Restructuring Charges - Reconciliation of Beginning and Ending Restructuring Reserve Balances (Detail) - USD ($) $ in Millions	3 Months Ended
	Jan. 31, 2017	Jan. 31, 2016
Restructuring Reserve [Roll Forward]
Beginning balance	$ 10.4
Costs incurred and charged to expense	(0.3)	$ 2.3
Costs paid or otherwise settled	(3.9)
Ending balance	6.2
Employee Separation Costs
Restructuring Reserve [Roll Forward]
Beginning balance	9.2
Costs incurred and charged to expense	(0.8)
Costs paid or otherwise settled	(3.3)
Ending balance	5.1
Other Costs
Restructuring Reserve [Roll Forward]
Beginning balance	1.2
Costs incurred and charged to expense	0.5
Costs paid or otherwise settled	(0.6)
Ending balance	$ 1.1