Name:	efsi_FairValueAssetsMeasurementsOnNonrecurringBasisLineItems
Namespace Prefix:	efsi_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Gain Loss On Disposition Of Assets Fair Value Disclosure Nonrecurring

+ References

No definition available.

+ Details

Name:	efsi_GainLossOnDispositionOfAssetsFairValueDisclosureNonrecurring
Namespace Prefix:	efsi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Sales Proceeds Fair Value Disclosure Nonrecurring

+ References

No definition available.

+ Details

Name:	efsi_SalesProceedsFairValueDisclosureNonrecurring
Namespace Prefix:	efsi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Transfers Into Level Three Fair Value Disclosure Nonrecurring

+ References

No definition available.

+ Details

Name:	efsi_TransfersIntoLevelThreeFairValueDisclosureNonrecurring
Namespace Prefix:	efsi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Transfers Out Of Level Three Fair Value Disclosure Nonrecurring

+ References

No definition available.

+ Details

Name:	efsi_TransfersOutOfLevelThreeFairValueDisclosureNonrecurring
Namespace Prefix:	efsi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Valuation Allowance Fair Value Disclosure Nonrecurring

+ References

No definition available.

+ Details

Name:	efsi_ValuationAllowanceFairValueDisclosureNonrecurring
Namespace Prefix:	efsi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

This element represents the aggregate of the assets reported on the balance sheet at period end measured at fair value by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258

+ Details

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

- Definition

This element represents the aggregate of the assets reported on the balance sheet at period end measured at fair value on a nonrecurring basis by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements.

+ References

No definition available.

+ Details

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

Fair Value Measurements (Level 3 Financial Assets Measured At Estimated Fair Value On Nonrecurring Basis) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Fair Value Assets Measurements On Nonrecurring Basis [Line Items]
Total assets at fair value	$ 112,359	$ 102,754
Significant Unobservable Inputs (Level 3) [Member]
Fair Value Assets Measurements On Nonrecurring Basis [Line Items]
Total assets at fair value
Impaired Loans [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Fair Value Assets Measurements On Nonrecurring Basis [Line Items]
Balance - January 1, 2012	1,321
Sales proceeds
Valuation allowance
(Loss) on disposition
Transfers into Level 3	617
Transfers out of Level 3	(364)
Total assets at fair value	1,574
Other Real Estate Owned [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Fair Value Assets Measurements On Nonrecurring Basis [Line Items]
Balance - January 1, 2012	608
Sales proceeds
Valuation allowance
(Loss) on disposition
Transfers into Level 3	148
Transfers out of Level 3	(608)
Total assets at fair value	$ 148