Securities (Amortized Costs And Fair Values Of Securities Available For Sale) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 97,608	$ 101,767
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	3,601	2,832
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	(923)	(2,001)
Securities available for sale, at fair value	100,286	102,598
Obligations Of U.S. Government Corporations And Agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	36,913	35,890
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	531	439
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	(739)	(1,585)
Securities available for sale, at fair value	36,705	34,744
Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	13,592	14,896
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	564	422
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	(61)	(121)
Securities available for sale, at fair value	14,095	15,197
Obligations Of States And Political Subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	39,548	42,442
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	1,364	969
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	(123)	(295)
Securities available for sale, at fair value	40,789	43,116
Corporate Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	6,511	7,495
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	996	928
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax
Securities available for sale, at fair value	7,507	8,423
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,044	1,044
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	146	74
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax
Securities available for sale, at fair value	$ 1,190	$ 1,118

Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax

No definition available.

Name:	efsi_AvailableforsaleSecuritiesAccumulatedGrossUnrealizedGainbeforeTax
Namespace Prefix:	efsi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax

+ References

No definition available.

+ Details

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

- Definition

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 25

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=28360136&loc=d3e22054-111558

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 5

-Subparagraph (aa)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27232-111563

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26610-111562

+ Details

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

- Definition

This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.2)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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

- Details

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