GOODWILL AND OTHER INTANGIBLE ASSETS (Changes in the Carrying Amount of Goodwill) (Details) - USD ($)	3 Months Ended	12 Months Ended
	Aug. 31, 2015	Aug. 31, 2016	Aug. 31, 2015	Aug. 31, 2014
Goodwill [Line Items]
Goodwill	$ 76,787,000	$ 76,772,000	$ 76,787,000	$ 84,127,000
Accumulated impairment losses	(10,404,000)	(10,399,000)	(10,404,000)	(9,808,000)
Goodwill, net	66,383,000	66,373,000	66,383,000	74,319,000
Impairment		0	(7,267,000)	0
Goodwill reclassified to assets held for sale			(6,643,000)
Accumulated impairment losses reclassified to assets held for sale			6,643,000
Translation		(10,000)	(669,000)
Americas Recycling
Goodwill [Line Items]
Goodwill	9,751,000	9,751,000	9,751,000	9,751,000
Accumulated impairment losses	(9,751,000)	(9,751,000)	(9,751,000)	(2,484,000)
Goodwill, net	0	0	0	7,267,000
Impairment		0	(7,267,000)
Goodwill reclassified to assets held for sale			0
Accumulated impairment losses reclassified to assets held for sale			0
Translation		0	0
Americas Mills
Goodwill [Line Items]
Goodwill	4,970,000	4,970,000	4,970,000	4,970,000
Accumulated impairment losses	0	0	0	0
Goodwill, net	4,970,000	4,970,000	4,970,000	4,970,000
Impairment			0
Goodwill reclassified to assets held for sale			0
Accumulated impairment losses reclassified to assets held for sale			0
Translation		0	0
Americas Fabrication
Goodwill [Line Items]
Goodwill	57,637,000	57,637,000	57,637,000	57,637,000
Accumulated impairment losses	(493,000)	(493,000)	(493,000)	(493,000)
Goodwill, net	57,144,000	57,144,000	57,144,000	57,144,000
Impairment			0
Goodwill reclassified to assets held for sale			0
Accumulated impairment losses reclassified to assets held for sale			0
Translation		0	0
International Mill
Goodwill [Line Items]
Goodwill	2,517,000	2,432,000	2,517,000	2,964,000
Accumulated impairment losses	(160,000)	(155,000)	(160,000)	(188,000)
Goodwill, net	2,357,000	2,277,000	2,357,000	2,776,000
Impairment			0
Translation		(80,000)	(419,000)
International Marketing and Distribution
Goodwill [Line Items]
Goodwill	1,912,000	1,982,000	1,912,000	8,805,000
Accumulated impairment losses	0	0	0	(6,643,000)
Goodwill, net	1,912,000	1,982,000	1,912,000	$ 2,162,000
Impairment			0
Goodwill reclassified to assets held for sale			(6,643,000)
Accumulated impairment losses reclassified to assets held for sale			6,643,000
Translation		$ 70,000	$ (250,000)
Assets Held-for-sale | International Marketing and Distribution
Goodwill, Impaired, Accumulated Impairment Loss [Abstract]
Goodwill related to assets sold	1,600,000
Goodwill amortization related to assets sold	$ 1,600,000