XML 55 R42.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Price Risk Management Net realized and unrealized gains and losses on derivative transactions (Details) (USD $) In Millions, unless otherwise specified | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2013 | Sep. 30, 2012 | Sep. 30, 2013 | Sep. 30, 2012
Commodity contracts: |  |  |  |
Electricity | $ (1) | $ (3) | $ 17 | $ 40
Natural Gas | $ 10 | $ (19) | $ 30 | $ 6

X
- Details
Name: | por_CurrentAssetsCommodityContractsAbstract
Namespace Prefix: | por_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Realized and unrealized gains and losses, net on commodity contracts related to electricity not designated as hedging instruments included in purchased power and fuel expense in the statement of income. + References No definition available. + Details
Name: | por_RealizedAndUnrealizedGainsAndLossesNetCommodityContractsElectricity
Namespace Prefix: | por_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- Definition Realized and unrealized gains and losses, net on commodity contracts related to natural gas not designated as hedging instruments included in purchased power and fuel expense in the statement of income. + References No definition available. + Details
Name: | por_RealizedAndUnrealizedGainsAndLossesNetCommodityContractsNaturalGas
Namespace Prefix: | por_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration