Other Real Estate Owned (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Summary of activity of real estate acquired in settlement of loans portion of other real estate owned
Balance, beginning of year	$ 1,198us-gaap_OtherRealEstate	$ 1,719us-gaap_OtherRealEstate
Additions	3,159us-gaap_OtherRealEstateAdditions	1,354us-gaap_OtherRealEstateAdditions
Sales	(730)us-gaap_OtherRealEstateDisposals	(1,745)us-gaap_OtherRealEstateDisposals
Write-downs	(320)sfst_OtherRealEstateWriteDowns	(130)sfst_OtherRealEstateWriteDowns
Balance, end of year	$ 3,307us-gaap_OtherRealEstate	$ 1,198us-gaap_OtherRealEstate

Carrying amount of other real estate not separately disclosed, including, but not limited to, real estate investments, real estate loans that qualify as investments in real estate, and premises that are no longer used in operations may also be included in real estate owned. This does not include real estate assets taken in settlement of troubled loans through surrender or foreclosure.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.10(4))

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Name:	us-gaap_OtherRealEstate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant