3.20.1 html 304 451 1 true 76 0 false 9 false false R1.htm 0001000 - Document - Document and Entity Information Sheet http://www.lutherburbanksavings.com/role/DocumentAndEntityInformation Document and Entity Information Cover 1 false false R2.htm 1001000 - Statement - CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION Sheet http://www.lutherburbanksavings.com/role/ConsolidatedStatementsOfFinancialCondition CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION Statements 2 false false R3.htm 1001001 - Statement - CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION (Parenthetical) Sheet http://www.lutherburbanksavings.com/role/ConsolidatedStatementsOfFinancialConditionParenthetical CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION (Parenthetical) Statements 3 false false R4.htm 1002000 - Statement - CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED) Sheet http://www.lutherburbanksavings.com/role/ConsolidatedStatementsOfIncomeUnaudited CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED) Statements 4 false false R5.htm 1003000 - Statement - CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) Sheet http://www.lutherburbanksavings.com/role/ConsolidatedStatementsOfComprehensiveIncomeUnaudited CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) Statements 5 false false R6.htm 1004000 - Statement - CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (UNAUDITED) Sheet http://www.lutherburbanksavings.com/role/ConsolidatedStatementsOfChangesInStockholdersEquityUnaudited CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (UNAUDITED) Statements 6 false false R7.htm 1004001 - Statement - CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (UNAUDITED) (Parenthetical) Sheet http://www.lutherburbanksavings.com/role/ConsolidatedStatementsOfChangesInStockholdersEquityUnauditedParenthetical CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (UNAUDITED) (Parenthetical) Statements 7 false false R8.htm 1005000 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS Sheet http://www.lutherburbanksavings.com/role/ConsolidatedStatementsOfCashFlows CONSOLIDATED STATEMENTS OF CASH FLOWS Statements 8 false false R9.htm 2101100 - Disclosure - NATURE OF OPERATIONS Sheet http://www.lutherburbanksavings.com/role/NatureOfOperations NATURE OF OPERATIONS Notes 9 false false R10.htm 2102100 - Disclosure - COVID-19 Sheet http://www.lutherburbanksavings.com/role/Covid19 COVID-19 Notes 10 false false R11.htm 2104100 - Disclosure - INVESTMENT SECURITIES Sheet http://www.lutherburbanksavings.com/role/InvestmentSecurities INVESTMENT SECURITIES Notes 11 false false R12.htm 2107100 - Disclosure - LOANS Sheet http://www.lutherburbanksavings.com/role/Loans LOANS Notes 12 false false R13.htm 2110100 - Disclosure - NONPERFORMING ASSETS Sheet http://www.lutherburbanksavings.com/role/NonperformingAssets NONPERFORMING ASSETS Notes 13 false false R14.htm 2113100 - Disclosure - MORTGAGE SERVICING RIGHTS Sheet http://www.lutherburbanksavings.com/role/MortgageServicingRights MORTGAGE SERVICING RIGHTS Notes 14 false false R15.htm 2116100 - Disclosure - DEPOSITS Sheet http://www.lutherburbanksavings.com/role/Deposits DEPOSITS Notes 15 false false R16.htm 2119100 - Disclosure - FEDERAL HOME LOAN BANK AND FEDERAL RESERVE BANK ADVANCES Sheet http://www.lutherburbanksavings.com/role/FederalHomeLoanBankAndFederalReserveBankAdvances FEDERAL HOME LOAN BANK AND FEDERAL RESERVE BANK ADVANCES Notes 16 false false R17.htm 2122100 - Disclosure - JUNIOR SUBORDINATED DEFERRABLE INTEREST DEBENTURES Sheet http://www.lutherburbanksavings.com/role/JuniorSubordinatedDeferrableInterestDebentures JUNIOR SUBORDINATED DEFERRABLE INTEREST DEBENTURES Notes 17 false false R18.htm 2125100 - Disclosure - SENIOR DEBT Sheet http://www.lutherburbanksavings.com/role/SeniorDebt SENIOR DEBT Notes 18 false false R19.htm 2140100 - Disclosure - DERIVATIVES AND HEDGING ACTIVITIES (Notes) Notes http://www.lutherburbanksavings.com/role/DerivativesAndHedgingActivitiesNotes DERIVATIVES AND HEDGING ACTIVITIES (Notes) Notes 19 false false R20.htm 2143100 - Disclosure - STOCK BASED COMPENSATION Sheet http://www.lutherburbanksavings.com/role/StockBasedCompensation STOCK BASED COMPENSATION Notes 20 false false R21.htm 2146100 - Disclosure - FAIR VALUE MEASUREMENTS Sheet http://www.lutherburbanksavings.com/role/FairValueMeasurements FAIR VALUE MEASUREMENTS Notes 21 false false R22.htm 2149100 - Disclosure - VARIABLE INTEREST ENTITIES (VIE) Sheet http://www.lutherburbanksavings.com/role/VariableInterestEntitiesVie VARIABLE INTEREST ENTITIES (VIE) Notes 22 false false R23.htm 2150100 - Disclosure - LOAN SALE AND SECURITIZATION ACTIVITIES Sheet http://www.lutherburbanksavings.com/role/LoanSaleAndSecuritizationActivities LOAN SALE AND SECURITIZATION ACTIVITIES Notes 23 false false R24.htm 2151100 - Disclosure - COMMITMENTS AND CONTINGENCIES Sheet http://www.lutherburbanksavings.com/role/CommitmentsAndContingencies COMMITMENTS AND CONTINGENCIES Notes 24 false false R25.htm 2201201 - Disclosure - NATURE OF OPERATIONS (Policies) Sheet http://www.lutherburbanksavings.com/role/NatureOfOperationsPolicies NATURE OF OPERATIONS (Policies) Policies 25 false false R26.htm 2301302 - Disclosure - NATURE OF OPERATIONS (Tables) Sheet http://www.lutherburbanksavings.com/role/NatureOfOperationsTables NATURE OF OPERATIONS (Tables) Tables http://www.lutherburbanksavings.com/role/NatureOfOperations 26 false false R27.htm 2304301 - Disclosure - INVESTMENT SECURITIES (Tables) Sheet http://www.lutherburbanksavings.com/role/InvestmentSecuritiesTables INVESTMENT SECURITIES (Tables) Tables http://www.lutherburbanksavings.com/role/InvestmentSecurities 27 false false R28.htm 2307301 - Disclosure - LOANS (Tables) Sheet http://www.lutherburbanksavings.com/role/LoansTables LOANS (Tables) Tables http://www.lutherburbanksavings.com/role/Loans 28 false false R29.htm 2310301 - Disclosure - NONPERFORMING ASSETS (Tables) Sheet http://www.lutherburbanksavings.com/role/NonperformingAssetsTables NONPERFORMING ASSETS (Tables) Tables http://www.lutherburbanksavings.com/role/NonperformingAssets 29 false false R30.htm 2313301 - Disclosure - MORTGAGE SERVICING RIGHTS (Tables) Sheet http://www.lutherburbanksavings.com/role/MortgageServicingRightsTables MORTGAGE SERVICING RIGHTS (Tables) Tables http://www.lutherburbanksavings.com/role/MortgageServicingRights 30 false false R31.htm 2316301 - Disclosure - DEPOSITS (Tables) Sheet http://www.lutherburbanksavings.com/role/DepositsTables DEPOSITS (Tables) Tables http://www.lutherburbanksavings.com/role/Deposits 31 false false R32.htm 2319301 - Disclosure - FEDERAL HOME LOAN BANK AND FEDERAL RESERVE BANK ADVANCES (Tables) Sheet http://www.lutherburbanksavings.com/role/FederalHomeLoanBankAndFederalReserveBankAdvancesTables FEDERAL HOME LOAN BANK AND FEDERAL RESERVE BANK ADVANCES (Tables) Tables http://www.lutherburbanksavings.com/role/FederalHomeLoanBankAndFederalReserveBankAdvances 32 false false R33.htm 2322301 - Disclosure - JUNIOR SUBORDINATED DEFERRABLE INTEREST DEBENTURES (Tables) Sheet http://www.lutherburbanksavings.com/role/JuniorSubordinatedDeferrableInterestDebenturesTables JUNIOR SUBORDINATED DEFERRABLE INTEREST DEBENTURES (Tables) Tables http://www.lutherburbanksavings.com/role/JuniorSubordinatedDeferrableInterestDebentures 33 false false R34.htm 2325301 - Disclosure - SENIOR DEBT (Tables) Sheet http://www.lutherburbanksavings.com/role/SeniorDebtTables SENIOR DEBT (Tables) Tables http://www.lutherburbanksavings.com/role/SeniorDebt 34 false false R35.htm 2340301 - Disclosure - DERIVATIVES AND HEDGING ACTIVITIES (Tables) Sheet http://www.lutherburbanksavings.com/role/DerivativesAndHedgingActivitiesTables DERIVATIVES AND HEDGING ACTIVITIES (Tables) Tables http://www.lutherburbanksavings.com/role/DerivativesAndHedgingActivitiesNotes 35 false false R36.htm 2343301 - Disclosure - STOCK BASED COMPENSATION (Tables) Sheet http://www.lutherburbanksavings.com/role/StockBasedCompensationTables STOCK BASED COMPENSATION (Tables) Tables http://www.lutherburbanksavings.com/role/StockBasedCompensation 36 false false R37.htm 2346301 - Disclosure - FAIR VALUE MEASUREMENTS (Tables) Sheet http://www.lutherburbanksavings.com/role/FairValueMeasurementsTables FAIR VALUE MEASUREMENTS (Tables) Tables http://www.lutherburbanksavings.com/role/FairValueMeasurements 37 false false R38.htm 2350301 - Disclosure - LOAN SALE AND SECURITIZATION ACTIVITIES (Tables) Sheet http://www.lutherburbanksavings.com/role/LoanSaleAndSecuritizationActivitiesTables LOAN SALE AND SECURITIZATION ACTIVITIES (Tables) Tables http://www.lutherburbanksavings.com/role/LoanSaleAndSecuritizationActivities 38 false false R39.htm 2351301 - Disclosure - COMMITMENTS AND CONTINGENCIES (Tables) Sheet http://www.lutherburbanksavings.com/role/CommitmentsAndContingenciesTables COMMITMENTS AND CONTINGENCIES (Tables) Tables http://www.lutherburbanksavings.com/role/CommitmentsAndContingencies 39 false false R40.htm 2401403 - Disclosure - NATURE OF OPERATIONS - Narrative (Details) Sheet http://www.lutherburbanksavings.com/role/NatureOfOperationsNarrativeDetails NATURE OF OPERATIONS - Narrative (Details) Details 40 false false R41.htm 2401404 - Disclosure - NATURE OF OPERATIONS - Earnings per Share (Details) Sheet http://www.lutherburbanksavings.com/role/NatureOfOperationsEarningsPerShareDetails NATURE OF OPERATIONS - Earnings per Share (Details) Details 41 false false R42.htm 2402401 - Disclosure - COVID-19 (Details) Sheet http://www.lutherburbanksavings.com/role/Covid19Details COVID-19 (Details) Details http://www.lutherburbanksavings.com/role/Covid19 42 false false R43.htm 2404402 - Disclosure - INVESTMENT SECURITIES - Available-for-sale Securities (Details) Sheet http://www.lutherburbanksavings.com/role/InvestmentSecuritiesAvailableForSaleSecuritiesDetails INVESTMENT SECURITIES - Available-for-sale Securities (Details) Details 43 false false R44.htm 2404403 - Disclosure - INVESTMENT SECURITIES - Narrative (Details) Sheet http://www.lutherburbanksavings.com/role/InvestmentSecuritiesNarrativeDetails INVESTMENT SECURITIES - Narrative (Details) Details 44 false false R45.htm 2404404 - Disclosure - INVESTMENT SECURITIES - Held-to-maturity Securities (Details) Sheet http://www.lutherburbanksavings.com/role/InvestmentSecuritiesHeldToMaturitySecuritiesDetails INVESTMENT SECURITIES - Held-to-maturity Securities (Details) Details 45 false false R46.htm 2404405 - Disclosure - INVESTMENT SECURITIES - Schedule of Investment Securities Maturities (Details) Sheet http://www.lutherburbanksavings.com/role/InvestmentSecuritiesScheduleOfInvestmentSecuritiesMaturitiesDetails INVESTMENT SECURITIES - Schedule of Investment Securities Maturities (Details) Details 46 false false R47.htm 2404406 - Disclosure - INVESTMENT SECURITIES - Equity securities (Details) Sheet http://www.lutherburbanksavings.com/role/InvestmentSecuritiesEquitySecuritiesDetails INVESTMENT SECURITIES - Equity securities (Details) Details 47 false false R48.htm 2407402 - Disclosure - LOANS - Loans Receivable (Details) Sheet http://www.lutherburbanksavings.com/role/LoansLoansReceivableDetails LOANS - Loans Receivable (Details) Details 48 false false R49.htm 2407403 - Disclosure - LOANS - Allowance for Loan Losses (Details) Sheet http://www.lutherburbanksavings.com/role/LoansAllowanceForLoanLossesDetails LOANS - Allowance for Loan Losses (Details) Details 49 false false R50.htm 2407404 - Disclosure - LOANS - Portfolio Allocated by Internal Risk Ratings (Details) Sheet http://www.lutherburbanksavings.com/role/LoansPortfolioAllocatedByInternalRiskRatingsDetails LOANS - Portfolio Allocated by Internal Risk Ratings (Details) Details 50 false false R51.htm 2407405 - Disclosure - LOANS - Aging Analysis (Details) Sheet http://www.lutherburbanksavings.com/role/LoansAgingAnalysisDetails LOANS - Aging Analysis (Details) Details 51 false false R52.htm 2407406 - Disclosure - LOANS - Impaired Loans (Details) Sheet http://www.lutherburbanksavings.com/role/LoansImpairedLoansDetails LOANS - Impaired Loans (Details) Details 52 false false R53.htm 2407407 - Disclosure - LOANS - Troubled Debt Restructurings (Details) Sheet http://www.lutherburbanksavings.com/role/LoansTroubledDebtRestructuringsDetails LOANS - Troubled Debt Restructurings (Details) Details 53 false false R54.htm 2410402 - Disclosure - NONPERFORMING ASSETS (Details) Sheet http://www.lutherburbanksavings.com/role/NonperformingAssetsDetails NONPERFORMING ASSETS (Details) Details http://www.lutherburbanksavings.com/role/NonperformingAssetsTables 54 false false R55.htm 2413402 - Disclosure - MORTGAGE SERVICING RIGHTS - Mortgage Loans Serviced for Others (Details) Sheet http://www.lutherburbanksavings.com/role/MortgageServicingRightsMortgageLoansServicedForOthersDetails MORTGAGE SERVICING RIGHTS - Mortgage Loans Serviced for Others (Details) Details 55 false false R56.htm 2413403 - Disclosure - MORTGAGE SERVICING RIGHTS - Narrative (Details) Sheet http://www.lutherburbanksavings.com/role/MortgageServicingRightsNarrativeDetails MORTGAGE SERVICING RIGHTS - Narrative (Details) Details 56 false false R57.htm 2413404 - Disclosure - MORTGAGE SERVICING RIGHTS - Mortgage Servicing Rights Activity (Details) Sheet http://www.lutherburbanksavings.com/role/MortgageServicingRightsMortgageServicingRightsActivityDetails MORTGAGE SERVICING RIGHTS - Mortgage Servicing Rights Activity (Details) Details 57 false false R58.htm 2416402 - Disclosure - DEPOSITS - Deposits (Details) Sheet http://www.lutherburbanksavings.com/role/DepositsDepositsDetails DEPOSITS - Deposits (Details) Details 58 false false R59.htm 2416403 - Disclosure - DEPOSITS - Narrative (Details) Sheet http://www.lutherburbanksavings.com/role/DepositsNarrativeDetails DEPOSITS - Narrative (Details) Details 59 false false R60.htm 2416404 - Disclosure - DEPOSITS - Maturities (Details) Sheet http://www.lutherburbanksavings.com/role/DepositsMaturitiesDetails DEPOSITS - Maturities (Details) Details 60 false false R61.htm 2419402 - Disclosure - FEDERAL HOME LOAN BANK AND FEDERAL RESERVE BANK ADVANCES - Narrative (Details) Sheet http://www.lutherburbanksavings.com/role/FederalHomeLoanBankAndFederalReserveBankAdvancesNarrativeDetails FEDERAL HOME LOAN BANK AND FEDERAL RESERVE BANK ADVANCES - Narrative (Details) Details http://www.lutherburbanksavings.com/role/FederalHomeLoanBankAndFederalReserveBankAdvancesTables 61 false false R62.htm 2419403 - Disclosure - FEDERAL HOME LOAN BANK AND FEDERAL RESERVE BANK ADVANCES - FHLB Advances (Details) Sheet http://www.lutherburbanksavings.com/role/FederalHomeLoanBankAndFederalReserveBankAdvancesFhlbAdvancesDetails FEDERAL HOME LOAN BANK AND FEDERAL RESERVE BANK ADVANCES - FHLB Advances (Details) Details 62 false false R63.htm 2419404 - Disclosure - FEDERAL HOME LOAN BANK AND FEDERAL RESERVE BANK ADVANCES - Schedule of Maturities (Details) Sheet http://www.lutherburbanksavings.com/role/FederalHomeLoanBankAndFederalReserveBankAdvancesScheduleOfMaturitiesDetails FEDERAL HOME LOAN BANK AND FEDERAL RESERVE BANK ADVANCES - Schedule of Maturities (Details) Details 63 false false R64.htm 2422402 - Disclosure - JUNIOR SUBORDINATED DEFERRABLE INTEREST DEBENTURES - Narrative (Details) Sheet http://www.lutherburbanksavings.com/role/JuniorSubordinatedDeferrableInterestDebenturesNarrativeDetails JUNIOR SUBORDINATED DEFERRABLE INTEREST DEBENTURES - Narrative (Details) Details http://www.lutherburbanksavings.com/role/JuniorSubordinatedDeferrableInterestDebenturesTables 64 false false R65.htm 2422403 - Disclosure - JUNIOR SUBORDINATED DEFERRABLE INTEREST DEBENTURES - Schedule of Trusts (Details) Sheet http://www.lutherburbanksavings.com/role/JuniorSubordinatedDeferrableInterestDebenturesScheduleOfTrustsDetails JUNIOR SUBORDINATED DEFERRABLE INTEREST DEBENTURES - Schedule of Trusts (Details) Details 65 false false R66.htm 2425402 - Disclosure - SENIOR DEBT - Narrative (Details) Sheet http://www.lutherburbanksavings.com/role/SeniorDebtNarrativeDetails SENIOR DEBT - Narrative (Details) Details 66 false false R67.htm 2425403 - Disclosure - SENIOR DEBT - Schedule of Debt (Details) Sheet http://www.lutherburbanksavings.com/role/SeniorDebtScheduleOfDebtDetails SENIOR DEBT - Schedule of Debt (Details) Details 67 false false R68.htm 2440402 - Disclosure - DERIVATIVES AND HEDGING ACTIVITIES - Narrative (Details) Sheet http://www.lutherburbanksavings.com/role/DerivativesAndHedgingActivitiesNarrativeDetails DERIVATIVES AND HEDGING ACTIVITIES - Narrative (Details) Details 68 false false R69.htm 2440403 - Disclosure - DERIVATIVES AND HEDGING ACTIVITIES - Schedule of Interest Rate Swap on Consolidated Statement of Income (Details) Sheet http://www.lutherburbanksavings.com/role/DerivativesAndHedgingActivitiesScheduleOfInterestRateSwapOnConsolidatedStatementOfIncomeDetails DERIVATIVES AND HEDGING ACTIVITIES - Schedule of Interest Rate Swap on Consolidated Statement of Income (Details) Details 69 false false R70.htm 2440404 - Disclosure - DERIVATIVES AND HEDGING ACTIVITIES - Schedule of Interest Rate Swap on Consolidated Balance Sheet (Details) Sheet http://www.lutherburbanksavings.com/role/DerivativesAndHedgingActivitiesScheduleOfInterestRateSwapOnConsolidatedBalanceSheetDetails DERIVATIVES AND HEDGING ACTIVITIES - Schedule of Interest Rate Swap on Consolidated Balance Sheet (Details) Details 70 false false R71.htm 2440405 - Disclosure - DERIVATIVES AND HEDGING ACTIVITIES - Schedule of Amounts Recorded on the Balance Sheet Related to Cumulative Adjustments on Fair Value Hedges (Details) Sheet http://www.lutherburbanksavings.com/role/DerivativesAndHedgingActivitiesScheduleOfAmountsRecordedOnBalanceSheetRelatedToCumulativeAdjustmentsOnFairValueHedgesDetails DERIVATIVES AND HEDGING ACTIVITIES - Schedule of Amounts Recorded on the Balance Sheet Related to Cumulative Adjustments on Fair Value Hedges (Details) Details 71 false false R72.htm 2443402 - Disclosure - STOCK BASED COMPENSATION - Narrative (Details) Sheet http://www.lutherburbanksavings.com/role/StockBasedCompensationNarrativeDetails STOCK BASED COMPENSATION - Narrative (Details) Details 72 false false R73.htm 2443403 - Disclosure - STOCK BASED COMPENSATION - Awards Activity (Details) Sheet http://www.lutherburbanksavings.com/role/StockBasedCompensationAwardsActivityDetails STOCK BASED COMPENSATION - Awards Activity (Details) Details 73 false false R74.htm 2446402 - Disclosure - FAIR VALUE MEASUREMENTS - Fair Value of Financial Instruments (Details) Sheet http://www.lutherburbanksavings.com/role/FairValueMeasurementsFairValueOfFinancialInstrumentsDetails FAIR VALUE MEASUREMENTS - Fair Value of Financial Instruments (Details) Details 74 false false R75.htm 2446403 - Disclosure - FAIR VALUE MEASUREMENTS - Assets and Liabilities Recorded at Fair Value (Details) Sheet http://www.lutherburbanksavings.com/role/FairValueMeasurementsAssetsAndLiabilitiesRecordedAtFairValueDetails FAIR VALUE MEASUREMENTS - Assets and Liabilities Recorded at Fair Value (Details) Details 75 false false R76.htm 2446404 - Disclosure - FAIR VALUE MEASUREMENTS - Narrative (Details) Sheet http://www.lutherburbanksavings.com/role/FairValueMeasurementsNarrativeDetails FAIR VALUE MEASUREMENTS - Narrative (Details) Details 76 false false R77.htm 2449401 - Disclosure - VARIABLE INTEREST ENTITIES (VIE) (Details) Sheet http://www.lutherburbanksavings.com/role/VariableInterestEntitiesVieDetails VARIABLE INTEREST ENTITIES (VIE) (Details) Details http://www.lutherburbanksavings.com/role/VariableInterestEntitiesVie 77 false false R78.htm 2450402 - Disclosure - LOAN SALE AND SECURITIZATION ACTIVITIES - Narrative (Details) Sheet http://www.lutherburbanksavings.com/role/LoanSaleAndSecuritizationActivitiesNarrativeDetails LOAN SALE AND SECURITIZATION ACTIVITIES - Narrative (Details) Details 78 false false R79.htm 2450403 - Disclosure - LOAN SALE AND SECURITIZATION ACTIVITIES - Cash Flow from Sale of Loans (Details) Sheet http://www.lutherburbanksavings.com/role/LoanSaleAndSecuritizationActivitiesCashFlowFromSaleOfLoansDetails LOAN SALE AND SECURITIZATION ACTIVITIES - Cash Flow from Sale of Loans (Details) Details 79 false false R80.htm 2450404 - Disclosure - LOAN SALE AND SECURITIZATION ACTIVITIES - Loans Transfered Through Loans or Securitization (Details) Sheet http://www.lutherburbanksavings.com/role/LoanSaleAndSecuritizationActivitiesLoansTransferedThroughLoansOrSecuritizationDetails LOAN SALE AND SECURITIZATION ACTIVITIES - Loans Transfered Through Loans or Securitization (Details) Details 80 false false R81.htm 2451402 - Disclosure - COMMITMENTS AND CONTINGENCIES - Narrative (Details) Sheet http://www.lutherburbanksavings.com/role/CommitmentsAndContingenciesNarrativeDetails COMMITMENTS AND CONTINGENCIES - Narrative (Details) Details 81 false false R82.htm 2451403 - Disclosure - COMMITMENTS AND CONTINGENCIES - Operating Lease Maturities (Details) Sheet http://www.lutherburbanksavings.com/role/CommitmentsAndContingenciesOperatingLeaseMaturitiesDetails COMMITMENTS AND CONTINGENCIES - Operating Lease Maturities (Details) Details 82 false false All Reports Book All Reports lbc-20200331.xml lbc-20200331.xsd lbc-20200331_cal.xml lbc-20200331_def.xml lbc-20200331_lab.xml lbc-20200331_pre.xml http://xbrl.sec.gov/stpr/2018-01-31 http://xbrl.sec.gov/dei/2018-01-31 http://fasb.org/us-gaap/2019-01-31 http://fasb.org/srt/2019-01-31 true true