Fair Value Measurements (Schedule of the Carrying Values and Fair Values of Financial Instruments) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2012
Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, including current portion carrying value	$ 5,137.8	$ 5,563.7
Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, including current portion fair value	5,343.9	5,804.1
Interest rate management contract [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	40.7	35.4
Derivative liabilities	9.7	9.6
Interest rate management contract [Member] | Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	40.7	35.4
Derivative liabilities	9.7	9.6
Interest rate management contract [Member] | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	40.7	35.4
Derivative liabilities	9.7	9.6
Forward Exchange Contracts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	76.6	90.5
Derivative liabilities	44.1	31.7
Forward Exchange Contracts [Member] | Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	76.6	90.5
Derivative liabilities	44.1	31.7
Forward Exchange Contracts [Member] | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	76.6	90.5
Derivative liabilities	$ 44.1	$ 31.7