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Commitments and Guarantees Schdule of Long term contracts for purchase of electric power (Details) (USD $) In Millions, unless otherwise specified | 12 Months Ended
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Dec. 31, 2012 MW | Dec. 31, 2011 | Dec. 31, 2010
Priest Rapids and Wanapum [Member] |  |  |
Long-term Contract for Purchase of Electric Power [Line Items] |  |  |
Revenue Bonds issued by the Public Utility Districts | $ 928 |  |
PGE Share of Output | 9.00% |  |
PGE Share of Capacity | 181 |  |
Long-term Contract for Purchase of Electric Power, Date of Contract Expiration | Dec. 31, 2052 |  |
commitment costs | 14 | 14 | 10
Wells [Member] |  |  |
Long-term Contract for Purchase of Electric Power [Line Items] |  |  |
Revenue Bonds issued by the Public Utility Districts | 238 |  |
PGE Share of Output | 19.40% |  |
PGE Share of Capacity | 159 |  |
Long-term Contract for Purchase of Electric Power, Date of Contract Expiration | Dec. 31, 2018 |  |
commitment costs | 10 | 10 | 7
Portland Hydro [Member] |  |  |
Long-term Contract for Purchase of Electric Power [Line Items] |  |  |
Revenue Bonds issued by the Public Utility Districts | 9 |  |
PGE Share of Output | 100.00% |  |
PGE Share of Capacity | 36 |  |
Long-term Contract for Purchase of Electric Power, Date of Contract Expiration | Dec. 31, 2017 |  |
commitment costs | $ 4 | $ 4 | $ 4

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- Definition PGE portion of Capacity from Public Utility Districts + References No definition available. + Details
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- Definition Revenue Bonds issued by the Public Utility Districts + References No definition available. + Details
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- Definition Date of contract expiration of long-term contract to purchase electricity from a production plant, in CCYY-MM-DD format. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB TOPIC 10.D) -URI http://asc.fasb.org/extlink&oid=6499423&loc=d3e659339-123030 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 10 -Section D + Details
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- Details
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