Commitments and Contingencies (Details) (USD $)	3 Months Ended		3 Months Ended						0 Months Ended		0 Months Ended
	Nov. 30, 2012	Aug. 31, 2012	Nov. 30, 2012 Metal Recycling Business [Member]	Nov. 30, 2012 Auto Parts Business [Member]	Nov. 30, 2012 Steel Manufacturing Business [Member] T	Nov. 30, 2012 Portland Harbor Superfund Site [Member]	Mar. 30, 2012 Portland Harbor Superfund Site [Member] alternatives	Nov. 30, 2012 Other Metals Recycling Business Sites [Member]	Mar. 30, 2012 Minimum [Member] Portland Harbor Superfund Site [Member]	Nov. 30, 2012 Minimum [Member] Portland Harbor Superfund Site [Member] potentially_responsible_party	Mar. 30, 2012 Maximum [Member] Portland Harbor Superfund Site [Member]	Mar. 30, 2012 Lower Willamette Group [Member] Portland Harbor Superfund Site [Member]	Mar. 30, 2012 Potential Responsible Parties [Member] Minimum [Member] Portland Harbor Superfund Site [Member]	Mar. 30, 2012 Potential Responsible Parties [Member] Maximum [Member] Portland Harbor Superfund Site [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	$ 47,059,000		$ 30,859,000	$ 16,200,000	$ 0	$ 1,000,000		$ 30,000,000
Liabilities Established (Released), Net	265,000		165,000	100,000
Payments and Other	(124,000)		(124,000)	0
Ending balance	47,200,000		30,900,000	16,300,000	0	1,000,000		30,000,000
Short-Term	2,261,000	2,185,000	1,707,000	554,000
Long-Term	44,939,000	44,874,000	29,193,000	15,746,000
Number Of Potentially Responsible Parties										80
Site Contingency Number of Years For Feasibility Study												10 years
Feasibiility Study Investigation Costs												100,000,000
Site Contingency Number of Remedial Alternatives							10
Site Contingency Least Costly Remediation Plan													170,000,000	250,000,000
Site Contingency Most Costly Remediation Plan													$ 1,080,000,000	$ 1,760,000,000
Site Contingency, Estimated Time Frame to Remediate									2 years		28 years
Annual production capacity (in tons)					950,000