Significant Accounting Policies (Policy)	6 Months Ended
Apr. 30, 2017
Significant Accounting Policies Policy [Abstract]
Basis of presentation policy	In the opinion of management, the accompanying unaudited interim Consolidated Financial Statements of Eaton Vance Corp. (the Company) include all adjustments necessary to present fairly the results for the interim periods in accordance with accounting principles generally accepted in the United States of America (U.S. GAAP). Such financial statements have been prepared in accordance with the instructions to Form 10-Q pursuant to the rules and regulations of the Securities and Exchange Commission. Certain information and footnote disclosures have been omitted pursuant to such rules and regulations. As a result, these financial statements should be read in conjunction with the audited Consolidated Financial Statements and related notes included in the Company's latest Annual Report on Form 10-K. During the first quarter of fiscal 2017, the Company changed the description of a line item in the Consolidated Statements of Income from investment advisory and administrative fees to management fees. The change in the description had no impact on the Company's previously reported net income or financial position, and does not represent a restatement of previously reported financial results. Management fees are defined as including both investment advisory fees and administration fees for all periods presented.
Principles of consolidation policy	Principles of consolidation With limited exceptions, each of the Company's sponsored mutual funds is organized as a separately managed component (or series) of a series trust. All assets of a series irrevocably belong to that series and are subject to the liabilities of that series; under no circumstances are the liabilities of one series payable by another series. The Company's series trusts have no equity investment at risk, rather, all equity is issued at the series level. However, decisions regarding the trustees of the trust and certain key activities of each series (i.e., sponsored fund) within the trust, such as appointment of each sponsored fund's investment adviser, typically reside at the trust level. As a result, shareholders of a sponsored fund that is organized as a series of a series trust lack the ability to control the key decision-making processes that most directly affect the performance of the sponsored fund. Accordingly, the Company believes that each trust is a VIE and each sponsored fund within the trust is a silo that also meets the definition of a VIE. Having concluded that each silo is a VIE, the primary beneficiary evaluation is focused on an analysis of economic interests in the silo. The Company may hold a significant interest in the shares of a sponsored fund during the seed investment stage when the sponsored fund's investment track record is being established. The Company consolidates a sponsored fund when it has a controlling financial interest in the fund. Given that the fees earned from each sponsored fund are commensurate with the services provided and consistent with market-based terms, the Company has generally concluded that its asset management arrangements with sponsored funds represent variable interests that convey both power and economics to the Company in instances in which the Company holds a greater than 10 percent ownership interest in the fund. Fee revenue earned on, as well as investments in, consolidated sponsored funds are eliminated in consolidation. The Company regularly seeds new sponsored funds and may consolidate one or more sponsored funds during a given reporting period. Due to the similarity of risks related to the Company's involvement with each sponsored fund, disclosures required under the VIE model, such as disclosures regarding the carrying amount and classification of assets of sponsored funds and the gains and losses that the Company recognizes from sponsored funds, are aggregated. When the Company is no longer deemed to hold a controlling financial interest in a sponsored fund, the Company deconsolidates the sponsored fund and removes the related assets, liabilities and non-controlling interests from its balance sheet and classifies the Company's remaining investment as available-for-sale. Because consolidated sponsored funds carry their assets and liabilities at fair value, there is no incremental gain or loss recognized upon deconsolidation. The extent of the Company's exposure to loss with respect to a consolidated sponsored fund is limited to the amount of the Company's investment in the sponsored fund. The Company is not obligated to provide financial support to sponsored funds. Only the assets of a sponsored fund are available to settle its obligations. Beneficial interest holders of sponsored funds do not have recourse to the general credit of the Company.
Consolidation of VIEs policy	Consolidation of VIEs Accounting guidance provides a framework for determining whether an entity should be considered a VIE and, if so, whether a company's involvement with the entity results in a variable interest in the entity. If the Company determines that it does have a variable interest in an entity, it must perform an analysis to determine whether it is the primary beneficiary of the VIE. If the Company determines it is the primary beneficiary of the VIE, it is required to consolidate the assets, liabilities, results of operations and cash flows of the VIE. The Company's evaluation of whether it qualifies as the primary beneficiary of a VIE is complex. The Company is the primary beneficiary of a VIE if it has a controlling financial interest in the VIE. A company is deemed to have a controlling financial interest in a VIE if it has both (i) the power to direct the activities of the VIE that most significantly impact the VIE's economic performance, and (ii) the obligation to absorb losses of the VIE that could potentially be significant to the VIE or the right to receive benefits from the VIE that could potentially be significant to the VIE. For collateralized loan obligation (CLO) entities, the Company must evaluate the relative size of the Company's residual interest and the overall magnitude and design of the collateral fees within each structure. There is also judgment involved in assessing whether the Company has the power to direct the activities that most significantly impact the VIE's economic performance and the obligation to absorb losses of or the right to receive benefits from the VIE that could potentially be significant to the entity. While the Company believes its overall evaluation of VIEs is appropriate, future changes in estimates, judgments and assumptions, changes in the ownership interests of the Company in a VIE and/or future accounting pronouncements may affect the resulting consolidation, or deconsolidation, of the assets, liabilities, results of operations and cash flows of a VIE.
Debt issuance costs policy	Debt issuance costs Deferred debt issuance costs are amortized using the effective interest method over the related debt term. Debt issuance costs related to the Company's term debt are included in debt in the Company's Consolidated Balance Sheets. The amortization of deferred debt issuance costs is included in interest expense on the Company's Consolidated Statements of Income.

Significant Accounting Policies (Policy)

6 Months Ended

Apr. 30, 2017

Significant Accounting Policies Policy [Abstract]

In the opinion of management, the accompanying unaudited interim Consolidated Financial Statements of Eaton Vance Corp. (the Company) include all adjustments necessary to present fairly the results for the interim periods in accordance with accounting principles generally accepted in the United States of America (U.S. GAAP). Such financial statements have been prepared in accordance with the instructions to Form 10-Q pursuant to the rules and regulations of the Securities and Exchange Commission. Certain information and footnote disclosures have been omitted pursuant to such rules and regulations. As a result, these financial statements should be read in conjunction with the audited Consolidated Financial Statements and related notes included in the Company's latest Annual Report on Form 10-K.

During the first quarter of fiscal 2017, the Company changed the description of a line item in the Consolidated Statements of Income from investment advisory and administrative fees to management fees. The change in the description had no impact on the Company's previously reported net income or financial position, and does not represent a restatement of previously reported financial results. Management fees are defined as including both investment advisory fees and administration fees for all periods presented.

Principles of consolidation policy

Principles of consolidation

With limited exceptions, each of the Company's sponsored mutual funds is organized as a separately managed component (or series) of a series trust. All assets of a series irrevocably belong to that series and are subject to the liabilities of that series; under no circumstances are the liabilities of one series payable by another series. The Company's series trusts have no equity investment at risk, rather, all equity is issued at the series level. However, decisions regarding the trustees of the trust and certain key activities of each series (i.e., sponsored fund) within the trust, such as appointment of each sponsored fund's investment adviser, typically reside at the trust level. As a result, shareholders of a sponsored fund that is organized as a series of a series trust lack the ability to control the key decision-making processes that most directly affect the performance of the sponsored fund. Accordingly, the Company believes that each trust is a VIE and each sponsored fund within the trust is a silo that also meets the definition of a VIE. Having concluded that each silo is a VIE, the primary beneficiary evaluation is focused on an analysis of economic interests in the silo. The Company may hold a significant interest in the shares of a sponsored fund during the seed investment stage when the sponsored fund's investment track record is being established. The Company consolidates a sponsored fund when it has a controlling financial interest in the fund. Given that the fees earned from each sponsored fund are commensurate with the services provided and consistent with market-based terms, the Company has generally concluded that its asset management arrangements with sponsored funds represent variable interests that convey both power and economics to the Company in instances in which the Company holds a greater than 10 percent ownership interest in the fund. Fee revenue earned on, as well as investments in, consolidated sponsored funds are eliminated in consolidation.

The Company regularly seeds new sponsored funds and may consolidate one or more sponsored funds during a given reporting period. Due to the similarity of risks related to the Company's involvement with each sponsored fund, disclosures required under the VIE model, such as disclosures regarding the carrying amount and classification of assets of sponsored funds and the gains and losses that the Company recognizes from sponsored funds, are aggregated.

When the Company is no longer deemed to hold a controlling financial interest in a sponsored fund, the Company deconsolidates the sponsored fund and removes the related assets, liabilities and non-controlling interests from its balance sheet and classifies the Company's remaining investment as available-for-sale. Because consolidated sponsored funds carry their assets and liabilities at fair value, there is no incremental gain or loss recognized upon deconsolidation.

The extent of the Company's exposure to loss with respect to a consolidated sponsored fund is limited to the amount of the Company's investment in the sponsored fund. The Company is not obligated to provide financial support to sponsored funds. Only the assets of a sponsored fund are available to settle its obligations. Beneficial interest holders of sponsored funds do not have recourse to the general credit of the Company.

Consolidation of VIEs policy

Consolidation of VIEs

Accounting guidance provides a framework for determining whether an entity should be considered a VIE and, if so, whether a company's involvement with the entity results in a variable interest in the entity. If the Company determines that it does have a variable interest in an entity, it must perform an analysis to determine whether it is the primary beneficiary of the VIE. If the Company determines it is the primary beneficiary of the VIE, it is required to consolidate the assets, liabilities, results of operations and cash flows of the VIE.

The Company's evaluation of whether it qualifies as the primary beneficiary of a VIE is complex. The Company is the primary beneficiary of a VIE if it has a controlling financial interest in the VIE. A company is deemed to have a controlling financial interest in a VIE if it has both (i) the power to direct the activities of the VIE that most significantly impact the VIE's economic performance, and (ii) the obligation to absorb losses of the VIE that could potentially be significant to the VIE or the right to receive benefits from the VIE that could potentially be significant to the VIE.

For collateralized loan obligation (CLO) entities, the Company must evaluate the relative size of the Company's residual interest and the overall magnitude and design of the collateral fees within each structure. There is also judgment involved in assessing whether the Company has the power to direct the activities that most significantly impact the VIE's economic performance and the obligation to absorb losses of or the right to receive benefits from the VIE that could potentially be significant to the entity.

While the Company believes its overall evaluation of VIEs is appropriate, future changes in estimates, judgments and assumptions, changes in the ownership interests of the Company in a VIE and/or future accounting pronouncements may affect the resulting consolidation, or deconsolidation, of the assets, liabilities, results of operations and cash flows of a VIE.

Debt issuance costs policy

Debt issuance costs

Deferred debt issuance costs are amortized using the effective interest method over the related debt term. Debt issuance costs related to the Company's term debt are included in debt in the Company's Consolidated Balance Sheets. The amortization of deferred debt issuance costs is included in interest expense on the Company's Consolidated Statements of Income.