Schedule II-Valuation and Qualifying Accounts (Detail) - Accounts receivable allowances - USD ($) $ in Millions	12 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance Beginning of Year	$ 22.4	$ 19.2	$ 25.5
Charges to Costs and Expenses	96.3	87.7	57.4
Write-offs/Allowance Taken	(83.2)	(84.6)	(63.6)
Balance End of Year	$ 35.5	$ 22.4	$ 19.2