Derivative Instruments and Hedging Activities - Effects of Derivative Instruments on Condensed Consolidated Statements of Income and Changes in AOCI and Noncontrolling Interest (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Not Designated as Hedging Instruments
Derivative Instruments, Gain (Loss)
Gain or (loss) recognized in income	$ (36.3)	$ 8.9	$ 0.8
Cash Flow Hedges
Derivative Instruments, Gain (Loss)
Derivative instruments gain loss recognized in accumulated other comprehensive income and noncontrolling interests	66.1	21.7	(135.3)
Derivative instruments gain loss reclassified from accumulated other comprehensive income and noncontrolling interest into income	47.3	(63.8)	(70.8)
Commodity Contracts | Not Designated as Hedging Instruments | Cost of Sales
Derivative Instruments, Gain (Loss)
Gain or (loss) recognized in income	(36.3)	9.3	0.1
Commodity Contracts | Not Designated as Hedging Instruments | Operating and Administrative Expenses/Other Income
Derivative Instruments, Gain (Loss)
Gain or (loss) recognized in income	0	0	0.2
Commodity Contracts | Cash Flow Hedges
Derivative Instruments, Gain (Loss)
Derivative instruments gain loss recognized in accumulated other comprehensive income and noncontrolling interests	50.8	8.3	(98.0)
Commodity Contracts | Cash Flow Hedges | Cost of Sales
Derivative Instruments, Gain (Loss)
Derivative instruments gain loss reclassified from accumulated other comprehensive income and noncontrolling interest into income	67.0	(49.5)	(61.4)
Foreign Currency Contracts | Not Designated as Hedging Instruments | Other income, net
Derivative Instruments, Gain (Loss)
Gain or (loss) recognized in income	0	(0.4)	0.5
Foreign Currency Contracts | Cash Flow Hedges
Derivative Instruments, Gain (Loss)
Derivative instruments gain loss recognized in accumulated other comprehensive income and noncontrolling interests	15.3	(8.3)	(0.5)
Foreign Currency Contracts | Cash Flow Hedges | Cost of Sales
Derivative Instruments, Gain (Loss)
Derivative instruments gain loss reclassified from accumulated other comprehensive income and noncontrolling interest into income	(3.7)	(0.1)	2.1
Foreign Currency Contracts | Net Investment Hedges
Derivative Instruments, Gain (Loss)
Derivative instruments gain loss recognized in accumulated other comprehensive income and noncontrolling interests	0	0	0.6
Cross Currency Contracts | Cash Flow Hedges
Derivative Instruments, Gain (Loss)
Derivative instruments gain loss recognized in accumulated other comprehensive income and noncontrolling interests	3.1	(1.2)	0
Cross Currency Contracts | Cash Flow Hedges | Interest Expense/Other Income
Derivative Instruments, Gain (Loss)
Derivative instruments gain loss reclassified from accumulated other comprehensive income and noncontrolling interest into income	(0.1)	0	0
Interest Rate Contracts | Cash Flow Hedges
Derivative Instruments, Gain (Loss)
Derivative instruments gain loss recognized in accumulated other comprehensive income and noncontrolling interests	(3.1)	22.9	(36.8)
Interest Rate Contracts | Cash Flow Hedges | Interest expense/other income, net [Member]
Derivative Instruments, Gain (Loss)
Derivative instruments gain loss reclassified from accumulated other comprehensive income and noncontrolling interest into income	$ (15.9)	$ (14.2)	$ (11.5)