Commitments and Contingencies - Recycling Operations - Recycling Operations (Details) $ in Thousands		1 Months Ended			12 Months Ended
	Dec. 01, 2017	Feb. 28, 2021	Apr. 30, 2020 USD ($)	Jan. 31, 2017 USD ($)	Aug. 31, 2023 USD ($)	Aug. 31, 2022 USD ($)	Aug. 31, 2021 USD ($)	Dec. 31, 2017 Potentially_responsible_party	Jan. 30, 2017 Party Potentially_responsible_party	Aug. 31, 2007 USD ($)
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies					$ 66,777	$ 68,500	$ 77,128
Liabilities Established					10,697	12,839
Insurance receivable						0	$ 10,000
Other Assets
Loss Contingencies [Line Items]
Insurance receivable					14,000	28,000
Portland Harbor Superfund Site
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies					5,000	6,000
Number Of Other Potentially Responsible Parties Signing Settlement Agreement and Order on Consent | Potentially_responsible_party								3
Number of Years for Pre-Remedial Design	2 years
Site contingency expected completion term for remedial design			4 years
Site contingency EPA estimated completion cost for remedial design			$ 4,000
Insurance receivable					1,000	$ 3,000
Number Of Potentially Responsible Parties Joining Allocation Process | Potentially_responsible_party									100
Environmental reserve					2,300
Parties named in Litigation | Party									30
Portland Harbor Superfund Site | Other Assets
Loss Contingencies [Line Items]
Insurance receivable					$ 2,300
Portland Harbor Superfund Site | Minimum
Loss Contingencies [Line Items]
Percentage of area require active clean up in remedial design phase		100.00%
Lower Willamette Group | Portland Harbor Superfund Site | Minimum
Loss Contingencies [Line Items]
Remedial Investigation and Feasibility Study Costs										$ 155,000
Potential Responsible Parties | Portland Harbor Superfund Site
Loss Contingencies [Line Items]
Estimated Cost of Selected Remedy Undiscounted				$ 1,700,000
Estimated Cost of Selected Remedy Discounted				$ 1,050,000
Estimated Cost of Selected Remedy, Discount Rate				7.00%
Site Contingency, Estimated Construction Time Frame				13 years
Potential Responsible Parties | Portland Harbor Superfund Site | Minimum
Loss Contingencies [Line Items]
Estimated Cost of Selected Remedy, Range				50.00%
Potential Responsible Parties | Portland Harbor Superfund Site | Maximum
Loss Contingencies [Line Items]
Estimated Cost of Selected Remedy, Range				(30.00%)