XML 60 R49.htm IDEA: XBRL DOCUMENT
v3.19.1

Fair Value Accounting (Details 1) - Fair Value on a Nonrecurring Basis [Member] - USD ($) $ in Thousands | 3 Months Ended | 12 Months Ended
--- | --- | ---
Mar. 31, 2019 | Dec. 31, 2018
Assets |  |
Impaired loans | $ 10,794 | $ 10,558
Total assets measured at fair value on a nonrecurring basis | 10,794 | 10,558
Level 1 [Member] |  |
Assets |  |
Impaired loans |  |
Total assets measured at fair value on a nonrecurring basis |  |
Level 2 [Member] |  |
Assets |  |
Impaired loans | 2,386 | 2,190
Total assets measured at fair value on a nonrecurring basis | 2,386 | 2,190
Level 3 [Member] |  |
Assets |  |
Impaired loans | 8,408 | 8,368
Total assets measured at fair value on a nonrecurring basis | $ 8,408 | $ 8,368

X
- Definition This element represents the aggregate of the assets reported on the balance sheet at period end measured at fair value on a nonrecurring basis by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. + References No definition available. + Details
Name: | sfst_AssetsFairValueDisclosuresNonRecurring
Namespace Prefix: | sfst_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Impaired loans, Fair value. + References No definition available. + Details
Name: | sfst_ImpairedLoansFairValue
Namespace Prefix: | sfst_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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

X
- Details
Name: | us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsNonrecurringMember
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: |