3.20.1 html 343 457 1 false 71 0 false 9 false false R1.htm 0001001 - Document - Cover Sheet http://www.franklinsynergybank.com/role/Cover Cover Cover 1 false false R2.htm 1001002 - Statement - CONSOLIDATED BALANCE SHEETS Sheet http://www.franklinsynergybank.com/role/CONSOLIDATEDBALANCESHEETS CONSOLIDATED BALANCE SHEETS Statements 2 false false R3.htm 1002003 - Statement - CONSOLIDATED BALANCE SHEETS (Parenthetical) Sheet http://www.franklinsynergybank.com/role/CONSOLIDATEDBALANCESHEETSParenthetical CONSOLIDATED BALANCE SHEETS (Parenthetical) Statements 3 false false R4.htm 1003004 - Statement - CONSOLIDATED STATEMENTS OF INCOME (Unaudited) Sheet http://www.franklinsynergybank.com/role/CONSOLIDATEDSTATEMENTSOFINCOMEUnaudited CONSOLIDATED STATEMENTS OF INCOME (Unaudited) Statements 4 false false R5.htm 1004005 - Statement - CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) Sheet http://www.franklinsynergybank.com/role/CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOMEUnaudited CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) Statements 5 false false R6.htm 1005006 - Statement - CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) Sheet http://www.franklinsynergybank.com/role/CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOMEParenthetical CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) Statements 6 false false R7.htm 1006007 - Statement - CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (Unaudited) Sheet http://www.franklinsynergybank.com/role/CONSOLIDATEDSTATEMENTSOFCHANGESINEQUITYUnaudited CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (Unaudited) Statements 7 false false R8.htm 1007008 - Statement - CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (Unaudited) (Parenthetical) Sheet http://www.franklinsynergybank.com/role/CONSOLIDATEDSTATEMENTSOFCHANGESINEQUITYUnauditedParenthetical CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (Unaudited) (Parenthetical) Statements 8 false false R9.htm 1008009 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) Sheet http://www.franklinsynergybank.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWSUnaudited CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) Statements 9 false false R10.htm 1109103 - Statement - LOANS Sheet http://www.franklinsynergybank.com/role/LOANS LOANS Statements 10 false false R11.htm 1110104 - Statement - LOAN SERVICING Sheet http://www.franklinsynergybank.com/role/LOANSERVICING LOAN SERVICING Statements 11 false false R12.htm 2101101 - Disclosure - BASIS OF PRESENTATION Sheet http://www.franklinsynergybank.com/role/BASISOFPRESENTATION BASIS OF PRESENTATION Notes 12 false false R13.htm 2104102 - Disclosure - SECURITIES Sheet http://www.franklinsynergybank.com/role/SECURITIES SECURITIES Notes 13 false false R14.htm 2126105 - Disclosure - LEASES Sheet http://www.franklinsynergybank.com/role/LEASES LEASES Notes 14 false false R15.htm 2130106 - Disclosure - SHARE-BASED PAYMENTS Sheet http://www.franklinsynergybank.com/role/SHAREBASEDPAYMENTS SHARE-BASED PAYMENTS Notes 15 false false R16.htm 2138107 - Disclosure - REGULATORY CAPITAL MATTERS Sheet http://www.franklinsynergybank.com/role/REGULATORYCAPITALMATTERS REGULATORY CAPITAL MATTERS Notes 16 false false R17.htm 2141108 - Disclosure - DERIVATIVE INSTRUMENTS Sheet http://www.franklinsynergybank.com/role/DERIVATIVEINSTRUMENTS DERIVATIVE INSTRUMENTS Notes 17 false false R18.htm 2149109 - Disclosure - COMMITMENTS AND CONTINGENCIES Sheet http://www.franklinsynergybank.com/role/COMMITMENTSANDCONTINGENCIES COMMITMENTS AND CONTINGENCIES Notes 18 false false R19.htm 2153110 - Disclosure - FAIR VALUE Sheet http://www.franklinsynergybank.com/role/FAIRVALUE FAIR VALUE Notes 19 false false R20.htm 2159111 - Disclosure - EARNINGS PER SHARE Sheet http://www.franklinsynergybank.com/role/EARNINGSPERSHARE EARNINGS PER SHARE Notes 20 false false R21.htm 2163112 - Disclosure - SUBORDINATED DEBT ISSUANCE Sheet http://www.franklinsynergybank.com/role/SUBORDINATEDDEBTISSUANCE SUBORDINATED DEBT ISSUANCE Notes 21 false false R22.htm 2202201 - Disclosure - BASIS OF PRESENTATION (Policies) Sheet http://www.franklinsynergybank.com/role/BASISOFPRESENTATIONPolicies BASIS OF PRESENTATION (Policies) Policies 22 false false R23.htm 2305301 - Disclosure - SECURITIES (Tables) Sheet http://www.franklinsynergybank.com/role/SECURITIESTables SECURITIES (Tables) Tables http://www.franklinsynergybank.com/role/SECURITIES 23 false false R24.htm 2311302 - Disclosure - LOANS (Tables) Sheet http://www.franklinsynergybank.com/role/LOANSTables LOANS (Tables) Tables 24 false false R25.htm 2321303 - Disclosure - LOAN SERVICING (Tables) Sheet http://www.franklinsynergybank.com/role/LOANSERVICINGTables LOAN SERVICING (Tables) Tables 25 false false R26.htm 2327304 - Disclosure - LEASES (Tables) Sheet http://www.franklinsynergybank.com/role/LEASESTables LEASES (Tables) Tables http://www.franklinsynergybank.com/role/LEASES 26 false false R27.htm 2331305 - Disclosure - SHARE-BASED PAYMENTS (Tables) Sheet http://www.franklinsynergybank.com/role/SHAREBASEDPAYMENTSTables SHARE-BASED PAYMENTS (Tables) Tables http://www.franklinsynergybank.com/role/SHAREBASEDPAYMENTS 27 false false R28.htm 2339306 - Disclosure - REGULATORY CAPITAL MATTERS (Tables) Sheet http://www.franklinsynergybank.com/role/REGULATORYCAPITALMATTERSTables REGULATORY CAPITAL MATTERS (Tables) Tables http://www.franklinsynergybank.com/role/REGULATORYCAPITALMATTERS 28 false false R29.htm 2342307 - Disclosure - DERIVATIVE INSTRUMENTS (Tables) Sheet http://www.franklinsynergybank.com/role/DERIVATIVEINSTRUMENTSTables DERIVATIVE INSTRUMENTS (Tables) Tables http://www.franklinsynergybank.com/role/DERIVATIVEINSTRUMENTS 29 false false R30.htm 2350308 - Disclosure - COMMITMENTS AND CONTINGENCIES (Tables) Sheet http://www.franklinsynergybank.com/role/COMMITMENTSANDCONTINGENCIESTables COMMITMENTS AND CONTINGENCIES (Tables) Tables http://www.franklinsynergybank.com/role/COMMITMENTSANDCONTINGENCIES 30 false false R31.htm 2354309 - Disclosure - FAIR VALUE (Tables) Sheet http://www.franklinsynergybank.com/role/FAIRVALUETables FAIR VALUE (Tables) Tables http://www.franklinsynergybank.com/role/FAIRVALUE 31 false false R32.htm 2360310 - Disclosure - EARNINGS PER SHARE (Tables) Sheet http://www.franklinsynergybank.com/role/EARNINGSPERSHARETables EARNINGS PER SHARE (Tables) Tables http://www.franklinsynergybank.com/role/EARNINGSPERSHARE 32 false false R33.htm 2364311 - Disclosure - SUBORDINATED DEBT ISSUANCE (Tables) Sheet http://www.franklinsynergybank.com/role/SUBORDINATEDDEBTISSUANCETables SUBORDINATED DEBT ISSUANCE (Tables) Tables http://www.franklinsynergybank.com/role/SUBORDINATEDDEBTISSUANCE 33 false false R34.htm 2403401 - Disclosure - BASIS OF PRESENTATION - Additional Information (Detail) Sheet http://www.franklinsynergybank.com/role/BASISOFPRESENTATIONAdditionalInformationDetail BASIS OF PRESENTATION - Additional Information (Detail) Details 34 false false R35.htm 2406402 - Disclosure - SECURITIES - Summary of Amortized Cost and Fair Value of Securities Available for Sale (Detail) Sheet http://www.franklinsynergybank.com/role/SECURITIESSummaryofAmortizedCostandFairValueofSecuritiesAvailableforSaleDetail SECURITIES - Summary of Amortized Cost and Fair Value of Securities Available for Sale (Detail) Details 35 false false R36.htm 2407403 - Disclosure - SECURITIES - Additional Information (Detail) Sheet http://www.franklinsynergybank.com/role/SECURITIESAdditionalInformationDetail SECURITIES - Additional Information (Detail) Details 36 false false R37.htm 2408404 - Disclosure - SECURITIES - Summary of Proceeds from Sales and Calls of Securities Available for Sale and Associated Gains and Losses (Detail) Sheet http://www.franklinsynergybank.com/role/SECURITIESSummaryofProceedsfromSalesandCallsofSecuritiesAvailableforSaleandAssociatedGainsandLossesDetail SECURITIES - Summary of Proceeds from Sales and Calls of Securities Available for Sale and Associated Gains and Losses (Detail) Details 37 false false R38.htm 2409405 - Disclosure - SECURITIES - Schedule of Amortized Cost and Fair Value of Investment Securities Portfolio by Contractual Maturity (Detail) Sheet http://www.franklinsynergybank.com/role/SECURITIESScheduleofAmortizedCostandFairValueofInvestmentSecuritiesPortfoliobyContractualMaturityDetail SECURITIES - Schedule of Amortized Cost and Fair Value of Investment Securities Portfolio by Contractual Maturity (Detail) Details 38 false false R39.htm 2410406 - Disclosure - SECURITIES - Schedule of Unrealized Losses and Fair Value by Major Security Type (Detail) Sheet http://www.franklinsynergybank.com/role/SECURITIESScheduleofUnrealizedLossesandFairValuebyMajorSecurityTypeDetail SECURITIES - Schedule of Unrealized Losses and Fair Value by Major Security Type (Detail) Details 39 false false R40.htm 2412407 - Disclosure - LOANS - Summary of Loans (Detail) Sheet http://www.franklinsynergybank.com/role/LOANSSummaryofLoansDetail LOANS - Summary of Loans (Detail) Details 40 false false R41.htm 2413408 - Disclosure - LOANS - Activity in Allowance for Loan Losses by Portfolio Segment (Detail) Sheet http://www.franklinsynergybank.com/role/LOANSActivityinAllowanceforLoanLossesbyPortfolioSegmentDetail LOANS - Activity in Allowance for Loan Losses by Portfolio Segment (Detail) Details 41 false false R42.htm 2414409 - Disclosure - LOANS - Allowance for Loan Losses and Recorded Investment in Loans by Portfolio Segment and Based on Impairment Method (Detail) Sheet http://www.franklinsynergybank.com/role/LOANSAllowanceforLoanLossesandRecordedInvestmentinLoansbyPortfolioSegmentandBasedonImpairmentMethodDetail LOANS - Allowance for Loan Losses and Recorded Investment in Loans by Portfolio Segment and Based on Impairment Method (Detail) Details 42 false false R43.htm 2415410 - Disclosure - LOANS - Additional Information (Detail) Sheet http://www.franklinsynergybank.com/role/LOANSAdditionalInformationDetail LOANS - Additional Information (Detail) Details 43 false false R44.htm 2416411 - Disclosure - LOANS - Summary of Impaired Loans by Class of Loans (Detail) Sheet http://www.franklinsynergybank.com/role/LOANSSummaryofImpairedLoansbyClassofLoansDetail LOANS - Summary of Impaired Loans by Class of Loans (Detail) Details 44 false false R45.htm 2417412 - Disclosure - LOANS - Average Recorded Investment of Impaired Loans by Class of Loan (Detail) Sheet http://www.franklinsynergybank.com/role/LOANSAverageRecordedInvestmentofImpairedLoansbyClassofLoanDetail LOANS - Average Recorded Investment of Impaired Loans by Class of Loan (Detail) Details 45 false false R46.htm 2418413 - Disclosure - LOANS - Schedule of Recorded Investment in Nonaccrual and Loans Past Due Over 90 Days on Accrual by Class of Loans (Detail) Sheet http://www.franklinsynergybank.com/role/LOANSScheduleofRecordedInvestmentinNonaccrualandLoansPastDueOver90DaysonAccrualbyClassofLoansDetail LOANS - Schedule of Recorded Investment in Nonaccrual and Loans Past Due Over 90 Days on Accrual by Class of Loans (Detail) Details 46 false false R47.htm 2419414 - Disclosure - LOANS - Schedule of Aging of Recorded Investment in Past Due Loans by Class of Loans (Detail) Sheet http://www.franklinsynergybank.com/role/LOANSScheduleofAgingofRecordedInvestmentinPastDueLoansbyClassofLoansDetail LOANS - Schedule of Aging of Recorded Investment in Past Due Loans by Class of Loans (Detail) Details 47 false false R48.htm 2420415 - Disclosure - LOANS - Summary of Risk Category of Loans by Class of Loans (Detail) Sheet http://www.franklinsynergybank.com/role/LOANSSummaryofRiskCategoryofLoansbyClassofLoansDetail LOANS - Summary of Risk Category of Loans by Class of Loans (Detail) Details 48 false false R49.htm 2422416 - Disclosure - LOAN SERVICING - Schedule of Loans Serviced Not Reported as Assets (Detail) Sheet http://www.franklinsynergybank.com/role/LOANSERVICINGScheduleofLoansServicedNotReportedasAssetsDetail LOAN SERVICING - Schedule of Loans Serviced Not Reported as Assets (Detail) Details 49 false false R50.htm 2423417 - Disclosure - LOAN SERVICING - Related Loan Servicing Rights Activity (Detail) Sheet http://www.franklinsynergybank.com/role/LOANSERVICINGRelatedLoanServicingRightsActivityDetail LOAN SERVICING - Related Loan Servicing Rights Activity (Detail) Details 50 false false R51.htm 2424418 - Disclosure - LOAN SERVICING - Components of Net Loan Servicing Fees (Detail) Sheet http://www.franklinsynergybank.com/role/LOANSERVICINGComponentsofNetLoanServicingFeesDetail LOAN SERVICING - Components of Net Loan Servicing Fees (Detail) Details 51 false false R52.htm 2425419 - Disclosure - LOAN SERVICING - Additional Information (Detail) Sheet http://www.franklinsynergybank.com/role/LOANSERVICINGAdditionalInformationDetail LOAN SERVICING - Additional Information (Detail) Details 52 false false R53.htm 2428420 - Disclosure - LEASES - Summary of Consolidated Statements of Condition Classification of ROU Assets And Lease Liabilities (Detail) Sheet http://www.franklinsynergybank.com/role/LEASESSummaryofConsolidatedStatementsofConditionClassificationofROUAssetsAndLeaseLiabilitiesDetail LEASES - Summary of Consolidated Statements of Condition Classification of ROU Assets And Lease Liabilities (Detail) Details 53 false false R54.htm 2429421 - Disclosure - LEASES - Additional Information (Detail) Sheet http://www.franklinsynergybank.com/role/LEASESAdditionalInformationDetail LEASES - Additional Information (Detail) Details 54 false false R55.htm 2432422 - Disclosure - SHARE-BASED PAYMENTS - Additional Information (Detail) Sheet http://www.franklinsynergybank.com/role/SHAREBASEDPAYMENTSAdditionalInformationDetail SHARE-BASED PAYMENTS - Additional Information (Detail) Details 55 false false R56.htm 2433423 - Disclosure - SHARE-BASED PAYMENTS - Fair Value Assumptions of Stock Options (Detail) Sheet http://www.franklinsynergybank.com/role/SHAREBASEDPAYMENTSFairValueAssumptionsofStockOptionsDetail SHARE-BASED PAYMENTS - Fair Value Assumptions of Stock Options (Detail) Details 56 false false R57.htm 2434424 - Disclosure - SHARE-BASED PAYMENTS - Summary of Company's Stock Options Activities (Detail) Sheet http://www.franklinsynergybank.com/role/SHAREBASEDPAYMENTSSummaryofCompanysStockOptionsActivitiesDetail SHARE-BASED PAYMENTS - Summary of Company's Stock Options Activities (Detail) Details 57 false false R58.htm 2435425 - Disclosure - SHARE-BASED PAYMENTS - Summary of Stock Options Exercised (Detail) Sheet http://www.franklinsynergybank.com/role/SHAREBASEDPAYMENTSSummaryofStockOptionsExercisedDetail SHARE-BASED PAYMENTS - Summary of Stock Options Exercised (Detail) Details 58 false false R59.htm 2436426 - Disclosure - SHARE-BASED PAYMENTS - Summary of Activity for Nonvested Restricted Share Awards (Detail) Sheet http://www.franklinsynergybank.com/role/SHAREBASEDPAYMENTSSummaryofActivityforNonvestedRestrictedShareAwardsDetail SHARE-BASED PAYMENTS - Summary of Activity for Nonvested Restricted Share Awards (Detail) Details 59 false false R60.htm 2437427 - Disclosure - Share-Based Payments - Summary of Outstanding Restricted Stock Units (Detail) Sheet http://www.franklinsynergybank.com/role/ShareBasedPaymentsSummaryofOutstandingRestrictedStockUnitsDetail Share-Based Payments - Summary of Outstanding Restricted Stock Units (Detail) Details 60 false false R61.htm 2440428 - Disclosure - REGULATORY CAPITAL MATTERS - Actual and Required Capital Amounts and Ratios (Detail) Sheet http://www.franklinsynergybank.com/role/REGULATORYCAPITALMATTERSActualandRequiredCapitalAmountsandRatiosDetail REGULATORY CAPITAL MATTERS - Actual and Required Capital Amounts and Ratios (Detail) Details 61 false false R62.htm 2443429 - Disclosure - DERIVATIVE INSTRUMENTS - Additional Information (Detail) Sheet http://www.franklinsynergybank.com/role/DERIVATIVEINSTRUMENTSAdditionalInformationDetail DERIVATIVE INSTRUMENTS - Additional Information (Detail) Details 62 false false R63.htm 2444430 - Disclosure - DERIVATIVE INSTRUMENTS - Schedule of Fair Value Hedge Relationships (Detail) Sheet http://www.franklinsynergybank.com/role/DERIVATIVEINSTRUMENTSScheduleofFairValueHedgeRelationshipsDetail DERIVATIVE INSTRUMENTS - Schedule of Fair Value Hedge Relationships (Detail) Details 63 false false R64.htm 2445431 - Disclosure - DERIVATIVE INSTRUMENTS - Schedule of Effects of Fair Value Hedge Relationships Reported in Interest Income on Securities on Consolidated Statements of Income (Detail) Sheet http://www.franklinsynergybank.com/role/DERIVATIVEINSTRUMENTSScheduleofEffectsofFairValueHedgeRelationshipsReportedinInterestIncomeonSecuritiesonConsolidatedStatementsofIncomeDetail DERIVATIVE INSTRUMENTS - Schedule of Effects of Fair Value Hedge Relationships Reported in Interest Income on Securities on Consolidated Statements of Income (Detail) Details 64 false false R65.htm 2446432 - Disclosure - DERIVATIVE INSTRUMENTS - Schedule of Amounts Related to Cumulative Basis Adjustments for Fair Value Hedges (Detail) Sheet http://www.franklinsynergybank.com/role/DERIVATIVEINSTRUMENTSScheduleofAmountsRelatedtoCumulativeBasisAdjustmentsforFairValueHedgesDetail DERIVATIVE INSTRUMENTS - Schedule of Amounts Related to Cumulative Basis Adjustments for Fair Value Hedges (Detail) Details 65 false false R66.htm 2447433 - Disclosure - DERIVATIVE INSTRUMENTS - Schedule of Cash Flow Hedge Relationships (Detail) Sheet http://www.franklinsynergybank.com/role/DERIVATIVEINSTRUMENTSScheduleofCashFlowHedgeRelationshipsDetail DERIVATIVE INSTRUMENTS - Schedule of Cash Flow Hedge Relationships (Detail) Details 66 false false R67.htm 2448434 - Disclosure - DERIVATIVE INSTRUMENTS - Schedule of Effects of Cash Flow Hedge Relationships on Statements of Comprehensive Income (Loss) (Detail) Sheet http://www.franklinsynergybank.com/role/DERIVATIVEINSTRUMENTSScheduleofEffectsofCashFlowHedgeRelationshipsonStatementsofComprehensiveIncomeLossDetail DERIVATIVE INSTRUMENTS - Schedule of Effects of Cash Flow Hedge Relationships on Statements of Comprehensive Income (Loss) (Detail) Details 67 false false R68.htm 2451435 - Disclosure - Commitments and Contingencies - Summary of Contractual Amounts of Financial Instruments with Off-Balance-Sheet Risk (Details) Sheet http://www.franklinsynergybank.com/role/CommitmentsandContingenciesSummaryofContractualAmountsofFinancialInstrumentswithOffBalanceSheetRiskDetails Commitments and Contingencies - Summary of Contractual Amounts of Financial Instruments with Off-Balance-Sheet Risk (Details) Details 68 false false R69.htm 2452436 - Disclosure - Commitments and Contingencies - Additional Information (Details) Sheet http://www.franklinsynergybank.com/role/CommitmentsandContingenciesAdditionalInformationDetails Commitments and Contingencies - Additional Information (Details) Details 69 false false R70.htm 2455437 - Disclosure - FAIR VALUE - Additional information (Detail) Sheet http://www.franklinsynergybank.com/role/FAIRVALUEAdditionalinformationDetail FAIR VALUE - Additional information (Detail) Details 70 false false R71.htm 2456438 - Disclosure - Fair Value - Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) Sheet http://www.franklinsynergybank.com/role/FairValueAssetsandLiabilitiesMeasuredatFairValueonRecurringBasisDetail Fair Value - Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) Details 71 false false R72.htm 2457439 - Disclosure - Fair Value, Assets Measured on Recurring and Nonrecurring Basis (Details) Sheet http://www.franklinsynergybank.com/role/FairValueAssetsMeasuredonRecurringandNonrecurringBasisDetails Fair Value, Assets Measured on Recurring and Nonrecurring Basis (Details) Details 72 false false R73.htm 2458440 - Disclosure - Fair Value - Carrying Amount and Estimated Fair Value of Financial Instruments (Detail) Sheet http://www.franklinsynergybank.com/role/FairValueCarryingAmountandEstimatedFairValueofFinancialInstrumentsDetail Fair Value - Carrying Amount and Estimated Fair Value of Financial Instruments (Detail) Details 73 false false R74.htm 2461441 - Disclosure - EARNINGS PER SHARE - Computation of Earnings per Share (Detail) Sheet http://www.franklinsynergybank.com/role/EARNINGSPERSHAREComputationofEarningsperShareDetail EARNINGS PER SHARE - Computation of Earnings per Share (Detail) Details 74 false false R75.htm 2462442 - Disclosure - EARNINGS PER SHARE - Additional Information (Detail) Sheet http://www.franklinsynergybank.com/role/EARNINGSPERSHAREAdditionalInformationDetail EARNINGS PER SHARE - Additional Information (Detail) Details 75 false false R76.htm 2465443 - Disclosure - SUBORDINATED DEBT ISSUANCE - Additional Information (Detail) Sheet http://www.franklinsynergybank.com/role/SUBORDINATEDDEBTISSUANCEAdditionalInformationDetail SUBORDINATED DEBT ISSUANCE - Additional Information (Detail) Details 76 false false R77.htm 2466444 - Disclosure - SUBORDINATED DEBT ISSUANCE - Summary of Terms of Each Subordinated Note offering (Detail) Sheet http://www.franklinsynergybank.com/role/SUBORDINATEDDEBTISSUANCESummaryofTermsofEachSubordinatedNoteofferingDetail SUBORDINATED DEBT ISSUANCE - Summary of Terms of Each Subordinated Note offering (Detail) Details 77 false false R9999.htm Uncategorized Items - fsb-20200331.htm Sheet http://xbrl.sec.gov/role/uncategorizedFacts Uncategorized Items - fsb-20200331.htm Cover 78 false false All Reports Book All Reports fsb-20200331.htm exhibit311.htm exhibit312.htm exhibit32.htm fsb-20200331.xsd fsb-20200331_cal.xml fsb-20200331_def.xml fsb-20200331_lab.xml fsb-20200331_pre.xml http://xbrl.sec.gov/dei/2019-01-31 http://fasb.org/srt/2019-01-31 http://fasb.org/us-gaap/2019-01-31 true true