XML 91 R78.htm IDEA: XBRL DOCUMENT
v3.6.0.2

Employee Benefits Schedule of Fair Value, Assets (Details) - USD ($) $ in Millions | Dec. 31, 2016 | Dec. 31, 2015 | Dec. 31, 2014
--- | --- | --- | ---
Defined Benefit Plan Disclosure [Line Items] |  |  |
Money Market Funds, at Carrying Value | $ 21 | $ 18 |
Investments, Fair Value Disclosure | 2 | 2 |
Equity securities: |  |  |
Domestic | 52 | 44 |
Defined Benefit Plan, Fair Value of Plan Assets |  | 550 |
Financial Instruments, Owned, at Fair Value | 23 | 21 |
Other Postretirement Benefit Plans assets: [Abstract] |  |  |
Money market funds |  | 0 |
Domestic equity securities - Other postretirement benefit plan assets at fair value |  | 3 |
International equity securities - other post retirement assets at fair value |  | 8 |
Private Equity Funds, Domestic [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Money Market Funds, at Carrying Value | 6 | 5 |
Investments, Fair Value Disclosure | 18 | 22 |
Equity Securities [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Investments, Fair Value Disclosure | 483 | 479 |
Fair Value, Inputs, Level 1 [Member] |  |  |
Equity securities: |  |  |
Domestic | 52 | 44 |
Private equity funds | 0 | 0 |
Defined Benefit Plan, Fair Value of Plan Assets | 52 | 44 |
Financial Instruments, Owned, at Fair Value | 8 | 10 |
Other Postretirement Benefit Plans assets: [Abstract] |  |  |
Money market funds | 4 | 0 |
Domestic equity securities - Other postretirement benefit plan assets at fair value | 0 | 0 |
International equity securities - other post retirement assets at fair value | 8 | 8 |
Other post retirement benefit plan assets total | 12 | 8 |
Fair Value, Inputs, Level 2 [Member] |  |  |
Equity securities: |  |  |
Domestic | 0 | 0 |
Private equity funds | 0 | 0 |
Defined Benefit Plan, Fair Value of Plan Assets | 0 | 0 |
Financial Instruments, Owned, at Fair Value | 39 | 26 |
Other Postretirement Benefit Plans assets: [Abstract] |  |  |
Money market funds | 0 | 0 |
Domestic equity securities - Other postretirement benefit plan assets at fair value | 3 | 3 |
International equity securities - other post retirement assets at fair value | 0 | 0 |
Other post retirement benefit plan assets total | 7 | 8 |
Fair Value, Inputs, Level 3 [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Money Market Funds, at Carrying Value | 0 |  |
Equity securities: |  |  |
Domestic | 0 | 0 |
Private equity funds | 0 | 0 |
Defined Benefit Plan, Fair Value of Plan Assets | 0 | 0 |
Financial Instruments, Owned, at Fair Value | 2 | 0 |
Other Postretirement Benefit Plans assets: [Abstract] |  |  |
Money market funds | 0 | 0 |
Domestic equity securities - Other postretirement benefit plan assets at fair value | 0 | 0 |
International equity securities - other post retirement assets at fair value | 0 | 0 |
Other post retirement benefit plan assets total | 0 | 0 |
Pension Plan [Member] |  |  |
Equity securities: |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 559 | 550 | $ 591
Financial Instruments, Owned, at Fair Value | 507 | 506 |
Other Postretirement Benefit Plans [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Money Market Funds, at Carrying Value | 4 | 7 |
Investments, Fair Value Disclosure | 7 | 7 |
Equity securities: |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 30 | 30 | $ 32
Financial Instruments, Owned, at Fair Value | 11 | $ 14 |
Other Postretirement Benefit Plans assets: [Abstract] |  |  |
Money market funds | 4 |  |
Domestic equity securities - Other postretirement benefit plan assets at fair value | 3 |  |
International equity securities - other post retirement assets at fair value | $ 8 |  |

X
- Definition Domestic equity securities - defined benefit pension plan assets + References No definition available. + Details
Name: | por_DomesticEquitySecuritiesDefinedBenefitPensionPlanAssets
Namespace Prefix: | por_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Domestic equity securities - Other postretirement benefit plan assets at fair value + References No definition available. + Details
Name: | por_DomesticEquitySecuritiesOtherPostretirementBenefitPlanAssetsAtFairValue
Namespace Prefix: | por_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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

X
- Definition Money market funds - other post retirement benefit plan assets at fair value + References No definition available. + Details
Name: | por_FairValueOfMoneyMarketFundsOtherPostRetirementBenefitPlanAssetsAtFairValue
Namespace Prefix: | por_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition International equity securities - other post retirement assets at fair value + References No definition available. + Details
Name: | por_InternationalEquitySecuritiesOtherPostRetirementAssetsAtFairValue
Namespace Prefix: | por_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition other post retirement benefit plan assets total + References No definition available. + Details
Name: | por_OtherPostRetirementBenefitPlanAssetsTotal
Namespace Prefix: | por_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Other Postretirement Benefit Plans assets: [Abstract] + References No definition available. + Details
Name: | por_OtherPostretirementBenefitPlansAssetsAbstract
Namespace Prefix: | por_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Private equity fund securities held in Defined Benefit Pension Plan assets + References No definition available. + Details
Name: | por_PrivateEquityFunds
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_DefinedBenefitPlanDisclosureLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fair value of assets that have been segregated and restricted to provide pension or postretirement benefits. Assets include, but are not limited to, stocks, bonds, other investments, earnings from investments, and contributions by the employer and employees. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 30 -Section 35 -Paragraph 50 -URI http://asc.fasb.org/extlink&oid=64937038&loc=d3e12355-114930 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e1928-114920 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Plan Assets -URI http://asc.fasb.org/extlink&oid=6749337 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Plan Assets -URI http://asc.fasb.org/extlink&oid=6520858 + Details
Name: | us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
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 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 -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(12)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: 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 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(5)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(6)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 5: 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 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(2)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 7: 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=65884222&loc=d3e22054-111558 Reference 8: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(1)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 Reference 9: 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 + Details
Name: | us-gaap_InvestmentsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_PrivateEquityFundsDomesticMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_EquitySecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis=us-gaap_PensionPlansDefinedBenefitMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis=us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |