Financial Instruments (Schedule of Outstanding Currency Price Risk Management Instruments) (Details) - Forward Exchange Contracts [Member] - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Sep. 30, 2016
Derivative [Line Items]
US$ Notional	$ 5,663.4	$ 7,746.8
Years Average Maturity	8 months	8 months
Hedges Not Designated [Member]
Derivative [Line Items]
US$ Notional	$ 1,526.1	$ 2,648.3
Years Average Maturity	4 months	5 months
Cash Flow Hedges [Member] | Designated as Hedging Instrument [Member]
Derivative [Line Items]
US$ Notional	$ 3,472.9	$ 4,130.3
Years Average Maturity	6 months	6 months
Net Investment Hedges [Member] | Designated as Hedging Instrument [Member]
Derivative [Line Items]
US$ Notional	$ 664.4	$ 968.2
Years Average Maturity	3 years 2 months	2 years 8 months