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 - Leases Within one year, fair value Note 5 - Other Real Estate Owned 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 - Goodwill and Intangible Assets Five to ten years, fair value Note 7 - Deposits Note 8 - Advances from the Federal Home Loan Bank Residential Mortgage Backed Securities [Member] Note 10 - Fair Values Measurement Income Tax Disclosure [Text Block] Note 11 - Income Taxes Collateralized Debt Obligations [Member] Note 12 - Stock Plans and Stock Based Compensation Note 13 - Earnings per Share Note 14 - Regulatory Capital Matters Note 15 - Off Balance Sheet Risks, Commitments, and Contingent Liabilities Schedule of Maturities of Long-term Debt [Table Text Block] 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) 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) US States and Political Subdivisions Debt Securities [Member] 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) Share-based Payment Arrangement, Nonvested Award, Cost [Table Text Block] Note 3 - Loans - Risk Category of Loans by Class of Loans (Details) Note 4 - Leases - Future Minimum Lease Payments (Details) Note 5 - Other Real Estate Owned - Major Categories of OREO (Details) Note 5 - Other Real Estate Owned - Activity Relating to Other Real Estate Owned (Details) Note 5 - Other Real Estate Owned - Expenses Related to Other Real Estate Owned (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 (in dollars per share) Note 6 - Goodwill and Intangible Assets - Schedule of Goodwill and Intangible Assets (Details) Pass [Member] us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss Available for sale, unrealized loss, 12 months or more Note 6 - Goodwill and Intangible Assets - Expected Amortization Expense (Details) Proceeds us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss Available for sale, unrealized loss Vested, weighted average grant price (in dollars per share) Note 7 - Deposits - Deposit Balances by Category (Details) Forfeited, weighted average grant price (in dollars per share) Note 7 - Deposits - Maturities of Time Deposits (Details) us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue Outstanding, weighted average grant price (in dollars per share) Outstanding, weighted average grant price (in dollars per share) Note 8 - Advances from the Federal Home Loan Bank - Advances From the Federal Home Loan Bank (Details) us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod Forfeited (in shares) Note 8 - Advances from the Federal Home Loan Bank - Advances From the Federal Home Loan Bank (Details) (Parentheticals) Note 8 - Advances from the Federal Home Loan Bank - Principal Payments on Advances From the Federal Home Loan Bank (Details) us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber Outstanding, beginning (in shares) Outstanding, ending (in shares) us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss Available for sale, unrealized loss, less than 12 months Note 10 - Fair Values Measurement - Financial Assets Measured at the Fair Value on Recurring and Non-recurring Basis (Details) Schedule of Nonvested Share Activity [Table Text Block] Note 10 - Fair Values Measurement - Carrying Amount and Estimated Fair Values of Financial Instruments (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 11 - Income Taxes - Deferred Tax Assets and Liabilities (Details) Internal Credit Assessment [Domain] Proceeds from maturities and prepayments of available for sale securities Note 12 - Stock Plans and Stock Based Compensation - Unvested Share Activity (Details) Granted (in shares) Note 12 - Stock Plans and Stock Based Compensation - Unrecognized Stock Based Compensation Expense Related to Unvested Shares (Details) Corporate Debt Securities [Member] us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod Vested (in shares) Note 13 - Earnings per Share - Basic and Diluted Loss Per Share (Details) Note 14 - Regulatory Capital Matters - Ratios and Amounts of Common Equity, Capital, and Total Capital to Risk-adjusted Assets (Details) 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 Note 15 - Off Balance Sheet Risks, Commitments, and Contingent Liabilities - Contractual Amounts of Financial Instruments With Off Balance Sheet Risk (Details) US Treasury and Government [Member] Notes To Financial Statements us-gaap_OtherComprehensiveIncomeLossBeforeTax Net unrealized gain (loss) recognized in comprehensive income (loss) Notes To Financial Statements [Abstract] 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 loss, 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] Goodwill, Gross 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, Modifications, Number of Contracts Goodwill and Intangible Assets Disclosure [Text Block] Agency mortgage-backed: residential, fair value Lessee, Operating Leases [Text Block] Agency mortgage-backed: residential, amortized cost us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number, Ending Balance (in shares) Loans, Notes, Trade and Other Receivables Disclosure [Text Block] 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 (in shares) Add: Dilutive effects of assumed exercises of common stock warrants (in shares) us-gaap_PaymentsToAcquirePropertyPlantAndEquipment Purchases of premises and equipment Transfer from loans to other real estate Supplemental non-cash disclosure: us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1 Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year) Troubled debt restructuring 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, Troubled Debt Restructuring, Subsequent Default, Number of Contracts Plan Name [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] Core Deposits [Member] Deposit account related expense Amount of noninterest expense on deposits. us-gaap_DeferredIncomeTaxAssetsNet Deferred taxes, net Share-based Payment Arrangement [Text Block] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets, Major Class Name [Domain] Earnings allocated to unvested shares Real estate acquired Award Type [Domain] Federal Home Loan Bank advances Advances from Federal Home Loan Banks, Total Total advances from the Federal Home Loan Bank Basis of Presentation and Significant Accounting Policies [Text Block] Net income Net income Award Type [Axis] Accumulated Amortization Financial Instrument Performance Status [Axis] us-gaap_FiniteLivedIntangibleAssetsNet Finite-Lived Intangible Assets, Net, Ending Balance 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. Financing Receivable Credit Quality Indicators [Table Text Block] Core deposit intangibles, Gross Past due Nonaccrual Financial Asset, 30 to 59 Days Past Due [Member] Financial Asset, 60 to 89 Days Past Due [Member] 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] Commitments and Contingencies Disclosure [Text Block] Premises and equipment, net Goodwill Goodwill, Ending Balance Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] us-gaap_FederalHomeLoanBankAdvancesWeightedAverageInterestRate Federal Home Loan Bank, Advances, Weighted Average Interest Rate us-gaap_PaymentsToAcquireFederalHomeLoanBankStock Purchases of Federal Home Loan Bank stock Proceeds from mandatory redemptions of Federal Home Loan Bank 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 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. lmst_SharebasedCompensationArrangementBySharebasedPaymentAwardExpectedFutureCompensationYearFour 2023 The expected future compensation expense related to unvested shares in year four. Insurance expense Interest bearing deposits in banks us-gaap_CashAndCashEquivalentsAtCarryingValue Beginning cash and cash equivalents Ending cash and cash equivalents 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 lmst_ImpairedLoansMeasurementInput Impaired Loans, Measurement Input Value of input used to measure impaired loans. Recoveries us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs Loans charged off us-gaap_ComprehensiveIncomeNetOfTax Comprehensive income (loss) 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, Comparability Adjustment [Policy Text Block] us-gaap_DebtInstrumentPeriodicPaymentPrincipal Debt Instrument, Periodic Payment, Principal 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 loss (gain) on sales Current Fiscal Year End Date us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 Debt Instrument, Basis Spread on Variable Rate us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent Operating Lease, Weighted Average Discount Rate, Percent Document Fiscal Period Focus Document Fiscal Year Focus Document Period End Date us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1 Operating Lease, Weighted Average Remaining Lease Term (Year) Tier 1 capital (to average assets), actual ratio Tier 1 capital (to average assets), for capital adequacy purposes, ratio Entity Emerging Growth Company 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 Entity Small Business Entity Shell Company us-gaap_CollateralizedAgreements Collateralized Agreements, Total Total common equity Tier 1 risk-based capital (to risk-weighted assets), actual ratio Document Information [Line Items] Document Information [Table] Total risk-based capital to risk-weighted assets, actual ratio Total risk-based capital to risk-weighted assets, for capital adequacy purposes, ratio 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 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 us-gaap_GoodwillImpairmentLoss Goodwill, Impairment Loss 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 Total common equity Tier 1 risk-based capital (to risk-weighted assets), actual amount Stock-based compensation expense Schedule of Real Estate Properties [Table Text Block] Statement of Comprehensive Income [Abstract] Total common equity Tier 1 risk-based capital (to risk-weighted assets), for capital adequacy purposes, amount Impairment of premises held for sale Total common equity Tier 1 risk-based capital (to risk-weighted assets), for minimum requirements to be well capitalized, amount 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] us-gaap_AmortizationOfIntangibleAssets Amortization of Intangible Assets, Total 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 owned OREO OREO 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] Marketable Securities [Table Text Block] Measurement Input, Recovery Rate Over One Year Lag [Member] Measurement input using recovery rate over a one year lag. Loans, net of allowance of $9,150 and $8,376, respectively Loans, net Measurement Input, Constant Default Rate for After First Four Years [Member] Measurement input for after the first four years using likelihood loan will not be repaid as proportion of outstanding loan. Measurement Input, Constant Default Rate for First Four Years [Member] Measurement input for the first four years using likelihood loan will not be repaid as proportion of outstanding loan. 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 Transfer from premises and equipment to premises held for sale Transfer of amount classified as property, plant and equipment to property, plant and equipment attributable to disposal group held for sale or disposed of, expected to be disposed of after one year or the normal operating cycle, if longer. Communications expense Data processing expense 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) 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 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.) 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 Retained deficit Accumulated other comprehensive loss Measurement Input, Discount Rate [Member] Premises held for sale us-gaap_InterestExpense Interest Expense, Total 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 Other intangible assets, net Amortization of operating lease right-of-use assets Represents the amortization of operating lease right-of-use assets. Subordinated capital note us-gaap_InterestExpenseSubordinatedNotesAndDebentures us-gaap_OperatingLeaseRightOfUseAsset Operating Lease, Right-of-Use Asset Branch Acquisition from Republic Bank and Trust [Member] Represents Branch Acquisition from Republic Bank and Trust. us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue Total minimum lease payments us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount Discount effect of cash flows Measurement Input, Constant Prepayment Rate [Member] us-gaap_DeferredIncomeTaxExpenseBenefit Deferred taxes, net Measurement Input Type [Axis] Thereafter us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree 2022 Measurement Input Type [Domain] April 2020 – December 2020 us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour 2023 us-gaap_DebtSecuritiesAvailableForSaleMeasurementInput Debt Securities, Available-for-sale, Measurement Input us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive 2024 Total, Gross Amount before accumulated amortization of intangible assets, including goodwill. us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive Thereafter 2021 Deposits us-gaap_InterestExpenseDeposits 2022 2023 2024 us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo 2021 Valuation Approach and Technique [Axis] Lease liability Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from lease liability. Valuation Approach and Technique [Domain] Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] Lease right-of-use assets Amount of deferred tax liability attributable to taxable temporary differences from lease right-of-use assets. Lessee, Operating Lease, Liability, Maturity [Table Text Block] Stock-based compensation expense us-gaap_ShareBasedCompensation us-gaap_LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear 2020 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 Interest and Dividend Income, Operating, Total 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 (in shares) Stock issued for share-based awards, net of withholdings to satisfy employee tax obligations upon award us-gaap_FederalHomeLoanBankBorrowingsFairValueDisclosure Federal Home Loan Bank advances us-gaap_CashAndCashEquivalentsFairValueDisclosure Cash and cash equivalents Year 4 us-gaap_TimeDepositMaturitiesYearFour Year 5 us-gaap_TimeDepositMaturitiesYearFive Thereafter us-gaap_TimeDepositMaturitiesAfterYearFive Taxable securities Tax exempt securities Year 1 us-gaap_TimeDepositMaturitiesYearOne Year 2 us-gaap_TimeDepositMaturitiesYearTwo Year 3 us-gaap_TimeDepositMaturitiesYearThree Fair Value, Nonrecurring [Member] Common stock, no par, 39,000,000 shares authorized, 6,269,305 and 6,251,975 voting, and 1,220,000 and 1,220,000 non-voting issued and outstanding, respectively 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. Ownership [Domain] Product and Service [Axis] Product and Service [Domain] Limestone Bank [Member] Limestone Bank. Statistical Measurement [Axis] Interest income us-gaap_OperatingLeasesRentExpenseNet Operating Leases, Rent Expense, Net, Total 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 Deferred Tax Assets, Gross, Total Certificates of deposit us-gaap_DeferredIncomeTaxLiabilities Deferred Tax Liabilities, Gross, Total Portion at Fair Value Measurement [Member] [Default] Interest checking Estimate of Fair Value Measurement [Member] Other us-gaap_NoninterestIncomeOtherOperatingIncome Noninterest Income, Total 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 Fair Value Hierarchy and NAV [Axis] us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss Net interest income after provision for loan losses 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: Assets lmst_PaymentsForProceedsFromLoanOriginationsAndPrincipalCollections Net changes in loans 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 15) 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 us-gaap_BankingRegulationCapitalConservationBufferCapitalConservedMinimum Banking Regulation, Capital Conservation Buffer, Capital Conserved, Minimum Total common equity Tier 1 risk-based capital (to risk-weighted assets), for capital adequacy purposes, ratio us-gaap_BankingRegulationCapitalConservationBufferTotalRiskBasedCapitalActual Banking Regulation, Capital Conservation Buffer, Tier One Risk-Based Capital, Actual us-gaap_BankingRegulationCapitalConservationBufferTierOneRiskBasedCapitalActual Banking Regulation, Capital Conservation Buffer, Tier One Risk-Based Capital, Actual us-gaap_BankingRegulationCapitalConservationBufferCommonEquityTierOneRiskBasedCapitalActual Banking Regulation, Capital Conservation Buffer, Common Equity Tier One Risk-Based Capital, Actual Subsidiaries [Member] FHLB stock dividends us-gaap_DeferredTaxLiabilitiesInvestments Total common equity Tier 1 risk-based capital (to risk-weighted assets), for minimum requirements to be well capitalized, ratio Net unrealized gain on securities Consolidated Entities [Axis] Consolidated Entities [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 Cash basis interest income recognized, with no related allowance recorded Cash basis interest income recognized, with an allowance recorded Cash basis interest income recognized 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 Noninterest Expense, Total Scenario [Domain] lmst_IncreaseDecreaseInCashSurrenderValueOfBankOwnedLifeInsuranceNet Increase in cash surrender value of 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. Scenario [Axis] Non-interest expense Additional Paid-in Capital [Member] Common Stock [Member] Collateral Held [Domain] Equity Components [Axis] Equity Component [Domain] Long term advances (fixed rates 0.00% to 5.24%) maturing April 2020 to August 2033 Collateral Held [Axis] Class of Financing Receivable [Domain] Other Liabilities [Member] 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] 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. us-gaap_SubordinatedDebt Subordinated capital note State and Local Jurisdiction [Member] 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_UnrecognizedTaxBenefits Unrecognized Tax Benefits, Ending Balance Accounting Policies [Abstract] us-gaap_EarlyRepaymentOfSeniorDebt Early Repayment of Senior Debt Basis of Accounting, Policy [Policy Text Block] lmst_FinancingReceivableModificationsPercentageOfPerformingTdrsToTotalTdrs Financing Receivable Modifications Percentage of Performing TDRs to Total TDRs The ratio of performing troubled debt restructurings to total troubled debt restructurings. Entity Interactive Data Current 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 0.13% to 0.22%) maturing April 2020 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. us-gaap_ProceedsFromIssuanceOfSubordinatedLongTermDebt 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] Postage and delivery Amount of expense associated with postage and other delivery services. Accrued interest payable and other liabilities Proceeds from sales and calls of available for sale securities 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. Business Acquisition [Axis] Basic income per common share (in dollars per share) Business Acquisition, Acquiree [Domain] 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] 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 Schedule of Intangible Assets and Goodwill [Table Text Block] us-gaap_TimeDeposits Time Deposits, Total Schedule of Realized Gain (Loss) [Table Text Block] Money market Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Table Text Block] Reclassification adjustment for gains (losses) included in net income Savings lmst_CommitmentsPeriod Commitments Period (Year) The commitments period of commitments to make loans. Unrealized gain (loss) arising during the period Deposits 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] Subordinated capital note The fair value of subordinated capital notes. 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 (in shares) 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. Unused lines of Credit [Member] us-gaap_StockholdersEquity Total stockholders' equity Balances Balances Nonvoting Common Stock [Member] Class of Stock [Axis] Class of Stock [Domain] lmst_ShareBasedCompensationArrangementByShareBasedPaymentAwardExpectedFutureCompensationYearTwo 2021 The expected future compensation expense related to unvested shares in year two. lmst_ShareBasedCompensationArrangementByShareBasedPaymentAwardExpectedFutureCompensationRemainderOfYear April 2020 – December 2020 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 2022 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 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