Investments In Equity Method Investees (Details) - USD ($) $ in Millions	Jan. 31, 2018	Oct. 31, 2017
Hexavest [Member]
Schedule Of Equity Method Investments [Line Items]
Equity method investment ownership percentage	49.00%	49.00%
Equity method investment aggregate cost	$ 149.1	$ 142.0
Equity method investment underlying equity in net assets	6.7	6.1
Intangible assets net excluding goodwill, equity in investee	24.4	23.7
Goodwill, equity in investee	124.6	118.6
Deferred tax liability, equity in investee	$ 6.6	$ 6.4
Private Equity Partnership [Member]
Schedule Of Equity Method Investments [Line Items]
Equity method investment ownership percentage	7.00%	7.00%
Equity method investment aggregate cost	$ 3.2	$ 2.9

The Company's share of deferred tax liability of its equity investee.

No definition available.

Name:	ev_DeferredTaxLiabilityEquityInvestee
Namespace Prefix:	ev_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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- Definition

The Company's share in goodwill of its equity investee.

+ References

No definition available.

+ Details

Name:	ev_GoodwillEquityInvestee
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The Company's share of intangible assets excluding goodwill of its equity investee.

+ References

No definition available.

+ Details

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Namespace Prefix:	ev_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66011266&loc=d3e33918-111571

+ Details

Name:	us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

This item represents the entity's ownership percentage in the investee multiplied by the investee's total equity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=66011266&loc=d3e33918-111571

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=66022249&loc=d3e33749-111570

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.12)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Details

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- Details

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