Segment Information Segment Operating Income Reconciliation to Consolidated (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Feb. 28, 2014	Feb. 28, 2013	Feb. 28, 2014	Feb. 28, 2013
Segment Reporting Information [Line Items]
Operating income	$ 6,584	$ 11,390	$ 2,957	$ 12,604
Restructuring charges and other exit-related costs	(2,006)	(1,540)	(3,819)	(3,133)
Interest expense	(2,816)	(2,354)	(5,517)	(4,371)
Other income (expense), net	(142)	(49)	33	271
Income (loss) before income taxes	3,626	8,987	(2,527)	8,504
Operating Segments [Member]
Segment Reporting Information [Line Items]
Operating income	18,753	21,910	26,697	37,332
Restructuring charges and other exit-related costs	(2,006)	(1,540)	(3,819)	(3,133)
Operating Segments [Member] | Metals Recycling Business [Member]
Segment Reporting Information [Line Items]
Operating income	10,605	14,158	11,195	19,812
Operating Segments [Member] | Auto Parts Business [Member]
Segment Reporting Information [Line Items]
Operating income	4,575	6,711	10,184	13,075
Operating Segments [Member] | Steel Manufacturing Business [Member]
Segment Reporting Information [Line Items]
Operating income	3,573	1,041	5,318	4,445
Corporate and eliminations [Member]
Segment Reporting Information [Line Items]
Operating income	$ (10,163)	$ (8,980)	$ (19,921)	$ (21,595)