Restructuring Charges and Other Exit-Related Costs Restructuring Charges and Other Exit-Related Costs by Segment (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Feb. 29, 2016	Feb. 28, 2015	Feb. 29, 2016	Feb. 28, 2015
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	$ 3,232	$ 2,019	$ 5,128	$ 2,642
Total restructuring charges and other exit-related costs	6,240	8,371	8,136	8,994
Total charges to date	21,512		21,512
Total expected charges	21,971		21,971
Total restructuring charges and other exit-related costs, incurred to date	31,588		31,588
Other exit-related costs
Restructuring Cost and Reserve [Line Items]
Other exit-related costs	3,008	6,352	3,008	6,352
Other Exit-Related Costs
Restructuring Cost and Reserve [Line Items]
Other exit-related costs	3,008	6,352	3,008	6,352
Auto and Metals Recycling
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	2,421	1,645	4,343	2,244
Auto and Metals Recycling | Other exit-related costs
Restructuring Cost and Reserve [Line Items]
Other exit-related costs	2,061	3,686	2,061	3,686
Operating Segments | Auto and Metals Recycling
Restructuring Cost and Reserve [Line Items]
Total charges to date	15,141		15,141
Total expected charges	15,593		15,593
Operating Segments | Auto and Metals Recycling | Other exit-related costs
Restructuring Cost and Reserve [Line Items]
Total restructuring charges and other exit-related costs, incurred to date	6,463		6,463
Unallocated (Corporate)
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	809	63	812	57
Total charges to date	4,819		4,819
Total expected charges	4,826		4,826
Segment Reconciling Items | Other Exit-Related Costs
Restructuring Cost and Reserve [Line Items]
Other exit-related costs	3,008	6,352	3,008	6,352
Total restructuring charges and other exit-related costs, incurred to date	10,076		10,076
Discontinued Operations | Segment Reconciling Items
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	2	311	(27)	341
Total restructuring charges and other exit-related costs	949	2,977	920	3,007
Total charges to date	1,552		1,552
Total expected charges	1,552		1,552
Discontinued Operations | Segment Reconciling Items | Other exit-related costs
Restructuring Cost and Reserve [Line Items]
Other exit-related costs	947	$ 2,666	947	$ 2,666
Total restructuring charges and other exit-related costs, incurred to date	$ 3,613		$ 3,613