XML 34 R24.htm IDEA: XBRL DOCUMENT
v3.21.2

Basis of Presentation (Details) retail_customers in Thousands, mi² in Thousands | Sep. 30, 2021 mi² retail_customers
--- | ---
Basis of Presentation [Abstract] |
Service Area Sq Miles | mi² | 4
Incorporated Cities | 51
Number of Retail Customers | retail_customers | 914

X
- Definition Basis of Presentation [Abstract] + References No definition available. + Details
Name: | por_BasisOfPresentationAbstract
Namespace Prefix: | por_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of incorporated cities in service area. + References No definition available. + Details
Name: | por_IncorporatedCities
Namespace Prefix: | por_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Includes residential, commercial and industrial. + References No definition available. + Details
Name: | por_NumberOfRetailCustomers
Namespace Prefix: | por_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Approximate square miles of service area. + References No definition available. + Details
Name: | por_ServiceAreaSqMiles
Namespace Prefix: | por_
Data Type: | dtr-types:areaItemType
Balance Type: | na
Period Type: | instant