XML 101 R64.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Net realized and unrealized gains and losses on derivative transactions (Details) (USD $) In Millions, unless otherwise specified | 12 Months Ended
--- | ---
Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012
Commodity contracts: [Abstract] |  |  |
Electricity | $ 13 por_RealizedAndUnrealizedGainsAndLossesNetCommodityContractsElectricity | $ 78 por_RealizedAndUnrealizedGainsAndLossesNetCommodityContractsElectricity | $ 56 por_RealizedAndUnrealizedGainsAndLossesNetCommodityContractsElectricity
Natural Gas | 72 por_RealizedAndUnrealizedGainsAndLossesNetCommodityContractsNaturalGas | 28 por_RealizedAndUnrealizedGainsAndLossesNetCommodityContractsNaturalGas | 19 por_RealizedAndUnrealizedGainsAndLossesNetCommodityContractsNaturalGas
Realized And Unrealized Losses Net Commodity Contracts, Foreign Currency | $ 0 por_RealizedAndUnrealizedGainsAndLossesNetCommodityContractsForeignCurrency | $ 1 por_RealizedAndUnrealizedGainsAndLossesNetCommodityContractsForeignCurrency | $ 0 por_RealizedAndUnrealizedGainsAndLossesNetCommodityContractsForeignCurrency

X
- Details
Name: | por_CommodityContractsAbstract
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: | credit
Period Type: | duration

X
- Definition Realized And Unrealized Gains And Losses Net Commodity Contracts, Foreign Currency + References No definition available. + Details
Name: | por_RealizedAndUnrealizedGainsAndLossesNetCommodityContractsForeignCurrency
Namespace Prefix: | por_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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: | credit
Period Type: | duration