Financial Instruments and Risk Management - Derivatives (Details) (USD $) In Millions, unless otherwise specified		3 Months Ended									3 Months Ended												3 Months Ended
	Dec. 31, 2013	Dec. 31, 2013 Not Designated as Hedging Instrument [Member]		Dec. 31, 2012 Not Designated as Hedging Instrument [Member]		Dec. 31, 2013 Not Designated as Hedging Instrument [Member] Share Option [Member]	Dec. 31, 2012 Not Designated as Hedging Instrument [Member] Share Option [Member]	Dec. 31, 2012 Not Designated as Hedging Instrument [Member] Commodity Contract [Member]	Dec. 31, 2013 Not Designated as Hedging Instrument [Member] Foreign Exchange Contract [Member] Contract	Dec. 31, 2012 Not Designated as Hedging Instrument [Member] Foreign Exchange Contract [Member]	Dec. 31, 2013 Sales, General and Administrative [Member] Not Designated as Hedging Instrument [Member] Share Option [Member]	Dec. 31, 2012 Sales, General and Administrative [Member] Not Designated as Hedging Instrument [Member] Share Option [Member]	Sep. 30, 2012 Sales, General and Administrative [Member] Not Designated as Hedging Instrument [Member] Commodity Contract [Member]	Dec. 31, 2013 Other Financing [Member] Not Designated as Hedging Instrument [Member] Foreign Exchange Contract [Member]	Dec. 31, 2012 Other Financing [Member] Not Designated as Hedging Instrument [Member] Foreign Exchange Contract [Member]	Dec. 31, 2013 Cash Flow Hedging [Member] Designated as Hedging Instrument [Member]		Dec. 31, 2012 Cash Flow Hedging [Member] Designated as Hedging Instrument [Member]		Dec. 31, 2013 Cash Flow Hedging [Member] Designated as Hedging Instrument [Member] Foreign Exchange Contract [Member] Contract	Dec. 31, 2012 Cash Flow Hedging [Member] Designated as Hedging Instrument [Member] Foreign Exchange Contract [Member]	Sep. 30, 2013 Cash Flow Hedging [Member] Designated as Hedging Instrument [Member] Foreign Exchange Contract [Member]	Dec. 31, 2012 Cash Flow Hedging [Member] Designated as Hedging Instrument [Member] Interest Rate Swap [Member]	Dec. 31, 2013 Cash Flow Hedging [Member] Other Financing [Member] Designated as Hedging Instrument [Member] Foreign Exchange Contract [Member]	Dec. 31, 2012 Cash Flow Hedging [Member] Other Financing [Member] Designated as Hedging Instrument [Member] Foreign Exchange Contract [Member]	Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 2 [Member] Share Option [Member]	Sep. 30, 2013 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 2 [Member] Share Option [Member]	Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 2 [Member] Foreign Exchange Contract [Member]	Sep. 30, 2013 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 2 [Member] Foreign Exchange Contract [Member]
Derivative [Line Items]
Derivative Asset (Liability) Fair Value		$ 7.0		$ 4.5		$ 0.8	$ 7.7	$ 0	$ 6.2	$ (3.2)						$ 3.8	[1],[2]	$ 1.5	[1],[2]	$ 3.8		$ 1.5	$ 0			$ 0.8	$ 7.7	$ 10.0	$ (1.7)
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred																				3.7
Derivative, Number of Instruments Held									18											78
Derivative, Notional Amount									311											306
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net																4.6	[3]	6.7	[3]	4.6	6.7		0
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net																2.3	[4],[5]	(1.3)	[4],[5]				(0.3)	2.3	(1.0)
Derivative Instruments, Gain (Loss) Recognized in Income, Net		16.2	[6]	2.2	[6]						7.4	3.8	(1.9)	8.8	0.3
Debt, Long-term and Short-term, Combined Amount	$ 2,299.9

[1] All derivative liabilities are presented in other current liabilities or other liabilities.

[2] All derivative assets are presented in other current assets or other assets.

[3] OCI is defined as other comprehensive income.

[4] Gain/(Loss) reclassified to Income was recorded as follows: Foreign currency contracts in Other financing items

[5] Each of these derivative instruments had a high correlation to the underlying exposure being hedged for the periods indicated and had been deemed highly effective in offsetting associated risk.

[6] Gain/(Loss) recognized in Income was recorded as follows: Share option in Selling, general and administrative expense and foreign currency contracts in Other financing items, net.