XML 95 R83.htm IDEA: XBRL DOCUMENT
v3.22.4

Derivative Financial Instruments (Details) - Schedule of outstanding financial derivative instruments - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2022 | Dec. 31, 2021
Mortgage loan interest rate lock commitments [Member] |  |
Derivative Financial Instruments (Details) - Schedule of outstanding financial derivative instruments [Line Items] |  |
Derivative financial instruments, Notional amount | $ 6,793 | $ 32,478
Balance Sheet Location, description | Other assets | Other assets
Derivative Asset/(Liability), Fair Value | $ 49 | $ 425
MBS forward sales commitments [Member] |  |
Derivative Financial Instruments (Details) - Schedule of outstanding financial derivative instruments [Line Items] |  |
Derivative financial instruments, Notional amount | $ 5,750 | $ 21,000
Balance Sheet Location, description | Other assets | Other liabilities
Derivative Asset/(Liability), Fair Value | $ 27 | $ (41)
Total derivative financial instruments [Member] |  |
Derivative Financial Instruments (Details) - Schedule of outstanding financial derivative instruments [Line Items] |  |
Derivative financial instruments, Notional amount | 12,543 | 53,478
Derivative Asset/(Liability), Fair Value | $ 76 | $ 384

X
- Definition Description of balance sheet location. + References No definition available. + Details
Name: | sfst_BalanceSheetLocationDescription
Namespace Prefix: | sfst_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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

X
- Definition Aggregate notional amount specified by the derivative(s). Expressed as an absolute value. + References No definition available. + Details
Name: | sfst_DerivativesNotionalAmount
Namespace Prefix: | sfst_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair values as of the balance sheet date of the net amount of all assets and liabilities resulting from contracts that meet the criteria of being accounted for as derivative instruments. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 45 -Paragraph 5 -URI https://asc.fasb.org/extlink&oid=126966630&loc=d3e41228-113958 + Details
Name: | us-gaap_DerivativeAssetsLiabilitiesAtFairValueNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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

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

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