Summary of Significant Accounting Policies (Policies)	3 Months Ended
Jan. 31, 2020
Summary of Significant Accounting Policies [Abstract]
Basis of presentation	Basis of presentation In the opinion of management, the accompanying unaudited interim Consolidated Financial Statements of Eaton Vance Corp. (the Company) include all normal recurring 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 Annual Report on Form 10-K for the year ended October 31, 2019.
Adoption of new accounting standard	Adoption of new accounting standard The Company adopted Accounting Standards Update (ASU) 2016-02, Leases, as of November 1, 2019. This guidance requires a lessee to recognize assets and liabilities on the balance sheet related to the rights and obligations created by those leases. The Company applied a modified retrospective approach to adoption and has not restated comparative periods. In order to reduce the complexity of adoption, the Company elected practical expedients that allowed it to forego reassessments of the following: whether an arrangement is or contains a lease, the classification of the lease, the recognition requirement for initial direct costs, and assumptions regarding renewal options that affect the lease term. Separately, the Company made accounting policy elections to 1) not separate lease and non-lease components such that all consideration required to be paid under its lease agreements will be allocated to the lease component, and 2) to report short-term leases with a term of twelve months or less off-balance sheet. Upon adoption of the new guidance on November 1, 2019, the Company recognized operating lease right‐of‐use (ROU) assets of approximately $270.0 million equal to forecasted operating lease liabilities less deferred rent of $48.8 million, which was recognized under previous lease accounting guidance, and operating lease liabilities of approximately $318.8 million, with no cumulative-effect adjustment to opening retained earnings. The new guidance does not have a significant impact on the Company’s results of operations or cash flows because operating lease costs continue to be recognized on a straight‐line basis over the remaining lease term and operating lease payments continue to be classified within operating activities in the Consolidated Statement of Cash Flows. The Company’s accounting policies related to leases, as provided below, have been updated to reflect the adoption of this new accounting standard as of November 1, 2019.
Leases	Leases Contracts are evaluated at inception to determine whether such contract is or contains a lease. The Company leases certain office space and equipment under non-cancelable operating leases. As leases expire, they are normally renewed or replaced in the ordinary course of business. Lease agreements may contain renewal options exercisable by the Company, rent escalation clauses and/or other incentives provided by the landlord. Renewal options that have been determined to be reasonably certain to be exercised are included in the lease term. Rights and obligations attributable to identified leases with a term in excess of twelve months are recognized on the Company’s Consolidated Balance Sheet in the form of ROU assets and lease liabilities as of the date the underlying assets are available for use, which may be the date the Company gains access to begin leasehold improvements. Lease payments related to short-term leases with a term of twelve months or less are recognized on a straight-line basis as short-term lease expense. Lease liabilities are initially and subsequently measured at the present value of future lease payments over the lease term. For the purposes of this calculation, lease payments consist of fixed monthly lease payments related to use of the underlying assets and related services. Discount rates used in the calculation of present value reflect estimated incremental borrowing rates determined for each lease as of the lease commencement date. ROU assets are initially measured equal to the corresponding lease liabilities, adjusted for any lease incentives payable to the Company. Subsequently, the amortization of ROU assets are recognized as a component of operating lease expense. The total cost of operating leases is recognized on a straight-line basis over the life of the related leases, and is comprised of imputed interest on lease liabilities measured using the effective interest method and amortization of the ROU asset. Variable lease payments are primarily related to services such as common-area maintenance and utilities, property taxes and insurance and are recognized as variable lease expense when incurred. ROU assets are tested for impairment whenever changes in facts or circumstances indicate that the carrying amount of an asset may not be recoverable. Modification of a lease term would result in re-measurement of the lease liability and a corresponding adjustment to the ROU asset.

Summary of Significant Accounting Policies (Policies)

3 Months Ended

Jan. 31, 2020

Summary of Significant Accounting Policies [Abstract]

In the opinion of management, the accompanying unaudited interim Consolidated Financial Statements of Eaton Vance Corp. (the Company) include all normal recurring 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 Annual Report on Form 10-K for the year ended October 31, 2019.

Adoption of new accounting standard

The Company adopted Accounting Standards Update (ASU) 2016-02, Leases, as of November 1, 2019. This guidance requires a lessee to recognize assets and liabilities on the balance sheet related to the rights and obligations created by those leases. The Company applied a modified retrospective approach to adoption and has not restated comparative periods. In order to reduce the complexity of adoption, the Company elected practical expedients that allowed it to forego reassessments of the following: whether an arrangement is or contains a lease, the classification of the lease, the recognition requirement for initial direct costs, and assumptions regarding renewal options that affect the lease term. Separately, the Company made accounting policy elections to 1) not separate lease and non-lease components such that all consideration required to be paid under its lease agreements will be allocated to the lease component, and 2) to report short-term leases with a term of twelve months or less off-balance sheet.

Upon adoption of the new guidance on November 1, 2019, the Company recognized operating lease right‐of‐use (ROU) assets of approximately $270.0 million equal to forecasted operating lease liabilities less deferred rent of $48.8 million, which was recognized under previous lease accounting guidance, and operating lease liabilities of approximately $318.8 million, with no cumulative-effect adjustment to opening retained earnings. The new guidance does not have a significant impact on the Company’s results of operations or cash flows because operating lease costs continue to be recognized on a straight‐line basis over the remaining lease term and operating lease payments continue to be classified within operating activities in the Consolidated Statement of Cash Flows.

The Company’s accounting policies related to leases, as provided below, have been updated to reflect the adoption of this new accounting standard as of November 1, 2019.

Leases

Contracts are evaluated at inception to determine whether such contract is or contains a lease. The Company leases certain office space and equipment under non-cancelable operating leases. As leases expire, they are normally renewed or replaced in the ordinary course of business. Lease agreements may contain renewal options exercisable by the Company, rent escalation clauses and/or other incentives

provided by the landlord. Renewal options that have been determined to be reasonably certain to be exercised are included in the lease term. Rights and obligations attributable to identified leases with a term in excess of twelve months are recognized on the Company’s Consolidated Balance Sheet in the form of ROU assets and lease liabilities as of the date the underlying assets are available for use, which may be the date the Company gains access to begin leasehold improvements. Lease payments related to short-term leases with a term of twelve months or less are recognized on a straight-line basis as short-term lease expense.

Lease liabilities are initially and subsequently measured at the present value of future lease payments over the lease term. For the purposes of this calculation, lease payments consist of fixed monthly lease payments related to use of the underlying assets and related services. Discount rates used in the calculation of present value reflect estimated incremental borrowing rates determined for each lease as of the lease commencement date.

ROU assets are initially measured equal to the corresponding lease liabilities, adjusted for any lease incentives payable to the Company. Subsequently, the amortization of ROU assets are recognized as a component of operating lease expense. The total cost of operating leases is recognized on a straight-line basis over the life of the related leases, and is comprised of imputed interest on lease liabilities measured using the effective interest method and amortization of the ROU asset. Variable lease payments are primarily related to services such as common-area maintenance and utilities, property taxes and insurance and are recognized as variable lease expense when incurred.

ROU assets are tested for impairment whenever changes in facts or circumstances indicate that the carrying amount of an asset may not be recoverable. Modification of a lease term would result in re-measurement of the lease liability and a corresponding adjustment to the ROU asset.