Price Risk Management Net volumes related to price risk management activities (Details) (CAD) In Millions, unless otherwise specified	Mar. 31, 2014 MMBTU MWh	Dec. 31, 2013 MWh MMBTU
Commodity contracts:
Electricity	22,000,000	14,000,000
Natural gas	104,000,000	106,000,000
Foreign currency	2	7

Net volume associated with the reporting entity's derivative instruments recorded as of the balance sheet date having arisen from price risk management activities related to natural gas.

No definition available.

Name:	por_VolumeRelatedToDerivativeInstrumentsAtBalanceSheetDateCommodityContractsNaturalGas
Namespace Prefix:	por_
Data Type:	num:energyItemType
Balance Type:	na
Period Type:	instant