GOODWILL AND OTHER INTANGIBLE ASSETS (Changes in the Carrying Amount of Goodwill) (Details) $ in Thousands	3 Months Ended
	Nov. 30, 2018 USD ($)
Goodwill [Roll Forward]
Goodwill, gross, balance, beginning	$ 74,509
Foreign currency translation	(62)
Impairment	0
Reclassification to assets of discontinued operations	0
Goodwill, gross, balance, ending	74,447
Accumulated impairment losses, beginning	(10,199)
Foreign currency translation	4
Reclassification to assets of discontinued operations	0
Accumulated impairment losses, ending	(10,195)
Balance, August 31, 2018	64,310
Foreign currency translation	(58)
Impairment	0
Balance, November 30, 2018	64,252
Americas Recycling
Goodwill [Roll Forward]
Goodwill, gross, balance, beginning	9,543
Foreign currency translation	0
Impairment	0
Reclassification to assets of discontinued operations	0
Goodwill, gross, balance, ending	9,543
Accumulated impairment losses, beginning	(9,543)
Foreign currency translation	0
Reclassification to assets of discontinued operations	0
Accumulated impairment losses, ending	(9,543)
Balance, August 31, 2018	0
Foreign currency translation	0
Impairment	0
Balance, November 30, 2018	0
Americas Mills
Goodwill [Roll Forward]
Goodwill, gross, balance, beginning	4,970
Foreign currency translation	0
Impairment	0
Reclassification to assets of discontinued operations	0
Goodwill, gross, balance, ending	4,970
Accumulated impairment losses, beginning	0
Foreign currency translation	0
Reclassification to assets of discontinued operations	0
Accumulated impairment losses, ending	0
Balance, August 31, 2018	4,970
Foreign currency translation	0
Impairment	0
Balance, November 30, 2018	4,970
Americas Fabrication
Goodwill [Roll Forward]
Goodwill, gross, balance, beginning	57,428
Foreign currency translation	0
Impairment	0
Reclassification to assets of discontinued operations	0
Goodwill, gross, balance, ending	57,428
Accumulated impairment losses, beginning	(493)
Foreign currency translation	0
Reclassification to assets of discontinued operations	0
Accumulated impairment losses, ending	(493)
Balance, August 31, 2018	56,935
Foreign currency translation	0
Impairment	0
Balance, November 30, 2018	56,935
International Mill
Goodwill [Roll Forward]
Goodwill, gross, balance, beginning	2,568
Foreign currency translation	(62)
Impairment	0
Reclassification to assets of discontinued operations	0
Goodwill, gross, balance, ending	2,506
Accumulated impairment losses, beginning	(163)
Foreign currency translation	4
Reclassification to assets of discontinued operations	0
Accumulated impairment losses, ending	(159)
Balance, August 31, 2018	2,405
Foreign currency translation	(58)
Impairment	0
Balance, November 30, 2018	$ 2,347