Investment Securities (Detail Textuals) - Issuer	Jun. 30, 2016	Dec. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Percentage of stockholder equity within investment portfolio	10.00%	10.00%
Number of issuers represented more than 10% or more of stockholders equity within investment portfolio	0	0

Represents number of issuers represented more than 10% or more of stockholders equity within the investment portfolio.

No definition available.

Name:	sbfc_NumberOfIssuersRepresentedMoreThan10PercentOrMoreOfStockholdersEquityWithinInvestmentPortfolio
Namespace Prefix:	sbfc_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant