XML 67 R59.htm IDEA: XBRL DOCUMENT
v2.4.0.6

Fair Value of FInancial Instruments Fair Value Options Quantitative Disclosure (Details) (USD $) | Dec. 31, 2012 | Dec. 31, 2011
--- | --- | ---
Fair Value, Option, Quantitative Disclosures [Line Items] |  |
Commodity Contract Liabilities, Electricity | $ 82,000,000 | $ 137,000,000
Commodity Contract Liabilities, Natural gas | 118,000,000 | 251,000,000
Minimum [Member] |  |
Fair Value, Option, Quantitative Disclosures [Line Items] |  |
commodity contracts assets, natural gas | 3.74 |
Commodity Contract Liabilities, Electricity | 7.12 |
Commodity Contract Liabilities, Natural gas | 3.67 |
Maximum [Member] |  |
Fair Value, Option, Quantitative Disclosures [Line Items] |  |
commodity contracts assets, natural gas | 5.21 |
Commodity Contract Liabilities, Electricity | 51.72 |
Commodity Contract Liabilities, Natural gas | 5.21 |
Weighted Average [Member] |  |
Fair Value, Option, Quantitative Disclosures [Line Items] |  |
commodity contracts assets, natural gas | 4.36 |
Commodity Contract Liabilities, Electricity | 41.14 |
Commodity Contract Liabilities, Natural gas | 4.20 |
Fair Value, Inputs, Level 3 [Member] |  |
Fair Value, Option, Quantitative Disclosures [Line Items] |  |
commodity contracts assets, natural gas | 2,000,000 |
Commodity Contract Liabilities, Electricity | 10,000,000 | 29,000,000
Commodity Contract Liabilities, Natural gas | $ 8,000,000 | $ 50,000,000

X
- Definition Carrying amount as of the balance sheet date of the liabilities arising from commodity contracts related to purchases or sales of electricity. + References No definition available. + Details
Name: | por_CommodityContractLiabilitiesElectricity
Namespace Prefix: | por_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | instant

X
- Definition Carrying amount as of the balance sheet date of the liabilities arising from commodity contracts related to purchases or sales of natural gas. + References No definition available. + Details
Name: | por_CommodityContractLiabilitiesNaturalGas
Namespace Prefix: | por_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | instant

X
- Definition commodity contracts assets, natural gas + References No definition available. + Details
Name: | por_CommodityContractsAssetsNaturalGas
Namespace Prefix: | por_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_FairValueOptionQuantitativeDisclosuresLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration