Commitments and Contingencies Contingencies Environmental (Details) (USD $)	12 Months Ended
	Aug. 31, 2011		Aug. 31, 2010
Loss Contingencies [Line Items]
Balance	$ 39,874,000		$ 41,908,000
Reserves Established (Released), Net	1,740,000	[1]	(1,090,000)	[2]
Payments	(759,000)		(944,000)
Ending Balance	40,855,000		39,874,000
Short-Term	2,983,000		2,588,000
Long-Term	37,872,000		37,286,000
Maximum [Member] | Auto Parts Business [Member]
Loss Contingencies [Line Items]
Environmental reserve per site	2,000,000
Maximum [Member] | Other Metals Recycling Business Sites [Member]
Loss Contingencies [Line Items]
Environmental reserve per site	2,000,000
Metal Recycling Business [Member]
Loss Contingencies [Line Items]
Balance	25,374,000		25,608,000
Reserves Established (Released), Net	1,040,000	[1]	710,000	[2]
Payments	(759,000)		(944,000)
Ending Balance	25,655,000		25,374,000
Short-Term	2,429,000
Long-Term	23,226,000
Auto Parts Business [Member]
Loss Contingencies [Line Items]
Balance	14,500,000		16,300,000
Reserves Established (Released), Net	700,000	[1]	(1,800,000)	[2]
Payments	0		0
Ending Balance	15,200,000		14,500,000
Short-Term	554,000
Long-Term	14,646,000
Steel Manufacturing Business [Member]
Loss Contingencies [Line Items]
Ending Balance	0
Annual production capacity (in tons)	950
Discontinued Operation or Asset Disposal [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Increase (Decrease) for Acquisitions and Divestitures			(2,000,000)
Acquisition [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Increase (Decrease) for Acquisitions and Divestitures	1,000,000		1,000,000
Portland Harbor Superfund Site [Member]
Loss Contingencies [Line Items]
Ending Balance	1,000,000		1,000,000
Number of Potentially Responsible Parties	80
Other Metals Recycling Business Sites [Member]
Loss Contingencies [Line Items]
Ending Balance	$ 25,000,000

[1] During fiscal 2011, the Company recorded $1 million in environmental liabilities in purchase accounting related to acquisitions completed in fiscal 2011.

[2] During fiscal 2010, the Company released $2 million in environmental reserves through discontinued operations related to the full-service auto parts operation, which was partially offset by $1 million in environmental liabilities recorded in purchase accounting.