BUSINESS SEGMENTS (Summary of Certain Financial Information from Continuing Operations by Reportable Segment and Major Product) (Details) - USD ($) $ in Thousands	3 Months Ended
	Nov. 30, 2022	Nov. 30, 2021	Aug. 31, 2022
Segment Reporting Information [Line Items]
Net sales	$ 2,227,313	$ 1,981,801
Adjusted EBITDA	402,736	314,022
Total assets	6,273,967		$ 6,237,027
Segments | Continuing Operations
Segment Reporting Information [Line Items]
Net sales	2,227,313	1,981,801
Adjusted EBITDA	402,736	314,022
Total assets	6,273,967		6,237,027
Segments | North America
Segment Reporting Information [Line Items]
Net sales	1,816,899	1,653,622
Adjusted EBITDA	377,956	268,524
Total assets	4,568,633		4,467,314
Segments | Europe
Segment Reporting Information [Line Items]
Net sales	406,513	329,056
Adjusted EBITDA	64,505	79,832
Total assets	1,171,324		1,056,101
Segments | Unaffiliated Customers
Segment Reporting Information [Line Items]
Net sales	2,227,313	1,981,801
Segments | Unaffiliated Customers | North America
Segment Reporting Information [Line Items]
Net sales	1,815,248	1,653,622
Segments | Unaffiliated Customers | Europe
Segment Reporting Information [Line Items]
Net sales	405,949	328,562
Segments | Raw materials
Segment Reporting Information [Line Items]
Net sales	297,187	360,052
Segments | Raw materials | North America
Segment Reporting Information [Line Items]
Net sales	292,320	353,092
Segments | Raw materials | Europe
Segment Reporting Information [Line Items]
Net sales	4,867	6,960
Segments | Steel Products
Segment Reporting Information [Line Items]
Net sales	1,017,398	918,187
Segments | Steel Products | North America
Segment Reporting Information [Line Items]
Net sales	705,462	675,042
Segments | Steel Products | Europe
Segment Reporting Information [Line Items]
Net sales	311,936	243,145
Segments | Downstream products
Segment Reporting Information [Line Items]
Net sales	701,516	584,468
Segments | Downstream products | North America
Segment Reporting Information [Line Items]
Net sales	641,934	514,396
Segments | Downstream products | Europe
Segment Reporting Information [Line Items]
Net sales	59,582	70,072
Segments | Construction-related solutions
Segment Reporting Information [Line Items]
Net sales	161,818	82,499
Segments | Construction-related solutions | North America
Segment Reporting Information [Line Items]
Net sales	142,372	82,499
Segments | Construction-related solutions | Europe
Segment Reporting Information [Line Items]
Net sales	19,446	0
Segments | Other
Segment Reporting Information [Line Items]
Net sales	49,394	36,595
Segments | Other | North America
Segment Reporting Information [Line Items]
Net sales	33,160	28,593
Segments | Other | Europe
Segment Reporting Information [Line Items]
Net sales	10,118	8,385
Segments | Corporate
Segment Reporting Information [Line Items]
Net sales	3,901	(877)
Adjusted EBITDA	(39,725)	(34,334)
Segments | Corporate | Unaffiliated Customers
Segment Reporting Information [Line Items]
Net sales	6,116	(383)
Segments | Corporate | Raw materials
Segment Reporting Information [Line Items]
Net sales	0	0
Segments | Corporate | Steel Products
Segment Reporting Information [Line Items]
Net sales	0	0
Segments | Corporate | Downstream products
Segment Reporting Information [Line Items]
Net sales	0	0
Segments | Corporate | Construction-related solutions
Segment Reporting Information [Line Items]
Net sales	0	0
Segments | Corporate | Other
Segment Reporting Information [Line Items]
Net sales	6,116	(383)
Segments | Corporate and Other
Segment Reporting Information [Line Items]
Total assets	534,010		$ 713,612
Intersegment
Segment Reporting Information [Line Items]
Net sales	0	0
Intersegment | North America
Segment Reporting Information [Line Items]
Net sales	1,651	0
Intersegment | Europe
Segment Reporting Information [Line Items]
Net sales	564	494
Intersegment | Corporate
Segment Reporting Information [Line Items]
Net sales	$ (2,215)	$ (494)