XML 43 R33.htm IDEA: XBRL DOCUMENT
v3.22.1

Loans and Allowance for Credit Losses (Details) - USD ($) $ in Millions | Mar. 31, 2022 | Dec. 31, 2021
--- | --- | ---
Loans and Allowance for Credit Losses (Details) [Line Items] |  |
Net of deferred loan fees and costs (in Dollars) | $ 5.5 | $ 5.0
Part of loans of 30 days or more past due as a percentage of total loan portfolio | 0.13% | 0.09%
Allowance for credit losses for loan commitments (in Dollars) | $ 2.1 |
Commercial Loan [Member] |  |
Loans and Allowance for Credit Losses (Details) [Line Items] |  |
Part of loans of 30 days or more past due as a percentage of total loan portfolio | 0.01% | 0.00%
Consumer Loan [Member] |  |
Loans and Allowance for Credit Losses (Details) [Line Items] |  |
Part of loans of 30 days or more past due as a percentage of total loan portfolio | 0.12% | 0.09%

X
- References No definition available. + Details
Name: | sfst_AllowanceForCreditLossesForLoanCommitments
Namespace Prefix: | sfst_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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

X
- Definition Part of loans of thirty days or more past due as a percentage of aggregate loan portfolio. + References No definition available. + Details
Name: | sfst_PartOfLoansOfThirtyDaysOrMorePastDueAsPercentageOfAggregateLoanPortfolio
Namespace Prefix: | sfst_
Data Type: | dtr:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of deferred interest and fee income, unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of acquired loans. Excludes amounts for loans and leases covered under loss sharing agreements. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.7) -URI https://asc.fasb.org/extlink&oid=126897435&loc=d3e534808-122878 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 840 -SubTopic 30 -Section 50 -Paragraph 4 -Subparagraph (a)(4) -URI https://asc.fasb.org/extlink&oid=123392090&loc=d3e45377-112738 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 4 -URI https://asc.fasb.org/extlink&oid=123577603&loc=d3e5074-111524 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 20 -Section 50 -Paragraph 3 -URI https://asc.fasb.org/extlink&oid=84159169&loc=d3e10152-111534 + Details
Name: | us-gaap_LoansAndLeasesReceivableDeferredIncome
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_CommercialLoanMember
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: |