Financial Instruments (Fair Value of Derivative Instruments) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013	Sep. 30, 2012
Derivative [Line Items]
Total Derivatives, Assets	$ 136.3	$ 127.6
Total Derivatives, Liabilities	32.9	46.8
Designated as Hedging Instrument [Member]
Derivative [Line Items]
Total Derivatives, Assets	133.9	126.7
Total Derivatives, Liabilities	31.1	44.6
Designated as Hedging Instrument [Member] | Other Receivables [Member] | Interest rate management contract [Member]
Derivative [Line Items]
Total Derivatives, Assets	0	1.1
Designated as Hedging Instrument [Member] | Other Receivables [Member] | Forward Exchange Contracts [Member]
Derivative [Line Items]
Total Derivatives, Assets	43.4	12.7
Designated as Hedging Instrument [Member] | Other Noncurrent Assets [Member] | Interest rate management contract [Member]
Derivative [Line Items]
Total Derivatives, Assets	42.6	48.6
Designated as Hedging Instrument [Member] | Other Noncurrent Assets [Member] | Forward Exchange Contracts [Member]
Derivative [Line Items]
Total Derivatives, Assets	47.9	64.3
Designated as Hedging Instrument [Member] | Accrued Liabilities [Member] | Interest rate management contract [Member]
Derivative [Line Items]
Total Derivatives, Liabilities	1.3	15.6
Designated as Hedging Instrument [Member] | Accrued Liabilities [Member] | Forward Exchange Contracts [Member]
Derivative [Line Items]
Total Derivatives, Liabilities	19.8	17.0
Designated as Hedging Instrument [Member] | Other Noncurrent Liabilities [Member] | Interest rate management contract [Member]
Derivative [Line Items]
Total Derivatives, Liabilities	9.1	9.5
Designated as Hedging Instrument [Member] | Other Noncurrent Liabilities [Member] | Forward Exchange Contracts [Member]
Derivative [Line Items]
Total Derivatives, Liabilities	0.9	2.5
Hedges Not Designated [Member] | Other Receivables [Member] | Forward Exchange Contracts [Member]
Derivative [Line Items]
Total Derivatives, Assets	2.4	0.9
Hedges Not Designated [Member] | Accrued Liabilities [Member] | Forward Exchange Contracts [Member]
Derivative [Line Items]
Total Derivatives, Liabilities	$ 1.8	$ 2.2