Segment Information Segment Operating Income Reconciliation to Consolidated (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	May 31, 2014	May 31, 2013	May 31, 2014	May 31, 2013
Segment Reporting Information [Line Items]
Operating income	$ 1,629	$ 7,187	$ 4,588	$ 19,791
Restructuring charges and other exit-related costs	(2,762)	(1,873)	(6,580)	(5,006)
Interest expense	(2,580)	(2,788)	(8,097)	(7,159)
Other income, net	570	141	604	414
Income (loss) before income taxes	(381)	4,540	(2,905)	13,046
Operating Segments [Member]
Segment Reporting Information [Line Items]
Operating income	15,064	16,990	41,762	54,323
Restructuring charges and other exit-related costs	(2,762)	(1,873)	(6,580)	(5,006)
Operating Segments [Member] | Metals Recycling Business [Member]
Segment Reporting Information [Line Items]
Operating income	3,736	8,789	14,932	28,602
Operating Segments [Member] | Auto Parts Business [Member]
Segment Reporting Information [Line Items]
Operating income	6,734	8,273	16,918	21,348
Operating Segments [Member] | Steel Manufacturing Business [Member]
Segment Reporting Information [Line Items]
Operating income	4,594	(72)	9,912	4,373
Corporate and eliminations [Member]
Segment Reporting Information [Line Items]
Operating income	$ (10,673)	$ (7,930)	$ (30,594)	$ (29,526)