XML 42 R31.htm IDEA: XBRL DOCUMENT v3.19.1

Investment Securities (Details Textual) $ in Millions	Mar. 31, 2019 USD ($) Investments	Dec. 31, 2018 Investments
Investment Securities (Textual)
Fair market value, less than 12 months, number of investments | Investments	7	8
Fair market value, less than 12 months | $	$ 9.0
Fair market value, 12 months or longer, number of investments | Investments	50
Fair market value, 12 months or longer | $	$ 44.2

X

- Definition

Investment securities.

+ References

No definition available.

+ Details

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

X

- Definition

Investments with fair market value in continuous unrealized loss position for less than twelve months.

+ References

No definition available.

+ Details

Name:	sfst_InvestmentsWithFairMarketValueInContinuousUnrealizedLossPositionLessThanTwelveMonths
Namespace Prefix:	sfst_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Investments with fair market value In continuous unrealized loss position twelve months or longer.

+ References

No definition available.

+ Details

Name:	sfst_InvestmentsWithFairMarketValueInContinuousUnrealizedLossPositionTwelveMonthsOrLonger
Namespace Prefix:	sfst_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Number of investment in continuous unrealized loss position twelve months or longer.

+ References

No definition available.

+ Details

Name:	sfst_NumberOfInvestmentInContinuousUnrealizedLossPositionTwelveMonthsOrLonger
Namespace Prefix:	sfst_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Number of investments in continuous unrealized loss position, less than twelve months.

+ References

No definition available.

+ Details

Name:	sfst_NumberOfInvestmentsInContinuousUnrealizedLossPositionLessThanTwelveMonths
Namespace Prefix:	sfst_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant