Document and Entity Information	9 Months Ended
Sep. 30, 2011	Oct. 28, 2011
Entity Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2011
Document Fiscal Year Focus	2011
Document Fiscal Period Focus	Q3
Trading Symbol	POR
Entity Registrant Name	PORTLAND GENERAL ELECTRIC CO /OR/
Entity Central Index Key	0000784977
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		75,345,583

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The end date of the period reflected on the cover page if a periodic report. For all other reports and registration statements containing historical data, it is the date up through which that historical data is presented. If there is no historical data in the report, use the filing date. The format of the date is CCYY-MM-DD.

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The type of document being provided (such as 10-K, 10-Q, N-1A, etc). The document type is limited to the same value as the supporting SEC submission type, minus any "/A" suffix. The acceptable values are as follows: S-1, S-3, S-4, S-11, F-1, F-3, F-4, F-9, F-10, 6-K, 8-K, 10, 10-K, 10-Q, 20-F, 40-F, N-1A, 485BPOS, 497, NCSR, N-CSR, N-CSRS, N-Q, 10-KT, 10-QT, 20-FT, and Other.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

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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.

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The exact name of the entity filing the report as specified in its charter, which is required by forms filed with the SEC.

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