INVENTORIES, NET (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	May. 31, 2015	May. 31, 2014	May. 31, 2015	May. 31, 2014	Aug. 31, 2014
Inventory [Line Items]
Percentage of total net inventories valued at LIFO	57.00%		57.00%		44.00%
LIFO inventory reserves	$ 83,000		$ 83,000		$ 198,800
Pre-tax LIFO income	37,100		115,800
Inventory write-down			11,697	$ 0
Raw materials before LIFO reserves	63,600		63,600		$ 84,300
Cost of goods sold
Inventory [Line Items]
Inventory write-down	$ 9,500	$ 0	$ 9,800	$ 0