Fair Value Measurements Transfer Narrative (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended
Jul. 31, 2013	Jul. 31, 2012	Jul. 31, 2013	Jul. 31, 2012
Fair Value Measurements Details [Abstract]
Transfers from Level 1 into level 2	$ 237	$ 7,861	$ 43	$ 18,104
Transfers from Level 2 into level 1	$ 149	$ 0	$ 1,332	$ 0

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