Significant Accounting Policies (Policy)	3 Months Ended
Jan. 31, 2018
Significant Accounting Policies Policy [Abstract]
Basis of presentation policy	Basis of presentation 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.
Stock-based compensation policy	Stock-based compensation The Company accounts for stock‐based compensation expense at fair value. Under the fair value method, stock‐based compensation expense, which reflects the fair value of stock‐based awards measured at grant date, is recognized on a straight‐line basis over the relevant service period (generally five years) and is adjusted each period for forfeitures as they occur. The fair value of each option award granted is estimated using the Black‐Scholes option valuation model. The Black‐Scholes option valuation model incorporates assumptions as to dividend yield, expected volatility, an appropriate risk‐free interest rate and the expected life of the option. The fair value of profit interests granted under subsidiary long‐term equity plans is estimated on the grant date by averaging fair value established using an income approach and fair value established using a market approach for each subsidiary. The tax effect of the difference, if any, between the cumulative compensation expense recognized for a stock-based award for financial reporting purposes and the deduction for such award for tax purposes is recognized as income tax expense (for tax deficiencies) or benefit (for excess tax benefits) in the Company's Consolidated Statements of Income in the period in which the tax deduction arises (generally in the period of vesting or settlement of a stock-based award, as applicable) and are reflected as an operating activity on the Company's Consolidated Statements of Cash Flows. Shares of non-voting common stock withheld for tax withholding purposes upon the vesting of restricted share awards are reflected as a financing activity in the Company's Consolidated Statements of Cash Flows.

Significant Accounting Policies (Policy)

3 Months Ended

Jan. 31, 2018

Significant Accounting Policies Policy [Abstract]

Basis of presentation

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.

Stock-based compensation policy

Stock-based compensation

The Company accounts for stock‐based compensation expense at fair value. Under the fair value method, stock‐based compensation expense, which reflects the fair value of stock‐based awards measured at grant date, is recognized on a straight‐line basis over the relevant service period (generally five years) and is adjusted each period for forfeitures as they occur.

The fair value of each option award granted is estimated using the Black‐Scholes option valuation model. The Black‐Scholes option valuation model incorporates assumptions as to dividend yield, expected volatility, an appropriate risk‐free interest rate and the expected life of the option.

The fair value of profit interests granted under subsidiary long‐term equity plans is estimated on the grant date by averaging fair value established using an income approach and fair value established using a market approach for each subsidiary.

The tax effect of the difference, if any, between the cumulative compensation expense recognized for a stock-based award for financial reporting purposes and the deduction for such award for tax purposes is recognized as income tax expense (for tax deficiencies) or benefit (for excess tax benefits) in the Company's Consolidated Statements of Income in the period in which the tax deduction arises (generally in the period of vesting or settlement of a stock-based award, as applicable) and are reflected as an operating activity on the Company's Consolidated Statements of Cash Flows. Shares of non-voting common stock withheld for tax withholding purposes upon the vesting of restricted share awards are reflected as a financing activity in the Company's Consolidated Statements of Cash Flows.