Investments (Investments in non-consolidated CLO entities Narrative) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2020	Apr. 30, 2019	Oct. 31, 2019
Investments [Abstract]
Impairment losses related to investments in non-consolidated CLO entities	$ 0	$ 0	$ 0	$ 0
Non-Consolidated Collateralized Loan Obligations Details [Line Items]
Non-Consolidated Variable Interest Entity Assets Under Management	400,000,000		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	$ 1,400,000		$ 1,400,000		$ 1,400,000