Restructuring Charges and Other Exit-Related Costs Restructuring Charges and Other Exit-Related Costs by Segment (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
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 2,762	$ 1,873	$ 6,014	$ 5,006
Restructuring charges and other exit-related costs	2,762	1,873	6,580	5,006
Total restructuring charges to date			18,932
Total expected restructuring charges			19,200
Restructuring and related cost, including other exit-related costs, cost incurred to date			19,498
Asset impairments [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges and other exit-related costs	0	0	566	0
Other Exit-Related Costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges and other exit-related costs	0	0	566	0
Total restructuring charges to date			566
Metals Recycling Business [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	1,818	997	3,969	1,607
Total restructuring charges to date			8,378
Total expected restructuring charges			8,500
Metals Recycling Business [Member] | Asset impairments [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges and other exit-related costs	0	0	566	0
Total restructuring charges to date			566
Auto Parts Business [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	466	(9)	962	202
Total restructuring charges to date			1,434
Total expected restructuring charges			1,600
Unallocated (Corporate) [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	478	885	1,083	3,197
Total restructuring charges to date			9,120
Total expected restructuring charges			$ 9,100