Summary of Significant Accounting Policies - Additional Information (Details)		3 Months Ended				9 Months Ended		12 Months Ended
	Nov. 07, 2022 USD ($) Jointventureinterest	May 31, 2023 USD ($)	May 31, 2022 USD ($)	Feb. 28, 2022 USD ($)	Nov. 30, 2021 USD ($)	May 31, 2023 USD ($) Segment	May 31, 2022 USD ($)	Aug. 31, 2022 USD ($) Jointventureinterest	Aug. 31, 2021 USD ($)
Significant Accounting Policies [Line Items]
Number of operating segments | Segment						1
Number of reportable segments | Segment						1
Bank Overdrafts		$ 55,000,000				$ 55,000,000		$ 56,000,000
Repayment of Advances with Scrap Metal						8,000,000	$ 9,000,000
Insurance receivable			$ 0				0		$ 10,000,000
Proceeds from legal settlements						7,000,000		$ 7,000,000
Insurance recovery gain				$ 12,000,000	$ 3,000,000		15,000,000
Increase in insurance receivable							25,000,000
Received payment related to claims from various insurers		13,000,000				43,000,000	30,000,000
Insurance amount received							$ 25,000,000
Impairment in other loss, net						(4,000)
Fair value adjustment of equity investment						$ 1,000,000
Gain on Business Interruption Insurance Recovery, Statement of Income or Comprehensive Income [Extensible Enumeration]						Cost of Goods and Services Sold		Cost of Goods and Services Sold
Impairment charges related to carrying value of plant and equipment assets lost in or damaged by fire						$ 7,000,000
Initial capital purchases and other costs of assets						13,000,000
Number of Equity Method Investments | Jointventureinterest								2
Number of Joint Venture Investments | Jointventureinterest	1
Cash, FDIC Insured Amount		250,000				250,000
Proceeds from sale of equity method investments	$ 2,000,000
Gain (loss) recognized as a result of the sale	$ 0
Equity investment to fair value		1,000,000				1,000,000
Insurance recovery gains recognized						20,000,000
Joint Venture Interests
Significant Accounting Policies [Line Items]
Equity Method Investment, Ownership Percentage	50.00%							50.00%
Damage From Fire at Metals Recycling Facility in Everett, Massachusetts
Significant Accounting Policies [Line Items]
Insurance receivable		5,000,000				5,000,000		$ 10,000,000
Received payment related to claims from various insurers		8,000,000	7,000,000
Canadian Recycling
Significant Accounting Policies [Line Items]
Investment, Original Cost		6,000,000				6,000,000
US Recycling
Significant Accounting Policies [Line Items]
Investment, Original Cost		5,000,000				5,000,000
Cost of Goods Sold
Significant Accounting Policies [Line Items]
Gain on insurance receivable recognized		2,000,000	$ 1,000,000	$ 10,000,000		2,000,000		17,000,000	$ 10,000,000
Prepaid Expenses and Other Current Assets
Significant Accounting Policies [Line Items]
Prepaid expense		33,000,000				33,000,000		43,000,000
Other Noncurrent Assets
Significant Accounting Policies [Line Items]
Insurance receivable		19,000,000				19,000,000		28,000,000
Property loss and damage and business interruption claims environmental claims insurance receivable		5,000,000				5,000,000		10,000,000
Environmental claims insurance receivable		10,000,000				10,000,000		7,000,000
Third party claims insurance receivable		1,000,000				1,000,000		6,000,000
Workers' Compensation insurance receivables		2,000,000				2,000,000		4,000,000
Investments, Carrying Value		$ 5,000,000				5,000,000		5,000,000
Other Accrued Liabilities
Significant Accounting Policies [Line Items]
Received payment related to claims from various insurers						$ 18,000,000		$ 5,000,000