BUSINESS SEGMENTS (External Net Sales from Continuing Operations by Major Product) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended																12 Months Ended
	Aug. 31, 2014		May 31, 2014		Feb. 28, 2014		Nov. 30, 2013		Aug. 31, 2013		May 31, 2013		Feb. 28, 2013		Nov. 30, 2012		Aug. 31, 2014	Aug. 31, 2013	Aug. 31, 2012
Entity-Wide Information, Revenue from External Customer [Line Items]
Net sales	$ 1,903,196	[1]	$ 1,804,774	[1]	$ 1,649,098	[1]	$ 1,682,891	[1]	$ 1,698,861	[1]	$ 1,752,534	[1]	$ 1,688,665	[1]	$ 1,749,515	[1]	$ 7,039,959	$ 6,889,575	$ 7,656,375
Steel products
Entity-Wide Information, Revenue from External Customer [Line Items]
Net sales																	4,746,404	4,318,072	4,699,226
Ferrous scrap
Entity-Wide Information, Revenue from External Customer [Line Items]
Net sales																	659,578	646,263	763,772
Industrial materials
Entity-Wide Information, Revenue from External Customer [Line Items]
Net sales																	659,251	928,472	1,147,386
Nonferrous scrap
Entity-Wide Information, Revenue from External Customer [Line Items]
Net sales																	639,961	682,611	765,349
Construction materials
Entity-Wide Information, Revenue from External Customer [Line Items]
Net sales																	199,154	189,046	177,827
Nonferrous products
Entity-Wide Information, Revenue from External Customer [Line Items]
Net sales																	8,761	5,674	2,689
Other
Entity-Wide Information, Revenue from External Customer [Line Items]
Net sales																	$ 126,850	$ 119,437	$ 100,126

[1] Excludes divisions classified as discontinued operations. See Note 10, Businesses Held for Sale, Discontinued Operations and Dispositions.