Dividend Investment Plan (Details)	Dec. 31, 2015
Dividend Investment Plan [Abstract]
Percentage of fair market value	95.00%

Percentage OF Fair Market Value Purchase Additional Shares Common Stock

No definition available.

Name:	efsi_PercentageOfFairMarketValuePurchaseAdditionalSharesCommonStock
Namespace Prefix:	efsi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant