Financial Instruments (Schedule Of Outstanding Currency Price Risk Management Instruments) (Details) (Forward Exchange Contracts [Member], USD $) In Millions, unless otherwise specified	6 Months Ended	12 Months Ended
	Mar. 31, 2012 Y	Sep. 30, 2011 Y
Derivative [Line Items]
US$ Notional	$ 2,683.5	$ 2,374.2
Years Average Maturity	0.6	0.8
Cash Flow Hedges [Member]
Derivative [Line Items]
US$ Notional	1,456.1	1,512.1
Years Average Maturity	0.5	0.4
Net Investment Hedges [Member]
Derivative [Line Items]
US$ Notional	928.7	635.8
Years Average Maturity	1.0	2.0
Not Designated [Member]
Derivative [Line Items]
US$ Notional	$ 298.7	$ 226.3
Years Average Maturity	0.1	0.1