XML 115 R102.htm IDEA: XBRL DOCUMENT v3.8.0.1

Related Party Transactions (Details Textual)	12 Months Ended
	Dec. 31, 2017 USD ($) Investment	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Related Party Transactions (Textual)
Number of offices | Investment	4
Executive officer and directors [Member]
Related Party Transactions (Textual)
Deposits by related parties	$ 3,500,000	$ 6,300,000
Director [Member]
Related Party Transactions (Textual)
Monthly payments of land lease by Company	5,388
Property management services expense for Bank	38,000	$ 29,000	$ 31,000
Payment for employment recruiting services	$ 87,000

X

- Definition

Number of offices.

+ References

No definition available.

+ Details

Name:	sfst_NumberOfOffices
Namespace Prefix:	sfst_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The amount of expense derived from property management services.

+ References

No definition available.

+ Details

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

X

- References

No definition available.

+ Details

Name:	sfst_RelatedPartyTransactionsTextualAbstract
Namespace Prefix:	sfst_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Rental expense for the reporting period incurred under operating leases, including minimum and any contingent rent expense, net of related sublease income.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=77902758&loc=d3e41499-112717

+ Details

Name:	us-gaap_OperatingLeasesRentExpenseNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Amount of deposits held by the entity for a related party (entity, shareholder, employee).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(k))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

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

X

- Definition

This element represents the cost of generating revenues attributable to a hotel's, or cruise line's, owned retail store operations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.2(d))
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

+ Details

Name:	us-gaap_RetailExpenses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=sfst_DirectorsAffiliatesAndExecutiveOfficersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=us-gaap_DirectorMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: