Derivative Financial Instruments (Details) In Millions, unless otherwise specified	12 Months Ended						12 Months Ended
	Sep. 30, 2012 Cash flow hedges Interest rate swap agreements USD ($)	Sep. 30, 2012 Derivatives designated as hedging instruments Cash flow hedges Interest rate swap agreements USD ($)	Sep. 30, 2012 Derivatives designated as hedging instruments Cash flow hedges Interest rate swap agreements expiring in September 2015 USD ($)	Sep. 30, 2011 Derivatives designated as hedging instruments Cash flow hedges Interest rate swap agreements expiring in September 2015 USD ($)	Sep. 30, 2012 Derivatives designated as hedging instruments Cash flow hedges Interest rate swap agreements expiring in December 2014 USD ($)	Sep. 30, 2012 Derivatives designated as hedging instruments Cash flow hedges Interest rate swap agreements expiring in December 2013 USD ($)	Sep. 30, 2012 Derivatives designated as hedging instruments Cash flow hedges Foreign currency options USD ($)	Sep. 30, 2012 Derivatives designated as hedging instruments Cash flow hedges Foreign currency options BRL	Sep. 30, 2012 Derivatives not designated as hedging instruments Foreign currency forward contracts USD ($)	Sep. 30, 2012 Derivatives not designated as hedging instruments Foreign currency forward contracts BRL	Sep. 30, 2011 Derivatives not designated as hedging instruments Foreign currency forward contracts USD ($)	Sep. 30, 2012 Derivatives not designated as hedging instruments Option contracts USD ($)
Derivative financial instruments
Effective portion of derivatives before tax effect	$ 6.2	$ (8.4)
Effective portion of derivatives expected to be reclassified from accumulated other comprehensive loss to interest expense	2.9
Notional Amount			250.0	250.0	200.0	150.0
Fixed Rate (as a percent)			0.95%	0.95%	0.68%	0.55%
Notional principal of derivative exchange contracts							8.1	16.4	4.9	9.7
Maximum maturity term							24 months	24 months
Notional principal of derivative contracts to purchase U.S. dollars with foreign currencies									60.1
Notional principal of derivative contracts to sell U.S. dollars for foreign currencies									$ 110.2		$ 57.1	$ 17.3