Related Party Transactions (Summary of sales proceeds and net realized gains (losses) from investments in non-consolidated sponsored funds) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2020	Apr. 30, 2019
Related Party Transaction [Line Items]
Proceeds from sales	$ 5,057	$ 2,349	$ 5,058	$ 6,625
Net realized gains	$ 175	$ 5,180	$ 180	$ 5,205

The net cash paid (received) associated with the acquisition or disposal of all investments, including securities and other assets.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 3
-Subparagraph (SX 210.12-04(a))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24072-122690

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration