XML 90 R76.htm IDEA: XBRL DOCUMENT
v3.24.0.1

Derivative Financial Instruments (Details) - Schedule of outstanding financial derivative instruments - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2023 | Dec. 31, 2022
Fair value swap [Member] |  |
Derivative Financial Instruments (Details) [Line Items] |  |
Derivative financial instruments, notional amount | $ 200,000 |
Balance Sheet Location, description | Other liabilities |
Derivative Asset/(Liability), Fair Value | $ (482) |
Mortgage loan interest rate lock commitments [Member] |  |
Derivative Financial Instruments (Details) [Line Items] |  |
Derivative financial instruments, notional amount | $ 12,973 | $ 6,793
Balance Sheet Location, description | Other assets | Other assets
Derivative Asset/(Liability), Fair Value | $ 159 | $ 49
MBS forward sales commitments [Member] |  |
Derivative Financial Instruments (Details) [Line Items] |  |
Derivative financial instruments, notional amount | $ 10,000 | $ 5,750
Balance Sheet Location, description | Other liabilities | Other assets
Derivative Asset/(Liability), Fair Value | $ (68) | $ 27
Total derivative financial instruments [Member] |  |
Derivative Financial Instruments (Details) [Line Items] |  |
Derivative financial instruments, notional amount | 222,973 | 12,543
Derivative Asset/(Liability), Fair Value | $ (391) | $ 76

X
- 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_DerivativeFinancialInstrumentsDetailsLineItems
Namespace Prefix: | SFST_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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 -Name Accounting Standards Codification -Section 45 -Paragraph 5 -SubTopic 10 -Topic 815 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480463/815-10-45-5 + Details
Name: | us-gaap_DerivativeAssetsLiabilitiesAtFairValueNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Nominal or face amount used to calculate payment on derivative. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1B -Publisher FASB -URI https://asc.fasb.org//1943274/2147480434/815-10-50-1B Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1A -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480434/815-10-50-1A + Details
Name: | us-gaap_DerivativeNotionalAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | instant

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

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: |