Inventories, net (Details) (USD $) In Thousands, unless otherwise specified	Feb. 28, 2014	Aug. 31, 2013
Inventory, Net [Abstract]
Processed and unprocessed scrap metal	$ 139,729	$ 132,485
Semi-finished goods (billets)	13,185	10,745
Finished goods	62,341	56,830
Supplies	37,594	35,989
Inventories, net	$ 252,849	$ 236,049