Non-operating Income (Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Interest and other income	$ 25,336	$ 43,665	$ 35,150
Net gains (losses) on investments and derivatives	(21,613)	8,255	(24,319)
Net foreign currency losses	(480)	(880)	(765)
Gains and other investment income, net	3,243	51,040	10,066
Interest expense	(23,940)	(23,795)	(23,629)
Other income (expense) of consolidated collateralized loan obligation (CLO) entities:
Interest income	73,307	74,512	14,883
Net gains (losses) on bank loans and other investments and note obligations	(37,184)	(4,240)	1,999
Gains and other investment income, net	36,123	70,272	16,882
Structuring and closing fees	(8,251)	(6,337)	(4,830)
Interest expense	(46,950)	(53,013)	(10,456)
Interest and other expense	(55,201)	(59,350)	(15,286)
Total non-operating income (expense)	$ (39,775)	$ 38,167	$ (11,967)
Hexavest [Member]
Gains (losses) on investment
Additional interest that may be purchased by the Company			26.00%
Loss recognized on determination not to acquire addition ownership percentage			$ 6,500