XML 99 R54.htm IDEA: XBRL DOCUMENT
v3.19.3.a.u2

Investment Securities (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2019 | Dec. 31, 2018
Available for sale |  |
Total investment securities available for sale, Amortized Cost | $ 68,071 | $ 76,065
Total investment securities available for sale, Gross Unrealized Gains | 56 | 174
Total investment securities available for sale, Gross Unrealized Losses | 433 | 1,334
Available-for-sale securities, investment securities, Fair Value | 67,694 | 74,905
US government agencies [Member] |  |
Available for sale |  |
Total investment securities available for sale, Amortized Cost | 500 | 8,975
Total investment securities available for sale, Gross Unrealized Gains |  | 1
Total investment securities available for sale, Gross Unrealized Losses | 1 | 194
Available-for-sale securities, investment securities, Fair Value | 499 | 8,782
SBA securities [Member] |  |
Available for sale |  |
Total investment securities available for sale, Amortized Cost | 550 | 3,628
Total investment securities available for sale, Gross Unrealized Gains |  |
Total investment securities available for sale, Gross Unrealized Losses | 19 | 103
Available-for-sale securities, investment securities, Fair Value | 531 | 3,525
State and political subdivisions [Member] |  |
Available for sale |  |
Total investment securities available for sale, Amortized Cost | 4,205 | 8,371
Total investment securities available for sale, Gross Unrealized Gains | 3 | 48
Total investment securities available for sale, Gross Unrealized Losses | 24 | 63
Available-for-sale securities, investment securities, Fair Value | 4,184 | 8,356
Asset-backed Securities [Member] |  |
Available for sale |  |
Total investment securities available for sale, Amortized Cost | 13,351 | 9,595
Total investment securities available for sale, Gross Unrealized Gains |  | 12
Total investment securities available for sale, Gross Unrealized Losses | 184 | 49
Available-for-sale securities, investment securities, Fair Value | 13,167 | 9,558
Mortgage-backed securities [Member] |  |
Available for sale |  |
Total investment securities available for sale, Amortized Cost | 49,465 | 45,496
Total investment securities available for sale, Gross Unrealized Gains | 53 | 113
Total investment securities available for sale, Gross Unrealized Losses | 205 | 925
Available-for-sale securities, investment securities, Fair Value | 49,313 | 44,684
Mortgage-backed securities [Member] | FHLMC [Member] |  |
Available for sale |  |
Total investment securities available for sale, Amortized Cost | 10,609 | 12,258
Total investment securities available for sale, Gross Unrealized Gains | 14 | 87
Total investment securities available for sale, Gross Unrealized Losses | 15 | 242
Available-for-sale securities, investment securities, Fair Value | 10,608 | 12,103
Mortgage-backed securities [Member] | FNMA [Member] |  |
Available for sale |  |
Total investment securities available for sale, Amortized Cost | 35,275 | 29,068
Total investment securities available for sale, Gross Unrealized Gains | 34 | 25
Total investment securities available for sale, Gross Unrealized Losses | 169 | 551
Available-for-sale securities, investment securities, Fair Value | 35,140 | 28,542
Mortgage-backed securities [Member] | GNMA [Member] |  |
Available for sale |  |
Total investment securities available for sale, Amortized Cost | 3,581 | 4,170
Total investment securities available for sale, Gross Unrealized Gains | 5 | 1
Total investment securities available for sale, Gross Unrealized Losses | 21 | 132
Available-for-sale securities, investment securities, Fair Value | $ 3,565 | $ 4,039

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

X
- Definition This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any. + References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecuritiesAmortizedCost
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=118942338&loc=SL82898722-210454 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=118954083&loc=d3e26610-111562 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (aa) -URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27161-111563 + Details
Name: | us-gaap_AvailableForSaleSecuritiesDebtSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of unrealized gain before deducting unrealized loss on investments in debt and equity securities classified as available-for-sale securities. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27161-111563 + Details
Name: | us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGains
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of unrealized loss before deducting unrealized gain on investments in available-for-sale securities. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27161-111563 + Details
Name: | us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_AgencySecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=sfst_SbaSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_USStatesAndPoliticalSubdivisionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_AssetBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_MortgageBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_FederalHomeLoanMortgageCorporationCertificatesAndObligationsFHLMCMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_FederalNationalMortgageAssociationCertificatesAndObligationsFNMAMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_GovernmentNationalMortgageAssociationCertificatesAndObligationsGNMAMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |