Restructuring Charges - Reconciliation of Beginning and Ending Restructuring Reserve Balances (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Apr. 30, 2013	Apr. 30, 2012	Apr. 30, 2013	Apr. 30, 2012
Restructuring Cost and Reserve [Line Items]
Beginning balance			$ 8.0
Costs incurred and charged to expense	(0.1)	10.1	1.2	19.0
Costs paid or otherwise settled			(5.4)
Ending balance	3.8		3.8
Employee Separation Costs [Member]
Restructuring Cost and Reserve [Line Items]
Beginning balance			6.2
Costs incurred and charged to expense	(1.0)		(0.4)
Costs paid or otherwise settled			(3.4)
Ending balance	2.4		2.4
Other Restructuring Costs [Member]
Restructuring Cost and Reserve [Line Items]
Beginning balance			1.8
Costs incurred and charged to expense	0.5		1.1
Costs paid or otherwise settled			(1.5)
Ending balance	1.4		1.4
Asset Impairments [Member]
Restructuring Cost and Reserve [Line Items]
Beginning balance
Costs incurred and charged to expense			0.5
Costs paid or otherwise settled			(0.5)
Ending balance