Fair Value Measurement (Tables)

9 Months Ended

Jun. 30, 2012

Fair Value Disclosures [Abstract]

Financial assets and financial liabilities that are measured at fair value on a recurring basis

The following table presents our financial assets and financial liabilities that are measured at fair value on a recurring basis for each of the fair value hierarchy levels, including both current and noncurrent portions, as of June 30, 2012, September 30, 2011 and June 30, 2011:

	Asset (Liability)
	Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1)			Significant Other Observable Inputs (Level 2)			Unobservable Inputs (Level 3)		Total
June 30, 2012:
Assets:
Derivative financial instruments:
Commodity contracts	$	5.1		$	12.3		$	—	$	17.4
Foreign currency contracts	$	—		$	7.1		$	—	$	7.1
Liabilities:
Derivative financial instruments:
Commodity contracts	$	(18.0	)	$	(102.0	)	$	—	$	(120.0	)
Interest rate contracts	$	—		$	(67.0	)	$	—	$	(67.0	)
September 30, 2011:
Assets:
Derivative financial instruments:
Commodity contracts	$	3.5		$	3.3		$	—	$	6.8
Foreign currency contracts	$	—		$	5.3		$	—	$	5.3
Liabilities:
Derivative financial instruments:
Commodity contracts	$	(28.1	)	$	(16.1	)	$	—	$	(44.2	)
Foreign currency contracts	$	—		$	(3.3	)	$	—	$	(3.3	)
Interest rate contracts	$	—		$	(44.4	)	$	—	$	(44.4	)
June 30, 2011:
Assets:
Derivative financial instruments:
Commodity contracts	$	0.6		$	10.1		$	—	$	10.7
Foreign currency contracts	$	—		$	—		$	—	$	—
Interest rate contracts	$	—		$	5.0		$	—	$	5.0
Liabilities:
Derivative financial instruments:
Commodity contracts	$	(12.2	)	$	(11.6	)	$	—	$	(23.8	)
Foreign currency contracts	$	—		$	(6.1	)	$	—	$	(6.1	)
Interest rate contracts	$	—		$	(3.6	)	$	—	$	(3.6	)