Fair Value Measurements Transfer Narrative (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2014	Apr. 30, 2013
Fair Value Measurements Details [Abstract]
Transfers from Level 1 into level 2	$ 542	$ 120	$ 214	$ 120
Transfers from Level 2 into level 1	$ 1,524	$ 137	$ 1,027	$ 1,743

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