Derivative Financial Instruments Not Designated for Hedge Accounting (Details) $ in Thousands	3 Months Ended
	Jan. 31, 2018 USD ($) Number	Jan. 31, 2017 USD ($)	Oct. 31, 2017 USD ($) Number
Stock Index Futures Contracts [Member]
Derivative Instruments Not Designated As Hedging Instruments [Line Items]
Number of contracts | Number	1,287		1,470
Notional amount of other derivative financial instruments not designated for hedge accounting	$ 119,100		$ 118,100
Other assets fair value	308		330
Other liabilities fair value	7,731		$ 3,021
Net realized gains (losses)	$ (7,656)	$ (5,933)
Total Return Swap Contracts [Member]
Derivative Instruments Not Designated As Hedging Instruments [Line Items]
Number of contracts | Number	6		2
Notional amount of other derivative financial instruments not designated for hedge accounting	$ 106,500		$ 50,200
Other assets fair value	0		0
Other liabilities fair value	1,195		$ 570
Net realized gains (losses)	$ (625)	(964)
Foreign Exchange Contracts [Member]
Derivative Instruments Not Designated As Hedging Instruments [Line Items]
Number of contracts | Number	38		31
Notional amount of other derivative financial instruments not designated for hedge accounting	$ 30,900		$ 28,100
Other assets fair value	222		650
Other liabilities fair value	1,075		$ 60
Net realized gains (losses)	$ (899)	(27)
Commodity Futures Contracts [Member]
Derivative Instruments Not Designated As Hedging Instruments [Line Items]
Number of contracts | Number	178		213
Notional amount of other derivative financial instruments not designated for hedge accounting	$ 9,200		$ 10,200
Other assets fair value	66		63
Other liabilities fair value	88		$ 120
Net realized gains (losses)	$ (403)	0
Currency Futures Contracts [Member]
Derivative Instruments Not Designated As Hedging Instruments [Line Items]
Number of contracts | Number	127		131
Notional amount of other derivative financial instruments not designated for hedge accounting	$ 14,300		$ 14,500
Other assets fair value	274		327
Other liabilities fair value	498		$ 178
Net realized gains (losses)	$ (86)	0
Interest Rate Futures Contracts [Member]
Derivative Instruments Not Designated As Hedging Instruments [Line Items]
Number of contracts | Number	141		134
Notional amount of other derivative financial instruments not designated for hedge accounting	$ 28,800		$ 25,600
Other assets fair value	277		48
Other liabilities fair value	182		226
Net realized gains (losses)	84	0
Total [Member]
Derivative Instruments Not Designated As Hedging Instruments [Line Items]
Other assets fair value	1,147		1,418
Other liabilities fair value	10,769		$ 4,175
Net realized gains (losses)	$ (9,585)	$ (6,924)