XML 40 R29.htm IDEA: XBRL DOCUMENT v3.23.1

Loans and Allowance for Credit Losses (Details) - USD ($)	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Loans and Allowance for Credit Losses (Details) [Line Items]
Net of deferred loan fees and costs	$ 7,400,000		$ 7,300,000
Part of loans of 30 days or more past due as a percentage of total loan portfolio	0.11%
Accrued interest	$ 23,000	$ 3,000
Provision for credit losses	1,900,000
Primarily loan growth	144,600,000
Allowance for credit losses for loan commitments	$ 2,800,000
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	0.03%		0.03%
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	0.08%		0.08%

X

- Definition

The predicted amount of loss a bank may be exposed to when a debtor defaults on a loan.

+ 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

The amount of primarily loan growth for the year.

+ References

No definition available.

+ Details

Name:	sfst_PrimarilyLoanGrowth
Namespace Prefix:	sfst_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Increase for accrued, but unpaid interest on the debt instrument for the period.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(f))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

+ Details

Name:	us-gaap_DebtInstrumentIncreaseAccruedInterest
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

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
-Name Accounting Standards Codification
-Topic 310
-SubTopic 20
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481569/310-20-50-3

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 840
-SubTopic 30
-Section 50
-Paragraph 4
-Subparagraph (a)(4)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481161/840-30-50-4

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481962/310-10-50-4

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.7)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479853/942-210-S99-1

+ Details

Name:	us-gaap_LoansAndLeasesReceivableDeferredIncome
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Amount of expense related to credit loss from transactions other than loan and lease transactions.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 28
-Subparagraph (a)
-SubTopic 10
-Topic 230
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482740/230-10-45-28

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 942
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(11))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483589/942-220-S99-1

+ Details

Name:	us-gaap_ProvisionForOtherCreditLosses
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_FinancialInstrumentAxis=us-gaap_ConsumerLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: