Fair Value Measurements (Schedule of Fair Value of Assets and Liabilities) (Details) - Fair Value [Member] - USD ($) $ in Millions	Sep. 30, 2015	Sep. 30, 2014
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total Assets at Fair Value	$ 318.9	$ 171.7
Total Liabilities at Fair Value	125.2	85.9
Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total Assets at Fair Value	318.9	171.7
Total Liabilities at Fair Value	125.2	85.9
Interest rate management contract [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	171.8	78.3
Derivative liabilities	0.8	19.1
Interest rate management contract [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	171.8	78.3
Derivative liabilities	0.8	19.1
Forward Exchange Contracts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	147.1	93.4
Derivative liabilities	124.4	66.8
Forward Exchange Contracts [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	147.1	93.4
Derivative liabilities	$ 124.4	$ 66.8