Deposits (Composition Of Deposits) (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Deposits [Abstract]
Noninterest bearing demand deposits	$ 193,276	$ 186,133
NOW accounts	77,699	86,199
Money market accounts	115,085	105,560
Regular savings accounts	86,249	80,455
Savings and interest bearing demand deposits	279,033	272,214
Time Deposits, Less than $250,000	69,825	80,444
Time Deposits, $250,000 or More	17,305	11,927
Time deposits	87,130	92,371
Total deposits	$ 559,439	$ 550,718

The aggregate amount of time deposit liabilities in denominations of $250,000 or more.

No definition available.

Name:	efsi_TimeDeposits250000orMore
Namespace Prefix:	efsi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The aggregate amount of time deposits that total to less than $250,000.

+ References

No definition available.

+ Details

Name:	efsi_TimeDepositsLessthan250000
Namespace Prefix:	efsi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- References

No definition available.

+ Details

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

- Definition

The aggregate of all domestic interest-bearing and noninterest-bearing deposit liabilities.

+ 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 210.9-03.12)
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

Name:	us-gaap_DepositsDomestic
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Total amount of interest-bearing domestic deposit liabilities, which may include brokered, retail, demand, checking, notice of withdrawal, money market and other interest-bearing deposits.

+ References

+ Details

Name:	us-gaap_InterestBearingDepositLiabilitiesDomestic
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of interest-bearing domestic money market demand account deposit liabilities.

+ References

+ Details

Name:	us-gaap_InterestBearingDomesticDepositMoneyMarket
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of interest-bearing domestic negotiable order of withdrawal (NOW) demand deposit liabilities.

+ References

+ Details

Name:	us-gaap_InterestBearingDomesticDepositNegotiableOrderOfWithdrawalNOW
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of interest-bearing domestic savings deposit liabilities. Saving deposits bear interest and have no stated maturity.

+ References

+ Details

Name:	us-gaap_InterestBearingDomesticDepositSavings
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of domestic noninterest-bearing deposits held by the entity, which may include demand deposits, checking, brokered and retail deposits.

+ References

+ Details

Name:	us-gaap_NoninterestBearingDepositLiabilitiesDomestic
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of deposits that cannot be withdrawn before a set date without penalty or for which notice of withdrawal is required. Time deposits include, but are not limited to, certificates of deposits, individual retirement accounts and open accounts.

+ References

+ Details

Name:	us-gaap_TimeDeposits
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant