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Counterparties representing 10% or more (Details) | Dec. 31, 2017 | Dec. 31, 2016
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Assets from price risk management activities: |  |
Counterparty A | 39.00% | 22.00%
Counterparty B | 12.00% | 17.00%
Counterparty C | 3.00% | 12.00%
Concentration of Risk, Derivative Instruments, Assets | 54.00% | 51.00%
Liabilities from price risk management activities: [Abstract] |  |
Counterparty D | 62.00% | 66.00%
Concentration of Risk, Derivative Instruments, Liabilities | 62.00% | 66.00%

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- Definition Assets from price risk management activities: [Abstract] + References No definition available. + Details
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- Definition Represents aggregate of individually significant counterparties of total assets arising from derivative instruments from price risk management activities. + References No definition available. + Details
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- Definition Represents aggregate of individually significant counterparties of total liabilities arising from derivative instruments from price risk management activities. + References No definition available. + Details
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- Definition Individually significant counterparty of total assets arising from derivative instruments from price risk management activities. + References No definition available. + Details
Name: | por_CounterpartyA
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- Definition Individually significant counterparty of total assets arising from derivative instruments from price risk management activities. + References No definition available. + Details
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- Definition Individually significant counterparty of total assets arising from derivative instruments from price risk management activities. + References No definition available. + Details
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- Definition Counterparty D for PRM Liab + References No definition available. + Details
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- Definition Liabilities from price risk management activities: [Abstract] + References No definition available. + Details
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