Restructuring Charges and Other Exit-Related Costs Restructuring Costs and Other Exit-Related Costs by Segment (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Aug. 31, 2013	Aug. 31, 2014	Aug. 31, 2013	Aug. 31, 2012
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 3,000	$ 6,401	$ 7,906	$ 5,012
Restructuring charges and other exit-related costs		6,967	7,906	5,012
Total restructuring charges to date		19,319
Total expected restructuring charges		19,750
Total Charges to Date		19,885
Asset impairments
Restructuring Cost and Reserve [Line Items]
Restructuring charges and other exit-related costs		566	0	0
Total exit-related costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges and other exit-related costs		566	0	0
Total restructuring charges to date		566
Metals Recycling Business
Restructuring Cost and Reserve [Line Items]
Restructuring charges		4,271	2,748	1,660
Total restructuring charges to date		8,679
Total expected restructuring charges		9,050
Metals Recycling Business | Asset impairments
Restructuring Cost and Reserve [Line Items]
Restructuring charges and other exit-related costs		566	0	0
Total restructuring charges to date		566
Auto Parts Business
Restructuring Cost and Reserve [Line Items]
Restructuring charges		1,057	239	233
Total restructuring charges to date		1,529
Total expected restructuring charges		1,550
Unallocated (Corporate)
Restructuring Cost and Reserve [Line Items]
Restructuring charges		1,073	4,919	3,119
Total restructuring charges to date		9,111
Total expected restructuring charges		$ 9,150