BUSINESS SEGMENTS (Summary of Certain Financial Information from Continuing Operations by Reportable Segment) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Nov. 30, 2014		Nov. 30, 2013	Aug. 31, 2014
Segment Reporting Information [Line Items]
Net sales	$ 1,679,990		$ 1,617,075
Adjusted operating profit (loss)	73,289		68,728
Total assets	3,616,300			3,688,520
Continuing Operations
Segment Reporting Information [Line Items]
Net sales	1,679,990		1,617,075
Adjusted operating profit (loss)	73,289		68,728
Total assets	3,514,031	[1]		3,681,510	[1]
Americas Recycling
Segment Reporting Information [Line Items]
Net sales	269,802		293,475
Adjusted operating profit (loss)	(1,143)		839
Total assets	310,139	[1]		296,564	[1]
Americas Mills
Segment Reporting Information [Line Items]
Net sales	303,859		291,573
Adjusted operating profit (loss)	75,382		65,814
Total assets	665,388	[1]		647,437	[1]
Americas Fabrication
Segment Reporting Information [Line Items]
Net sales	408,237		353,992
Adjusted operating profit (loss)	(3,009)		2,217
Total assets	678,267	[1]		691,765	[1]
International Mill
Segment Reporting Information [Line Items]
Net sales	177,629		228,492
Adjusted operating profit (loss)	4,223		15,268
Total assets	454,143	[1]		466,449	[1]
International Marketing and Distribution
Segment Reporting Information [Line Items]
Net sales	519,631		443,358
Adjusted operating profit (loss)	18,252		2,042
Total assets	1,022,760	[1]		949,016	[1]
Corporate
Segment Reporting Information [Line Items]
Net sales	832		6,185
Adjusted operating profit (loss)	(19,611)		(18,049)
Total assets	1,035,764	[1]		1,100,995	[1]
Eliminations
Segment Reporting Information [Line Items]
Net sales	0		0
Adjusted operating profit (loss)	(805)		597
Total assets	(652,430)	[1]		(470,716)	[1]
Segments | Continuing Operations
Segment Reporting Information [Line Items]
Net sales	1,679,990		1,617,075
Segments | Americas Recycling
Segment Reporting Information [Line Items]
Net sales	316,059		338,202
Segments | Americas Mills
Segment Reporting Information [Line Items]
Net sales	524,851		481,151
Segments | Americas Fabrication
Segment Reporting Information [Line Items]
Net sales	412,488		358,218
Segments | International Mill
Segment Reporting Information [Line Items]
Net sales	177,629		229,150
Segments | International Marketing and Distribution
Segment Reporting Information [Line Items]
Net sales	537,806		445,342
Segments | Corporate
Segment Reporting Information [Line Items]
Net sales	832		6,185
Segments | Eliminations
Segment Reporting Information [Line Items]
Net sales	(289,675)		(241,173)
Intersegment | Continuing Operations
Segment Reporting Information [Line Items]
Net sales	0		0
Intersegment | Americas Recycling
Segment Reporting Information [Line Items]
Net sales	46,257		44,727
Intersegment | Americas Mills
Segment Reporting Information [Line Items]
Net sales	220,992		189,578
Intersegment | Americas Fabrication
Segment Reporting Information [Line Items]
Net sales	4,251		4,226
Intersegment | International Mill
Segment Reporting Information [Line Items]
Net sales	0		658
Intersegment | International Marketing and Distribution
Segment Reporting Information [Line Items]
Net sales	18,175		1,984
Intersegment | Corporate
Segment Reporting Information [Line Items]
Net sales	0		0
Intersegment | Eliminations
Segment Reporting Information [Line Items]
Net sales	$ (289,675)		$ (241,173)

[1] Excludes total assets from discontinued operations of $102.3 million at November 30, 2014 and $7.0 million at August 31, 2014.