Effect of Derivative Instruments on OCI and the Condensed, Consolidated Statements of Operations (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Cash Flow Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain/(Loss) Recognized in AOCI	$ (4.9)	$ (3.3)
Amount of Gain/(Loss) Reclassified From AOCI Into Statement of Operations	(9.5)	(8.4)
Cash Flow Hedging | Interest rate swap agreements
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain/(Loss) Recognized in AOCI	(6.6)	(1.0)
Cash Flow Hedging | Interest rate swap agreements | Interest expense
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain/(Loss) Reclassified From AOCI Into Statement of Operations	(10.0)	(8.4)
Cash Flow Hedging | Commodity hedging instruments
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain/(Loss) Recognized in AOCI	1.7	(2.3)
Cash Flow Hedging | Commodity hedging instruments | Cost of sales
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain/(Loss) Reclassified From AOCI Into Statement of Operations	0.5	0
DERIVATIVES NOT DESIGNATED AS HEDGING INSTRUMENTS
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain/(Loss) Recognized in Statement of Operations	(1.7)	6.1
DERIVATIVES NOT DESIGNATED AS HEDGING INSTRUMENTS | Commodity hedging instruments | Cost of sales
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain/(Loss) Recognized in Statement of Operations	(1.0)	(0.6)
DERIVATIVES NOT DESIGNATED AS HEDGING INSTRUMENTS | Foreign currency swap contracts | Other income (expense), net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain/(Loss) Recognized in Statement of Operations	$ (0.7)	$ 6.7