XML 51 R40.htm IDEA: XBRL DOCUMENT
v3.21.1

Loans and Allowance for Loan Losses (Schedule of Outstanding Consumer Loans by Risk Category) (Details) - Consumer Loan [Member] - USD ($) $ in Thousands | Mar. 31, 2021 | Dec. 31, 2020
--- | --- | ---
Outstanding commercial and consumer loans by risk category |  |
Outstanding consumer loans | $ 795,099 | $ 755,212
Other Consumer [Member] |  |
Outstanding commercial and consumer loans by risk category |  |
Outstanding consumer loans | 22,231 | 21,419
Pass [Member] |  |
Outstanding commercial and consumer loans by risk category |  |
Outstanding consumer loans | 779,135 | 744,484
Pass [Member] | Other Consumer [Member] |  |
Outstanding commercial and consumer loans by risk category |  |
Outstanding consumer loans | 22,013 | 21,290
Special Mention [Member] |  |
Outstanding commercial and consumer loans by risk category |  |
Outstanding consumer loans | 8,248 | 3,064
Special Mention [Member] | Other Consumer [Member] |  |
Outstanding commercial and consumer loans by risk category |  |
Outstanding consumer loans | 167 | 91
Substandard [Member] |  |
Outstanding commercial and consumer loans by risk category |  |
Outstanding consumer loans | 7,716 | 7,664
Substandard [Member] | Other Consumer [Member] |  |
Outstanding commercial and consumer loans by risk category |  |
Outstanding consumer loans | 51 | 38
Doubtful [Member] |  |
Outstanding commercial and consumer loans by risk category |  |
Outstanding consumer loans |  |
Doubtful [Member] | Other Consumer [Member] |  |
Outstanding commercial and consumer loans by risk category |  |
Outstanding consumer loans |  |
Real Estate Loan [Member] |  |
Outstanding commercial and consumer loans by risk category |  |
Outstanding consumer loans | 574,541 | 536,311
Real Estate Loan [Member] | Pass [Member] |  |
Outstanding commercial and consumer loans by risk category |  |
Outstanding consumer loans | 565,956 | 530,515
Real Estate Loan [Member] | Special Mention [Member] |  |
Outstanding commercial and consumer loans by risk category |  |
Outstanding consumer loans | 3,993 | 1,968
Real Estate Loan [Member] | Substandard [Member] |  |
Outstanding commercial and consumer loans by risk category |  |
Outstanding consumer loans | 4,592 | 3,828
Real Estate Loan [Member] | Doubtful [Member] |  |
Outstanding commercial and consumer loans by risk category |  |
Outstanding consumer loans |  |
Home Equity Loan [Member] |  |
Outstanding commercial and consumer loans by risk category |  |
Outstanding consumer loans | 154,157 | 156,957
Home Equity Loan [Member] | Pass [Member] |  |
Outstanding commercial and consumer loans by risk category |  |
Outstanding consumer loans | 147,196 | 152,154
Home Equity Loan [Member] | Special Mention [Member] |  |
Outstanding commercial and consumer loans by risk category |  |
Outstanding consumer loans | 3,888 | 1,005
Home Equity Loan [Member] | Substandard [Member] |  |
Outstanding commercial and consumer loans by risk category |  |
Outstanding consumer loans | 3,073 | 3,798
Home Equity Loan [Member] | Doubtful [Member] |  |
Outstanding commercial and consumer loans by risk category |  |
Outstanding consumer loans |  |
Construction Loans [Member] |  |
Outstanding commercial and consumer loans by risk category |  |
Outstanding consumer loans | 44,170 | 40,525
Construction Loans [Member] | Pass [Member] |  |
Outstanding commercial and consumer loans by risk category |  |
Outstanding consumer loans | 43,970 | 40,525
Construction Loans [Member] | Special Mention [Member] |  |
Outstanding commercial and consumer loans by risk category |  |
Outstanding consumer loans | 200 |
Construction Loans [Member] | Substandard [Member] |  |
Outstanding commercial and consumer loans by risk category |  |
Outstanding consumer loans |  |
Construction Loans [Member] | Doubtful [Member] |  |
Outstanding commercial and consumer loans by risk category |  |
Outstanding consumer loans |  |

X
- Definition Amount, before allowance and fees, of loans and leases receivable. Excludes loans and leases covered under loss sharing agreements. + References No definition available. + Details
Name: | sfst_LoanAndLeasesReceivableBeforeFeesGross
Namespace Prefix: | sfst_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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

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

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=sfst_OtherConsumerMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InternalCreditAssessmentAxis=us-gaap_PassMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InternalCreditAssessmentAxis=us-gaap_SpecialMentionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InternalCreditAssessmentAxis=us-gaap_SubstandardMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InternalCreditAssessmentAxis=us-gaap_DoubtfulMember
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: |

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