Pension and Postretirement Benefit Plans (Schedule of Funded Status for the Pension and Postretirement Benefit Plans) (Details) (Postretirement Benefits Plan [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Funded status	$ (137)	$ (138)	$ (150)
Unrecognized net actuarial loss	0	0	0
Unrecognized net transition obligation	0	0	0
Unrecognized prior service cost	0	0	0
Accrued benefits	(137)	(138)	(150)
Accrued liability	(137)	(138)	(150)
Amounts Recognized in Consolidated Balance Sheets	(137)	(138)	(150)
Net actuarial loss (gain)	(57)	(65)	(65)
Net transition obligation	0	0	0
Deferred tax (benefit)/liability	19	21	21
Amounts recognized in Accumulated Other Comprehensive Income	$ (38)	$ (44)	$ (44)

Pension and Postretirement Benefit Plans (Schedule of Funded Status for the Pension and Postretirement Benefit Plans) (Details) (Postretirement Benefits Plan [Member], USD $)
In Thousands, unless otherwise specified

12 Months Ended

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2012

Postretirement Benefits Plan [Member]

Defined Benefit Plan Disclosure [Line Items]

Funded status

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$ (138)us-gaap_DefinedBenefitPlanFundedStatusOfPlan
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$ (150)us-gaap_DefinedBenefitPlanFundedStatusOfPlan
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= us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember

Unrecognized net actuarial loss

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Unrecognized net transition obligation

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Unrecognized prior service cost

0us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax
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Accrued benefits

(137)us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTax
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(138)us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTax
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(150)us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTax
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Accrued liability

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(138)us-gaap_PostemploymentBenefitsLiabilityCurrentAndNoncurrent
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember

(150)us-gaap_PostemploymentBenefitsLiabilityCurrentAndNoncurrent
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember

Amounts Recognized in Consolidated Balance Sheets

(137)us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheet
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(138)us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheet
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember

(150)us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheet
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember

Net actuarial loss (gain)

(57)us-gaap_DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeLossNetGainLossBeforeTax
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember

(65)us-gaap_DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeLossNetGainLossBeforeTax
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember

Net transition obligation

0us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetTransitionAssetObligationBeforeTax
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember

Deferred tax (benefit)/liability

19efsi_OtherComprehensiveIncomeDefinedBenefitPlanDeferredTaxBenefitLiability
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember

21efsi_OtherComprehensiveIncomeDefinedBenefitPlanDeferredTaxBenefitLiability
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember

Amounts recognized in Accumulated Other Comprehensive Income

$ (38)efsi_RecognizedAccumulatedOtherComprehensiveIncomeDefinedBenefitPlan
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember

$ (44)efsi_RecognizedAccumulatedOtherComprehensiveIncomeDefinedBenefitPlan
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember

- Definition

Other Comprehensive Income Defined Benefit Plan Deferred Tax Benefit (Liability)

+ References

No definition available.

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- Definition

Recognized Accumulated Other Comprehensive Income Defined Benefit Plan

+ References

No definition available.

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- Definition

The pretax total of net gain (loss), prior service cost (credit), and transition assets (obligations), as well as minimum pension liability if still remaining, included in accumulated other comprehensive income associated with a defined benefit pension or other postretirement plan(s) because they have yet to be recognized as components of net periodic benefit cost.

+ References

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- Definition

The pretax net amount of gains and losses that are not yet recognized as a component of net periodic benefit cost, and that are recognized as increases or decreases in other comprehensive income as they arise. Gains and losses are due to changes in the value of either the benefit obligation or the plan assets resulting from experience different from that assumed or from a change in an actuarial assumption, or the consequence of a decision to temporarily deviate from the substantive plan.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 10A

-Subparagraph (i)

-URI http://asc.fasb.org/extlink&oid=28358780&loc=SL7669646-108580

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (j)

-URI http://asc.fasb.org/extlink&oid=28361610&loc=d3e1928-114920

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- Definition

Amount related to the pretax cost of benefit changes attributable to plan participants' prior service pursuant to a plan amendment or a plan initiation, which has not yet been recognized as components of net periodic benefit cost.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (j)

-URI http://asc.fasb.org/extlink&oid=28361610&loc=d3e1928-114920

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 10A

-Subparagraph (j)

-URI http://asc.fasb.org/extlink&oid=28358780&loc=SL7669646-108580

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 60

-Glossary Prior Service Cost

-URI http://asc.fasb.org/extlink&oid=6521920

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 30

-Glossary Prior Service Cost

-URI http://asc.fasb.org/extlink&oid=6521884

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Period Type:	instant

- Definition

Before tax amount of net transition assets (obligations) which has yet to be recognized as a component of net periodic benefit cost.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (i)-(j)

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Transition Asset

-URI http://asc.fasb.org/extlink&oid=6749452

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Transition Obligation

-URI http://asc.fasb.org/extlink&oid=6749492

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 10A

-Subparagraph (k)

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- Definition

The aggregate net amount recognized in the balance sheet associated with the defined benefit plan(s). Will normally be the same as the Defined Benefit Plan, Funded Status of Plan, Total.

+ References

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- Definition

Amount before tax, after reclassification adjustments, of actuarial gain (loss) that has not been recognized in the income statement.

+ References

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- Definition

The funded status is measured as the difference between the fair value of plan assets and the benefit obligation. Will normally be the same as the net Defined Benefit Plan, Amounts Recognized in Balance Sheet, Total.

+ References

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- Definition

Amount before tax of reclassification adjustment from accumulated other comprehensive income (loss) for net transition asset (obligation) related to pension and other postretirement benefit plans.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 11

-URI http://asc.fasb.org/extlink&oid=28358780&loc=d3e637-108580

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-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 15

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-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (j)

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- Definition

The carrying amount as of the balance sheet date of the obligations recognized for the various benefits provided to former or inactive employees, their beneficiaries, and covered dependents after employment but before retirement.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.15)

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-Name Accounting Standards Codification

-Topic 942

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-Subparagraph (SX 210.9-03.15)

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-Name Accounting Standards Codification

-Topic 712

-SubTopic 10

-Section 25

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-SubTopic 10

-Section 25

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=6410138&loc=d3e79708-111665

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