Restructuring Charges - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jul. 31, 2016	Jul. 31, 2015	Jul. 31, 2016	Jul. 31, 2015	Oct. 31, 2015
Restructuring and Related Costs [Line Items]
Restructuring charges	$ 10.2	$ 16.2	$ 17.9	$ 26.7
Amounts Remaining to be Incurred	12.9		12.9		$ 14.7
Employee Separation Costs
Restructuring and Related Costs [Line Items]
Restructuring charges	5.3		10.7
Other Costs
Restructuring and Related Costs [Line Items]
Restructuring charges	$ 4.9		$ 7.2