XML 63 R50.htm IDEA: XBRL DOCUMENT
v3.20.2

Troubled Debt Restructurings (Summary of Concession at the Time Of Modification) (Details) $ in Thousands | 6 Months Ended
--- | ---
Jun. 30, 2020 USD ($) Investments | Jun. 30, 2019 USD ($) Investments
Summary of concession at the time of modification and the recorded investment in TDRs before and after their modification |  |
Renewals deemed a concession | 6 | 1
Reduced or deferred payments |  |
Converted to interest only |  |
Maturity date extensions |  |
Total number of loans | 6 | 1
Pre-modification outstanding recorded investment | $ | $ 3,408 | $ 832
Post-modification outstanding recorded investment | $ | $ 3,408 | $ 832
Commercial Loan [Member] | Business [Member] |  |
Summary of concession at the time of modification and the recorded investment in TDRs before and after their modification |  |
Renewals deemed a concession | 1 |
Reduced or deferred payments |  |
Converted to interest only |  |
Maturity date extensions |  |
Total number of loans | 1 |
Pre-modification outstanding recorded investment | $ | $ 1,037 |
Post-modification outstanding recorded investment | $ | $ 1,037 |
Consumer Loan [Member] | Real Estate Loan [Member] |  |
Summary of concession at the time of modification and the recorded investment in TDRs before and after their modification |  |
Renewals deemed a concession | 2 |
Reduced or deferred payments |  |
Converted to interest only |  |
Maturity date extensions |  |
Total number of loans | 2 |
Pre-modification outstanding recorded investment | $ | $ 849 |
Post-modification outstanding recorded investment | $ | $ 849 |
Consumer Loan [Member] | Home Equity Loan [Member] |  |
Summary of concession at the time of modification and the recorded investment in TDRs before and after their modification |  |
Renewals deemed a concession | 3 | 1
Reduced or deferred payments |  |
Converted to interest only |  |
Maturity date extensions |  |
Total number of loans | 3 | 1
Pre-modification outstanding recorded investment | $ | $ 1,522 | $ 832
Post-modification outstanding recorded investment | $ | $ 1,522 | $ 832

X
- Definition Converted to interest only. + References No definition available. + Details
Name: | sfst_ConvertedToInterestOnly
Namespace Prefix: | sfst_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Maturity date extensions. + References No definition available. + Details
Name: | sfst_MaturityDateExtensions
Namespace Prefix: | sfst_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Reduced or deferred payments. + References No definition available. + Details
Name: | sfst_ReducedOrDeferredPayments
Namespace Prefix: | sfst_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Renewals deemed concession. + References No definition available. + Details
Name: | sfst_RenewalsDeemedConcession
Namespace Prefix: | sfst_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- References No definition available. + Details
Name: | sfst_SummaryOfConcessionAtTimeOfModificationAndRecordedInvestmentAbstract
Namespace Prefix: | sfst_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Total number of loans. + References No definition available. + Details
Name: | sfst_TotalNumberOfLoans
Namespace Prefix: | sfst_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount, after troubled debt restructuring, of modified financing receivable. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 33 -URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953676-111524 + Details
Name: | us-gaap_FinancingReceivableModificationsPostModificationRecordedInvestment2
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount, before troubled debt restructuring, of financing receivable to be modified. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 33 -URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953676-111524 + Details
Name: | us-gaap_FinancingReceivableModificationsPreModificationRecordedInvestment2
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_CommercialLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=sfst_BusinessMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_ConsumerLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_RealEstateLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_HomeEquityLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |