Goodwill (Details) (USD $)	6 Months Ended
	Feb. 29, 2012
Goodwill [Roll Forward]
Goodwill, beginning of period	$ 627,805,000
Purchase price adjustment	1,540,000
Purchase accounting adjustments	370,000
Foreign currency translation adjustment	(1,636,000)
Goodwill, end of period	628,079,000
Goodwill, Impaired, Accumulated Impairment Loss	0
Metal Recycling Business [Member]
Goodwill [Roll Forward]
Goodwill, beginning of period	464,646,000
Purchase price adjustment	1,540,000
Purchase accounting adjustments	370,000
Foreign currency translation adjustment	(1,417,000)
Goodwill, end of period	465,139,000
Auto Parts Business [Member]
Goodwill [Roll Forward]
Goodwill, beginning of period	163,159,000
Purchase price adjustment	0
Purchase accounting adjustments	0
Foreign currency translation adjustment	(219,000)
Goodwill, end of period	$ 162,940,000