Variable Interest Entities Investments in VIEs That Are Not Consolidated (Details) - USD ($) $ in Millions	Jan. 31, 2017	Oct. 31, 2016
Non Consolidated Clo Entities [Abstract]
Total assets held by the non-consolidated CLO entities	$ 1,900.0	$ 2,000.0
Total collateral management fees receivable held by the Company in non-consolidated entities	1.0	1.4
Other Entities [Abstract]
Total assets of the privately offered equity funds that the Company holds a variable interest in but is not deemed to be a primary beneficiary	14,800.0	13,500.0
Total investments of the privately offered equity funds that the Company holds a variable interest in but is not deemed to be a primary beneficiary	2.4	2.2
Total collateral management fees receivable of the privately offered equity funds that the Company holds a variable interest in but is not deemed to be a primary beneficiary	0.9	0.8
Variable interest investment in private equity partnership that is not consolidated	$ 2.8	$ 2.6