3.19.3 html 372 383 1 true 50 0 false 5 false false R1.htm 00000001 - Document - Document and Entity Information Sheet http://southernfirst.com/role/Documentandentityinformation Document and Entity Information Cover 1 false false R2.htm 00000002 - Statement - CONSOLIDATED BALANCE SHEETS Sheet http://southernfirst.com/role/ConsolidatedBalanceSheets CONSOLIDATED BALANCE SHEETS Statements 2 false false R3.htm 00000003 - Statement - CONSOLIDATED BALANCE SHEETS (Parenthetical) Sheet http://southernfirst.com/role/ConsolidatedBalanceSheetsParenthetical CONSOLIDATED BALANCE SHEETS (Parenthetical) Statements 3 false false R4.htm 00000004 - Statement - CONSOLIDATED STATEMENTS OF INCOME (Unaudited) Sheet http://southernfirst.com/role/ConsolidatedStatementsOfIncome CONSOLIDATED STATEMENTS OF INCOME (Unaudited) Statements 4 false false R5.htm 00000005 - Statement - CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) Sheet http://southernfirst.com/role/ConsolidatedStatementsOfComprehensiveIncome CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) Statements 5 false false R6.htm 00000006 - Statement - CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (Unaudited) Sheet http://southernfirst.com/role/ConsolidatedStatementsOfShareholdersEquity CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (Unaudited) Statements 6 false false R7.htm 00000007 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) Sheet http://southernfirst.com/role/ConsolidatedStatementsOfCashFlows CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) Statements 7 false false R8.htm 00000008 - Disclosure - Nature of Business and Basis of Presentation Sheet http://southernfirst.com/role/NatureOfBusinessAndBasisOfPresentation Nature of Business and Basis of Presentation Notes 8 false false R9.htm 00000009 - Disclosure - Investment Securities Sheet http://southernfirst.com/role/InvestmentSecurities Investment Securities Notes 9 false false R10.htm 00000010 - Disclosure - Mortgage Loans Held for Sale Sheet http://southernfirst.com/role/MortgageLoansHeldForSale Mortgage Loans Held for Sale Notes 10 false false R11.htm 00000011 - Disclosure - Loans and Allowance for Loan Losses Sheet http://southernfirst.com/role/LoansAndAllowanceForLoanLosses Loans and Allowance for Loan Losses Notes 11 false false R12.htm 00000012 - Disclosure - Troubled Debt Restructurings Sheet http://southernfirst.com/role/TroubledDebtRestructurings Troubled Debt Restructurings Notes 12 false false R13.htm 00000013 - Disclosure - Derivative Financial Instruments Sheet http://southernfirst.com/role/DerivativeFinancialInstruments Derivative Financial Instruments Notes 13 false false R14.htm 00000014 - Disclosure - Fair Value Accounting Sheet http://southernfirst.com/role/FairValueAccounting Fair Value Accounting Notes 14 false false R15.htm 00000015 - Disclosure - Leases Sheet http://southernfirst.com/role/Leases Leases Notes 15 false false R16.htm 00000016 - Disclosure - Earnings Per Common Share Sheet http://southernfirst.com/role/EarningsPerCommonShare Earnings Per Common Share Notes 16 false false R17.htm 00000017 - Disclosure - Reportable Segments Sheet http://southernfirst.com/role/ReportableSegments Reportable Segments Notes 17 false false R18.htm 00000018 - Disclosure - Nature of Business and Basis of Presentation (Policies) Sheet http://southernfirst.com/role/NatureOfBusinessAndBasisOfPresentationPolicies Nature of Business and Basis of Presentation (Policies) Policies http://southernfirst.com/role/FairValueAccounting 18 false false R19.htm 00000019 - Disclosure - Investment Securities (Tables) Sheet http://southernfirst.com/role/InvestmentSecuritiesTables Investment Securities (Tables) Tables http://southernfirst.com/role/InvestmentSecurities 19 false false R20.htm 00000020 - Disclosure - Loans and Allowance for Loan Losses (Tables) Sheet http://southernfirst.com/role/LoansandAllowanceforLoanLossesTables Loans and Allowance for Loan Losses (Tables) Tables http://southernfirst.com/role/LoansAndAllowanceForLoanLosses 20 false false R21.htm 00000021 - Disclosure - Troubled Debt Restructurings (Tables) Sheet http://southernfirst.com/role/TroubledDebtRestructuringsTables Troubled Debt Restructurings (Tables) Tables http://southernfirst.com/role/TroubledDebtRestructurings 21 false false R22.htm 00000022 - Disclosure - Derivative Financial Instruments (Tables) Sheet http://southernfirst.com/role/DerivativeFinancialInstrumentsTables Derivative Financial Instruments (Tables) Tables http://southernfirst.com/role/DerivativeFinancialInstruments 22 false false R23.htm 00000023 - Disclosure - Fair Value Accounting (Tables) Sheet http://southernfirst.com/role/FairValueAccountingTables Fair Value Accounting (Tables) Tables http://southernfirst.com/role/FairValueAccounting 23 false false R24.htm 00000024 - Disclosure - Leases (Tables) Sheet http://southernfirst.com/role/LeasesTables Leases (Tables) Tables http://southernfirst.com/role/Leases 24 false false R25.htm 00000025 - Disclosure - Earnings Per Common Share (Tables) Sheet http://southernfirst.com/role/Earningspercommonsharetables Earnings Per Common Share (Tables) Tables http://southernfirst.com/role/EarningsPerCommonShare 25 false false R26.htm 00000026 - Disclosure - Reportable Segments (Tables) Sheet http://southernfirst.com/role/ReportableSegmentsTables Reportable Segments (Tables) Tables http://southernfirst.com/role/ReportableSegments 26 false false R27.htm 00000027 - Disclosure - Nature of Business and Basis of Presentation (Narrative) (Details) Sheet http://southernfirst.com/role/NatureOfBusinessAndBasisOfPresentationNarrativeDetails Nature of Business and Basis of Presentation (Narrative) (Details) Details http://southernfirst.com/role/NatureOfBusinessAndBasisOfPresentationPolicies 27 false false R28.htm 00000028 - Disclosure - Investment Securities (Narrative) (Details) Sheet http://southernfirst.com/role/InvestmentSecuritiesNarrativeDetails Investment Securities (Narrative) (Details) Details http://southernfirst.com/role/InvestmentSecuritiesTables 28 false false R29.htm 00000029 - Disclosure - Investment Securities (Schedule of Amortized Costs and Fair Value of Investment Securities) (Details) Sheet http://southernfirst.com/role/InvestmentSecuritiesScheduleOfAmortizedCostsAndFairValueOfInvestmentSecuritiesDetails Investment Securities (Schedule of Amortized Costs and Fair Value of Investment Securities) (Details) Details http://southernfirst.com/role/InvestmentSecuritiesTables 29 false false R30.htm 00000030 - Disclosure - Investment Securities (Schedule of Fair Values Investment Securities Available for Contractual Maturities) (Details) Sheet http://southernfirst.com/role/InvestmentSecuritiesScheduleOfFairValuesInvestmentSecuritiesAvailableForContractualMaturitiesDetails Investment Securities (Schedule of Fair Values Investment Securities Available for Contractual Maturities) (Details) Details http://southernfirst.com/role/InvestmentSecuritiesTables 30 false false R31.htm 00000031 - Disclosure - Investment Securities (Schedule of Gross Unrealized Losses on Investment Securities and Fair Market Value) (Details) Sheet http://southernfirst.com/role/InvestmentSecuritiesScheduleOfGrossUnrealizedLossesOnInvestmentSecuritiesAndFairMarketValueDetails Investment Securities (Schedule of Gross Unrealized Losses on Investment Securities and Fair Market Value) (Details) Details http://southernfirst.com/role/InvestmentSecuritiesTables 31 false false R32.htm 00000032 - Disclosure - Investment Securities (Schedule of Other Investments) (Details) Sheet http://southernfirst.com/role/InvestmentSecuritiesScheduleOfOtherInvestmentsDetails Investment Securities (Schedule of Other Investments) (Details) Details http://southernfirst.com/role/InvestmentSecuritiesTables 32 false false R33.htm 00000033 - Disclosure - Mortgage Loans Held for Sale (Narrative) (Details) Sheet http://southernfirst.com/role/MortgageLoansHeldForSaleNarrativeDetails Mortgage Loans Held for Sale (Narrative) (Details) Details http://southernfirst.com/role/MortgageLoansHeldForSale 33 false false R34.htm 00000034 - Disclosure - Loans and Allowance for Loan Losses (Narrative) (Details) Sheet http://southernfirst.com/role/Loansandallowanceforloanlossesdetailstextual Loans and Allowance for Loan Losses (Narrative) (Details) Details http://southernfirst.com/role/LoansandAllowanceforLoanLossesTables 34 false false R35.htm 00000035 - Disclosure - Loans and Allowance for Loan Losses (Schedule of Composition of Loan Portfolio) (Details) Sheet http://southernfirst.com/role/LoansAndAllowanceForLoanLossesScheduleOfCompositionOfLoanPortfolioDetails Loans and Allowance for Loan Losses (Schedule of Composition of Loan Portfolio) (Details) Details http://southernfirst.com/role/LoansandAllowanceforLoanLossesTables 35 false false R36.htm 00000036 - Disclosure - Loans and Allowance for Loan Losses (Schedule of Loan Maturity Distribution by Type and Related Interest Rate) (Details) Sheet http://southernfirst.com/role/LoansAndAllowanceForLoanLossesScheduleOfLoanMaturityDistributionByTypeAndRelatedInterestRateDetails Loans and Allowance for Loan Losses (Schedule of Loan Maturity Distribution by Type and Related Interest Rate) (Details) Details http://southernfirst.com/role/LoansandAllowanceforLoanLossesTables 36 false false R37.htm 00000037 - Disclosure - Loans and Allowance for Loan Losses (Schedule of Breakdown of Outstanding Loans by Risk Category) (Details) Sheet http://southernfirst.com/role/LoansAndAllowanceForLoanLossesScheduleOfBreakdownOfOutstandingLoansByRiskCategoryDetails Loans and Allowance for Loan Losses (Schedule of Breakdown of Outstanding Loans by Risk Category) (Details) Details http://southernfirst.com/role/LoansandAllowanceforLoanLossesTables 37 false false R38.htm 00000038 - Disclosure - Loans and Allowance for Loan Losses (Schedule of Outstanding Commercial and Consumer Loans as Non-Accruals by Class) (Details) Sheet http://southernfirst.com/role/LoansAndAllowanceForLoanLossesDetails3 Loans and Allowance for Loan Losses (Schedule of Outstanding Commercial and Consumer Loans as Non-Accruals by Class) (Details) Details http://southernfirst.com/role/LoansandAllowanceforLoanLossesTables 38 false false R39.htm 00000039 - Disclosure - Loans and Allowance for Loan Losses (Schedule of Outstanding Consumer Loans by Risk Category) (Details) Sheet http://southernfirst.com/role/LoansAndAllowanceForLoanLossesDetails4 Loans and Allowance for Loan Losses (Schedule of Outstanding Consumer Loans by Risk Category) (Details) Details http://southernfirst.com/role/LoansandAllowanceforLoanLossesTables 39 false false R40.htm 00000040 - Disclosure - Loans and Allowance for Loan Losses (Schedule of Aging of Past Due Loans) (Details) Sheet http://southernfirst.com/role/LoansAndAllowanceForLoanLossesDetails5 Loans and Allowance for Loan Losses (Schedule of Aging of Past Due Loans) (Details) Details http://southernfirst.com/role/LoansandAllowanceforLoanLossesTables 40 false false R41.htm 00000041 - Disclosure - Loans and Allowance for Loan Losses (Schedule of Nonperforming Assets, Including Nonaccruing TDRs) (Details) Sheet http://southernfirst.com/role/LoansAndAllowanceForLoanLossesDetails6 Loans and Allowance for Loan Losses (Schedule of Nonperforming Assets, Including Nonaccruing TDRs) (Details) Details http://southernfirst.com/role/LoansandAllowanceforLoanLossesTables 41 false false R42.htm 00000042 - Disclosure - Loans and Allowance for Loan Losses (Schedule of Key Information for Impaired Loans) (Details) Sheet http://southernfirst.com/role/LoansAndAllowanceForLoanLossesDetails7 Loans and Allowance for Loan Losses (Schedule of Key Information for Impaired Loans) (Details) Details http://southernfirst.com/role/LoansandAllowanceforLoanLossesTables 42 false false R43.htm 00000043 - Disclosure - Loans and Allowance for Loan Losses (Average Recorded Investment and Interest Income Recognized on Impaired Loans) (Details) Sheet http://southernfirst.com/role/LoansAndAllowanceForLoanLossesDetails8 Loans and Allowance for Loan Losses (Average Recorded Investment and Interest Income Recognized on Impaired Loans) (Details) Details http://southernfirst.com/role/LoansandAllowanceforLoanLossesTables 43 false false R44.htm 00000044 - Disclosure - Loans and Allowance for Loan Losses (Allowance for Loan Losses by Commercial and Consumer Portfolio Segments) (Details) Sheet http://southernfirst.com/role/LoansAndAllowanceForLoanLossesDetails9 Loans and Allowance for Loan Losses (Allowance for Loan Losses by Commercial and Consumer Portfolio Segments) (Details) Details http://southernfirst.com/role/LoansandAllowanceforLoanLossesTables 44 false false R45.htm 00000045 - Disclosure - Loans and Allowance for Loan Losses (Allowance for Loan Losses and Recorded Investment in Loans by Impairment) (Details) Sheet http://southernfirst.com/role/LoansAndAllowanceForLoanLossesDetails10 Loans and Allowance for Loan Losses (Allowance for Loan Losses and Recorded Investment in Loans by Impairment) (Details) Details http://southernfirst.com/role/LoansandAllowanceforLoanLossesTables 45 false false R46.htm 00000046 - Disclosure - Troubled Debt Restructurings (Summary of Concession at the Time Of Modification) (Details) Sheet http://southernfirst.com/role/TroubledDebtRestructuringsSummaryOfConcessionAtTimeOfModificationDetails Troubled Debt Restructurings (Summary of Concession at the Time Of Modification) (Details) Details http://southernfirst.com/role/TroubledDebtRestructuringsTables 46 false false R47.htm 00000047 - Disclosure - Troubled Debt Restructurings (Narrative) (Details) Sheet http://southernfirst.com/role/TroubledDebtRestructuringsNarrativeDetails Troubled Debt Restructurings (Narrative) (Details) Details http://southernfirst.com/role/TroubledDebtRestructuringsTables 47 false false R48.htm 00000048 - Disclosure - Derivative Financial Instruments (Schedule of Outstanding Financial Derivative Instruments) (Details) Sheet http://southernfirst.com/role/DerivativeFinancialInstrumentsScheduleOfOutstandingFinancialDerivativeInstrumentsDetails Derivative Financial Instruments (Schedule of Outstanding Financial Derivative Instruments) (Details) Details http://southernfirst.com/role/DerivativeFinancialInstrumentsTables 48 false false R49.htm 00000049 - Disclosure - Fair Value Accounting (Schedule of Assets And Liabilities Measured at Fair Value on Recurring Basis) (Details) Sheet http://southernfirst.com/role/FairValueAccountingScheduleOfAssetsAndLiabilitiesMeasuredAtFairValueOnRecurringBasisDetails Fair Value Accounting (Schedule of Assets And Liabilities Measured at Fair Value on Recurring Basis) (Details) Details http://southernfirst.com/role/FairValueAccountingTables 49 false false R50.htm 00000050 - Disclosure - Fair Value Accounting (Schedule of Assets And Liabilities Measured at Fair Value on Nonrecurring Basis) (Details) Sheet http://southernfirst.com/role/FairValueAccountingScheduleOfAssetsAndLiabilitiesMeasuredAtFairValueOnNonrecurringBasisDetails Fair Value Accounting (Schedule of Assets And Liabilities Measured at Fair Value on Nonrecurring Basis) (Details) Details http://southernfirst.com/role/FairValueAccountingTables 50 false false R51.htm 00000051 - Disclosure - Fair Value Accounting (Schedule of Estimated Fair Values of the Company's Financial Instruments) (Details) Sheet http://southernfirst.com/role/FairValueAccountingScheduleOfEstimatedFairValuesOfCompanysFinancialInstrumentsDetails Fair Value Accounting (Schedule of Estimated Fair Values of the Company's Financial Instruments) (Details) Details http://southernfirst.com/role/FairValueAccountingTables 51 false false R52.htm 00000052 - Disclosure - Leases (Narrative) (Details) Sheet http://southernfirst.com/role/LeasesNarrativeDetails Leases (Narrative) (Details) Details http://southernfirst.com/role/LeasesTables 52 false false R53.htm 00000053 - Disclosure - Leases (Maturities of lease liabilities) (Details) Sheet http://southernfirst.com/role/LeasesMaturitiesOfLeaseLiabilitiesDetails Leases (Maturities of lease liabilities) (Details) Details http://southernfirst.com/role/LeasesTables 53 false false R54.htm 00000054 - Disclosure - Earnings Per Common Share (Narrative) (Details) Sheet http://southernfirst.com/role/EarningsPerCommonShareNarrativeDetails Earnings Per Common Share (Narrative) (Details) Details http://southernfirst.com/role/Earningspercommonsharetables 54 false false R55.htm 00000055 - Disclosure - Earnings Per Common Share (Schedule of earnings per share calculation) (Details) Sheet http://southernfirst.com/role/EarningsPerCommonShareScheduleOfEarningsPerShareCalculationDetails Earnings Per Common Share (Schedule of earnings per share calculation) (Details) Details http://southernfirst.com/role/Earningspercommonsharetables 55 false false R56.htm 00000056 - Disclosure - Reportable Segments (Narrative) (Details) Sheet http://southernfirst.com/role/ReportableSegmentsNarrativeDetails Reportable Segments (Narrative) (Details) Details http://southernfirst.com/role/ReportableSegmentsTables 56 false false R57.htm 00000057 - Disclosure - Reportable Segments (Schedule of financial information for each reportable segment) (Details) Sheet http://southernfirst.com/role/ReportableSegmentsScheduleOfFinancialInformationForEachReportableSegmentDetails Reportable Segments (Schedule of financial information for each reportable segment) (Details) Details http://southernfirst.com/role/ReportableSegmentsTables 57 false false All Reports Book All Reports sfst-20190930.xml sfst-20190930.xsd sfst-20190930_cal.xml sfst-20190930_def.xml sfst-20190930_lab.xml sfst-20190930_pre.xml http://fasb.org/us-gaap/2019-01-31 http://fasb.org/srt/2019-01-31 http://xbrl.sec.gov/dei/2019-01-31 true true