Earnings Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Jul. 31, 2013	Jul. 31, 2012	Jul. 31, 2013	Jul. 31, 2012
Earnings Per Share Reconciliation [Abstract]
Net income attributable to Eaton Vance Corp. shareholders	$ 23,203	$ 50,206	$ 136,689	$ 150,347
Less: Allocation of earnings to participating restricted shares	793	1,423	6,258	4,213
Net income available to common shareholders (basic)	22,410	48,783	130,431	146,134
Net income available to common shareholders (diluted)	$ 22,410	$ 48,783	$ 130,431	$ 146,134
Weighted-average shares outstanding - basic	117,594,000	112,110,000	116,399,000	112,354,000
Incremental common shares	6,278,000	2,481,000	5,756,000	2,677,000
Weighted-average shares outstanding - diluted	123,872,000	114,591,000	122,155,000	115,031,000
Earnings per share (Basic) ($ per share)	$ 0.19	$ 0.44	$ 1.12	$ 1.30
Earnings per share (Diluted) ($ per share)	$ 0.18	$ 0.43	$ 1.07	$ 1.27
Antidilutive common shares	3,000,000	14,400,000	3,000,000	15,000,000