GOODWILL AND OTHER INTANGIBLE ASSETS (Changes in the Carrying Amount of Goodwill) (Details) $ in Thousands	9 Months Ended
	May 31, 2017 USD ($)
Goodwill [Roll Forward]
Balance at August 31, 2016	$ 76,772
Acquisitions	306
Foreign currency translation	93
Balance at May 31, 2017	77,171
Foreign currency translation	(10,399)
Foreign currency translation	(8)
Accumulated impairment losses	(10,407)
Balance at August 31, 2016	66,373
Acquisitions	306
Foreign currency translation	85
Balance at May 31, 2017	66,764
Americas Recycling
Goodwill [Roll Forward]
Balance at August 31, 2016	9,751
Acquisitions	0
Foreign currency translation	0
Balance at May 31, 2017	9,751
Foreign currency translation	(9,751)
Foreign currency translation	0
Accumulated impairment losses	(9,751)
Balance at August 31, 2016	0
Acquisitions	0
Foreign currency translation	0
Balance at May 31, 2017	0
Americas Mills
Goodwill [Roll Forward]
Balance at August 31, 2016	4,970
Acquisitions	0
Foreign currency translation	0
Balance at May 31, 2017	4,970
Foreign currency translation	0
Foreign currency translation	0
Accumulated impairment losses	0
Balance at August 31, 2016	4,970
Acquisitions	0
Foreign currency translation	0
Balance at May 31, 2017	4,970
Americas Fabrication
Goodwill [Roll Forward]
Balance at August 31, 2016	57,637
Acquisitions	306
Foreign currency translation	0
Balance at May 31, 2017	57,943
Foreign currency translation	(493)
Foreign currency translation	0
Accumulated impairment losses	(493)
Balance at August 31, 2016	57,144
Acquisitions	306
Foreign currency translation	0
Balance at May 31, 2017	57,450
International Mill
Goodwill [Roll Forward]
Balance at August 31, 2016	2,432
Acquisitions	0
Foreign currency translation	123
Balance at May 31, 2017	2,555
Foreign currency translation	(155)
Foreign currency translation	(8)
Accumulated impairment losses	(163)
Balance at August 31, 2016	2,277
Acquisitions	0
Foreign currency translation	115
Balance at May 31, 2017	2,392
International Marketing and Distribution
Goodwill [Roll Forward]
Balance at August 31, 2016	1,982
Acquisitions	0
Foreign currency translation	(30)
Balance at May 31, 2017	1,952
Foreign currency translation	0
Foreign currency translation	0
Accumulated impairment losses	0
Balance at August 31, 2016	1,982
Acquisitions	0
Foreign currency translation	(30)
Balance at May 31, 2017	$ 1,952