Revenue - Summary of Revenues Disaggregated by Major Product and Sales Destination (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	May 31, 2022	May 31, 2021	May 31, 2022	May 31, 2021
Disaggregation of Revenue [Line Items]
Revenues	$ 1,010,087	$ 820,718	$ 2,591,403	$ 1,912,936
Ferrous Revenues
Disaggregation of Revenue [Line Items]
Revenues	530,303	448,684	1,434,473	1,023,569
Nonferrous Revenues
Disaggregation of Revenue [Line Items]
Revenues	272,208	204,512	662,779	471,543
Steel Revenues
Disaggregation of Revenue [Line Items]
Revenues	165,210	129,057	384,644	316,662
Retail and Other Revenues
Disaggregation of Revenue [Line Items]
Revenues	42,366	38,465	109,507	101,162
Foreign
Disaggregation of Revenue [Line Items]
Revenues	533,087	466,739	1,439,731	1,067,335
Domestic
Disaggregation of Revenue [Line Items]
Revenues	$ 477,000	$ 353,979	$ 1,151,672	$ 845,601