Concentrations of Credit Risk and Significant Relationships (Details) - Number	12 Months Ended
Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Concentration of Credit Risk and Significant Relationship [Abstract]
Number of sponsored funds that provide over 10 percent of total revenue	0	0	0

Number Of Sponsored Funds That Provide Over 10 Percent Of Total Revenue

No definition available.

Name:	ev_NumberOfSponsoredFundsThatProvideOver10PercentOfTotalRevenue
Namespace Prefix:	ev_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration