Derivative Financial (Other derivative financial instruments not designated for hedge accounting) (Details)	12 Months Ended
	Oct. 31, 2020 USD ($) Number	Oct. 31, 2019 USD ($) Number	Oct. 31, 2018 USD ($)
Derivative [Line Items]
Total other assets fair value	$ 4,580,000	$ 2,074,000
Total other liabilities fair value	1,279,000	3,314,000
Net gains (losses)	$ 5,282,000	$ (15,913,000)	$ 984,000
Weighted average term of derivative contracts outstanding	3 months 24 days	6 months 9 days
Collateral Pledged [Member]
Derivative [Line Items]
Other assets, restricted cash	$ 12,800,000	$ 7,500,000
Payables to counterparties	$ 700,000	$ 0
Credit Default Swap [Member]
Derivative [Line Items]
Number of contracts | Number	1	1
Notional amount of other derivative financial instruments not designated for hedge accounting	$ 18,800,000	$ 8,000,000.0
Total other assets fair value	1,038,000	360,000
Total other liabilities fair value	0	0
Net gains (losses)	$ 445,000	$ (251,000)	178,000
Total Return Swap [Member]
Derivative [Line Items]
Number of contracts | Number	2	2
Notional amount of other derivative financial instruments not designated for hedge accounting	$ 87,000,000.0	$ 84,000,000.0
Total other assets fair value	732,000	396,000
Total other liabilities fair value	989,000	114,000
Net gains (losses)	$ 230,000	$ (5,535,000)	(2,708,000)
Stock Index Futures [Member]
Derivative [Line Items]
Number of contracts | Number	997	1,370
Notional amount of other derivative financial instruments not designated for hedge accounting	$ 85,500,000	$ 108,300,000
Total other assets fair value	2,725,000	615,000
Total other liabilities fair value	134,000	1,841,000
Net gains (losses)	$ 2,579,000	$ (6,701,000)	4,267,000
Commodity Futures [Member]
Derivative [Line Items]
Number of contracts | Number	0	415
Notional amount of other derivative financial instruments not designated for hedge accounting	$ 0	$ 15,200,000
Total other assets fair value	0	319,000
Total other liabilities fair value	0	334,000
Net gains (losses)	$ 1,027,000	$ 531,000	(1,044,000)
Foreign Exchange Contracts [Member]
Derivative [Line Items]
Number of contracts | Number	14	26
Notional amount of other derivative financial instruments not designated for hedge accounting	$ 11,500,000	$ 56,400,000
Total other assets fair value	62,000	51,000
Total other liabilities fair value	156,000	615,000
Net gains (losses)	$ 407,000	$ (1,749,000)	(51,000)
Currency Futures [Member]
Derivative [Line Items]
Number of contracts | Number	0	231
Notional amount of other derivative financial instruments not designated for hedge accounting	$ 0	$ 24,000,000.0
Total other assets fair value	0	128,000
Total other liabilities fair value	0	153,000
Net gains (losses)	$ 832,000	$ 442,000	(24,000)
Interest Rate Futures [Member]
Derivative [Line Items]
Number of contracts | Number	53	151
Notional amount of other derivative financial instruments not designated for hedge accounting	$ 7,000,000.0	$ 22,300,000
Total other assets fair value	23,000	144,000
Total other liabilities fair value	0	22,000
Net gains (losses)	$ (71,000)	$ (2,402,000)	366,000
Interest Rate Swap [Member]
Derivative [Line Items]
Number of contracts | Number	0	6
Notional amount of other derivative financial instruments not designated for hedge accounting	$ 0	$ 24,400,000
Total other assets fair value	0	61,000
Total other liabilities fair value	0	235,000
Net gains (losses)	$ (167,000)	$ (248,000)	$ 0