Investment in Federal Home Loan Bank of Atlanta Stock (Details)	Dec. 31, 2016
Investment in Federal Home Loan Bank of Atlanta Stock [Abstract]
Minimum percentage of the unpaid principal balances	1.00%
Ratio of outstanding advances from FHLB	5.00%

Minimum percentage of the unpaid principal balances of the Bank's residential mortgage loans which amount Bank is required to maintain an investment in the stock of the Federal Home Loan Bank of Atlanta ("FHLB").

No definition available.

Name:	svbi_MinimumPercentageOfInvestmentInStockOfFhlb
Namespace Prefix:	svbi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant