Fair Value Measurement (Details) (Fair Value, Measurements, Recurring [Member], USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Commodity contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments, assets	$ 23.3	$ 13.1
Derivative financial instruments, liabilities	(16.0)	(61.0)
Foreign currency contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments, assets	0.9	1.8
Derivative financial instruments, liabilities	(7.2)
Interest rate contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments, liabilities	(31.0)	(71.9)
Cross Currency Interest Rate Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments, liabilities	(1.2)
Fair Value, Inputs, Level 1 [Member] | Commodity contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments, assets	2.1	8.6
Derivative financial instruments, liabilities	(9.7)	(7.8)
Fair Value, Inputs, Level 1 [Member] | Foreign currency contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments, assets	0	0
Derivative financial instruments, liabilities	0
Fair Value, Inputs, Level 1 [Member] | Interest rate contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments, liabilities	0	0
Fair Value, Inputs, Level 1 [Member] | Cross Currency Interest Rate Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments, liabilities	0
Fair Value, Inputs, Level 2 [Member] | Commodity contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments, assets	21.2	4.5
Derivative financial instruments, liabilities	(6.3)	(53.2)
Fair Value, Inputs, Level 2 [Member] | Foreign currency contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments, assets	0.9	1.8
Derivative financial instruments, liabilities	(7.2)
Fair Value, Inputs, Level 2 [Member] | Interest rate contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments, liabilities	(31.0)	(71.9)
Fair Value, Inputs, Level 2 [Member] | Cross Currency Interest Rate Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments, liabilities	(1.2)
Fair Value, Inputs, Level 3 [Member] | Commodity contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments, assets	0	0
Derivative financial instruments, liabilities	0	0
Fair Value, Inputs, Level 3 [Member] | Foreign currency contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments, assets	0	0
Derivative financial instruments, liabilities	0
Fair Value, Inputs, Level 3 [Member] | Interest rate contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments, liabilities	0	0
Fair Value, Inputs, Level 3 [Member] | Cross Currency Interest Rate Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments, liabilities	$ 0