Commitments and Contingencies (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017
Commitments And Contingencies Disclosure Details [Abstract]
Description of expiration term of leases	The office space leases expire over various terms that extend through 2039
Operating Leases, Rent Expense, Net [Abstract]
Current year rent expense	$ 24.5	$ 23.2	$ 21.9

Amount of rent expense incurred for leased assets, including but not limited to, furniture and equipment, that is not directly or indirectly associated with the manufacture, sale or creation of a product or product line.

No definition available.

Name:	us-gaap_LeaseAndRentalExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration