Investments (Investments in non-consolidated clo entities - Narrative) (Details) - USD ($)	12 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Investments [Abstract]
Impairment losses related to investments in non-consolidated CLO entities	$ 0	$ 0	$ 200,000
Non-Consolidated Collateralized Loan Obligations Details [Line Items]
Non-Consolidated Variable Interest Entity Assets Under Management	400,000,000	400,000,000
Investments In Non-consolidated CLO Entities [Member]
Non-Consolidated Collateralized Loan Obligations Details [Line Items]
Non-Consolidated Variable Interest Entity Assets Under Management	$ 1,100,000	$ 1,400,000