Fair Value Measurements (Schedule of Recurring Fair Value Measurements) (Details) - Fair Value [Member] - USD ($) $ in Millions	Jun. 30, 2017	Sep. 30, 2016
Forward Exchange Contracts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	$ 143.1	$ 193.8
Derivative liabilities	72.1	82.6
Interest Rate Management Contract [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	164.7	179.9
Derivative liabilities	23.5	12.7
Recurring Basis [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total Assets at Fair Value	307.8	373.7
Total Liabilities at Fair Value	95.6	95.3
Recurring Basis [Member] | Forward Exchange Contracts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	143.1	193.8
Derivative liabilities	72.1	82.6
Recurring Basis [Member] | Interest Rate Management Contract [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	164.7	179.9
Derivative liabilities	23.5	12.7
Recurring Basis [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total Assets at Fair Value	0.0	0.0
Total Liabilities at Fair Value	0.0	0.0
Recurring Basis [Member] | Level 1 [Member] | Forward Exchange Contracts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	0.0	0.0
Derivative liabilities	0.0	0.0
Recurring Basis [Member] | Level 1 [Member] | Interest Rate Management Contract [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	0.0	0.0
Derivative liabilities	0.0	0.0
Recurring Basis [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total Assets at Fair Value	307.8	373.7
Total Liabilities at Fair Value	95.6	95.3
Recurring Basis [Member] | Level 2 [Member] | Forward Exchange Contracts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	143.1	193.8
Derivative liabilities	72.1	82.6
Recurring Basis [Member] | Level 2 [Member] | Interest Rate Management Contract [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	164.7	179.9
Derivative liabilities	23.5	12.7
Recurring Basis [Member] | Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total Assets at Fair Value	0.0	0.0
Total Liabilities at Fair Value	0.0	0.0
Recurring Basis [Member] | Level 3 [Member] | Forward Exchange Contracts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	0.0	0.0
Derivative liabilities	0.0	0.0
Recurring Basis [Member] | Level 3 [Member] | Interest Rate Management Contract [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	0.0	0.0
Derivative liabilities	$ 0.0	$ 0.0