XML 58 R47.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Fair Value Accounting (Details) - Fair Value on a Recurring Basis [Member] - USD ($) $ in Thousands | Jun. 30, 2018 | Dec. 31, 2017
--- | --- | ---
Securities available for sale |  |
US government agencies | $ 8,714 | $ 8,653
SBA securities | 3,769 | 4,063
State and political subdivisions | 8,472 | 11,396
Asset-backed securities | 6,691 |
Mortgage-backed securities | 42,421 | 43,491
Mortgage loans held for sale | 8,075 | 11,790
Interest rate lock commitments | 320 | 196
Total assets measured at fair value on a recurring basis | 78,462 | 79,589
Liabilities |  |
MBS forward sales commitments | 60 | 28
Total liabilities measured at fair value on a recurring basis | 60 | 28
Level 1 [Member] |  |
Securities available for sale |  |
US government agencies |  |
SBA securities |  |
State and political subdivisions |  |
Asset-backed securities |  |
Mortgage-backed securities |  |
Mortgage loans held for sale |  |
Interest rate lock commitments |  |
Total assets measured at fair value on a recurring basis |  |
Liabilities |  |
MBS forward sales commitments |  |
Total liabilities measured at fair value on a recurring basis |  |
Level 2 [Member] |  |
Securities available for sale |  |
US government agencies | 8,714 | 8,653
SBA securities | 3,769 | 4,063
State and political subdivisions | 8,472 | 11,396
Asset-backed securities | 6,691 |
Mortgage-backed securities | 42,421 | 43,491
Mortgage loans held for sale | 8,075 | 11,790
Interest rate lock commitments | 320 | 196
Total assets measured at fair value on a recurring basis | 78,462 | 79,589
Liabilities |  |
MBS forward sales commitments | 60 | 28
Total liabilities measured at fair value on a recurring basis | 60 | 28
Level 3 [Member] |  |
Securities available for sale |  |
US government agencies |  |
SBA securities |  |
State and political subdivisions |  |
Asset-backed securities |  |
Mortgage-backed securities |  |
Mortgage loans held for sale |  |
Interest rate lock commitments |  |
Total assets measured at fair value on a recurring basis |  |
Liabilities |  |
MBS forward sales commitments |  |
Total liabilities measured at fair value on a recurring basis |  |

X
- Definition Asset-backed securities. + References No definition available. + Details
Name: | sfst_AssetBackedSecurities
Namespace Prefix: | sfst_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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

X
- Definition Securities Available for Sale, Fair value, SBA Securities. + References No definition available. + Details
Name: | sfst_SecuritiesAvailableForSaleFairValueSbaSecurities
Namespace Prefix: | sfst_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Securities Available for Sale, Fair value, State and political subdivisions. + References No definition available. + Details
Name: | sfst_SecuritiesAvailableForSaleFairValueStateAndPoliticalSubdivisions
Namespace Prefix: | sfst_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Securities Available for Sale, Fair value, US agency securities. + References No definition available. + Details
Name: | sfst_SecuritiesAvailableForSaleFairValueUsAgencySecurities
Namespace Prefix: | sfst_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=99377789&loc=d3e19207-110258 + Details
Name: | us-gaap_AssetsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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 -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41228-113958 + Details
Name: | us-gaap_DerivativeAssetsLiabilitiesAtFairValueNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value of obligations incurred from short sales. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 940 -SubTopic 320 -Section 35 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=35711043&loc=d3e42429-110968 + Details
Name: | us-gaap_FinancialInstrumentsSoldNotYetPurchasedAtFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Fair value of financial and nonfinancial obligations. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=99377789&loc=d3e19207-110258 + Details
Name: | us-gaap_LiabilitiesFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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

X
- Definition Fair value portion of loans held-for-sale including, but not limited to, mortgage loans and finance receivables. + References No definition available. + Details
Name: | us-gaap_LoansHeldForSaleFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value of securitized, pay-through debt securities collateralized by real estate mortgage loans classified as available-for-sale. + References No definition available. + Details
Name: | us-gaap_MortgageBackedSecuritiesAvailableForSaleFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsRecurringMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |