Revenue - Summary of Revenues Disaggregated by Major Product and Sales Destination (Details) - USD ($) $ in Thousands	12 Months Ended
	Aug. 31, 2023	Aug. 31, 2022	Aug. 31, 2021
Disaggregation of Revenue [Line Items]
Revenues	$ 2,882,224	$ 3,485,815	$ 2,758,551
Ferrous Revenues
Disaggregation of Revenue [Line Items]
Revenues	1,439,983	1,914,255	1,557,891
Nonferrous Revenues
Disaggregation of Revenue [Line Items]
Revenues	781,102	892,444	684,862
Steel Revenues
Disaggregation of Revenue [Line Items]
Revenues	507,550	531,731	379,203
Retail and Other Revenues
Disaggregation of Revenue [Line Items]
Revenues	153,589	147,385	136,595
Foreign
Disaggregation of Revenue [Line Items]
Revenues	1,508,019	1,925,235	1,612,744
Domestic
Disaggregation of Revenue [Line Items]
Revenues	$ 1,374,205	$ 1,560,580	$ 1,145,807