Inventories, net (Details) (USD $) In Thousands, unless otherwise specified	Aug. 31, 2014	Aug. 31, 2013
Inventory, Net [Abstract]
Processed and unprocessed scrap metal	$ 106,877	$ 132,485
Semi-finished goods (billets)	12,920	10,745
Finished goods	59,039	56,830
Supplies	37,336	35,989
Inventories, net	$ 216,172	$ 236,049