Variable Interest Entities Investments in VIEs That Are Consolidated (Details) (USD $)	12 Months Ended
	Oct. 31, 2012	Oct. 31, 2011
Investments In Variable Interest Entities That Are Consolidated Details [Abstract]
Unpaid principal balance (Total CLO bank loan investments)	$ 425,153,000	$ 474,515,000
Excess unpaid principal balance over fair value (Total CLO bank loan investments)	(863,000)	(17,820,000)
Fair Value (Total CLO bank loan investments)	424,290,000	456,695,000
Unpaid principal balance (90 days or more past due)	500,000	1,192,000
Excess unpaid principal balance over fair value (90 days or more past due)	(485,000)	(617,000)
Fair Value (90 days or more past due)	15,000	575,000
Unpaid principal balance (Senior and subordinated note obligations)	471,546,000	500,066,000
Excess unpaid principal balance over fair value (Senior and subordinated note obligations)	(24,941,000)	(22,367,000)
Senior and subordinated note obligations	446,605,000	477,699,000
CLO Bank Loan Investments And Note Obligations Activity
Net (losses) gains resulting from change in fair value of the CLO entitys investments	20,200,000	(4,600,000)
Net gains (losses) resulting from an increase in the fair value of the CLOs note obligations.	2,400,000	(33,600,000)
Minimum variable interest rate on the note obligations held by the CLO entitys (as a percent)	0.21%
Maximum variable interest rate on the note obligations held by the CLO entitys (as a percent)	1.50%
Maturity date	2019-04-20
Assets of consolidated collateralized loan obligation ("CLO") entity:
Cash and cash equivalents	36,758,000	16,521,000
Bank loans and other investments	430,583,000	462,586,000
Other assets	1,107,000	2,715,000
Liabilities of consolidated CLO entity:
Senior and subordinated note obligations	446,605,000	477,699,000
Other liabilities	766,000	5,193,000
Appropriated retained earnings (deficit)	18,699,000	(3,867,000)
Total net interest in consolidated collateralized loan obligation entity	2,378,000	2,797,000
Direct equity interest in the Consolidated CLO entity	1,900,000	2,300,000
The CLOs net income (loss) recorded in the Company's Consolidated Statement of Income	25,900,000	(31,000,000)
The third-party note holders of the CLO entities net gain (loss) recorded during the period included in net income attributable to non-controlling and other beneficial interests	22,600,000	(34,500,000)
Net income attributable to Eaton Vance Corp. shareholders related to the consolidated CLO entity	$ 3,300,000	$ 3,500,000