Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended										12 Months Ended
	Aug. 31, 2012 segments		May 31, 2012	Feb. 29, 2012	Nov. 30, 2011	Aug. 31, 2011		May 31, 2011	Feb. 28, 2011	Nov. 30, 2010	Aug. 31, 2012 customer segments		Aug. 31, 2011 customer		Aug. 31, 2010 customer
Segment Reporting Information [Line Items]
Number of operating and reporting segments	3										3
Total assets	$ 1,763,573					$ 1,890,169					$ 1,763,573		$ 1,890,169
Property, plant and equipment, net	564,185	[1]				555,284	[1]				564,185	[1]	555,284	[1]
Investments in joint venture partnerships	17,126					17,208					17,126		17,208
Revenues from external customers											3,340,938		3,459,194		2,301,240
Depreciation and amortization											82,256		74,866		63,418
Total depreciation and amortization											82,256		74,866		63,228
Capital expenditures											78,560		104,964		64,324
Operating income (Loss)	(1,367)		22,078	17,987	14,970	56,255		55,332	45,937	28,440	53,668		185,964		125,897
Restructuring charges	(5,000)										(5,012)		0		0
Interest expense											(11,880)		(8,436)		(2,343)
Other income, net											1,168		3,277		1,779
Income from continuing operations before income taxes											42,956		180,805		125,333
Income from joint ventures											2,636		4,622		3,135
Foreign											2,284,152		2,471,737		1,570,936
Domestic											1,056,786		987,457		730,304
Total revenues from external customers											3,340,938		3,459,194		2,301,240
Number Of External Customers With More Than 10% of Consolidated Revenue											0		0		0
Metal Recycling Business [Member]
Segment Reporting Information [Line Items]
Total assets	1,696,296	[2]				1,668,778	[2]				1,696,296	[2]	1,668,778	[2]
Investments in joint venture partnerships	17,000					17,000					17,000		17,000
Revenues Including intercompany											2,948,707		3,070,004		1,979,770
Less: Intersegment revenues											(183,906)		(169,331)		(155,310)
Revenues from external customers											2,764,801		2,900,673		1,824,460
Depreciation and amortization											57,855		49,773		38,516
Capital expenditures											60,212		88,917		53,753
Operating income (Loss)											63,872	[3]	164,646	[3]	118,449	[3]
Income from joint ventures											2,000		5,000		3,000
Total revenues from external customers											2,764,801		2,900,673		1,824,460
Auto Parts Business [Member]
Segment Reporting Information [Line Items]
Total assets	329,327					304,060					329,327		304,060
Revenues Including intercompany											316,884		319,833		241,233
Less: Intersegment revenues											(73,974)		(78,795)		(49,538)
Revenues from external customers											242,910		241,038		191,695
Depreciation and amortization											10,920		10,131		7,568
Capital expenditures											7,525		7,099		4,682
Operating income (Loss)											33,304		64,027		51,096
Total revenues from external customers											242,910		241,038		191,695
Steel Manufacturing Business [Member]
Segment Reporting Information [Line Items]
Total assets	322,398					324,596					322,398		324,596
Revenues from external customers											333,227		317,483		285,085
Depreciation and amortization											9,436		10,782		12,879
Capital expenditures											5,556		3,328		3,255
Operating income (Loss)											(2,081)		2,562		(5,862)
Total revenues from external customers											333,227		317,483		285,085
Operating Segments [Member]
Segment Reporting Information [Line Items]
Total assets	2,348,021					2,297,434					2,348,021		2,297,434
Depreciation and amortization											78,211		70,686		58,963
Capital expenditures											73,293		99,344		61,690
Operating income (Loss)											95,095		231,235		163,683
Corporate and elimination [Member]
Segment Reporting Information [Line Items]
Total assets	(584,448)					(407,265)					(584,448)		(407,265)
Depreciation and amortization											4,045		4,180		4,265
Capital expenditures											5,267		5,620		2,634
Operating income (Loss)											(36,415)		(45,271)		(37,786)
Ferrous Scrap Metal [Member]
Segment Reporting Information [Line Items]
Revenues from external customers											2,117,055		2,259,229		1,403,354
Total revenues from external customers											2,117,055		2,259,229		1,403,354
Nonferrous Scrap Metal [Member]
Segment Reporting Information [Line Items]
Revenues from external customers											647,746		641,444		421,106
Total revenues from external customers											647,746		641,444		421,106
Auto Parts [Member]
Segment Reporting Information [Line Items]
Revenues from external customers											242,910		241,038		191,695
Total revenues from external customers											242,910		241,038		191,695
Finished Steel Products [Member]
Segment Reporting Information [Line Items]
Revenues from external customers											332,719		317,338		270,712
Total revenues from external customers											332,719		317,338		270,712
Semi-finished Steel Products [Member]
Segment Reporting Information [Line Items]
Revenues from external customers											508		145		14,373
Total revenues from external customers											508		145		14,373
Canada
Segment Reporting Information [Line Items]
Property, plant and equipment, net	67,000					49,000					67,000		49,000
China
Segment Reporting Information [Line Items]
Foreign											719,979		884,744		487,098
% of Revenue											22.00%		25.60%		21.20%
Turkey
Segment Reporting Information [Line Items]
Foreign											435,558
% of Revenue											13.00%
South Korea
Segment Reporting Information [Line Items]
Foreign											$ 397,525				$ 260,456
% of Revenue											12.00%				11.30%
Customer Concentration Risk [Member]
Segment Reporting Information [Line Items]
Concentration Risk Benchmark Percentage											10.00%		10.00%		10.00%
Geographic Concentration Risk [Member]
Segment Reporting Information [Line Items]
Concentration Risk Benchmark Percentage											10.00%		10.00%		10.00%

[1] Property, plant and equipment, net includes $67 million and $49 million as of August 31, 2012 and 2011, respectively, at our Canadian locations.

[2] MRB total assets include $17 million as of August 31, 2012 and 2011, for investments in joint venture partnerships.

[3] MRB operating income includes $2 million, $5 million and $3 million in income from joint ventures accounted for by the equity method in fiscal 2012, 2011 and 2010, respectively.