Variable Interest Entities (Investments in vies that are not consolidated - Narrative) (Details) - Variable Interest Entity, Not Primary Beneficiary [Member] - USD ($) $ in Millions	Oct. 31, 2020	Oct. 31, 2019
Non-Consolidated CLO Entities [Abstract]
Total investments held by the Company in non-consolidated entities	$ 1.1	$ 1.4
Total collateral management fees receivable held by the Company in non-consolidated entities	0.1	0.1
Non-consolidated CLO entity with non-recourse assets	31,700.0	26,300.0
Total investments in the privately offered equity funds that the Company holds a variable interest in but is not deemed to be a primary beneficiary	0.6	0.5
Total investment advisory fees receivable from the privately offered equity funds that the Company holds a variable interest in but is not deemed to be a primary beneficiary	2.0	1.3
Variable interest investment in private equity partnership that is not consolidated	$ 0.2	$ 3.5