Commitments And Contingencies (Litigation And Environmental) (Narrative) (Details) In Millions, unless otherwise specified	6 Months Ended		6 Months Ended	12 Months Ended
	Mar. 31, 2012 Environmental [Member] USD ($)	Sep. 30, 2011 Environmental [Member] USD ($)	Mar. 31, 2012 Brazil Alleged Anticompete [Member] USD ($)	Sep. 30, 2010 Brazil Alleged Anticompete [Member] BRL
Loss Contingencies [Line Items]
Civil fines imposed			$ 98.0	179.2
Maximum of loss contingency range subject to interest			98.0	179.2
Provision for litigation			0
Approximate number of sites on which settlement has not been reached	36
Accrual for environmental loss contingencies	80.2	82.3
Accruals for environmental loss contingencies, maximum payout period, years	30
Accruals for environmental loss contingencies, minimum exposure	80
Accruals for environmental loss contingencies, maximum exposure	$ 94