Derivative Financial Instruments (Details 2) (USD $) In Millions, unless otherwise specified			9 Months Ended	3 Months Ended	9 Months Ended			3 Months Ended		9 Months Ended						3 Months Ended		9 Months Ended		3 Months Ended	9 Months Ended			3 Months Ended		9 Months Ended
	Jun. 30, 2013	Sep. 30, 2012	Jun. 30, 2013 Interest rate swap agreements Cash flow hedges	Jun. 30, 2013 Derivatives designated as hedging instruments Foreign currency options Cash flow hedges	Jun. 30, 2013 Derivatives designated as hedging instruments Foreign currency options Cash flow hedges	Jun. 30, 2013 Derivatives designated as hedging instruments Foreign currency options Prepaid expenses and other current assets	Sep. 30, 2012 Derivatives designated as hedging instruments Foreign currency options Prepaid expenses and other current assets	Jun. 30, 2013 Derivatives designated as hedging instruments Interest rate swap agreements Cash flow hedges	Jun. 30, 2012 Derivatives designated as hedging instruments Interest rate swap agreements Cash flow hedges	Jun. 30, 2013 Derivatives designated as hedging instruments Interest rate swap agreements Cash flow hedges	Jun. 30, 2012 Derivatives designated as hedging instruments Interest rate swap agreements Cash flow hedges	Jun. 30, 2013 Derivatives designated as hedging instruments Interest rate swap agreements Accrued expenses and other current liabilities	Sep. 30, 2012 Derivatives designated as hedging instruments Interest rate swap agreements Accrued expenses and other current liabilities	Jun. 30, 2013 Derivatives designated as hedging instruments Interest rate swap agreements Other long-term liabilities	Sep. 30, 2012 Derivatives designated as hedging instruments Interest rate swap agreements Other long-term liabilities	Jun. 30, 2013 Derivatives not designated as hedging instruments	Jun. 30, 2012 Derivatives not designated as hedging instruments	Jun. 30, 2013 Derivatives not designated as hedging instruments	Jun. 30, 2012 Derivatives not designated as hedging instruments	Jun. 30, 2013 Derivatives not designated as hedging instruments Option contracts Other income (expense)	Jun. 30, 2013 Derivatives not designated as hedging instruments Option contracts Other income (expense)	Jun. 30, 2013 Derivatives not designated as hedging instruments Option contracts Prepaid expenses and other current assets	Sep. 30, 2012 Derivatives not designated as hedging instruments Option contracts Prepaid expenses and other current assets	Jun. 30, 2013 Derivatives not designated as hedging instruments Foreign currency forward contracts General and administrative expenses	Jun. 30, 2012 Derivatives not designated as hedging instruments Foreign currency forward contracts General and administrative expenses	Jun. 30, 2013 Derivatives not designated as hedging instruments Foreign currency forward contracts General and administrative expenses	Jun. 30, 2012 Derivatives not designated as hedging instruments Foreign currency forward contracts General and administrative expenses	Jun. 30, 2013 Derivatives not designated as hedging instruments Foreign currency forward contracts Prepaid expenses and other current assets	Sep. 30, 2012 Derivatives not designated as hedging instruments Foreign currency forward contracts Prepaid expenses and other current assets	Jun. 30, 2013 Derivatives not designated as hedging instruments Foreign currency forward contracts Accrued expenses and other current liabilities	Sep. 30, 2012 Derivatives not designated as hedging instruments Foreign currency forward contracts Accrued expenses and other current liabilities
Fair values of outstanding derivative instruments
Derivative assets	$ 5.3	$ 0.6				$ 0.1	$ 0.1															$ 0.2	$ 0.1					$ 5.0	$ 0.4
Derivative liabilities	8.7	6.7										2.6	2.9	0.9	3.2															5.2	0.6
Effect of derivative instruments on income and other comprehensive income
Decrease /(Increase) in Losses Recognized in Accumulated Other Comprehensive Loss on Derivatives Before Tax Effect (Effective Portion)			3.5		0.1			0.4	(2.9)	0.4	(5.8)
Losses Reclassified from Accumulated Other Comprehensive Loss into Income (Effective Portion)					0			(0.8)	(0.6)	(2.3)	(1.6)
Gains /(Losses) Recognized in Income on Derivatives (Amount Excluded from Effectiveness Testing and Ineffective Portion)				0.1	0			0
Non designated derivatives, Gains/(Losses) Recognized in Income on Derivatives (Amount Excluded from Effectiveness Testing and Ineffective Portion)																$ (3.9)	$ 0.1	$ (4.2)	$ 2.8	$ 0.1	$ (0.3)			$ (4.0)	$ 0.1	$ (3.9)	$ 2.8