XML 70 R57.htm IDEA: XBRL DOCUMENT
v3.6.0.2

Fair Value of FInancial Instruments Fair Value Options Quantitative Disclosure (Details) - USD ($) | Dec. 31, 2016 | Dec. 31, 2015
--- | --- | ---
Minimum [Member] |  |
Fair Value, Option, Quantitative Disclosures [Line Items] |  |
Electricity physical forward purchase | $ 14.25 | $ 8.50
Natural gas financial swaps | 1.85 | 2.06
Fnancial swaps - electricity | 8.57 | 9.98
Maximum [Member] |  |
Fair Value, Option, Quantitative Disclosures [Line Items] |  |
Electricity physical forward purchase | 54.73 | 84.47
Natural gas financial swaps | 4.92 | 3.70
Fnancial swaps - electricity | 33.60 | 27.36
Weighted Average [Member] |  |
Fair Value, Option, Quantitative Disclosures [Line Items] |  |
Electricity physical forward purchase | 38.18 | 30.69
Natural gas financial swaps | 2.64 | 2.54
Fnancial swaps - electricity | 25.10 | 19.26
Assets [Member] |  |
Fair Value, Option, Quantitative Disclosures [Line Items] |  |
Electricity physical forward purchase | 0 | 0
Natural gas financial swaps | 1,000,000 | 0
Fnancial swaps - electricity | 1,000,000 | 0
Total commodity contracts | 2,000,000 | 0
Liabilities [Member] |  |
Fair Value, Option, Quantitative Disclosures [Line Items] |  |
Electricity physical forward purchase | 112,000,000 | 105,000,000
Natural gas financial swaps | 9,000,000 | 14,000,000
Fnancial swaps - electricity | 0 | 0
Total commodity contracts | $ 121,000,000 | $ 119,000,000

X
- Definition Electricity physical forward purchase + References No definition available. + Details
Name: | por_ElectricityPhysicalForwardPurchase
Namespace Prefix: | por_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fnancial swaps - electricity + References No definition available. + Details
Name: | por_FnancialSwapsElectricity
Namespace Prefix: | por_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Natural gas financial swaps + References No definition available. + Details
Name: | por_NaturalGasFinancialSwaps
Namespace Prefix: | por_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Total commodity contracts + References No definition available. + Details
Name: | por_TotalCommodityContracts
Namespace Prefix: | por_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition 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. + References No definition available. + Details
Name: | us-gaap_FairValueOptionQuantitativeDisclosuresLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_WeightedAverageMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_AvailableforsaleSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_DerivativeFinancialInstrumentsLiabilitiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |