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Amount of litigation expense, including but not limited to legal, forensic, accounting, and investigative fees.

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Cash outflows made during the period for environmental remediation activities.

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Contingencies (Details) $ in Millions	12 Months Ended
Contingencies (Details) $ in Millions	Dec. 31, 2020 USD ($) name	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Loss Contingencies [Line Items]
Proceeds from Insurance Settlement, Investing Activities	$ 0	$ 0	$ 120
Site Contingency, Names of Other Potentially Responsible Parties \| name	100
Litigation Settlement, Expense	$ 115
Loss Contingency, Range of Possible Loss, Maximum	1,700
Loss Contingency, Range of Possible Loss, Portion Not Accrued	500
Payments for Environmental Liabilities	$ 6
Loss Contingency, Damages Sought	260 million
EPA Investigation of Portland Harbor [Member]
Loss Contingencies [Line Items]
Loss Contingency, Damages Sought, Value	$ 1,200
Putative Shareholder Derivative Lawsuit [Member]
Loss Contingencies [Line Items]
Loss Contingency, Damages Sought, Value	$ 10