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	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Designated as Hedging Instruments | Cash Flow Hedges
Derivative Instruments, Gain (Loss)
Derivative instruments gain loss recognized in accumulated other comprehensive income and noncontrolling interests	$ 24.8	$ 66.1	$ 21.7
Derivative instruments gain loss reclassified from accumulated other comprehensive income and noncontrolling interest into income	(4.4)	47.3	(63.8)
Designated as Hedging Instruments | Cash Flow Hedges | Commodity Contracts
Derivative Instruments, Gain (Loss)
Derivative instruments gain loss recognized in accumulated other comprehensive income and noncontrolling interests	0.0	50.8	8.3
Designated as Hedging Instruments | Cash Flow Hedges | Commodity Contracts | Cost of Sales
Derivative Instruments, Gain (Loss)
Derivative instruments gain loss reclassified from accumulated other comprehensive income and noncontrolling interest into income	(2.2)	67.0	(49.5)
Designated as Hedging Instruments | Cash Flow Hedges | Foreign Currency Contracts
Derivative Instruments, Gain (Loss)
Derivative instruments gain loss recognized in accumulated other comprehensive income and noncontrolling interests	26.0	15.3	(8.3)
Designated as Hedging Instruments | Cash Flow Hedges | Foreign Currency Contracts | Cost of Sales
Derivative Instruments, Gain (Loss)
Derivative instruments gain loss reclassified from accumulated other comprehensive income and noncontrolling interest into income	9.7	(3.7)	(0.1)
Designated as Hedging Instruments | Cash Flow Hedges | Cross Currency Contracts
Derivative Instruments, Gain (Loss)
Derivative instruments gain loss recognized in accumulated other comprehensive income and noncontrolling interests	5.4	3.1	(1.2)
Designated as Hedging Instruments | Cash Flow Hedges | Cross Currency Contracts | Interest Expense
Derivative Instruments, Gain (Loss)
Derivative instruments gain loss reclassified from accumulated other comprehensive income and noncontrolling interest into income	8.5	(0.1)	0.0
Designated as Hedging Instruments | Cash Flow Hedges | Interest Rate Contracts
Derivative Instruments, Gain (Loss)
Derivative instruments gain loss recognized in accumulated other comprehensive income and noncontrolling interests	(6.6)	(3.1)	22.9
Designated as Hedging Instruments | Cash Flow Hedges | Interest Rate Contracts | Interest Expense / Other Income, Net
Derivative Instruments, Gain (Loss)
Derivative instruments gain loss reclassified from accumulated other comprehensive income and noncontrolling interest into income	(20.4)	(15.9)	(14.2)
Not Designated as Hedging Instruments
Derivative Instruments, Gain (Loss)
Gain or (loss) recognized in income	(376.3)	(36.3)	8.9
Not Designated as Hedging Instruments | Commodity Contracts | Cost of Sales
Derivative Instruments, Gain (Loss)
Gain or (loss) recognized in income	(375.8)	(36.3)	9.3
Not Designated as Hedging Instruments | Commodity Contracts | Revenues
Derivative Instruments, Gain (Loss)
Gain or (loss) recognized in income	0.3	0.0	0.0
Not Designated as Hedging Instruments | Commodity Contracts | Operating and Administrative Expenses / Other Income, Net
Derivative Instruments, Gain (Loss)
Gain or (loss) recognized in income	(0.8)	$ 0.0
Not Designated as Hedging Instruments | Foreign Currency Contracts | Other Income, Net
Derivative Instruments, Gain (Loss)
Gain or (loss) recognized in income	$ 0.0		$ (0.4)