Fair Value Measurements Transfer Narrative (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Oct. 31, 2014	Oct. 31, 2013
Fair Value Measurements Details [Abstract]
Transfers from Level 1 into level 2	$ 249	$ 29
Transfers from Level 2 into level 1	$ 1,192	$ 1,304

Amount of transfers of assets measured on a recurring basis out of Level 1 of the fair value hierarchy into Level 2 during the reporting periods.

No definition available.

Name:	ev_FairValueAssetsLevel1ToLevel2TransferAmounts
Namespace Prefix:	ev_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration