Summary of Significant Accounting Policies - Additional Information (Details)	3 Months Ended	12 Months Ended
	Aug. 31, 2021 USD ($) ExternalCustomer	Aug. 31, 2022 USD ($) Segment shares	Aug. 31, 2021 USD ($) ExternalCustomer	Aug. 31, 2020 USD ($) ExternalCustomer	Aug. 31, 2022 Jointventureinterest	Aug. 31, 2022	Aug. 31, 2022 ExternalCustomer	May 31, 2022 USD ($)
Significant Accounting Policies [Line Items]
Number of operating segments | Segment		1
Number of reportable segments | Segment		1
Retained earnings, cumulative-effect adjustment	$ 793,712,000	$ 941,146,000	$ 793,712,000
Bank Overdrafts	47,000,000	56,000,000	47,000,000
Allowance for Credit losses	2,000,000	2,000,000	2,000,000
Repayment of Advances with Scrap Metal		11,000,000	10,000,000	$ 9,000,000
Operating lease carrying value		$ 13,000,000	$ 11,000,000
Operating Lease, Lease Income, Statement of Income or Comprehensive Income [Extensible Enumeration]		Property, Plant and Equipment, Net	Property, Plant and Equipment, Net
Insurance receivable	$ 10,000,000	$ 0	$ 10,000,000
Proceeds from legal settlements		7,000,000	$ 8,000,000
Increase in insurance receivable		25,000,000
Insurance recovery gain		$ 15,000,000
Gain on Business Interruption Insurance Recovery, Statement of Income or Comprehensive Income [Extensible Enumeration]		Cost of Goods and Services Sold
Received payment related to claims from various insurers		$ 30,000,000
Insurance amount received		25,000,000
Impairment charges related to carrying value of plant and equipment assets lost in or damaged by fire		7,000,000
Initial capital purchases other costs and applicable losses of assets		10,000,000
Asset impairment charges, net		1,570,000		$ 5,729,000
Number of Equity Method Investments | Jointventureinterest					2
Cumulative Undistributed Earnings, Equity Method Joint Ventures		12,000,000
Number of Joint Venture Investments	0		0	0	1		0
Goodwill impairment charges		0	$ 0	$ 0
Advertising Expense		$ 6,000,000	6,000,000	5,000,000
Percentage likelihood of tax benefit being realized upon settlement with tax authority		50.00%
Cash, FDIC Insured Amount		$ 250,000
Class A Common Stock
Significant Accounting Policies [Line Items]
Common Stock, Voting Rights		one
Number Of Shares Class B Common Stock Convertible To Class A Common Stock | shares		1
Number of Shares of Class A Common Stock Reserved For Class B Common Stock | shares		1
Class B Common Stock
Significant Accounting Policies [Line Items]
Common Stock, Voting Rights		one
Impairment Associated with Abandonment of Obsolete Machinery and Equipment Assets
Significant Accounting Policies [Line Items]
Asset impairment charges, net		$ 2,000,000		2,000,000
Impairments of Two Auto Parts Stores
Significant Accounting Policies [Line Items]
Asset impairment charges, net				2,000,000
Impairment Associated with Accelerated Depreciation due to Shortening of Useful Lives of Certain Metals Recovery Assets
Significant Accounting Policies [Line Items]
Asset impairment charges, net				$ 2,000,000
Cost of Goods Sold
Significant Accounting Policies [Line Items]
Gain on insurance receivable recognized	$ 10,000,000	17,000,000
Prepaid Expenses and Other Current Assets
Significant Accounting Policies [Line Items]
Prepaid expense	22,000,000	43,000,000	22,000,000
Other Assets
Significant Accounting Policies [Line Items]
Insurance receivable	21,000,000	28,000,000	21,000,000
Property loss and damage and business interruption claims environmental claims insurance receivable	10,000,000	10,000,000	10,000,000
Third party claims insurance receivable		6,000,000
Environmental claims insurance receivable	6,000,000	7,000,000	6,000,000
Workers' Compensation insurance receivables	4,000,000	4,000,000	4,000,000
Investment, Carrying Value	6,000,000	11,000,000	6,000,000
Other Accrued Liabilities
Significant Accounting Policies [Line Items]
Received payment related to claims from various insurers		5,000,000
Workers' Compensation Liability	7,000,000	6,000,000	7,000,000
Other Current Assets
Significant Accounting Policies [Line Items]
Workers' Compensation insurance receivables	$ 4,000,000	$ 4,000,000	$ 4,000,000
Maximum
Significant Accounting Policies [Line Items]
Shipment Period		60 days
Short-term election non-cancellable lease term		12 months
Short-term election lease term renewal option		12 months
Minimum
Significant Accounting Policies [Line Items]
Shipment Period		30 days
Accounting Standards Update 2016-02 | Cumulative Effect, Period of Adoption, Adjustment | Maximum
Significant Accounting Policies [Line Items]
Retained earnings, cumulative-effect adjustment		$ 1,000,000
US Recycling
Significant Accounting Policies [Line Items]
Investment, Original Cost								$ 6,000,000
Canadian Recycling
Significant Accounting Policies [Line Items]
Investment, Original Cost								$ 5,000,000
Joint Venture Interests
Significant Accounting Policies [Line Items]
Equity Method Investment, Ownership Percentage						50.00%
Damage From Fire at Metals Recycling Facility in Everett, Massachusetts
Significant Accounting Policies [Line Items]
Insurance receivable		10,000,000
Received payment related to claims from various insurers		$ 7,000,000