3.6.0.2 html 541 607 1 false 120 0 false 5 false false R1.htm 101 - Document - Document And Entity Information Sheet http://www.fsbbank.net/role/DocumentAndEntityInformation Document And Entity Information Cover 1 false false R2.htm 102 - Statement - CONSOLIDATED BALANCE SHEETS Sheet http://www.fsbbank.net/role/ConsolidatedBalanceSheets CONSOLIDATED BALANCE SHEETS Statements 2 false false R3.htm 103 - Statement - CONSOLIDATED BALANCE SHEETS (Parenthetical) Sheet http://www.fsbbank.net/role/ConsolidatedBalanceSheetsParenthetical CONSOLIDATED BALANCE SHEETS (Parenthetical) Statements 3 false false R4.htm 104 - Statement - CONSOLIDATED STATEMENTS OF INCOME Sheet http://www.fsbbank.net/role/ConsolidatedStatementsOfIncome CONSOLIDATED STATEMENTS OF INCOME Statements 4 false false R5.htm 105 - Statement - CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME Sheet http://www.fsbbank.net/role/ConsolidatedStatementsOfComprehensiveIncome CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME Statements 5 false false R6.htm 106 - Statement - CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY Sheet http://www.fsbbank.net/role/ConsolidatedStatementsOfChangesInStockholdersEquity CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY Statements 6 false false R7.htm 107 - Statement - CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Parenthetical) Sheet http://www.fsbbank.net/role/ConsolidatedStatementsOfChangesInStockholdersEquityParenthetical CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Parenthetical) Statements 7 false false R8.htm 108 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS Sheet http://www.fsbbank.net/role/ConsolidatedStatementsOfCashFlows CONSOLIDATED STATEMENTS OF CASH FLOWS Statements 8 false false R9.htm 109 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Sheet http://www.fsbbank.net/role/SummaryOfSignificantAccountingPolicies SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Notes 9 false false R10.htm 110 - Disclosure - RESTRICTION ON CASH AND DUE FROM BANKS Sheet http://www.fsbbank.net/role/RestrictionOnCashAndDueFromBanks RESTRICTION ON CASH AND DUE FROM BANKS Notes 10 false false R11.htm 111 - Disclosure - INVESTMENT SECURITIES Sheet http://www.fsbbank.net/role/InvestmentSecurities INVESTMENT SECURITIES Notes 11 false false R12.htm 112 - Disclosure - LOANS AND ALLOWANCE FOR LOAN LOSSES Sheet http://www.fsbbank.net/role/LoansAndAllowanceForLoanLosses LOANS AND ALLOWANCE FOR LOAN LOSSES Notes 12 false false R13.htm 113 - Disclosure - REAL ESTATE DEVELOPMENT AND CONSTRUCTION Sheet http://www.fsbbank.net/role/RealEstateDevelopmentAndConstruction REAL ESTATE DEVELOPMENT AND CONSTRUCTION Notes 13 false false R14.htm 114 - Disclosure - INVESTMENT IN HISTORIC TAX CREDIT ENTITY Sheet http://www.fsbbank.net/role/InvestmentInHistoricTaxCreditEntity INVESTMENT IN HISTORIC TAX CREDIT ENTITY Notes 14 false false R15.htm 115 - Disclosure - PREMISES AND EQUIPMENT Sheet http://www.fsbbank.net/role/PremisesAndEquipment PREMISES AND EQUIPMENT Notes 15 false false R16.htm 116 - Disclosure - OTHER REAL ESTATE OWNED Sheet http://www.fsbbank.net/role/OtherRealEstateOwned OTHER REAL ESTATE OWNED Notes 16 false false R17.htm 117 - Disclosure - GOODWILL AND OTHER INTANGIBLES Sheet http://www.fsbbank.net/role/GoodwillAndOtherIntangibles GOODWILL AND OTHER INTANGIBLES Notes 17 false false R18.htm 118 - Disclosure - DEPOSITS Sheet http://www.fsbbank.net/role/Deposits DEPOSITS Notes 18 false false R19.htm 119 - Disclosure - FEDERAL FUNDS PURCHASED Sheet http://www.fsbbank.net/role/FederalFundsPurchased FEDERAL FUNDS PURCHASED Notes 19 false false R20.htm 120 - Disclosure - REPURCHASE AGREEMENTS Sheet http://www.fsbbank.net/role/RepurchaseAgreements REPURCHASE AGREEMENTS Notes 20 false false R21.htm 121 - Disclosure - BORROWINGS FROM FEDERAL HOME LOAN BANK Sheet http://www.fsbbank.net/role/BorrowingsFromFederalHomeLoanBank BORROWINGS FROM FEDERAL HOME LOAN BANK Notes 21 false false R22.htm 122 - Disclosure - OTHER LONG-TERM DEBT Sheet http://www.fsbbank.net/role/OtherLongtermDebt OTHER LONG-TERM DEBT Notes 22 false false R23.htm 123 - Disclosure - DEFERRED COMPENSATION PLANS Sheet http://www.fsbbank.net/role/DeferredCompensationPlans DEFERRED COMPENSATION PLANS Notes 23 false false R24.htm 124 - Disclosure - BENEFIT PLANS Sheet http://www.fsbbank.net/role/BenefitPlans BENEFIT PLANS Notes 24 false false R25.htm 125 - Disclosure - STOCK BASED COMPENSATION PLANS Sheet http://www.fsbbank.net/role/StockBasedCompensationPlans STOCK BASED COMPENSATION PLANS Notes 25 false false R26.htm 126 - Disclosure - INCOME TAXES Sheet http://www.fsbbank.net/role/IncomeTaxes INCOME TAXES Notes 26 false false R27.htm 127 - Disclosure - COMMITMENTS AND CONTINGENT LIABILITIES Sheet http://www.fsbbank.net/role/CommitmentsAndContingentLiabilities COMMITMENTS AND CONTINGENT LIABILITIES Notes 27 false false R28.htm 128 - Disclosure - OPERATING LEASES Sheet http://www.fsbbank.net/role/OperatingLeases OPERATING LEASES Notes 28 false false R29.htm 129 - Disclosure - FINANCIAL INSTRUMENTS WITH OFF-BALANCE-SHEET RISK Sheet http://www.fsbbank.net/role/FinancialInstrumentsWithOffbalancesheetRisk FINANCIAL INSTRUMENTS WITH OFF-BALANCE-SHEET RISK Notes 29 false false R30.htm 130 - Disclosure - FAIR VALUE MEASUREMENTS Sheet http://www.fsbbank.net/role/FairValueMeasurements FAIR VALUE MEASUREMENTS Notes 30 false false R31.htm 131 - Disclosure - DISCLOSURES ABOUT FAIR VALUE OF FINANCIAL INSTRUMENTS Sheet http://www.fsbbank.net/role/DisclosuresAboutFairValueOfFinancialInstruments DISCLOSURES ABOUT FAIR VALUE OF FINANCIAL INSTRUMENTS Notes 31 false false R32.htm 132 - Disclosure - STOCKHOLDERS' EQUITY Sheet http://www.fsbbank.net/role/StockholdersEquity STOCKHOLDERS' EQUITY Notes 32 false false R33.htm 133 - Disclosure - PREFERRED STOCK Sheet http://www.fsbbank.net/role/PreferredStock PREFERRED STOCK Notes 33 false false R34.htm 134 - Disclosure - DIVIDEND RESTRICTION Sheet http://www.fsbbank.net/role/DividendRestriction DIVIDEND RESTRICTION Notes 34 false false R35.htm 135 - Disclosure - REGULATORY MATTERS Sheet http://www.fsbbank.net/role/RegulatoryMatters REGULATORY MATTERS Notes 35 false false R36.htm 136 - Disclosure - SUPPLEMENTAL DISCLOSURE FOR EARNINGS PER SHARE Sheet http://www.fsbbank.net/role/SupplementalDisclosureForEarningsPerShare SUPPLEMENTAL DISCLOSURE FOR EARNINGS PER SHARE Notes 36 false false R37.htm 137 - Disclosure - PARENT COMPANY CONDENSED FINANCIAL INFORMATION Sheet http://www.fsbbank.net/role/ParentCompanyCondensedFinancialInformation PARENT COMPANY CONDENSED FINANCIAL INFORMATION Notes 37 false false R38.htm 138 - Disclosure - CONCENTRATION OF CREDIT RISK Sheet http://www.fsbbank.net/role/ConcentrationOfCreditRisk CONCENTRATION OF CREDIT RISK Notes 38 false false R39.htm 139 - Disclosure - SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION Sheet http://www.fsbbank.net/role/SupplementalDisclosureOfCashFlowInformation SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION Notes 39 false false R40.htm 140 - Disclosure - SELECTED QUARTERLY FINANCIAL INFORMATION Sheet http://www.fsbbank.net/role/SelectedQuarterlyFinancialInformation SELECTED QUARTERLY FINANCIAL INFORMATION Notes 40 false false R41.htm 141 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies) Sheet http://www.fsbbank.net/role/SummaryOfSignificantAccountingPoliciesPolicies SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies) Policies 41 false false R42.htm 142 - Disclosure - INVESTMENT SECURITIES (Tables) Sheet http://www.fsbbank.net/role/InvestmentSecuritiesTables INVESTMENT SECURITIES (Tables) Tables http://www.fsbbank.net/role/InvestmentSecurities 42 false false R43.htm 143 - Disclosure - LOANS AND ALLOWANCE FOR LOAN LOSSES (Tables) Sheet http://www.fsbbank.net/role/LoansAndAllowanceForLoanLossesTables LOANS AND ALLOWANCE FOR LOAN LOSSES (Tables) Tables http://www.fsbbank.net/role/LoansAndAllowanceForLoanLosses 43 false false R44.htm 144 - Disclosure - REAL ESTATE DEVELOPMENT AND CONSTRUCTION (Tables) Sheet http://www.fsbbank.net/role/RealEstateDevelopmentAndConstructionTables REAL ESTATE DEVELOPMENT AND CONSTRUCTION (Tables) Tables http://www.fsbbank.net/role/RealEstateDevelopmentAndConstruction 44 false false R45.htm 145 - Disclosure - PREMISES AND EQUIPMENT (Tables) Sheet http://www.fsbbank.net/role/PremisesAndEquipmentTables PREMISES AND EQUIPMENT (Tables) Tables http://www.fsbbank.net/role/PremisesAndEquipment 45 false false R46.htm 146 - Disclosure - GOODWILL AND OTHER INTANGIBLES (Tables) Sheet http://www.fsbbank.net/role/GoodwillAndOtherIntangiblesTables GOODWILL AND OTHER INTANGIBLES (Tables) Tables http://www.fsbbank.net/role/GoodwillAndOtherIntangibles 46 false false R47.htm 147 - Disclosure - DEPOSITS (Tables) Sheet http://www.fsbbank.net/role/DepositsTables DEPOSITS (Tables) Tables http://www.fsbbank.net/role/Deposits 47 false false R48.htm 148 - Disclosure - REPURCHASE AGREEMENTS (Tables) Sheet http://www.fsbbank.net/role/RepurchaseAgreementsTables REPURCHASE AGREEMENTS (Tables) Tables http://www.fsbbank.net/role/RepurchaseAgreements 48 false false R49.htm 149 - Disclosure - BORROWINGS FROM FEDERAL HOME LOAN BANK (Tables) Sheet http://www.fsbbank.net/role/BorrowingsFromFederalHomeLoanBankTables BORROWINGS FROM FEDERAL HOME LOAN BANK (Tables) Tables http://www.fsbbank.net/role/BorrowingsFromFederalHomeLoanBank 49 false false R50.htm 150 - Disclosure - BENEFIT PLANS (Tables) Sheet http://www.fsbbank.net/role/BenefitPlansTables BENEFIT PLANS (Tables) Tables http://www.fsbbank.net/role/BenefitPlans 50 false false R51.htm 151 - Disclosure - STOCK BASED COMPENSATION PLANS (Tables) Sheet http://www.fsbbank.net/role/StockBasedCompensationPlansTables STOCK BASED COMPENSATION PLANS (Tables) Tables http://www.fsbbank.net/role/StockBasedCompensationPlans 51 false false R52.htm 152 - Disclosure - INCOME TAXES (Tables) Sheet http://www.fsbbank.net/role/IncomeTaxesTables INCOME TAXES (Tables) Tables http://www.fsbbank.net/role/IncomeTaxes 52 false false R53.htm 153 - Disclosure - COMMITMENTS AND CONTINGENT LIABILITIES (Tables) Sheet http://www.fsbbank.net/role/CommitmentsAndContingentLiabilitiesTables COMMITMENTS AND CONTINGENT LIABILITIES (Tables) Tables http://www.fsbbank.net/role/CommitmentsAndContingentLiabilities 53 false false R54.htm 154 - Disclosure - OPERATING LEASES (Tables) Sheet http://www.fsbbank.net/role/OperatingLeasesTables OPERATING LEASES (Tables) Tables http://www.fsbbank.net/role/OperatingLeases 54 false false R55.htm 155 - Disclosure - FAIR VALUE MEASUREMENTS (Tables) Sheet http://www.fsbbank.net/role/FairValueMeasurementsTables FAIR VALUE MEASUREMENTS (Tables) Tables http://www.fsbbank.net/role/FairValueMeasurements 55 false false R56.htm 156 - Disclosure - DISCLOSURES ABOUT FAIR VALUE OF FINANCIAL INSTRUMENTS (Tables) Sheet http://www.fsbbank.net/role/DisclosuresAboutFairValueOfFinancialInstrumentsTables DISCLOSURES ABOUT FAIR VALUE OF FINANCIAL INSTRUMENTS (Tables) Tables http://www.fsbbank.net/role/DisclosuresAboutFairValueOfFinancialInstruments 56 false false R57.htm 157 - Disclosure - REGULATORY MATTERS (Tables) Sheet http://www.fsbbank.net/role/RegulatoryMattersTables REGULATORY MATTERS (Tables) Tables http://www.fsbbank.net/role/RegulatoryMatters 57 false false R58.htm 158 - Disclosure - SUPPLEMENTAL DISCLOSURE FOR EARNINGS PER SHARE (Tables) Sheet http://www.fsbbank.net/role/SupplementalDisclosureForEarningsPerShareTables SUPPLEMENTAL DISCLOSURE FOR EARNINGS PER SHARE (Tables) Tables http://www.fsbbank.net/role/SupplementalDisclosureForEarningsPerShare 58 false false R59.htm 159 - Disclosure - PARENT COMPANY CONDENSED FINANCIAL INFORMATION (Tables) Sheet http://www.fsbbank.net/role/ParentCompanyCondensedFinancialInformationTables PARENT COMPANY CONDENSED FINANCIAL INFORMATION (Tables) Tables http://www.fsbbank.net/role/ParentCompanyCondensedFinancialInformation 59 false false R60.htm 160 - Disclosure - SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION (Tables) Sheet http://www.fsbbank.net/role/SupplementalDisclosureOfCashFlowInformationTables SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION (Tables) Tables http://www.fsbbank.net/role/SupplementalDisclosureOfCashFlowInformation 60 false false R61.htm 161 - Disclosure - SELECTED QUARTERLY FINANCIAL INFORMATION (Tables) Sheet http://www.fsbbank.net/role/SelectedQuarterlyFinancialInformationTables SELECTED QUARTERLY FINANCIAL INFORMATION (Tables) Tables http://www.fsbbank.net/role/SelectedQuarterlyFinancialInformation 61 false false R62.htm 162 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Additional Information) (Detail) Sheet http://www.fsbbank.net/role/SummaryOfSignificantAccountingPoliciesAdditionalInformationDetail SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Additional Information) (Detail) Details http://www.fsbbank.net/role/SummaryOfSignificantAccountingPoliciesPolicies 62 false false R63.htm 163 - Disclosure - RESTRICTION ON CASH AND DUE FROM BANKS (Additional Information) (Detail) Sheet http://www.fsbbank.net/role/RestrictionOnCashAndDueFromBanksAdditionalInformationDetail RESTRICTION ON CASH AND DUE FROM BANKS (Additional Information) (Detail) Details http://www.fsbbank.net/role/RestrictionOnCashAndDueFromBanks 63 false false R64.htm 164 - Disclosure - INVESTMENT SECURITIES (Amortized Cost And Fair Value Of Securities) (Detail) Sheet http://www.fsbbank.net/role/InvestmentSecuritiesAmortizedCostAndFairValueOfSecuritiesDetail INVESTMENT SECURITIES (Amortized Cost And Fair Value Of Securities) (Detail) Details http://www.fsbbank.net/role/InvestmentSecuritiesTables 64 false false R65.htm 165 - Disclosure - INVESTMENT SECURITIES (Amortized Cost And Fair Value Of Investment Securities By Contractual Maturity) (Detail) Sheet http://www.fsbbank.net/role/InvestmentSecuritiesAmortizedCostAndFairValueOfInvestmentSecuritiesByContractualMaturityDetail INVESTMENT SECURITIES (Amortized Cost And Fair Value Of Investment Securities By Contractual Maturity) (Detail) Details http://www.fsbbank.net/role/InvestmentSecuritiesTables 65 false false R66.htm 166 - Disclosure - INVESTMENT SECURITIES (Available For Sale Securities With Gross Unrealized Losses By Investment Category And Length Of Time Individual Securities Have Been In Continuous Loss Position) (Detail) Sheet http://www.fsbbank.net/role/InvestmentSecuritiesAvailableForSaleSecuritiesWithGrossUnrealizedLossesByInvestmentCategoryAndLengthOfTimeIndividualSecuritiesHaveBeenInContinuousLossPositionDetail INVESTMENT SECURITIES (Available For Sale Securities With Gross Unrealized Losses By Investment Category And Length Of Time Individual Securities Have Been In Continuous Loss Position) (Detail) Details http://www.fsbbank.net/role/InvestmentSecuritiesTables 66 false false R67.htm 167 - Disclosure - INVESTMENT SECURITIES (Additional Information) (Detail) Sheet http://www.fsbbank.net/role/InvestmentSecuritiesAdditionalInformationDetail INVESTMENT SECURITIES (Additional Information) (Detail) Details http://www.fsbbank.net/role/InvestmentSecuritiesTables 67 false false R68.htm 168 - Disclosure - LOANS AND ALLOWANCE FOR LOAN LOSSES (Loans) (Detail) Sheet http://www.fsbbank.net/role/LoansAndAllowanceForLoanLossesLoansDetail LOANS AND ALLOWANCE FOR LOAN LOSSES (Loans) (Detail) Details http://www.fsbbank.net/role/LoansAndAllowanceForLoanLossesTables 68 false false R69.htm 169 - Disclosure - LOANS AND ALLOWANCE FOR LOAN LOSSES (Activity For Related Party Loans) (Detail) Sheet http://www.fsbbank.net/role/LoansAndAllowanceForLoanLossesActivityForRelatedPartyLoansDetail LOANS AND ALLOWANCE FOR LOAN LOSSES (Activity For Related Party Loans) (Detail) Details http://www.fsbbank.net/role/LoansAndAllowanceForLoanLossesTables 69 false false R70.htm 170 - Disclosure - LOANS AND ALLOWANCE FOR LOAN LOSSES (Components Of Recorded Investment In Loans For Each Portfolio Class) (Detail) Sheet http://www.fsbbank.net/role/LoansAndAllowanceForLoanLossesComponentsOfRecordedInvestmentInLoansForEachPortfolioClassDetail LOANS AND ALLOWANCE FOR LOAN LOSSES (Components Of Recorded Investment In Loans For Each Portfolio Class) (Detail) Details http://www.fsbbank.net/role/LoansAndAllowanceForLoanLossesTables 70 false false R71.htm 171 - Disclosure - LOANS AND ALLOWANCE FOR LOAN LOSSES (Allowance For Loan Losses) (Detail) Sheet http://www.fsbbank.net/role/LoansAndAllowanceForLoanLossesAllowanceForLoanLossesDetail LOANS AND ALLOWANCE FOR LOAN LOSSES (Allowance For Loan Losses) (Detail) Details http://www.fsbbank.net/role/LoansAndAllowanceForLoanLossesTables 71 false false R72.htm 172 - Disclosure - LOANS AND ALLOWANCE FOR LOAN LOSSES (Impaired Loans Individually Evaluated For Impairment) (Detail) Sheet http://www.fsbbank.net/role/LoansAndAllowanceForLoanLossesImpairedLoansIndividuallyEvaluatedForImpairmentDetail LOANS AND ALLOWANCE FOR LOAN LOSSES (Impaired Loans Individually Evaluated For Impairment) (Detail) Details http://www.fsbbank.net/role/LoansAndAllowanceForLoanLossesTables 72 false false R73.htm 173 - Disclosure - LOANS AND ALLOWANCE FOR LOAN LOSSES (Recorded Investment In Nonperforming Loans By Class Of Loans) (Detail) Sheet http://www.fsbbank.net/role/LoansAndAllowanceForLoanLossesRecordedInvestmentInNonperformingLoansByClassOfLoansDetail LOANS AND ALLOWANCE FOR LOAN LOSSES (Recorded Investment In Nonperforming Loans By Class Of Loans) (Detail) Details http://www.fsbbank.net/role/LoansAndAllowanceForLoanLossesTables 73 false false R74.htm 174 - Disclosure - LOANS AND ALLOWANCE FOR LOAN LOSSES (Aging of Recorded Investment in Past Due Loans) (Detail) Sheet http://www.fsbbank.net/role/LoansAndAllowanceForLoanLossesAgingOfRecordedInvestmentInPastDueLoansDetail LOANS AND ALLOWANCE FOR LOAN LOSSES (Aging of Recorded Investment in Past Due Loans) (Detail) Details http://www.fsbbank.net/role/LoansAndAllowanceForLoanLossesTables 74 false false R75.htm 175 - Disclosure - LOANS AND ALLOWANCE FOR LOAN LOSSES (Recorded Investment in Loans by Risk Category) (Detail) Sheet http://www.fsbbank.net/role/LoansAndAllowanceForLoanLossesRecordedInvestmentInLoansByRiskCategoryDetail LOANS AND ALLOWANCE FOR LOAN LOSSES (Recorded Investment in Loans by Risk Category) (Detail) Details http://www.fsbbank.net/role/LoansAndAllowanceForLoanLossesTables 75 false false R76.htm 176 - Disclosure - LOANS AND ALLOWANCE FOR LOAN LOSSES (Recorded Investment in Troubled Debt Restructurings by Class of Loan and Accrual Status) (Detail) Sheet http://www.fsbbank.net/role/LoansAndAllowanceForLoanLossesRecordedInvestmentInTroubledDebtRestructuringsByClassOfLoanAndAccrualStatusDetail LOANS AND ALLOWANCE FOR LOAN LOSSES (Recorded Investment in Troubled Debt Restructurings by Class of Loan and Accrual Status) (Detail) Details http://www.fsbbank.net/role/LoansAndAllowanceForLoanLossesTables 76 false false R77.htm 177 - Disclosure - LOANS AND ALLOWANCE FOR LOAN LOSSES (Troubled Debt Restructurings) (Detail) Sheet http://www.fsbbank.net/role/LoansAndAllowanceForLoanLossesTroubledDebtRestructuringsDetail LOANS AND ALLOWANCE FOR LOAN LOSSES (Troubled Debt Restructurings) (Detail) Details http://www.fsbbank.net/role/LoansAndAllowanceForLoanLossesTables 77 false false R78.htm 178 - Disclosure - LOANS AND ALLOWANCE FOR LOAN LOSSES (Loan Servicing Rights) (Detail) Sheet http://www.fsbbank.net/role/LoansAndAllowanceForLoanLossesLoanServicingRightsDetail LOANS AND ALLOWANCE FOR LOAN LOSSES (Loan Servicing Rights) (Detail) Details http://www.fsbbank.net/role/LoansAndAllowanceForLoanLossesTables 78 false false R79.htm 179 - Disclosure - LOANS AND ALLOWANCE FOR LOAN LOSSES (Additional Information) (Detail) Sheet http://www.fsbbank.net/role/LoansAndAllowanceForLoanLossesAdditionalInformationDetail LOANS AND ALLOWANCE FOR LOAN LOSSES (Additional Information) (Detail) Details http://www.fsbbank.net/role/LoansAndAllowanceForLoanLossesTables 79 false false R80.htm 180 - Disclosure - REAL ESTATE DEVELOPMENT AND CONSTRUCTION (Real Estate Development and Construction Properties) (Detail) Sheet http://www.fsbbank.net/role/RealEstateDevelopmentAndConstructionRealEstateDevelopmentAndConstructionPropertiesDetail REAL ESTATE DEVELOPMENT AND CONSTRUCTION (Real Estate Development and Construction Properties) (Detail) Details http://www.fsbbank.net/role/RealEstateDevelopmentAndConstructionTables 80 false false R81.htm 181 - Disclosure - REAL ESTATE DEVELOPMENT AND CONSTRUCTION (Additional Information) (Detail) Sheet http://www.fsbbank.net/role/RealEstateDevelopmentAndConstructionAdditionalInformationDetail REAL ESTATE DEVELOPMENT AND CONSTRUCTION (Additional Information) (Detail) Details http://www.fsbbank.net/role/RealEstateDevelopmentAndConstructionTables 81 false false R82.htm 182 - Disclosure - INVESTMENT IN HISTORIC TAX CREDIT ENTITY (Additional Information) (Detail) Sheet http://www.fsbbank.net/role/InvestmentInHistoricTaxCreditEntityAdditionalInformationDetail INVESTMENT IN HISTORIC TAX CREDIT ENTITY (Additional Information) (Detail) Details http://www.fsbbank.net/role/InvestmentInHistoricTaxCreditEntity 82 false false R83.htm 183 - Disclosure - PREMISES AND EQUIPMENT (Premises And Equipment) (Detail) Sheet http://www.fsbbank.net/role/PremisesAndEquipmentPremisesAndEquipmentDetail PREMISES AND EQUIPMENT (Premises And Equipment) (Detail) Details http://www.fsbbank.net/role/PremisesAndEquipmentTables 83 false false R84.htm 184 - Disclosure - PREMISES AND EQUIPMENT (Additional Information) (Detail) Sheet http://www.fsbbank.net/role/PremisesAndEquipmentAdditionalInformationDetail PREMISES AND EQUIPMENT (Additional Information) (Detail) Details http://www.fsbbank.net/role/PremisesAndEquipmentTables 84 false false R85.htm 185 - Disclosure - OTHER REAL ESTATE OWNED (Additional Information) (Detail) Sheet http://www.fsbbank.net/role/OtherRealEstateOwnedAdditionalInformationDetail OTHER REAL ESTATE OWNED (Additional Information) (Detail) Details http://www.fsbbank.net/role/OtherRealEstateOwned 85 false false R86.htm 186 - Disclosure - GOODWILL AND OTHER INTANGIBLES (Changes In The Carrying Amount Of Goodwill) (Detail) Sheet http://www.fsbbank.net/role/GoodwillAndOtherIntangiblesChangesInCarryingAmountOfGoodwillDetail GOODWILL AND OTHER INTANGIBLES (Changes In The Carrying Amount Of Goodwill) (Detail) Details http://www.fsbbank.net/role/GoodwillAndOtherIntangiblesTables 86 false false R87.htm 187 - Disclosure - GOODWILL AND OTHER INTANGIBLES (Summary Of Other Intangible Assets) (Detail) Sheet http://www.fsbbank.net/role/GoodwillAndOtherIntangiblesSummaryOfOtherIntangibleAssetsDetail GOODWILL AND OTHER INTANGIBLES (Summary Of Other Intangible Assets) (Detail) Details http://www.fsbbank.net/role/GoodwillAndOtherIntangiblesTables 87 false false R88.htm 188 - Disclosure - GOODWILL AND OTHER INTANGIBLES (Estimated Amortization Expense For The Core Deposit Intangibles) (Detail) Sheet http://www.fsbbank.net/role/GoodwillAndOtherIntangiblesEstimatedAmortizationExpenseForCoreDepositIntangiblesDetail GOODWILL AND OTHER INTANGIBLES (Estimated Amortization Expense For The Core Deposit Intangibles) (Detail) Details http://www.fsbbank.net/role/GoodwillAndOtherIntangiblesTables 88 false false R89.htm 189 - Disclosure - GOODWILL AND OTHER INTANGIBLES (Additional Information) (Detail) Sheet http://www.fsbbank.net/role/GoodwillAndOtherIntangiblesAdditionalInformationDetail GOODWILL AND OTHER INTANGIBLES (Additional Information) (Detail) Details http://www.fsbbank.net/role/GoodwillAndOtherIntangiblesTables 89 false false R90.htm 190 - Disclosure - DEPOSITS (Scheduled Maturities Of Certificates Of Deposit) (Detail) Sheet http://www.fsbbank.net/role/DepositsScheduledMaturitiesOfCertificatesOfDepositDetail DEPOSITS (Scheduled Maturities Of Certificates Of Deposit) (Detail) Details http://www.fsbbank.net/role/DepositsTables 90 false false R91.htm 191 - Disclosure - DEPOSITS (Additional Information) (Detail) Sheet http://www.fsbbank.net/role/DepositsAdditionalInformationDetail DEPOSITS (Additional Information) (Detail) Details http://www.fsbbank.net/role/DepositsTables 91 false false R92.htm 192 - Disclosure - FEDERAL FUNDS PURCHASED (Additional Information) (Detail) Sheet http://www.fsbbank.net/role/FederalFundsPurchasedAdditionalInformationDetail FEDERAL FUNDS PURCHASED (Additional Information) (Detail) Details http://www.fsbbank.net/role/FederalFundsPurchased 92 false false R93.htm 193 - Disclosure - REPURCHASE AGREEMENTS (Deposit Customers And Long-Term Repurchase Agreements) (Detail) Sheet http://www.fsbbank.net/role/RepurchaseAgreementsDepositCustomersAndLongtermRepurchaseAgreementsDetail REPURCHASE AGREEMENTS (Deposit Customers And Long-Term Repurchase Agreements) (Detail) Details http://www.fsbbank.net/role/RepurchaseAgreementsTables 93 false false R94.htm 194 - Disclosure - REPURCHASE AGREEMENTS (Borrowings Under Retail Repurchase Agreements) (Detail) Sheet http://www.fsbbank.net/role/RepurchaseAgreementsBorrowingsUnderRetailRepurchaseAgreementsDetail REPURCHASE AGREEMENTS (Borrowings Under Retail Repurchase Agreements) (Detail) Details http://www.fsbbank.net/role/RepurchaseAgreementsTables 94 false false R95.htm 195 - Disclosure - BORROWINGS FROM FEDERAL HOME LOAN BANK (Borrowings From The FHLB) (Detail) Sheet http://www.fsbbank.net/role/BorrowingsFromFederalHomeLoanBankBorrowingsFromFhlbDetail BORROWINGS FROM FEDERAL HOME LOAN BANK (Borrowings From The FHLB) (Detail) Details http://www.fsbbank.net/role/BorrowingsFromFederalHomeLoanBankTables 95 false false R96.htm 196 - Disclosure - BORROWINGS FROM FEDERAL HOME LOAN BANK (Additional Information) (Detail) Sheet http://www.fsbbank.net/role/BorrowingsFromFederalHomeLoanBankAdditionalInformationDetail BORROWINGS FROM FEDERAL HOME LOAN BANK (Additional Information) (Detail) Details http://www.fsbbank.net/role/BorrowingsFromFederalHomeLoanBankTables 96 false false R97.htm 197 - Disclosure - OTHER LONG-TERM DEBT (Additional Information) (Detail) Sheet http://www.fsbbank.net/role/OtherLongtermDebtAdditionalInformationDetail OTHER LONG-TERM DEBT (Additional Information) (Detail) Details http://www.fsbbank.net/role/OtherLongtermDebt 97 false false R98.htm 198 - Disclosure - DEFERRED COMPENSATION PLANS (Additional Information) (Detail) Sheet http://www.fsbbank.net/role/DeferredCompensationPlansAdditionalInformationDetail DEFERRED COMPENSATION PLANS (Additional Information) (Detail) Details http://www.fsbbank.net/role/DeferredCompensationPlans 98 false false R99.htm 199 - Disclosure - BENEFIT PLANS (Common Stock Held By The ESOP) (Detail) Sheet http://www.fsbbank.net/role/BenefitPlansCommonStockHeldByEsopDetail BENEFIT PLANS (Common Stock Held By The ESOP) (Detail) Details http://www.fsbbank.net/role/BenefitPlansTables 99 false false R100.htm 200 - Disclosure - BENEFIT PLANS (Additional Information) (Detail) Sheet http://www.fsbbank.net/role/BenefitPlansAdditionalInformationDetail BENEFIT PLANS (Additional Information) (Detail) Details http://www.fsbbank.net/role/BenefitPlansTables 100 false false R101.htm 201 - Disclosure - STOCK BASED COMPENSATION PLANS (Fair Value Of Options Granted) (Detail) Sheet http://www.fsbbank.net/role/StockBasedCompensationPlansFairValueOfOptionsGrantedDetail STOCK BASED COMPENSATION PLANS (Fair Value Of Options Granted) (Detail) Details http://www.fsbbank.net/role/StockBasedCompensationPlansTables 101 false false R102.htm 202 - Disclosure - STOCK BASED COMPENSATION PLANS (Stock Option Activity Under The Plan) (Detail) Sheet http://www.fsbbank.net/role/StockBasedCompensationPlansStockOptionActivityUnderPlanDetail STOCK BASED COMPENSATION PLANS (Stock Option Activity Under The Plan) (Detail) Details http://www.fsbbank.net/role/StockBasedCompensationPlansTables 102 false false R103.htm 203 - Disclosure - STOCK BASED COMPENSATION PLANS (Additional Information) (Detail) Sheet http://www.fsbbank.net/role/StockBasedCompensationPlansAdditionalInformationDetail STOCK BASED COMPENSATION PLANS (Additional Information) (Detail) Details http://www.fsbbank.net/role/StockBasedCompensationPlansTables 103 false false R104.htm 204 - Disclosure - INCOME TAXES (Consolidated Income Tax Expense) (Detail) Sheet http://www.fsbbank.net/role/IncomeTaxesConsolidatedIncomeTaxExpenseDetail INCOME TAXES (Consolidated Income Tax Expense) (Detail) Details http://www.fsbbank.net/role/IncomeTaxesTables 104 false false R105.htm 205 - Disclosure - INCOME TAXES (Reconciliation Of Income Tax Expense) (Detail) Sheet http://www.fsbbank.net/role/IncomeTaxesReconciliationOfIncomeTaxExpenseDetail INCOME TAXES (Reconciliation Of Income Tax Expense) (Detail) Details http://www.fsbbank.net/role/IncomeTaxesTables 105 false false R106.htm 206 - Disclosure - INCOME TAXES (Deferred Tax Assets And Liabilities) (Detail) Sheet http://www.fsbbank.net/role/IncomeTaxesDeferredTaxAssetsAndLiabilitiesDetail INCOME TAXES (Deferred Tax Assets And Liabilities) (Detail) Details http://www.fsbbank.net/role/IncomeTaxesTables 106 false false R107.htm 207 - Disclosure - INCOME TAXES (Additional Information) (Detail) Sheet http://www.fsbbank.net/role/IncomeTaxesAdditionalInformationDetail INCOME TAXES (Additional Information) (Detail) Details http://www.fsbbank.net/role/IncomeTaxesTables 107 false false R108.htm 208 - Disclosure - COMMITMENTS AND CONTINGENT LIABILITIES (Commitments To Extend Credit) (Detail) Sheet http://www.fsbbank.net/role/CommitmentsAndContingentLiabilitiesCommitmentsToExtendCreditDetail COMMITMENTS AND CONTINGENT LIABILITIES (Commitments To Extend Credit) (Detail) Details http://www.fsbbank.net/role/CommitmentsAndContingentLiabilitiesTables 108 false false R109.htm 209 - Disclosure - COMMITMENTS AND CONTINGENT LIABILITIES (Additional Information) (Detail) Sheet http://www.fsbbank.net/role/CommitmentsAndContingentLiabilitiesAdditionalInformationDetail COMMITMENTS AND CONTINGENT LIABILITIES (Additional Information) (Detail) Details http://www.fsbbank.net/role/CommitmentsAndContingentLiabilitiesTables 109 false false R110.htm 210 - Disclosure - OPERATING LEASES (Detail) Sheet http://www.fsbbank.net/role/OperatingLeasesDetail OPERATING LEASES (Detail) Details http://www.fsbbank.net/role/OperatingLeasesTables 110 false false R111.htm 211 - Disclosure - OPERATING LEASES (Additional Information) (Detail) Sheet http://www.fsbbank.net/role/OperatingLeasesAdditionalInformationDetail OPERATING LEASES (Additional Information) (Detail) Details http://www.fsbbank.net/role/OperatingLeasesTables 111 false false R112.htm 212 - Disclosure - FAIR VALUE MEASUREMENTS (Balances Of Financial Assets Measured At Fair Value On Recurring And Nonrecurring) (Detail) Sheet http://www.fsbbank.net/role/FairValueMeasurementsBalancesOfFinancialAssetsMeasuredAtFairValueOnRecurringAndNonrecurringDetail FAIR VALUE MEASUREMENTS (Balances Of Financial Assets Measured At Fair Value On Recurring And Nonrecurring) (Detail) Details http://www.fsbbank.net/role/FairValueMeasurementsTables 112 false false R113.htm 213 - Disclosure - FAIR VALUE MEASUREMENTS (Additional information) (Detail) Sheet http://www.fsbbank.net/role/FairValueMeasurementsAdditionalInformationDetail FAIR VALUE MEASUREMENTS (Additional information) (Detail) Details http://www.fsbbank.net/role/FairValueMeasurementsTables 113 false false R114.htm 214 - Disclosure - DISCLOSURES ABOUT FAIR VALUE OF FINANCIAL INSTRUMENTS (Carrying Value And Estimated Fair Value Of Financial Instruments) (Detail) Sheet http://www.fsbbank.net/role/DisclosuresAboutFairValueOfFinancialInstrumentsCarryingValueAndEstimatedFairValueOfFinancialInstrumentsDetail DISCLOSURES ABOUT FAIR VALUE OF FINANCIAL INSTRUMENTS (Carrying Value And Estimated Fair Value Of Financial Instruments) (Detail) Details http://www.fsbbank.net/role/DisclosuresAboutFairValueOfFinancialInstrumentsTables 114 false false R115.htm 215 - Disclosure - STOCKHOLDERS' EQUITY (Additional Information) (Detail) Sheet http://www.fsbbank.net/role/StockholdersEquityAdditionalInformationDetail STOCKHOLDERS' EQUITY (Additional Information) (Detail) Details http://www.fsbbank.net/role/StockholdersEquity 115 false false R116.htm 216 - Disclosure - PREFERRED STOCK (Additional Information) (Detail) Sheet http://www.fsbbank.net/role/PreferredStockAdditionalInformationDetail PREFERRED STOCK (Additional Information) (Detail) Details http://www.fsbbank.net/role/PreferredStock 116 false false R117.htm 217 - Disclosure - REGULATORY MATTERS (Bank's Actual Capital Amounts And Ratios) (Detail) Sheet http://www.fsbbank.net/role/RegulatoryMattersBanksActualCapitalAmountsAndRatiosDetail REGULATORY MATTERS (Bank's Actual Capital Amounts And Ratios) (Detail) Details http://www.fsbbank.net/role/RegulatoryMattersTables 117 false false R118.htm 218 - Disclosure - SUPPLEMENTAL DISCLOSURE FOR EARNINGS PER SHARE (Earnings Per Share Information) (Detail) Sheet http://www.fsbbank.net/role/SupplementalDisclosureForEarningsPerShareEarningsPerShareInformationDetail SUPPLEMENTAL DISCLOSURE FOR EARNINGS PER SHARE (Earnings Per Share Information) (Detail) Details http://www.fsbbank.net/role/SupplementalDisclosureForEarningsPerShareTables 118 false false R119.htm 219 - Disclosure - PARENT COMPANY CONDENSED FINANCIAL INFORMATION (Condensed Financial Information) (Detail) Sheet http://www.fsbbank.net/role/ParentCompanyCondensedFinancialInformationCondensedFinancialInformationDetail PARENT COMPANY CONDENSED FINANCIAL INFORMATION (Condensed Financial Information) (Detail) Details http://www.fsbbank.net/role/ParentCompanyCondensedFinancialInformationTables 119 false false R120.htm 220 - Disclosure - PARENT COMPANY CONDENSED FINANCIAL INFORMATION (Condensed Statements of Income) (Detail) Sheet http://www.fsbbank.net/role/ParentCompanyCondensedFinancialInformationCondensedStatementsOfIncomeDetail PARENT COMPANY CONDENSED FINANCIAL INFORMATION (Condensed Statements of Income) (Detail) Details http://www.fsbbank.net/role/ParentCompanyCondensedFinancialInformationTables 120 false false R121.htm 221 - Disclosure - PARENT COMPANY CONDENSED FINANCIAL INFORMATION (Statements Of Cash Flows) (Detail) Sheet http://www.fsbbank.net/role/ParentCompanyCondensedFinancialInformationStatementsOfCashFlowsDetail PARENT COMPANY CONDENSED FINANCIAL INFORMATION (Statements Of Cash Flows) (Detail) Details http://www.fsbbank.net/role/ParentCompanyCondensedFinancialInformationTables 121 false false R122.htm 222 - Disclosure - CONCENTRATION OF CREDIT RISK (Additional Information) (Detail) Sheet http://www.fsbbank.net/role/ConcentrationOfCreditRiskAdditionalInformationDetail CONCENTRATION OF CREDIT RISK (Additional Information) (Detail) Details http://www.fsbbank.net/role/ConcentrationOfCreditRisk 122 false false R123.htm 223 - Disclosure - SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION (Cash Flow Information) (Detail) Sheet http://www.fsbbank.net/role/SupplementalDisclosureOfCashFlowInformationCashFlowInformationDetail SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION (Cash Flow Information) (Detail) Details http://www.fsbbank.net/role/SupplementalDisclosureOfCashFlowInformationTables 123 false false R124.htm 224 - Disclosure - SELECTED QUARTERLY FINANCIAL INFORMATION (Financial Information) (Detail) Sheet http://www.fsbbank.net/role/SelectedQuarterlyFinancialInformationFinancialInformationDetail SELECTED QUARTERLY FINANCIAL INFORMATION (Financial Information) (Detail) Details http://www.fsbbank.net/role/SelectedQuarterlyFinancialInformationTables 124 false false All Reports Book All Reports fsfg-20160930.xml fsfg-20160930.xsd fsfg-20160930_cal.xml fsfg-20160930_def.xml fsfg-20160930_lab.xml fsfg-20160930_pre.xml true true