Axis] us-gaap_ImpairedFinancingReceivableInterestIncomeCashBasisMethod Impaired Financing Receivable, Interest Income, Cash Basis Method, Total Interest income recognized, with no related allowance recorded Interest income recognized, with an allowance recorded Deferred tax liabilities: Interest income recognized, total Recorded investment, with no related allowance recorded Recorded investment, with an allowance recorded Impaired Financing Receivable, with Related Allowance, Recorded Investment Recorded investment, total Average recorded investment, with no related allowance recorded Average recorded investment, with an allowance recorded Average recorded investment, total Unpaid principal balance, with no related allowance recorded Unpaid principal balance, with an allowance recorded Unpaid principal balance, total us-gaap_OtherNoninterestExpense Other us-gaap_NoninterestExpense Scenario [Domain] lmst_IncreaseDecreaseInCashSurrenderValueOfBankOwnedLifeInsuranceNet Earnings on bank owned life insurance, net of premium expense The amount of increase (decrease) during the period in the cash surrender value of bank owned life insurance, net of premium expense. Forecast [Member] FDIC Insurance us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense, Total Retained Earnings [Member] Short-term advances from the FHLB, fixed rate Rate of Federal Home Loan Bank (FHLB) advances which have fixed interest rates maturing in the next fiscal year following the latest fiscal year. Long term advances from the FHLB, fixed rate Rate of Federal Home Loan Bank (FHLB) advances which have fixed interest rates maturing after the latest fiscal year. Issuance of common stock Scenario [Axis] Non-interest expense Additional Paid-in Capital [Member] Common Stock [Member] Preferred Stock [Member] Collateral [Domain] Equity Components [Axis] Equity Component [Domain] Long term advances (fixed rates 0.00% to 5.24%) maturing April 2020 to August 2033 us-gaap_PaymentsForRepurchaseOfRedeemablePreferredStock Redemption of preferred stock Collateral [Axis] Class of Financing Receivable [Domain] us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1 Class of Warrant or Right, Exercise Price of Warrants or Rights Construction Loans [Member] Other Assets [Member] Commercial Real Estate Portfolio Segment [Member] Class of Financing Receivable [Axis] us-gaap_SeniorNotes Senior debt Financing Receivable Portfolio Segment [Domain] Commercial Portfolio Segment [Member] Residential Portfolio Segment [Member] Consumer Portfolio Segment [Member] Financing Receivable Portfolio Segment [Axis] PBI Bank [Member] The legal entity PBI Bank. Junior subordinated debentures Other comprehensive income (loss): us-gaap_LineOfCredit Long-term Line of Credit, Total Reclassification out of Accumulated Other Comprehensive Income [Table Text Block] lmst_ConcentrationRiskNumber Concentration Risk Number Represents the number of holdings of securities by any one issuer, other than the U.S. Government and its agencies, in an amount greater than 10% of stockholders' equity. Subordinated capital note State and Local Jurisdiction [Member] Income Tax Authority, Name [Axis] Income Tax Authority, Name [Domain] Income Tax Authority [Axis] Income Tax Authority [Domain] Domestic Tax Authority [Member] Revenue from Contract with Customer [Text Block] us-gaap_RepaymentsOfFederalHomeLoanBankBorrowings Repayment of Federal Home Loan Bank advances Balance Sheet Location [Axis] Balance Sheet Location [Domain] us-gaap_RepaymentsOfSubordinatedDebt Repayment of subordinated capital note us-gaap_UnrecognizedTaxBenefits Unrecognized Tax Benefits, Ending Balance Accounting Policies [Abstract] us-gaap_EarlyRepaymentOfSeniorDebt Early Repayment of Senior Debt Basis of Accounting, Policy [Policy Text Block] us-gaap_RepaymentsOfSeniorDebt Repayment of senior debt lmst_FinancingReceivableModificationsPercentageOfPerformingTdrsToTotalTdrs Financing Receivable Modifications Percentage of Performing TDRs to Total TDRs The ratio of performing troubled debt restructurings to total troubled debt restructurings. lmst_MinimumOutstandingBalanceForLoansToBeQualifiedForCreditRiskAnalysis Minimum Outstanding Balance for Loans to be Qualified for Credit Risk Analysis The minimum outstanding balance for loans to be qualified for credit risk analysis. lmst_TroubledDebtRestructuringReserve Troubled Debt Restructuring Reserve The troubled debt restructuring reserve. Nonfarm Nonresidential [Member] Related to Nonfarm Nonresidential loans. Farmland Loans [Member] Related to farmland loans. Multifamily Loans [Member] Related to multifamily loans. Agriculture Portfolio Segment [Member] Related to the agriculture portfolio segment. Short term advances (fixed rates 2.03% to 2.11%) maturing October 2019 One- to Four-family Residential Properties [Member] Related to one to four family residential properties loans. Title of 12(b) Security Other Portfolio Segment [Member] Related to the other portfolio segment. Proceeds from issuance of subordinated capital note Proceeds from Issuance of Subordinated Long-term Debt Advances from Federal Home Loan Bank Impairment Evaluation of Financing Receivables [Table Text Block] Impairment Evaluation of Financing Receivables. us-gaap_DepositsFairValueDisclosure Deposits Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block] Real Estate, Type of Property [Axis] Real Estate [Domain] Accrued interest payable and other liabilities Sales and calls of available for sale securities us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding Weighted average common shares and potential common shares (in shares) Total past due and nonaccrual The recorded investment on nonaccrual status and past due financing receivables. Basic and diluted income per common share (in dollars per share) us-gaap_OperatingLossCarryforwards Operating Loss Carryforwards, Total Watch [Member] Related to watch rating. Construction, Land Development, and Other Land Loans [Member] Related to construction land development and other land loans. Asset Class [Axis] Operating expense The foreclosed real estate operating expense. Asset Class [Domain] Schedule of Expenses Related to Foreclosed Real Estate [Table Text Block] The tabular disclosure for the activity during the period relating to other real estate owned. Statement [Table] us-gaap_MinorityInterestOwnershipPercentageByParent Noncontrolling Interest, Ownership Percentage by Parent Statement of Financial Position [Abstract] Diluted income per common share (in dollars per share) Weighted average shares outstanding (in shares) Schedule of Deposits [Table Text Block] The tabular disclosure of deposit balances by category. Schedule of Maturities of Time Deposits [Table Text Block] The tabular disclosure of maturities for time deposits. Basic income per common share (in dollars per share) Statement of Cash Flows [Abstract] Routine Real Estate Collateral [Member] Related to routine real estate collateral. Thin Trading Market or Specialized Collateral [Member] Related to thin trading market or specialized collateral. Impaired Loans [Member] Related to impaired loans. Statement of Stockholders' Equity [Abstract] Other Real Estate Owned [Member] Related to other real estate owned. Income Statement [Abstract] lmst_ImpairedFinancingReceivableProvisionForLoanLosses Impaired Financing Receivable Provision for Loan Losses Represents the provision for loan losses on impaired loans. Measured for Impairment Using Fair Value of Collateral [Member] Related to the measurement used for impairment using fair value for collateral. Financing Receivable, Nonaccrual [Table Text Block] Total Total deposits Investments Classified by Contractual Maturity Date [Table Text Block] Interest bearing Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Schedule of Unrealized Loss on Investments [Table Text Block] Net change in deposits Non-interest bearing Non-interest bearing us-gaap_TimeDeposits Schedule of Realized Gain (Loss) [Table Text Block] Money market Fair Value Assets Measured on Nonrecurring Basis Unobservable Input Reconciliation [Table Text Block] Fair Value, Assets Measured on Nonrecurring Basis, Unobservable Input Reconciliation. Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Table Text Block] Reclassification adjustment for gains (losses) included in net income Savings us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent lmst_CommitmentsPeriod Commitments Period The commitments period of commitments to make loans. Unrealized gain (loss) arising during the period Deposits Contractual Interest Rate Reduction [Member] Fixed Rate [Member] Loan to purchase in which the interest rate and the amount of each payment remain constant throughout the life of the loan. lmst_AccruedInterestReceivableFairValue Accrued interest receivable Represents the fair value of accrued interest receivable. Cash flows from financing activities Loan Commitment [Axis] Information by loan commitment. lmst_AccruedInterestPayableFairValue Accrued interest payable Represents the fair value of accrued interest payable. Loan Commitment [Domain] lmst_CommonStockOwnershipPercentage Common Stock Ownership Percentage The minimum aggregate ownership percentage that would limit the company's ability to utilize its NOL. Variable Rate [Member] Loan to purchase in which the interest rate and the amount of each payment varies throughout the life of the loan. lmst_CommonStockOwnershipPercentageByIndividual Common Stock Ownership Percentage by Individual The minimum individual shareholder's ownership percentage that would limit the company's ability to utilize its NOL. lmst_DividendDeclaredPreferredStockPurchaseRightPerEachShareOfCommonStock Dividend Declared Preferred Stock Purchase Right Per Each Share of Common Stock The number of preferred stock purchase rights for each share of common stock outstanding declared as a dividend. Commitments to Make Loans [Member] Represents the commitments to make loans. OREO write-down Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from impairment losses. Nonaccrual loan interest Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from nonaccrual interest on loans. Non-Employee Directors Stock Incentive Plan 2006 [Member] Related to the nonemployee directors stock incentive plan. Unvested Shares [Member] Related to unvested shares. us-gaap_SecurityOwnedAndPledgedAsCollateralFairValue Security Owned and Pledged as Collateral, Fair Value, Total lmst_ShareBasedCompensationArrangementByShareBasedPaymentAwardAnnualAwardToNonEmployeeDirectorsValue Share-based Compensation Arrangement by Share-based Payment Award, Annual Award to Non Employee Directors, Value Represents the fair market value of the annual awards to each non-employee director. Valuation, Cost Approach [Member] Series E Preferred Stock [Member] Unused lines of Credit [Member] Series F Preferred Stock [Member] us-gaap_StockholdersEquity Total stockholders' equity Balances Balances Nonvoting Common Stock [Member] Class of Stock [Axis] Class of Stock [Domain] lmst_ShareBasedCompensationArrangementByShareBasedPaymentAwardExpectedFutureCompensationYearTwo 2020 The expected future compensation expense related to unvested shares in year two. lmst_ShareBasedCompensationArrangementByShareBasedPaymentAwardExpectedFutureCompensationRemainderOfYear October 2019 – December 2019 The expected future compensation expense related to unvested shares for the remainder of the fiscal year. Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] lmst_ShareBasedCompensationArrangementByShareBasedPaymentAwardExpectedFutureCompensationYearThree 2021 The expected future compensation expense related to unvested shares in year three. us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax Available for sale securities, gross unrealized losses Available for sale securities, gross unrealized gains lmst_MaximumAssetForOptOutRequirementInCapitalCalculation Maximum Asset for Opt Out Requirement in Capital Calculation For banks and their holding companies with less than $250 billion in assets, a one-time opportunity to opt-out of a requirement to include unrealized gains and losses in accumulated other comprehensive income in the capital calculation was allowed. Available for sale securities, amortized cost Total, amortized cost One to five years, amortized cost Five to ten years, amortized cost Beyond ten years, amortized cost