Financial Instruments (Fair Value of Derivative Instruments) (Details) - USD ($) $ in Millions	Mar. 31, 2016	Sep. 30, 2015
Derivative [Line Items]
Total Derivatives, Assets	$ 371.4	$ 318.9
Total Derivatives, Liabilities	75.7	125.2
Designated as Hedging Instrument [Member]
Derivative [Line Items]
Total Derivatives, Assets	331.9	291.6
Total Derivatives, Liabilities	68.1	120.7
Designated as Hedging Instrument [Member] | Other Receivables [Member] | Interest rate management contract [Member]
Derivative [Line Items]
Total Derivatives, Assets	15.2	17.6
Designated as Hedging Instrument [Member] | Other Receivables [Member] | Forward Exchange Contracts [Member]
Derivative [Line Items]
Total Derivatives, Assets	107.0	52.1
Designated as Hedging Instrument [Member] | Other Noncurrent Assets [Member] | Interest rate management contract [Member]
Derivative [Line Items]
Total Derivatives, Assets	170.2	153.4
Designated as Hedging Instrument [Member] | Other Noncurrent Assets [Member] | Forward Exchange Contracts [Member]
Derivative [Line Items]
Total Derivatives, Assets	39.5	68.5
Designated as Hedging Instrument [Member] | Accrued Liabilities [Member] | Interest rate management contract [Member]
Derivative [Line Items]
Total Derivatives, Liabilities	0.0	0.0
Designated as Hedging Instrument [Member] | Accrued Liabilities [Member] | Forward Exchange Contracts [Member]
Derivative [Line Items]
Total Derivatives, Liabilities	54.9	110.7
Designated as Hedging Instrument [Member] | Other Noncurrent Liabilities [Member] | Interest rate management contract [Member]
Derivative [Line Items]
Total Derivatives, Liabilities	2.3	0.8
Designated as Hedging Instrument [Member] | Other Noncurrent Liabilities [Member] | Forward Exchange Contracts [Member]
Derivative [Line Items]
Total Derivatives, Liabilities	10.9	9.2
Hedges Not Designated [Member]
Derivative [Line Items]
Total Derivatives, Assets	39.5	27.3
Total Derivatives, Liabilities	7.6	4.5
Hedges Not Designated [Member] | Other Receivables [Member] | Interest rate management contract [Member]
Derivative [Line Items]
Total Derivatives, Assets	0.0	0.0
Hedges Not Designated [Member] | Other Receivables [Member] | Forward Exchange Contracts [Member]
Derivative [Line Items]
Total Derivatives, Assets	39.5	3.2
Hedges Not Designated [Member] | Other Noncurrent Assets [Member] | Interest rate management contract [Member]
Derivative [Line Items]
Total Derivatives, Assets	0.0	0.8
Hedges Not Designated [Member] | Other Noncurrent Assets [Member] | Forward Exchange Contracts [Member]
Derivative [Line Items]
Total Derivatives, Assets	0.0	23.3
Hedges Not Designated [Member] | Accrued Liabilities [Member] | Interest rate management contract [Member]
Derivative [Line Items]
Total Derivatives, Liabilities	0.0	0.0
Hedges Not Designated [Member] | Accrued Liabilities [Member] | Forward Exchange Contracts [Member]
Derivative [Line Items]
Total Derivatives, Liabilities	7.6	3.9
Hedges Not Designated [Member] | Other Noncurrent Liabilities [Member] | Interest rate management contract [Member]
Derivative [Line Items]
Total Derivatives, Liabilities	0.0	0.0
Hedges Not Designated [Member] | Other Noncurrent Liabilities [Member] | Forward Exchange Contracts [Member]
Derivative [Line Items]
Total Derivatives, Liabilities	$ 0.0	$ 0.6