XML 44 R34.htm IDEA: XBRL DOCUMENT
v3.5.0.2

Fair Value of Financial Instruments Financial Assets and Liabilities Recognized at Fair Value (Details) - USD ($) $ in Millions | Jun. 30, 2016 | Dec. 31, 2015
--- | --- | ---
Debt securities: |  |
Domestic government | $ 13 | $ 14
Corporate credit | 9 | 8
Money market funds | 19 | 18
Investments, Fair Value Disclosure | 2 | 2
Non-qualified benefit plan trust: (2) |  |
Domestic | 3 | 3
Debt securities—domestic government | 1 | 1
Alternative Investments, Fair Value Disclosure | 1 | 1
Assets from price risk management activities: (1) (3) |  |
Electricity | 9 | 7
Natural gas | 8 | 3
Total | 65 | 57
Liabilities from price risk management activities: (1) (3) |  |
Electricity | 152 | 133
Natural gas | 100 | 158
Total | 252 | 291
Fair Value, Inputs, Level 1 [Member] |  |
Debt securities: |  |
Domestic government | 4 | 6
Corporate credit | 0 | 0
Non-qualified benefit plan trust: (2) |  |
Domestic | 3 | 3
Debt securities—domestic government | 1 | 1
Assets from price risk management activities: (1) (3) |  |
Electricity | 0 | 0
Natural gas | 0 | 0
Total | 8 | 10
Liabilities from price risk management activities: (1) (3) |  |
Electricity | 0 | 0
Natural gas | 0 | 0
Total | 0 | 0
Fair Value, Inputs, Level 2 [Member] |  |
Debt securities: |  |
Domestic government | 9 | 8
Corporate credit | 9 | 8
Non-qualified benefit plan trust: (2) |  |
Domestic | 0 | 0
Debt securities—domestic government | 0 | 0
Assets from price risk management activities: (1) (3) |  |
Electricity | 8 | 7
Natural gas | 8 | 3
Total | 34 | 26
Liabilities from price risk management activities: (1) (3) |  |
Electricity | 7 | 28
Natural gas | 86 | 144
Total | 93 | 172
Fair Value, Inputs, Level 3 [Member] |  |
Debt securities: |  |
Domestic government | 0 | 0
Corporate credit | 0 | 0
Non-qualified benefit plan trust: (2) |  |
Domestic | 0 | 0
Debt securities—domestic government | 0 | 0
Assets from price risk management activities: (1) (3) |  |
Electricity | 1 | 0
Natural gas | 0 | 0
Total | 1 | 0
Liabilities from price risk management activities: (1) (3) |  |
Electricity | 145 | 105
Natural gas | 14 | 14
Total | 159 | 119
Reported Value Measurement [Member] |  |
Debt securities: |  |
Money market funds | 19 | 18
Investments, Fair Value Disclosure | 2 | 2
Non-qualified benefit plan trust: (2) |  |
Alternative Investments, Fair Value Disclosure | 1 | 1
Estimate of Fair Value Measurement [Member] |  |
Assets from price risk management activities: (1) (3) |  |
Total | $ 22 | $ 21

X
- Definition Assets from price risk management activities: [Abstract] + References No definition available. + Details
Name: | por_AssetsFromPriceRiskManagementActivitiesAbstract
Namespace Prefix: | por_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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

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

X
- Definition Debt securities: [Abstract] + References No definition available. + Details
Name: | por_DebtSecuritiesAbstract
Namespace Prefix: | por_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Liabilities from price risk management activities: [Abstract] + References No definition available. + Details
Name: | por_LiabilitiesFromPriceRiskManagementActivitiesAbstract
Namespace Prefix: | por_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Debt mutual funds assets in the Non-qualified benefit plan trust, which are carried at fair value. + References No definition available. + Details
Name: | por_MutualFundsDebt
Namespace Prefix: | por_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Equity mutual fund assets held in the Non-qualified benefit plan trust, which are carried at fair value. + References No definition available. + Details
Name: | por_MutualFundsEquity
Namespace Prefix: | por_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Non-qualified benefit plan trust: [Abstract] + References No definition available. + Details
Name: | por_NonqualifiedBenefitPlanTrustAbstract
Namespace Prefix: | por_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fair value of investments in certain entities that calculate net asset value per share, including, but not limited to, by unit, membership interest, or other ownership interest. Investments include, but are not limited to, investments in certain hedge funds, venture capital funds, private equity funds, real estate partnerships or funds. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 6A -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=36462937&loc=SL6742756-110258 + Details
Name: | us-gaap_AlternativeInvestmentsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The aggregate fair value as of the balance sheet date of financial instruments and other positions owned by the entity including: (1) mortgages, mortgage-backed and asset backed securities; (2) US government and agency obligations; (3) state and municipal government obligations; (4) other sovereign government debt; (5) corporate obligations; (6) corporate equities; (7) principal investments; (8) derivative contracts; and (9) physical commodities. Includes both pledged and unpledged holdings. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 940 -SubTopic 320 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=35711157&loc=d3e42546-110969 + Details
Name: | us-gaap_FinancialInstrumentsOwnedAtFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The fair value as of the balance sheet date of firm holdings in fixed income or other debt securities issued by a corporation or other issuer not elsewhere specified in the taxonomy. Includes both pledged (to counterparties as collateral for financing transactions) and unpledged holdings. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 940 -SubTopic 320 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=35711157&loc=d3e42546-110969 + Details
Name: | us-gaap_FinancialInstrumentsOwnedCorporateDebtAtFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Trading Securities -URI http://asc.fasb.org/extlink&oid=6526789 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 35 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=27723805&loc=d3e24584-111560 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 25 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=51813488&loc=d3e22054-111558 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Available-for-Sale Securities -URI http://asc.fasb.org/extlink&oid=6505594 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 1 -Subparagraph a, f, g -Article 7 + Details
Name: | us-gaap_InvestmentsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value of financial and nonfinancial obligations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258 + Details
Name: | us-gaap_LiabilitiesFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Investment in short-term money-market instruments (such as commercial paper, banker's acceptances, repurchase agreements, government securities, certificates of deposit, and so forth) which are highly liquid (that is, readily convertible to known amounts of cash) and so near their maturity that they present an insignificant risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify as cash equivalents by definition. Original maturity means an original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three-years ago does not become a cash equivalent when its remaining maturity is three months. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Cash Equivalents -URI http://asc.fasb.org/extlink&oid=6507016 + Details
Name: | us-gaap_MoneyMarketFundsAtCarryingValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Debt (bills, notes or bonds) that are issued by the government of the United States which are short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three-years ago does not become a cash equivalent when its remaining maturity is three months. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Cash Equivalents -URI http://asc.fasb.org/extlink&oid=6507016 + Details
Name: | us-gaap_USGovernmentSecuritiesAtCarryingValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_CarryingReportedAmountFairValueDisclosureMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_EstimateOfFairValueFairValueDisclosureMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |