Fair Value Measurements (Schedule of the Carrying Values and Fair Values of Financial Instruments) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Sep. 30, 2011
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other liabilities		$ 51.0
Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, including current portion	3,846.2	3,999.7
Other liabilities	0	51.0
Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, including current portion	4,164.1	4,284.5
Other liabilities	0	51.0
Interest rate management contract [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	53.0	48.2
Derivative liabilities	14.1	6.0
Interest rate management contract [Member] | Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	53.0	48.2
Derivative liabilities	14.1	6.0
Interest rate management contract [Member] | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	53.0	48.2
Derivative liabilities	14.1	6.0
Forward Exchange Contracts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	93.1	70.0
Derivative liabilities	23.5	37.8
Forward Exchange Contracts [Member] | Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	93.1	70.0
Derivative liabilities	23.5	37.8
Forward Exchange Contracts [Member] | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	93.1	70.0
Derivative liabilities	$ 23.5	$ 37.8