Financial Instruments (Schedule of Gain/Loss Related to Derivative Instruments) (Details) - USD ($) $ in Millions		12 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Derivative [Line Items]
Interest expense		$ 103.5	$ 125.1	$ 141.8
Other (income) expense, net		(47.3)	(52.8)	(70.2)
Reclassification Out Of Accumulated Other Comprehensive Income [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Derivative [Line Items]
Interest expense		3.3	(1.1)	0.3
Other (income) expense, net		16.9	(8.7)	$ (21.5)
Cash Flow Hedges [Member]
Derivative [Line Items]
Net gain (loss) recognized in OCI (effective portion)		(35.0)	(15.2)
Net (gain) loss reclassified from OCI to sales/cost of sales (effective portion)		0.6	0.7
Net (gain) loss reclassified from OCI to other income (expense), net (effective portion)		15.4	(7.8)
Net (gain) loss reclassified from OCI to interest expense (effective portion)		3.3	(1.1)
Net (gain) loss reclassified from OCI to other income (expense), net (ineffective portion)		1.5	(0.9)
Cash Flow Hedges [Member] | Forward Exchange Contracts [Member]
Derivative [Line Items]
Net gain (loss) recognized in OCI (effective portion)		(44.9)	(4.5)
Net (gain) loss reclassified from OCI to sales/cost of sales (effective portion)		0.6	0.7
Net (gain) loss reclassified from OCI to other income (expense), net (effective portion)		35.6	1.7
Net (gain) loss reclassified from OCI to interest expense (effective portion)		0.7	(1.4)
Net (gain) loss reclassified from OCI to other income (expense), net (ineffective portion)		1.5	(0.9)
Cash Flow Hedges [Member] | Other Contracts [Member]
Derivative [Line Items]
Net gain (loss) recognized in OCI (effective portion)	[1]	9.9	(10.7)
Net (gain) loss reclassified from OCI to sales/cost of sales (effective portion)	[1]	0.0	0.0
Net (gain) loss reclassified from OCI to other income (expense), net (effective portion)	[1]	(20.2)	(9.5)
Net (gain) loss reclassified from OCI to interest expense (effective portion)	[1]	2.6	0.3
Net (gain) loss reclassified from OCI to other income (expense), net (ineffective portion)	[1]	0.0	0.0
Fair Value Hedges [Member]
Derivative [Line Items]
Net (gain) loss recognized in interest expense	[2]	9.9	(5.0)
Fair Value Hedges [Member] | Forward Exchange Contracts [Member]
Derivative [Line Items]
Net (gain) loss recognized in interest expense	[2]	0.0	0.0
Fair Value Hedges [Member] | Other Contracts [Member]
Derivative [Line Items]
Net (gain) loss recognized in interest expense	[1],[2]	9.9	(5.0)
Net Investment Hedges [Member]
Derivative [Line Items]
Net gain (loss) recognized in OCI		201.0	85.6
Net Investment Hedges [Member] | Forward Exchange Contracts [Member]
Derivative [Line Items]
Net gain (loss) recognized in OCI		60.1	17.1
Net Investment Hedges [Member] | Foreign Currency Debt [Member]
Derivative [Line Items]
Net gain (loss) recognized in OCI		91.4	51.5
Net Investment Hedges [Member] | Other Contracts [Member]
Derivative [Line Items]
Net gain (loss) recognized in OCI	[1]	49.5	17.0
Hedges Not Designated [Member]
Derivative [Line Items]
Net gain (loss) recognized in net income (loss)	[3]	(6.7)	(5.7)
Hedges Not Designated [Member] | Forward Exchange Contracts [Member]
Derivative [Line Items]
Net gain (loss) recognized in net income (loss)	[3]	(7.3)	(7.2)
Hedges Not Designated [Member] | Other Contracts [Member]
Derivative [Line Items]
Net gain (loss) recognized in net income (loss)	[1],[3]	$ 0.6	$ 1.5

[1] Other includes the impact on other comprehensive income (OCI) and earnings primarily related to interest rate swaps.

[2] The impact of fair value hedges noted above was largely offset by gains and losses resulting from the impact of changes in related interest rates on recognized outstanding debt.

[3] The impact of the non-designated hedges noted above was largely offset by gains and losses resulting from the impact of changes in exchange rates on recognized assets and liabilities denominated in nonfunctional currencies.