Inventories, net (Details) (USD $) In Thousands, unless otherwise specified	Nov. 30, 2013	Aug. 31, 2013
Inventory, Net [Abstract]
Processed and unprocessed scrap metal	$ 174,966	$ 132,485
Semi-finished goods (billets)	14,000	10,745
Finished goods	53,825	56,830
Supplies	37,309	35,989
Inventories, net	$ 280,100	$ 236,049