Commitments and Contingencies - Recycling Operations and Other Legacy (Details)			1 Months Ended	3 Months Ended
	Dec. 31, 2017 potentially_responsible_party	Aug. 31, 2007 USD ($)	Jan. 31, 2017 USD ($)	Nov. 30, 2018 USD ($)	Nov. 30, 2017 USD ($)	Aug. 31, 2018 USD ($)	Jan. 30, 2017 potentially_responsible_party party
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies				$ 53,601,000		$ 53,832,000
Parties Liable in Litigation | party							30
Liabilities Established				781,000
Insurance Receivable				16,000,000		36,000,000
Legacy Environmental Site 1 - Remediation of Shredder Residue
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies				4,000,000		4,000,000
Environmental remediation expense accrued in the period					$ 4,000,000
Legacy Environmental Site 2 - Remediation of Soil and Groundwater Conditions
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies				6,000,000		0
Portland Harbor Superfund Site
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies				2,000,000
Number Of Potentially Responsible Parties Joining Allocation Process | potentially_responsible_party							100
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
Liabilities Established					2,000,000
Insurance Receivable					$ 2,000,000
Other Auto and Metals Recycling Business Sites
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies				54,000,000		$ 54,000,000
Minimum | Legacy Environmental Site 1 - Remediation of Shredder Residue
Loss Contingencies [Line Items]
Loss contingency, range of possible loss				0
Maximum | Legacy Environmental Site 1 - Remediation of Shredder Residue
Loss Contingencies [Line Items]
Loss contingency, range of possible loss				28,000,000
Lower Willamette Group | Portland Harbor Superfund Site
Loss Contingencies [Line Items]
Remedial Investigation and Feasibility Study Costs		$ 115,000,000
Number of Years for Remedial Investigation and Feasibility Study		10 years
Potential Responsible Parties | Portland Harbor Superfund Site
Loss Contingencies [Line Items]
Estimated Cost of Selected Remedy			$ 1,700,000,000
Estimated Cost of Selected Remedy, Discount			$ 1,050,000,000.00
Estimated Cost of Selected Remedy, Discount Rate			7.00%
Site Contingency, Estimated Time Frame to Remediate			13 years
Potential Responsible Parties | Minimum | Portland Harbor Superfund Site
Loss Contingencies [Line Items]
Site Contingency, Least Costly Remediation Plan, Discount				170,000,000
Estimated Cost of Selected Remedy, Range			(30.00%)
Potential Responsible Parties | Maximum | Portland Harbor Superfund Site
Loss Contingencies [Line Items]
Site Contingency, Most Costly Remediation Plan, Discount				$ 2,500,000,000
Estimated Cost of Selected Remedy, Range			50.00%