BUSINESS SEGMENTS (Summary of Certain Financial Information from Continuing Operations by Reportable Segment) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended			6 Months Ended
	Feb. 28, 2015		Feb. 28, 2014	Feb. 28, 2015		Feb. 28, 2014	Aug. 31, 2014
Segment Reporting Information [Line Items]
Net sales	$ 1,391,117		$ 1,597,461	$ 3,071,107		$ 3,214,536
Adjusted operating profit (loss)	112,224		37,045	185,513		105,773
Total assets	3,589,502			3,589,502			3,688,520
Continuing Operations
Segment Reporting Information [Line Items]
Net sales	1,391,117		1,597,461	3,071,107		3,214,536
Adjusted operating profit (loss)	112,224		37,045	185,513		105,773
Total assets	3,497,778	[1]		3,497,778	[1]		3,681,510	[1]
Americas Recycling
Segment Reporting Information [Line Items]
Net sales	227,499		293,146	497,301		586,622
Adjusted operating profit (loss)	(172)		(863)	(1,315)		(24)
Total assets	284,790	[1]		284,790	[1]		296,564	[1]
Americas Mills
Segment Reporting Information [Line Items]
Net sales	247,727		277,562	551,586		569,135
Adjusted operating profit (loss)	98,489		44,062	173,871		109,876
Total assets	715,306	[1]		715,306	[1]		647,437	[1]
Americas Fabrication
Segment Reporting Information [Line Items]
Net sales	341,679		322,572	749,916		676,564
Adjusted operating profit (loss)	11,773		(5,330)	8,764		(3,113)
Total assets	667,648	[1]		667,648	[1]		691,765	[1]
International Mill
Segment Reporting Information [Line Items]
Net sales	138,449		181,245	316,078		409,737
Adjusted operating profit (loss)	819		8,331	5,042		23,600
Total assets	407,271	[1]		407,271	[1]		466,449	[1]
International Marketing and Distribution
Segment Reporting Information [Line Items]
Net sales	433,046		517,770	952,677		961,127
Adjusted operating profit (loss)	15,678		4,487	33,930		6,529
Total assets	1,052,922	[1]		1,052,922	[1]		949,016	[1]
Corporate
Segment Reporting Information [Line Items]
Net sales	2,717		5,166	3,549		11,351
Adjusted operating profit (loss)	(16,400)		(15,064)	(36,011)		(33,113)
Total assets	939,847	[1]		939,847	[1]		1,100,995	[1]
Eliminations
Segment Reporting Information [Line Items]
Net sales	0		0	0		0
Adjusted operating profit (loss)	2,037		1,422	1,232		2,018
Total assets	(570,006)	[1]		(570,006)	[1]		(470,716)	[1]
Segments | Continuing Operations
Segment Reporting Information [Line Items]
Net sales	1,391,117		1,597,461	3,071,107		3,214,536
Segments | Americas Recycling
Segment Reporting Information [Line Items]
Net sales	259,079		342,267	575,138		680,470
Segments | Americas Mills
Segment Reporting Information [Line Items]
Net sales	428,845		456,849	953,696		938,000
Segments | Americas Fabrication
Segment Reporting Information [Line Items]
Net sales	344,410		325,890	756,898		684,108
Segments | International Mill
Segment Reporting Information [Line Items]
Net sales	138,449		181,362	316,078		410,512
Segments | International Marketing and Distribution
Segment Reporting Information [Line Items]
Net sales	465,238		520,171	1,003,044		965,512
Segments | Corporate
Segment Reporting Information [Line Items]
Net sales	2,717		5,166	3,549		11,351
Segments | Eliminations
Segment Reporting Information [Line Items]
Net sales	(247,621)		(234,244)	(537,296)		(475,417)
Intersegment | Continuing Operations
Segment Reporting Information [Line Items]
Net sales	0		0	0		0
Intersegment | Americas Recycling
Segment Reporting Information [Line Items]
Net sales	31,580		49,121	77,837		93,848
Intersegment | Americas Mills
Segment Reporting Information [Line Items]
Net sales	181,118		179,287	402,110		368,865
Intersegment | Americas Fabrication
Segment Reporting Information [Line Items]
Net sales	2,731		3,318	6,982		7,544
Intersegment | International Mill
Segment Reporting Information [Line Items]
Net sales	0		117	0		775
Intersegment | International Marketing and Distribution
Segment Reporting Information [Line Items]
Net sales	32,192		2,401	50,367		4,385
Intersegment | Corporate
Segment Reporting Information [Line Items]
Net sales	0		0	0		0
Intersegment | Eliminations
Segment Reporting Information [Line Items]
Net sales	$ (247,621)		$ (234,244)	$ (537,296)		$ (475,417)

[1] Excludes total assets from discontinued operations of $91.7 million at February 28, 2015 and $7.0 million at August 31, 2014.