Loans Receivable, Troubled Debt Restructurings (Details) (USD $)	3 Months Ended
Mar. 31, 2015 Contract	Mar. 31, 2014 Contract	Dec. 31, 2014 Contract
Financing Receivable, Modifications [Line Items]
Number of performing loans	60svbi_NumberOfPerformingLoans
Amount of performing loans	$ 22,343,000svbi_AmountOfPerformingLoans
Number of contract defaults	0	0
Method used to account for interest on TDRs [Abstract]
Number of Contracts	75svbi_NumberOfContract		76svbi_NumberOfContract
Accrual Status	26,175,000svbi_AccrualStatus		27,724,000svbi_AccrualStatus
Number of Contracts	9svbi_NumberOfContracts		9svbi_NumberOfContracts
Non-Accrual Status	2,620,000svbi_NonaccrualStatus		2,641,000svbi_NonaccrualStatus
Total Number of Contracts	84svbi_TotalNumberOfContracts		85svbi_TotalNumberOfContracts
Total Modifications	28,795,000svbi_TotalModifications		30,365,000svbi_TotalModifications
Residential Mortgage [Member]
Method used to account for interest on TDRs [Abstract]
Number of Contracts	57		57
Accrual Status	21,730,000		22,154,000
Number of Contracts	5		5
Non-Accrual Status	2,382,000		2,402,000
Total Number of Contracts	62		62
Total Modifications	24,112,000		24,556,000
Construction Acquisition and Development [Member]
Method used to account for interest on TDRs [Abstract]
Number of Contracts	2		2
Accrual Status	802,000		803,000
Number of Contracts	0		0
Non-Accrual Status	0		0
Total Number of Contracts	2		2
Total Modifications	802,000		803,000
Land [Member]
Method used to account for interest on TDRs [Abstract]
Number of Contracts	5		5
Accrual Status	973,000		982,000
Number of Contracts	1		1
Non-Accrual Status	6,000		6,000
Total Number of Contracts	6		6
Total Modifications	979,000		988,000
Lines of Credit [Member]
Method used to account for interest on TDRs [Abstract]
Number of Contracts	0		0
Accrual Status	0		0
Number of Contracts	0		0
Non-Accrual Status	0		0
Total Number of Contracts	0		0
Total Modifications	0		0
Commercial Real Estate [Member]
Method used to account for interest on TDRs [Abstract]
Number of Contracts	5		6
Accrual Status	2,513,000		3,623,000
Number of Contracts	1		1
Non-Accrual Status	108,000		109,000
Total Number of Contracts	6		7
Total Modifications	2,621,000		3,732,000
Commercial Non-Real Estate [Member]
Method used to account for interest on TDRs [Abstract]
Number of Contracts	5		5
Accrual Status	145,000		150,000
Number of Contracts	2		2
Non-Accrual Status	124,000		124,000
Total Number of Contracts	7		7
Total Modifications	269,000		274,000
Home Equity [Member]
Method used to account for interest on TDRs [Abstract]
Number of Contracts	0		0
Accrual Status	0		0
Number of Contracts	0		0
Non-Accrual Status	0		0
Total Number of Contracts	0		0
Total Modifications	0		0
Consumer [Member]
Method used to account for interest on TDRs [Abstract]
Number of Contracts	1		1
Accrual Status	12,000		12,000
Number of Contracts	0		0
Non-Accrual Status	0		0
Total Number of Contracts	1		1
Total Modifications	12,000		12,000
Pre-Modification [Member]
Newly restructured loans during the period [Abstract]
Rate Modification	0	0
Contracts	0	0
Combination Modifications	91,000	949,000
Contracts	1	3
Total	91,000	949,000
Total Contracts	1	3
Pre-Modification [Member] \| Residential Mortgage [Member]
Newly restructured loans during the period [Abstract]
Rate Modification	0	0
Contracts	0	0
Combination Modifications	91,000	598,000
Contracts	1	2
Total	91,000	598,000
Total Contracts	1	2
Pre-Modification [Member] \| Construction Acquisition and Development [Member]
Newly restructured loans during the period [Abstract]
Rate Modification	0	0
Contracts	0	0
Combination Modifications	0	0
Contracts	0	0
Total	0	0
Total Contracts	0	0
Pre-Modification [Member] \| Land [Member]
Newly restructured loans during the period [Abstract]
Rate Modification	0	0
Contracts	0	0
Combination Modifications	0	0
Contracts	0	0
Total	0	0
Total Contracts	0	0
Pre-Modification [Member] \| Lines of Credit [Member]
Newly restructured loans during the period [Abstract]
Rate Modification	0	0
Contracts	0	0
Combination Modifications	0	0
Contracts	0	0
Total	0	0
Total Contracts	0	0
Pre-Modification [Member] \| Commercial Real Estate [Member]
Newly restructured loans during the period [Abstract]
Rate Modification	0	0
Contracts	0	0
Combination Modifications	0	351,000
Contracts	0	1
Total	0	351,000
Total Contracts	0	1
Pre-Modification [Member] \| Commercial Non-Real Estate [Member]
Newly restructured loans during the period [Abstract]
Rate Modification	0	0
Contracts	0	0
Combination Modifications	0	0
Contracts	0	0
Total	0	0
Total Contracts	0	0
Pre-Modification [Member] \| Home Equity [Member]
Newly restructured loans during the period [Abstract]
Rate Modification	0	0
Contracts	0	0
Combination Modifications	0	0
Contracts	0	0
Total	0	0
Total Contracts	0	0
Pre-Modification [Member] \| Consumer [Member]
Newly restructured loans during the period [Abstract]
Rate Modification	0	0
Contracts	0	0
Combination Modifications	0	0
Contracts	0	0
Total	0	0
Total Contracts	0	0
Post Modification [Member]
Newly restructured loans during the period [Abstract]
Rate Modification	0	0
Contracts	0	0
Combination Modifications	91,000	791,000
Contracts	1	3
Total	91,000	791,000
Total Contracts	1	3
Post Modification [Member] \| Residential Mortgage [Member]
Newly restructured loans during the period [Abstract]
Rate Modification	0	0
Contracts	0	0
Combination Modifications	91,000	446,000
Contracts	1	2
Total	91,000	446,000
Total Contracts	1	2
Post Modification [Member] \| Construction Acquisition and Development [Member]
Newly restructured loans during the period [Abstract]
Rate Modification	0	0
Contracts	0	0
Combination Modifications	0	0
Contracts	0	0
Total	0	0
Total Contracts	0	0
Post Modification [Member] \| Land [Member]
Newly restructured loans during the period [Abstract]
Rate Modification	0	0
Contracts	0	0
Combination Modifications	0	0
Contracts	0	0
Total	0	0
Total Contracts	0	0
Post Modification [Member] \| Lines of Credit [Member]
Newly restructured loans during the period [Abstract]
Rate Modification	0	0
Contracts	0	0
Combination Modifications	0	0
Contracts	0	0
Total	0	0
Total Contracts	0	0
Post Modification [Member] \| Commercial Real Estate [Member]
Newly restructured loans during the period [Abstract]
Rate Modification	0	0
Contracts	0	0
Combination Modifications	0	345,000
Contracts	0	1
Total	0	345,000
Total Contracts	0	1
Post Modification [Member] \| Commercial Non-Real Estate [Member]
Newly restructured loans during the period [Abstract]
Rate Modification	0	0
Contracts	0	0
Combination Modifications	0	0
Contracts	0	0
Total	0	0
Total Contracts	0	0
Post Modification [Member] \| Home Equity [Member]
Newly restructured loans during the period [Abstract]
Rate Modification	0	0
Contracts	0	0
Combination Modifications	0	0
Contracts	0	0
Total	0	0
Total Contracts	0	0
Post Modification [Member] \| Consumer [Member]
Newly restructured loans during the period [Abstract]
Rate Modification	0	0
Contracts	0	0
Combination Modifications	0	0
Contracts	0	0
Total	$ 0	0
Total Contracts	0	0

Troubled debt restructuring on accrual status used to account for interest as of the balance sheet date.

No definition available.

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Namespace Prefix:	svbi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of performing loans have not been late on a payment during the last 2 years.

+ References

No definition available.

+ Details

Name:	svbi_AmountOfPerformingLoans
Namespace Prefix:	svbi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of combination modifications during the period of newly restructured loans.

+ References

No definition available.

+ Details

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

- Definition

Number of financing receivables that have been modified by troubled debt restructurings during the period.

+ References

No definition available.

+ Details

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Namespace Prefix:	svbi_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Details

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Balance Type:	na
Period Type:	duration

- Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Troubled debt restructurings on nonaccrual status used to account for interest as of the balance sheet date.

+ References

No definition available.

+ Details

Name:	svbi_NonaccrualStatus
Namespace Prefix:	svbi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Number of financing receivables that have been modified by troubled debt restructurings.

+ References

No definition available.

+ Details

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

- Definition

Number of contracts in TDRs used to account for interest as of the balance sheet date.

+ References

No definition available.

+ Details

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

- Definition

Number of performing loans which are have not been late on payment during the last 2 years.

+ References

No definition available.

+ Details

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

- Definition

This element represents interest rate modification on newly restructured loans.

+ References

No definition available.

+ Details

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

- Definition

Represents newly restructured loans that occurred during the period.

+ References

No definition available.

+ Details

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

- Definition

Total amount of troubled debt restructurings.

+ References

No definition available.

+ Details

Name:	svbi_TotalModifications
Namespace Prefix:	svbi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Total number of contracts in TDRs used to account for interest as of the balance sheet date.

+ References

No definition available.

+ Details

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

- Details

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

- Definition

Number of financing receivables that have been modified by troubled debt restructurings.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 33

-URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953676-111524

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The total number of new claims filed pertaining to a loss contingency during the period.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 450

-SubTopic 20

-Section 50

-Paragraph 4

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14435-108349

+ Details

Name:	us-gaap_LossContingencyNewClaimsFiledNumber
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of positions eliminated during the period as a result of restructuring activities.

+ References

No definition available.

+ Details

Name:	us-gaap_RestructuringAndRelatedCostNumberOfPositionsEliminated
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Details

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Namespace Prefix:
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- Details

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Namespace Prefix:
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Namespace Prefix:
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Namespace Prefix:
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- Details

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Namespace Prefix:
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Namespace Prefix:
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- Details

Name:	us-gaap_FinancingReceivableTroubledDebtRestructuringAxis=svbi_PostModificationMember
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