Foreclosed Real Estate (Details) (USD $)	12 Months Ended
Dec. 31, 2014 Property	Dec. 31, 2013
Foreclosed Real Estate [Abstract]
Number of residential properties	11us-gaap_NumberOfRealEstateProperties
Number of properties sold	21svbi_NumberOfPropertiesSold
Transfer from loans to foreclosed real estate, write-downs	$ 2,338,000
Net gain (loss) on sale of foreclosed real estate	302,000	(367,000)
Expense on sale of property	1,103,000svbi_ExpenseOnSaleOfProperty
Foreclosed real estate [Abstract]
Foreclosed real estate at beginning balance	8,972,000us-gaap_ForeclosedAssets	11,441,000us-gaap_ForeclosedAssets
Transferred from impaired loans	847,000svbi_TransferForeclosedRealEstate	10,169,000svbi_TransferForeclosedRealEstate
Property improvements	0svbi_PaymentsInForeclosedRealEstate	925,000svbi_PaymentsInForeclosedRealEstate
Additional write downs	0us-gaap_ProvisionForOtherLosses	(4,610,000)us-gaap_ProvisionForOtherLosses
Property sold, including loss on sale	(7,872,000)	(8,953,000)
Foreclosed real estate at ending balance	1,947,000us-gaap_ForeclosedAssets	8,972,000us-gaap_ForeclosedAssets
Specific reserves on transferred from impaired loans	3,303,000	3,267,000
Foreclosed real estate expenses, net	10,000us-gaap_ForeclosedRealEstateExpense	6,132,000us-gaap_ForeclosedRealEstateExpense
Foreclosed real estate operating expenses	$ 312,000	$ 1,155,000

This element represents the amount of expenditure incurred on sale of real estate property during period.

No definition available.

Name:	svbi_ExpenseOnSaleOfProperty
Namespace Prefix:	svbi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The value of operating expenses pertaining to foreclosed real estate during the reporting period.

+ References

No definition available.

+ Details

Name:	svbi_ForeclosedRealEstateOperatingExpenses
Namespace Prefix:	svbi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	svbi_ForeclosedRealEstatesAbstract
Namespace Prefix:	svbi_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents number of properties sold which previously included in foreclosed real estate.

+ References

No definition available.

+ Details

Name:	svbi_NumberOfPropertiesSold
Namespace Prefix:	svbi_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

The cash outflow associated with capital repairs and completion of foreclosed real estate in order to sell the property.

+ References

No definition available.

+ Details

Name:	svbi_PaymentsInForeclosedRealEstate
Namespace Prefix:	svbi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Sale of assets received in full or partial satisfaction of a receivable including real and personal property; equity interests in corporations, partnerships, and joint ventures; and beneficial interests in trusts. Foreclosed assets also include loans that are treated as if the underlying collateral had been foreclosed because the institution has taken possession of the collateral, even though legal foreclosure or repossession proceedings have not taken place.

+ References

No definition available.

+ Details

Name:	svbi_SaleOfForeclosedAssetsIncludingLossOnSale
Namespace Prefix:	svbi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The value of specific reserves on transferred to foreclosed real estate in noncash transactions during the reporting period.

+ References

No definition available.

+ Details

Name:	svbi_SpecificReservesOnTransferredFromImpairedLoans
Namespace Prefix:	svbi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The value of net loans transferred to foreclosed real estate in noncash transactions during the reporting period.

+ References

No definition available.

+ Details

Name:	svbi_TransferForeclosedRealEstate
Namespace Prefix:	svbi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Carrying amount as of the balance sheet date of all assets obtained in full or partial satisfaction of a debt arrangement through foreclosure proceedings or defeasance; includes real and personal property; equity interests in corporations, partnerships, and joint ventures; and beneficial interests in trusts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 45

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=28367877&loc=d3e4437-111522

+ Details

Name:	us-gaap_ForeclosedAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of expense recognized during the period for the foreclosure on real estate assets.

+ References

No definition available.

+ Details

Name:	us-gaap_ForeclosedRealEstateExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The net gain (loss) resulting from sales and other disposals of other real estate owned, increases (decreases) in the valuation allowance for foreclosed real estate, and write-downs of other real estate owned after acquisition or physical possession.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-04.14(d))

-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 14

-Subparagraph d

-Article 9

+ Details

Name:	us-gaap_GainsLossesOnSalesOfOtherRealEstate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The number of real estate properties owned as of the balance sheet date.

+ References

No definition available.

+ Details

Name:	us-gaap_NumberOfRealEstateProperties
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of expense related to other loss.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.5)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 5

-Article 5

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 11

-Article 9

+ Details

Name:	us-gaap_ProvisionForOtherLosses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_RealEstateAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of the valuation allowance for real estate owned that was applied in the period against the carrying amount of real estate owned that was sold, written down or written off.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.10(4))

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 10

-Subparagraph 4

-Article 9

+ Details

Name:	us-gaap_RealEstateOwnedValuationAllowanceAmountsApplied
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration