Fair Value Measurements Level 3 (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2012
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Principal repayments of senior note obligations	$ (128,362)ev_CloPrincipalPaydown	$ (177,500)ev_CloPrincipalPaydown	$ (28,614)ev_CloPrincipalPaydown
Bank Loans And Other Investments Of Consolidated CLO Entity [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value measurements with unobservable inputs reconciliation recurring basis asset value, beginning of period (asset)	1,245	2,203
Net gains (losses) on investments and note obligations included in net income	(183)	25
Sales (asset)	(1,061)	(132)
Settlements (asset)	0	(408)
Payment in-kind	0	7
Transfers into Level 3 (asset)	800	922
Transfers out of Level 3 (asset)	0	(1,372)
Fair value measurements with unobservable inputs reconciliation recurring basis asset value, end of period (asset)	801	1,245
Change in unrealized (losses) gains included in net income relating to assets and liabilities held (asset)	35	25
Senior And Subordinated Note Obligations And Redeemable Preferred Shares Of Consolidated CLO Entities [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value measurements with unobservable inputs reconciliation recurring basis liability value, beginning of period (liability)	276,476	443,946
Issuance of senior and subordinated notes and redeemable preferred shares	421,523
Deconsolidation of senior and subordinated notes and redeemable preferred shares	(419,193)
Net gains (losses) on investments and note obligations included in net income	(1,209)	10,030
Amortization of original issue discount on senior notes	75
Principal repayments of senior note obligations	(128,362)	(177,500)
Fair value measurements with unobservable inputs reconciliation recurring basis liability value, end of period (liability)	149,310	276,476
Change in unrealized (losses) gains included in net income relating to assets and liabilities held (liability)	$ (1,196)	$ 10,030
Senior and subordinated note obligations prepayment rate	30.00%	30.00%
Senior and subordinated note obligations recovery rate	70.00%	70.00%
Senior and subordinated note obligations and redeemable preferred shares probability of default	2.00%	2.00%
Senior and subordinated note obligations minimum discount rate	0.75%	1.05%
Senior and subordinated note obligations maximum discount rate	2.50%	3.75%

The cash outflow during the period from the principal repayment of debt of the consolidated CLO entity.

No definition available.

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The proceeds received related to the consolidated CLO entities, associated with security instrument that either represents a creditor or an ownership relationship with the holder of the investment security with a maturity of beyond one year or normal operating cycle, if longer. Includes proceeds from (a) debt, (b) capital lease obligations, (c) mandatory redeemable capital securities, and (d) any combination of (a), (b), or (c).

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Recovery rate is the expected recovery of defaulted amounts received through asset sale or recovery through bankruptcy restructuring or other settlement processes.

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- Definition

Settlements that have taken place during the period in relation to liabilities measured at fair value and categorized within Level 3 of the fair value hierarchy related to the deconsolidation of the Eaton Vance CLO 2013-1 entity

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Minimum interest rate used to find the present value of an amount to be paid or received in the future as an input to measure fair value. For example, but not limited to, weighted average cost of capital (WACC), cost of capital, cost of equity and cost of debt.

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Interest accruing on bank loans and other investments of the consolidated CLO entity.

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Amount of noncash expense included in interest expense to amortize debt discount and premium associated with the related debt instruments. Excludes amortization of financing costs. Alternate captions include noncash interest expense.

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This item represents the amount of the total realized and unrealized gains or losses for the period which are included in the statement of income (or changes in net assets); the fair value of which assets and liabilities was or is measured on a recurring basis using significant unobservable inputs (Level 3).

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Interest rate used to find the present value of an amount to be paid or received in the future as an input to measure fair value. For example, but not limited to, weighted average cost of capital (WACC), cost of capital, cost of equity and cost of debt.

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Rate at which loans or a loan portfolio are expected to prepay principal balances, used as an input to measure fair value.

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Percentage of likelihood a loan will not be repaid and instead default, used as an input to measure fair value.

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Amount of increase (decrease) of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of sale of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of settlement of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of transfer of financial instrument classified as an asset into level 3 of the fair value hierarchy.

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Amount of transfers of financial instrument classified as an asset out of level 3 of the fair value hierarchy.

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Fair value of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of increase (decrease) of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Fair value of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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