Comparative Quarterly Financial Information (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Oct. 31, 2016	Jul. 31, 2016	Apr. 30, 2016	Jan. 31, 2016	Oct. 31, 2015	Jul. 31, 2015	Apr. 30, 2015	Jan. 31, 2015	Oct. 31, 2016	Oct. 31, 2015	Oct. 31, 2014
Quarterly Financial Data [Abstract]
Total revenue	$ 346,846	$ 341,168	$ 323,290	$ 331,556	$ 341,458	$ 355,511	$ 351,664	$ 354,930	$ 1,342,860	$ 1,403,563	$ 1,450,294
Operating income	111,150	106,725	95,768	100,625	110,933	116,733	122,221	50,560	414,268	400,447	519,857
Net income	66,296	65,774	69,455	63,232	60,815	68,974	75,893	32,509	264,757	238,191	321,164
Net income attributable to Eaton Vance Corp. shareholders	$ 65,055	$ 62,899	$ 54,967	$ 58,386	$ 62,203	$ 68,709	$ 70,384	$ 29,003	$ 241,307	$ 230,299	$ 304,316
Earnings per share
Basic	$ 0.59	$ 0.57	$ 0.50	$ 0.52	$ 0.55	$ 0.60	$ 0.61	$ 0.25	$ 2.20	$ 2.00	$ 2.55
Diluted	$ 0.57	$ 0.55	$ 0.48	$ 0.50	$ 0.53	$ 0.57	$ 0.58	$ 0.24	$ 2.12	$ 1.92	$ 2.44