Environmental Matters (Details)	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017
OREGON
Site Contingency [Line Items]
Remediation Recovery Percentage	96.68%	96.68%	96.68%

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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