Other Required Disclosures - Summarization of Remaining Accrual Balance Associated with Initiatives and Activity (Detail) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Mar. 31, 2013
Restructuring Cost and Reserve [Line Items]
Accrual Balance at September 30, 2012	$ 6.6
Provisions	4.8
Cash Expenditures	(3.7)
Accrual Balance at March 31, 2013	7.7
Expensed as Incurred	7.1	[1]
Global Cost Reduction Initiatives [Member]
Restructuring Cost and Reserve [Line Items]
Accrual Balance at September 30, 2012	4.4
Provisions	4.8
Cash Expenditures	(3.3)
Accrual Balance at March 31, 2013	5.9
Expensed as Incurred	6.9	[1]
Termination benefits [Member]
Restructuring Cost and Reserve [Line Items]
Accrual Balance at September 30, 2012	3.3
Provisions	4.5
Cash Expenditures	(2.7)
Accrual Balance at March 31, 2013	5.1
Expensed as Incurred	0.7	[1]
Other costs [Member]
Restructuring Cost and Reserve [Line Items]
Accrual Balance at September 30, 2012	1.1
Provisions	0.3
Cash Expenditures	(0.6)
Accrual Balance at March 31, 2013	0.8
Expensed as Incurred	6.2	[1]
Other initiatives [Member]
Restructuring Cost and Reserve [Line Items]
Accrual Balance at September 30, 2012	2.2
Provisions	0
Cash Expenditures	(0.4)
Accrual Balance at March 31, 2013	1.8
Expensed as Incurred	$ 0.2	[1]

[1] Consists of amounts not impacting the accrual for restructuring and related charges.