XML 115 R102.htm IDEA: XBRL DOCUMENT v3.10.0.1

Contingencies (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jun. 30, 2018	Dec. 31, 1993
Loss Contingencies [Line Items]
Malpractice Loss Contingency, Letters of Credit and Surety Bonds		$ 145.6
Long-term Purchase Commitment, Amount	$ 130.0
Proceeds from Insurance Settlement, Investing Activities	120.0	120.0	$ 0.0	$ 0.0
Former Gain Contingency, Recognized in Current Period	$ 10.0
Loss Contingency, Damages Sought, Value		$ 1,200.0
Site Contingency, Names of Other Potentially Responsible Parties		100
Litigation Settlement, Expense		$ 115.0
Loss Contingency, Range of Possible Loss, Maximum		1,700.0
Loss Contingency, Range of Possible Loss, Portion Not Accrued		500.0
Loss Contingency, Inestimable Loss		1,100.0
Payments for Environmental Liabilities		6.0
investment in Trojan						87.00%
Class action damages sought		260.0
Public Utilities, Property, Plant and Equipment, Amount of Construction Work in Process Included in Rate Base		514.0
Public Utilities, Property, Plant and Equipment, Other Property, Plant and Equipment					$ 640.0
Loss Contingency, Accrual, Current		$ 8.0	$ 14.0

X

- Definition

Class action lawsuit damages sought by plaintiffs against the Company.

+ References

No definition available.

+ Details

Name:	por_ClassActionLawsuitDamagesSought
Namespace Prefix:	por_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Estimated total remediation costs, discounted

+ References

No definition available.

+ Details

Name:	por_Estimatedtotalremediationcostsdiscounted
Namespace Prefix:	por_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

The portion of the Company's remaining investment in its Trojan plant that the OPUC allowed the Company to recover.

+ References

No definition available.

+ Details

Name:	por_InvestmentInTrojan
Namespace Prefix:	por_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Amount of gain recognized in the period that had been disclosed in prior periods as a contingent gain.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 30
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6397426&loc=d3e17499-108355

+ Details

Name:	us-gaap_FormerGainContingencyRecognizedInCurrentPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

The amount or range of possible amounts of gain that could be realized upon the resolution of a contingency.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 30
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6397426&loc=d3e17499-108355

+ Details

Name:	us-gaap_GainContingencyUnrecordedAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Amount of litigation expense, including but not limited to legal, forensic, accounting, and investigative fees.

+ References

No definition available.

+ Details

Name:	us-gaap_LitigationSettlementExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

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_LossContingenciesLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Amount of loss contingency liability expected to be resolved within one year or the normal operating cycle, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=82911808&loc=d3e14326-108349

+ Details

Name:	us-gaap_LossContingencyAccrualCarryingValueCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

The value (monetary amount) of the award the plaintiff seeks in the legal matter.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 9
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=82911808&loc=d3e14557-108349

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=82911808&loc=d3e14435-108349

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=82911808&loc=d3e14326-108349

+ Details

Name:	us-gaap_LossContingencyDamagesSoughtValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Reflects the estimated amount of loss from the specified contingency as of the balance sheet date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=82911808&loc=d3e14435-108349

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 9
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=82911808&loc=d3e14557-108349

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=115931803&loc=d3e12021-110248

+ Details

Name:	us-gaap_LossContingencyEstimateOfPossibleLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

The difference between the maximum amount of estimated loss and the amount recorded as of the balance sheet date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 05
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=99385795&loc=d3e12631-108344

+ Details

Name:	us-gaap_LossContingencyRangeOfPossibleLossPortionNotAccrued
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Amount of letters of credit and other surety bonds that are available for the future payment of malpractice claims.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 954
-SubTopic 450
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6491354&loc=d3e6049-115624

+ Details

Name:	us-gaap_MalpracticeLossContingencyLettersOfCreditAndSuretyBonds
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Cash outflows made during the period for environmental remediation activities.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 17
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3367-108585

+ Details

Name:	us-gaap_PaymentsForEnvironmentalLiabilities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Amount of cash inflow for proceeds from settlement of insurance claim, classified as investing activities. Excludes insurance settlement classified as operating activities.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 21B
-URI http://asc.fasb.org/extlink&oid=109223946&loc=SL94080549-108585

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3179-108585

+ Details

Name:	us-gaap_ProceedsFromInsuranceSettlementInvestingActivities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Discloses the amount of construction work in process that is included in the rate making process at period end.

+ References

No definition available.

+ Details

Name:	us-gaap_PublicUtilitiesPropertyPlantAndEquipmentAmountOfConstructionWorkInProcessIncludedInRateBase
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Period end book value of other property, plant and equipment (PPE) owned (but not classified elsewhere) by the public utility.

+ References

No definition available.

+ Details

Name:	us-gaap_PublicUtilitiesPropertyPlantAndEquipmentOtherPropertyPlantAndEquipment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Names of other potentially responsible parties for an individual site.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 30
-Section 50
-Paragraph 10
-Subparagraph (d)(3)
-URI http://asc.fasb.org/extlink&oid=6393242&loc=d3e13237-110859

+ Details

Name:	us-gaap_SiteContingencyNamesOfOtherPotentiallyResponsibleParties
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration