Fair Value Measurement (Tables)

9 Months Ended

Jun. 30, 2013

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, 2013, September 30, 2012 and June 30, 2012:

	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, 2013:
Assets:
Derivative financial instruments:
Commodity contracts	$	2.2		$	7.4		$	—	$	9.6
Foreign currency contracts	$	—		$	1.0		$	—	$	1.0
Interest rate contracts	$	—		$	8.1		$	—	$	8.1
Liabilities:
Derivative financial instruments:
Commodity contracts	$	(8.0	)	$	(24.1	)	$	—	$	(32.1	)
Foreign currency contracts	$	—		$	(1.7	)	$	—	$	(1.7	)
Interest rate contracts	$	—		$	(46.9	)	$	—	$	(46.9	)
September 30, 2012:
Assets:
Derivative financial instruments:
Commodity contracts	$	8.6		$	4.5		$	—	$	13.1
Foreign currency contracts	$	—		$	1.8		$	—	$	1.8
Liabilities:
Derivative financial instruments:
Commodity contracts	$	(7.8	)	$	(53.2	)	$	—	$	(61.0	)
Interest rate contracts	$	—		$	(71.9	)	$	—	$	(71.9	)
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	)