Fair Value Measurements (Tables)

12 Months Ended

Sep. 30, 2014

Fair Value Disclosures [Abstract]

Financial Assets and Financial Liabilities at Fair Value

The following table presents on a gross basis our financial assets and liabilities including both current and noncurrent portions, that are measured at fair value on a recurring basis within the fair value hierarchy as described in Note 2, as of September 30, 2014 and 2013:

	Asset (Liability)
	Level 1		Level 2			Level 3		Total
September 30, 2014:
Derivative instruments:
Assets:
Commodity contracts	$	—	$	3,065		$	—	$	3,065
Liabilities:
Commodity contracts	$	—	$	(9,472	)	$	—	$	(9,472	)
September 30, 2013 (a):
Derivative instruments:
Assets:
Commodity contracts	$	—	$	19,621		$	—	$	19,621
Liabilities:
Commodity contracts	$	—	$	(1,504	)	$	—	$	(1,504	)

(a) Certain immaterial amounts have been revised to correct the classification of derivatives.