OPERATING SEGMENTS (External Net Sales from Continuing Operations by Major Product) (Details) - USD ($) $ in Thousands	12 Months Ended
Aug. 31, 2023	Aug. 31, 2022	Aug. 31, 2021
Entity-Wide Information, Revenue from External Customer [Line Items]
Net sales	$ 8,799,533	$ 8,913,481	$ 6,729,760
Segments \| North America
Entity-Wide Information, Revenue from External Customer [Line Items]
Net sales	7,347,020	7,298,632	5,670,976
Segments \| Europe
Entity-Wide Information, Revenue from External Customer [Line Items]
Net sales	1,416,704	1,621,642	1,049,059
Intersegment
Entity-Wide Information, Revenue from External Customer [Line Items]
Net sales	0	0	0
Intersegment \| North America
Entity-Wide Information, Revenue from External Customer [Line Items]
Net sales	841	1,989	0
Intersegment \| Europe
Entity-Wide Information, Revenue from External Customer [Line Items]
Net sales	8,043	2,071	1,814
Corporate \| Segments
Entity-Wide Information, Revenue from External Customer [Line Items]
Net sales	35,809	(6,793)	9,725
Corporate \| Intersegment
Entity-Wide Information, Revenue from External Customer [Line Items]
Net sales	(8,884)	(4,060)	(1,814)
Unaffiliated Customers \| Segments
Entity-Wide Information, Revenue from External Customer [Line Items]
Net sales	8,799,533	8,913,481	6,729,760
Unaffiliated Customers \| Segments \| North America
Entity-Wide Information, Revenue from External Customer [Line Items]
Net sales	7,346,179	7,296,643	5,670,976
Unaffiliated Customers \| Segments \| Europe
Entity-Wide Information, Revenue from External Customer [Line Items]
Net sales	1,408,661	1,619,571	1,047,245
Unaffiliated Customers \| Corporate \| Segments
Entity-Wide Information, Revenue from External Customer [Line Items]
Net sales	44,693	(2,733)	11,539
Raw material products \| Segments
Entity-Wide Information, Revenue from External Customer [Line Items]
Net sales	1,342,815	1,529,366	1,182,838
Raw material products \| Segments \| North America
Entity-Wide Information, Revenue from External Customer [Line Items]
Net sales	1,322,781	1,504,107	1,162,997
Raw material products \| Segments \| Europe
Entity-Wide Information, Revenue from External Customer [Line Items]
Net sales	20,034	25,259	19,841
Raw material products \| Corporate \| Segments
Entity-Wide Information, Revenue from External Customer [Line Items]
Net sales	0	0	0
Steel products \| Segments
Entity-Wide Information, Revenue from External Customer [Line Items]
Net sales	3,854,212	4,190,812	3,098,637
Steel products \| Segments \| North America
Entity-Wide Information, Revenue from External Customer [Line Items]
Net sales	2,785,266	2,955,121	2,289,975
Steel products \| Segments \| Europe
Entity-Wide Information, Revenue from External Customer [Line Items]
Net sales	1,068,946	1,235,691	808,662
Steel products \| Corporate \| Segments
Entity-Wide Information, Revenue from External Customer [Line Items]
Net sales	0	0	0
Downstream products \| Segments
Entity-Wide Information, Revenue from External Customer [Line Items]
Net sales	2,718,104	2,537,870	2,006,367
Downstream products \| Segments \| North America
Entity-Wide Information, Revenue from External Customer [Line Items]
Net sales	2,517,908	2,245,734	1,814,192
Downstream products \| Segments \| Europe
Entity-Wide Information, Revenue from External Customer [Line Items]
Net sales	200,196	292,136	192,175
Downstream products \| Corporate \| Segments
Entity-Wide Information, Revenue from External Customer [Line Items]
Net sales	0	0	0
Other \| Segments
Entity-Wide Information, Revenue from External Customer [Line Items]
Net sales	216,993	174,637	152,274
Other \| Segments \| North America
Entity-Wide Information, Revenue from External Customer [Line Items]
Net sales	132,651	138,164	114,168
Other \| Segments \| Europe
Entity-Wide Information, Revenue from External Customer [Line Items]
Net sales	39,649	39,206	26,567
Other \| Corporate \| Segments
Entity-Wide Information, Revenue from External Customer [Line Items]
Net sales	44,693	(2,733)	11,539
Construction Related Solutions \| Segments
Entity-Wide Information, Revenue from External Customer [Line Items]
Net sales	667,409	480,796	289,644
Construction Related Solutions \| Segments \| North America
Entity-Wide Information, Revenue from External Customer [Line Items]
Net sales	587,573	453,517	289,644
Construction Related Solutions \| Segments \| Europe
Entity-Wide Information, Revenue from External Customer [Line Items]
Net sales	79,836	27,279	0
Construction Related Solutions \| Corporate \| Segments
Entity-Wide Information, Revenue from External Customer [Line Items]
Net sales	$ 0	$ 0	$ 0