Derivative Instruments and Fair Value Measurement (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Sep. 30, 2012
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	$ 902.6
Derivative Instruments in Hedges, Net Investment in Foreign Operations, Liabilities, Fair Value	13.9
Assets and liabilities measured at fair value on a recurring basis
Net derivative asset / (liability) designated as hedging instruments	5.7	0.1
Net derivative asset / (liability) not designated as hedging instruments	5.3	(10.7)
Other current assets [Member]
Assets and liabilities measured at fair value on a recurring basis
Derivatives assets designated as hedging instruments	11.7	8.7
Derivatives assets not designated as hedging instruments	6.1	2.3
Other assets [Member]
Assets and liabilities measured at fair value on a recurring basis
Derivatives assets designated as hedging instruments	0.9	1.3
Derivatives assets not designated as hedging instruments	1.8	0.1
Other current liabilities [Member]
Assets and liabilities measured at fair value on a recurring basis
Derivatives liabilities designated as hedging instruments	(6.0)	(8.4)
Derivatives liabilities not designated as hedging instruments	(2.6)	(13.1)
Other liabilities [Member]
Assets and liabilities measured at fair value on a recurring basis
Derivatives liabilities designated as hedging instruments	(0.9)	(1.5)
Cash Flow Hedging [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	$ 575.5