XML 65 R54.htm IDEA: XBRL DOCUMENT
v3.24.0.1

Summary of Significant Accounting Policies Estimated average service lives (Details) | 12 Months Ended
--- | ---
Dec. 31, 2023
Generation, excluding thermal: |
Hydro | 95 years
Wind | 30 years
Transmission | 61 years
Distribution | 51 years
General | 16 years

X
- Definition estimated average service life - hydro production plant + References No definition available. + Details
Name: | por_Estimatedaverageservicelifehydroproductionplant
Namespace Prefix: | por_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition estimated average service life - wind production plant + References No definition available. + Details
Name: | por_Estimatedaverageservicelifewindproductionplant
Namespace Prefix: | por_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Production plant, excluding thermal: [Abstract] + References No definition available. + Details
Name: | por_ProductionExcludingThermalAbstract
Namespace Prefix: | por_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Useful life of assets common to business units owned by public utility, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesPropertyPlantAndEquipmentCommonUsefulLife
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Useful life of utility distribution assets owned by public utility, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesPropertyPlantAndEquipmentDistributionUsefulLife
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Useful life of utility transmission equipment owned by public utility, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesPropertyPlantAndEquipmentTransmissionUsefulLife
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration