Segment Information - Segment Revenue and Segment Reconciliation (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Aug. 31, 2014	May 31, 2014	Feb. 28, 2014	Nov. 30, 2013	Aug. 31, 2013	May 31, 2013	Feb. 28, 2013	Nov. 30, 2012	Aug. 31, 2014		Aug. 31, 2013		Aug. 31, 2012
Segment Reporting Information [Line Items]
Revenues									$ 2,543,583		$ 2,621,911		$ 3,340,938
Depreciation and amortization									79,209		83,070		82,256
Capital expenditures									39,147		90,381		78,560
Operating income (loss)	15,728	1,629	6,584	(3,625)	(347,579)	7,187	11,390	1,213	20,316		(327,789)		53,668
Restructuring charges and other exit-related costs									6,967		7,906		5,012
Interest expense									(10,804)		(9,743)		(11,880)
Other income, net									1,223		83		1,168
Income (loss) from continuing operations before income taxes									10,735		(337,449)		42,956
Income from joint ventures									1,196		1,183		2,636
Goodwill impairment charge					321,000				0		321,000		0
Other asset impairment charges					13,000				1,460		13,053		0
Metals Recycling Business
Segment Reporting Information [Line Items]
Revenues									1,914,832		2,032,143		2,764,801
Depreciation and amortization									56,368		58,964		57,855
Capital expenditures									16,881		61,930		60,212
Operating income (loss)									30,083	[1]	(311,549)	[1]	63,872	[1]
Income from joint ventures									1,000		1,000		2,000
Goodwill impairment charge											321,000
Other asset impairment charges											13,000
Auto Parts Business
Segment Reporting Information [Line Items]
Revenues									240,111		237,314		242,910
Depreciation and amortization									11,861		11,793		10,920
Capital expenditures									12,400		12,769		7,525
Operating income (loss)									21,434		24,539		33,304
Goodwill impairment charge											0
Steel Manufacturing Business
Segment Reporting Information [Line Items]
Revenues									388,640		352,454		333,227
Depreciation and amortization									8,256		9,072		9,436
Capital expenditures									5,379		7,582		5,556
Operating income (loss)									18,538		6,541		(2,081)
Operating Segments
Segment Reporting Information [Line Items]
Depreciation and amortization									76,485		79,829		78,211
Capital expenditures									34,660		82,281		73,293
Operating income (loss)									70,055		(280,469)		95,095
Operating Segments | Metals Recycling Business
Segment Reporting Information [Line Items]
Revenues									2,102,935		2,210,484		2,948,707
Operating Segments | Auto Parts Business
Segment Reporting Information [Line Items]
Revenues									327,569		313,306		316,884
Less: Intersegment revenues | Metals Recycling Business
Segment Reporting Information [Line Items]
Revenues									(188,103)		(178,341)		(183,906)
Less: Intersegment revenues | Auto Parts Business
Segment Reporting Information [Line Items]
Revenues									(87,458)		(75,992)		(73,974)
Corporate
Segment Reporting Information [Line Items]
Depreciation and amortization									2,724		3,241		4,045
Capital expenditures									4,487		8,100		5,267
Segment Reconciling Items
Segment Reporting Information [Line Items]
Restructuring charges and other exit-related costs									6,967		7,906		5,012
Corporate and eliminations
Segment Reporting Information [Line Items]
Operating income (loss)									$ (42,772)		$ (39,414)		$ (36,415)

[1] MRB operating income (loss) includes $1 million, $1 million and $2 million in income from joint ventures accounted for by the equity method in fiscal 2014, 2013 and 2012, respectively. The MRB operating loss for fiscal 2013 also includes a goodwill impairment charge of $321 million and other asset impairment charges of $13 million.