Earnings Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Oct. 31, 2014	Jul. 31, 2014	Apr. 30, 2014	Jan. 31, 2014	Oct. 31, 2013	Jul. 31, 2013	Apr. 30, 2013	Jan. 31, 2013	Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2012
Earnings Per Share Reconciliation [Abstract]
Net income attributable to Eaton Vance Corp. shareholders	$ 80,122	$ 77,935	$ 74,901	$ 71,358	$ 57,152	$ 23,203	$ 63,681	$ 49,805	$ 304,316	$ 193,841	$ 203,465
Less: Allocation of earnings to participating restricted shares									7,611	7,124	5,676
Net income available to common shareholders (basic)									$ 296,705	$ 186,717	$ 197,789
Weighted-average shares outstanding - basic									116,440,000	116,597,000	112,359,000
Incremental common shares									5,155,000	5,847,000	2,767,000
Weighted-average shares outstanding - diluted									121,595,000	122,444,000	115,126,000
Earnings per share (Basic) ($ per share)	$ 0.68	$ 0.66	$ 0.62	$ 0.59	$ 0.47	$ 0.19	$ 0.53	$ 0.39	$ 2.55	$ 1.60	$ 1.76
Earnings per share (Diluted) ($ per share)	$ 0.66	$ 0.63	$ 0.59	$ 0.56	$ 0.45	$ 0.18	$ 0.50	$ 0.38	$ 2.44	$ 1.53	$ 1.72
Antidilutive common shares									5,100,000	3,000,000	14,900,000