Segment Information - Segment Revenue and Segment Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended									12 Months Ended
	Aug. 31, 2015	May. 31, 2015	Feb. 28, 2015	Nov. 30, 2014	Aug. 31, 2014	May. 31, 2014	Feb. 28, 2014	Nov. 30, 2013	Feb. 28, 2013	Aug. 31, 2015	Aug. 31, 2014	Aug. 31, 2013
Segment Reporting Information [Line Items]
Revenues	$ 457,017	$ 467,309	$ 437,449	$ 553,624	$ 689,763	$ 635,472	$ 624,045	$ 585,646		$ 1,915,399	$ 2,534,926	$ 2,616,792
Depreciation and amortization										67,936	79,209	83,070
Capital expenditures										32,297	39,147	90,381
Operating income (loss)	$ 8,717	$ (4,020)	(201,011)	$ 785	$ 16,576	$ 2,597	$ 7,723	$ (2,532)		(195,529)	24,364	(323,178)
Restructuring charges and other exit-related costs										13,008	6,830	7,906
Interest expense										(9,191)	(10,597)	(9,623)
Other income, net										4,256	1,215	77
Income (loss) from continuing operations before income taxes										(200,464)	14,982	(332,724)
Income from joint ventures										1,490	1,196	1,183
Goodwill impairment charges			141,000						$ 0	141,021	0	321,000
Other asset impairment charges			$ 44,000							45,119	1,460	13,053
Continuing Operations
Segment Reporting Information [Line Items]
Depreciation and amortization										67,115	77,874	82,209
Capital expenditures										32,297	39,147	90,381
Operating income (loss)										(195,529)	24,364	(323,178)
Interest expense										(9,191)	(10,597)	(9,623)
Other income, net										4,256	1,215	77
Income (loss) from continuing operations before income taxes										(200,464)	14,982	(332,724)
Auto and Metals Recycling
Segment Reporting Information [Line Items]
Revenues										1,540,362	2,146,286	2,264,338
Income from joint ventures										2,000	1,000	1,000
Goodwill impairment charges										141,021	0	321,000
Other asset impairment charges										44,000	1,000	13,000
Auto and Metals Recycling | Continuing Operations
Segment Reporting Information [Line Items]
Operating income (loss)										(164,031)	55,089	(281,812)
Steel Manufacturing Business
Segment Reporting Information [Line Items]
Revenues										375,037	388,640	352,454
Steel Manufacturing Business | Continuing Operations
Segment Reporting Information [Line Items]
Operating income (loss)										20,378	18,538	6,541
Operating Segments | Continuing Operations
Segment Reporting Information [Line Items]
Depreciation and amortization										64,290	75,150	78,968
Capital expenditures										29,661	34,660	82,281
Operating income (loss)										(143,653)	73,627	(275,271)
Operating Segments | Auto and Metals Recycling
Segment Reporting Information [Line Items]
Revenues										1,716,296	2,334,389	2,442,679
Operating Segments | Auto and Metals Recycling | Continuing Operations
Segment Reporting Information [Line Items]
Depreciation and amortization										56,767	66,894	69,896
Capital expenditures										22,762	29,281	74,699
Operating Segments | Steel Manufacturing Business | Continuing Operations
Segment Reporting Information [Line Items]
Depreciation and amortization										7,523	8,256	9,072
Capital expenditures										6,899	5,379	7,582
Less: Intersegment revenues | Auto and Metals Recycling
Segment Reporting Information [Line Items]
Revenues										(175,934)	(188,103)	(178,341)
Corporate | Continuing Operations
Segment Reporting Information [Line Items]
Depreciation and amortization										2,825	2,724	3,241
Capital expenditures										2,636	4,487	8,100
Segment Reconciling Items | Continuing Operations
Segment Reporting Information [Line Items]
Restructuring charges and other exit-related costs										13,008	6,830	7,906
Corporate and eliminations | Continuing Operations
Segment Reporting Information [Line Items]
Operating income (loss)										$ (38,868)	$ (42,433)	$ (40,001)