Intangible Assets (Schedule of the Carrying Amounts of Intangible Assets) (Details) - USD ($) $ in Thousands	Jan. 31, 2020	Oct. 31, 2019
Amortizing intangible assets:
Accumulated amortization	$ (119,691)	$ (118,669)
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Gross intangible assets	194,576	194,576
Net carrying amount	74,885	75,907
Mutual Fund Management Contract Acquired [Member]
Non-amortizing intangible assets:
Net carrying amount	54,408	54,408
Client Relationships Acquired [Member]
Amortizing intangible assets:
Gross carrying amount	134,247	134,247
Accumulated amortization	(116,810)	(115,921)
Net carrying amount	17,437	18,326
Intellectual Property Acquired [Member]
Amortizing intangible assets:
Gross carrying amount	1,025	1,025
Accumulated amortization	(603)	(586)
Net carrying amount	422	439
Trademark Acquired [Member]
Amortizing intangible assets:
Gross carrying amount	4,257	4,257
Accumulated amortization	(1,639)	(1,558)
Net carrying amount	2,618	2,699
Research System Aquired [Member]
Amortizing intangible assets:
Gross carrying amount	639	639
Accumulated amortization	(639)	(604)
Net carrying amount	$ 0	$ 35