Balance Sheet Components [Abstract] Balance Sheet Components [Abstract] Schedule of Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Electric utility plant Public Utilities, Property, Plant and Equipment, Plant in Service Construction work-in-progress Public Utilities, Property, Plant and Equipment, Construction Work in Progress Total cost Property, Plant and Equipment, Gross Less: accumulated depreciation and amortization Public Utilities, Property, Plant and Equipment, Accumulated Depreciation Electric utility plant, net Public Utilities, Property, Plant and Equipment, Net Fair Value of Financial Instruments [Abstract] Fair Value of Financial Instruments [Abstract] Fair Value of Financial Instruments, Policy [Policy Text Block] Fair Value of Financial Instruments, Policy [Policy Text Block] Allocation of Financial Asset to Hierarchy Levels [Policy Text Block] Allocation of Financial Asset to Hierarchy Levels [Policy Text Block] Allocation of Financial Asset to Hierarchy Levels [Policy Text Block] Fair Value Transfer, Policy [Policy Text Block] Fair Value Transfer, Policy [Policy Text Block] Debt, Policy [Policy Text Block] Debt, Policy [Policy Text Block] Basis of Presentation [Abstract] Basis of Presentation [Abstract] Consolidation, Policy [Policy Text Block] Consolidation, Policy [Policy Text Block] Earnings Per Share [Abstract] Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Other Current Liabilities [Abstract] Other Current Liabilities [Abstract] Other Current Liabilities [Table] Other Current Liabilities [Table] Other Current Liabilities [Table] Scenario [Axis] Scenario, Unspecified [Domain] Statement [Line Items] Accrued employee compensation and benefits Employee-related Liabilities, Current Accrued interest payable Interest Payable Accrued dividends payable Dividends Payable, Current Accrued taxes payable Taxes Payable, Current Regulatory liabilities—current Regulatory Liability, Current Other Other Current Liabilities - Other Other Current Liabilities - Other Total accrued expenses and other current liabilities Other Liabilities, Current Additional Fair Value Elements [Abstract] Fair Value, Option, Quantitative Disclosures [Table] Fair Value, Option, Quantitative Disclosures [Table] Fair Value, Hierarchy [Axis] Fair Value, Hierarchy [Axis] Fair Value Hierarchy [Domain] Fair Value Hierarchy [Domain] Fair Value, Inputs, Level 2 [Member] Fair Value, Inputs, Level 2 [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Inputs, Level 3 [Member] Measurement Frequency [Axis] Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Fair Value, Measurement Frequency [Domain] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Net gain or loss recognized in the statement of income offset by regulatory accounting Net gain or loss recognized in the statement of income offset by regulatory accounting Net gain or loss recognized in the statement of income for derivative instruments related to price risk management activities offset by regulatory accounting. Defined Benefit Plan, Transfers Between Measurement Levels Defined Benefit Plan, Transfers Between Measurement Levels Cash Surrender Value, Fair Value Disclosure Cash Surrender Value, Fair Value Disclosure Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3 Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3 Long-term Debt Long-term Debt Long-term Debt, Fair Value Long-term Debt, Fair Value Price Risk Management [Abstract] Price Risk Management [Abstract] Derivative [Table] Derivative [Table] Derivative, by Nature [Axis] Derivative, by Nature [Axis] Derivative, Name [Domain] Derivative, Name [Domain] Derivative [Line Items] Derivative [Line Items] Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block] Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block] Schedule of Derivative Instruments [Table Text Block] Schedule of Derivative Instruments [Table Text Block] Price Risk Management Assets and Liabilities Subject to Master Netting Agreements [Table Text Block] Price Risk Management Assets and Liabilities Subject to Master Netting Agreements [Table Text Block] Price Risk Management Assets and Liabilities Subject to Master Netting Agreements [Table Text Block] Schedule of Other Derivatives Not Designated as Hedging Instruments, Statements of Financial Performance and Financial Position, Location [Table Text Block] Schedule of Other Derivatives Not Designated as Hedging Instruments, Statements of Financial Performance and Financial Position, Location [Table Text Block] Schedule of Price Risk Derivatives [Table Text Block] Schedule of Price Risk Derivatives [Table Text Block] Schedule of Concentration of Risk, by Counterparty [Table Text Block] Schedule of Concentration of Risk, by Counterparty [Table Text Block] Tabular disclosure of counterparties representing 10% or more of assets and liabilities from price risk management activities recorded in the reporting entity's statement of financial position. BASIS OF PRESENTATION Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Derivative Instrument [Axis] Derivative Instrument [Axis] Derivative Contract [Domain] Derivative Contract [Domain] Electricity [Member] Electricity [Member] Electricity [Member] Natural Gas [Member] Natural Gas [Member] Unrealized Gain Loss On Derivatives [Member] Unrealized Gain Loss On Derivatives [Member] Unrealized Gain Loss On Derivatives [Member] Schedule of Future Expected Realized Gains or Losses [Axis] Schedule of Future Expected Realized Gains or Losses [Axis] Schedule of Future Expected Realized Gains or Losses [Domain] Schedule of Future Expected Realized Gains or Losses [Domain] Commodity contracts: Current Assets, Commodity Contracts: [Abstract] Commodity contracts: [Abstract] Other Commitment, Due in Next Twelve Months Other Commitment, Due in Next Twelve Months Other Commitment, Due in Second Year Other Commitment, Due in Second Year Other Commitment, Due in Third Year Other Commitment, Due in Third Year Other Commitment, Due in Fourth Year Other Commitment, Due in Fourth Year Other Commitment, Due in Fifth Year Other Commitment, Due in Fifth Year Other Commitment, Due after Fifth Year Other Commitment, Due after Fifth Year Electricity Other Commitment Valuation and Qualifying Accounts Disclosure [Table] Valuation and Qualifying Accounts Disclosure [Table] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Debt [Member] Debt [Member] 4.35%, May 15 [Member] 4.35%, May 15 [Member] 4.35%, May 15, 2014 [Member] 4.45%, May 30 [Member] 4.45%, May 30 [Member] 4.45%, May 30, 2014 [Member] 4.45%, June 30 [Member] 4.55%, June 30 [Member] 4.55%, June 30, 2014 [Member] July 31 [Member] July 31 [Member] July 31, 2014 [Member] 4.39%, August 15, 2014 [Member] 4.39%, August 15, 2014 [Member] 4.39%, August 15, 2014 [Member] 4.44%, October 15, 2014 [Member] 4.44%, October 15, 2014 [Member] 4.44%, October 15, 2014 [Member] 3.51%, November 17, 2014 [Member] 3.51%, November 17, 2014 [Member] 3.51%, November 17, 2014 [Member] Valuation Allowances and Reserves Type [Axis] Valuation Allowances and Reserves Type [Axis] Valuation Allowances and Reserves [Domain] Valuation Allowances and Reserves [Domain] Valuation and Qualifying Accounts Disclosure [Line Items] Valuation and Qualifying Accounts Disclosure [Line Items] Allowance for Doubtful Accounts Receivable, Current Allowance for Doubtful Accounts Receivable, Current Finite-Lived Intangible Assets, Accumulated Amortization Finite-Lived Intangible Assets, Accumulated Amortization Amortization of Intangible Assets Amortization of Intangible Assets Expenses related to Cascade Crossing Expenses related to Cascade Crossing Expenses related to Cascade Crossing Line of Credit Facility scheduled to terminate in 2017 Credit Facility expiring in 2017 Credit Facility expiring in 2017 Credit Facilities - $300 million revolver Credit Facilities - $300 million revolver Credit Facilities - $300 million revolver Debt Instrument, Covenant Description Debt Instrument, Covenant Description Ratio of Indebtedness to Net Capital Ratio of Indebtedness to Net Capital Authorized Short-Term Debt Authorized Short-Term Debt FERC-authorized short-term debt through February 6, 2012 Short-term Debt Short-term Debt Commercial Paper Commercial Paper Borrowings Line of Credit Facility, Amount Outstanding Line of Credit Facility, Remaining Borrowing Capacity Line of Credit Facility, Remaining Borrowing Capacity Line of Credit Facility, Current Borrowing Capacity Line of Credit Facility, Current Borrowing Capacity Pledged Financial Instruments, Not Separately Reported, Securities for Letter of Credit Facilities Pledged Financial Instruments, Not Separately Reported, Securities for Letter of Credit Facilities letter of credit facility amount available letter of credit facility amount available Letter of credit facility amount available, after deducting amount outstanding from total capacity. Proceeds from Long-term Lines of Credit Proceeds from Long-term Lines of Credit Debt Instrument, Description of Variable Rate Basis Debt Instrument, Description of Variable Rate Basis Debt Instrument, Interest Rate During Period Debt Instrument, Interest Rate During Period Proceeds from Issuance of Long-term Debt Debt Instrument, Face Amount Debt Instrument, Interest Rate, Stated Percentage Debt Instrument, Interest Rate, Stated Percentage Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value, Measurements, Fair Value Hierarchy [Domain] Estimate of Fair Value, Fair Value Disclosure [Member] Estimate of Fair Value Measurement [Member] Fair Value, Inputs, Level 1 [Member] Fair Value, Inputs, Level 1 [Member] Assets: Assets [Abstract] Nuclear decommissioning trust: (1) Nuclear decommissioning trust: [Abstract] Nuclear decommissioning trust: [Abstract] Money market funds Money Market Funds, at Carrying Value Debt securities: Debt securities: [Abstract] Debt securities: [Abstract] Domestic government US Government Securities, at Carrying Value Corporate credit Financial Instruments, Owned, Corporate Debt, at Fair Value Non-qualified benefit plan trust: (2) Nonqualified Benefit Plan Trust: [Abstract] Non-qualified benefit plan trust: [Abstract] Equity securities: Marketable Securities, Equity Securities [Abstract] Domestic Mutual Funds, Equity Equity mutual fund assets held in the Non-qualified benefit plan trust, which are carried at fair value. International Common Stock Asset Securities Held In Nonqualified Benefit Plan Trust Common stock asset securities held in Non-qualified benefit plan trust, which are carried at fair value Debt securities - domestic government Mutual Funds, Debt Debt mutual funds assets in the Non-qualified benefit plan trust, which are carried at fair value. Assets from price risk management activities: (1) (3) Assets from price risk management activities: [Abstract] Assets from price risk management activities: [Abstract] Electricity Commodity Contract Asset, Electricity Carrying amount as of the balance sheet date of the asset arising from commodity contracts related to purchases or sales of electricity. Natural gas Commodity Contract Asset, Natural gas Carrying amount as of the balance sheet date of the asset arising from commodity contracts related to purchases or sales of natural gas. Total Financial Instruments, Owned, at Fair Value Liabilities from price risk management activities: (1) (3) Liabilities from price risk management activities: [Abstract] Liabilities from price risk management activities: [Abstract] Electricity Commodity Contract Liabilities, Electricity Carrying amount as of the balance sheet date of the liabilities arising from commodity contracts related to purchases or sales of electricity. Natural gas Commodity Contract Liabilities, Natural gas Carrying amount as of the balance sheet date of the liabilities arising from commodity contracts related to purchases or sales of natural gas. Total Financial and Nonfinancial Liabilities, Fair Value Disclosure EARNINGS PER SHARE Earnings Per Share [Text Block] Equity [Abstract] Issuance Costs Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs Stock Offering stock offering Public stock offering Share Price Share Price Common Stock, Discount on Shares Common Stock, Discount on Shares Equity Forward Sale Agreement, Settlement Threshold Equity Forward Sale Agreement, Settlement Threshold Shares required to contractually settle Equity forward sale agreement requirements. Equity Forward Sale Agreement future settlement amount equity forward sale agreement future settlement amount Funds that would be received undter the equity forward sale agreement in the future. Option Indexed to Issuer's Equity, Settlement Alternatives, Cash, at Fair Value Option Indexed to Issuer's Equity, Settlement Alternatives, Cash, at Fair Value Net share settlement Net share settlement Net share settlement Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Fair Value, Option, Quantitative Disclosures [Table Text Block] Fair Value, Option, Quantitative Disclosures [Table Text Block] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Schedule of Defined Benefit Plans Disclosures [Table] Schedule of Defined Benefit Plans Disclosures [Table] Defined Benefit Plans and Other Postretirement Benefit Plans [Axis] Defined Benefit Plan and Other Postretirement Benefit Plan [Domain] Pension Plan, Defined Benefit [Member] Other Postretirement Benefit Plan, Defined Benefit [Member] Non Qualified Benefit Plans [Member] Non Qualified Benefit Plans [Member] Non Qualified Benefit Plans [Member] Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan Disclosure [Line Items] Service cost Defined Benefit Plan, Service Cost Interest cost Defined Benefit Plan, Interest Cost Expected return on plan assets Defined Benefit Plan, Expected Return on Plan Assets Defined Benefit Plan, Future Amortization of Prior Service Cost (Credit) Defined Benefit Plan, Future Amortization of Prior Service Cost (Credit) Amortization of net actuarial loss Defined Benefit Plan, Amortization of Gains (Losses) Net periodic benefit cost Defined Benefit Plan, Net Periodic Benefit Cost Contingencies [Abstract] Contingencies [Abstract] CONTINGENCIES Commitments and Contingencies Disclosure [Text Block] Incremental Common Shares Attributable to Dilutive Effect of Contingently Issuable Shares Incremental Common Shares Attributable to Dilutive Effect of Contingently Issuable Shares Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Equity Stockholders' Equity Note Disclosure [Text Block] Guarantees [Abstract] GUARANTEES Guarantees [Text Block] Schedule of Stockholders Equity [Table Text Block] Schedule of Stockholders Equity [Table Text Block] Statement of Financial Position [Abstract] Statement [Table] Statement [Table] Scenario [Axis] Scenario, Unspecified [Domain] Statement [Line Items] ASSETS Current assets: Assets, Current [Abstract] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Accounts receivable, net Accounts Receivable, Net, Current Unbilled revenues Unbilled Receivables, Current Inventories Energy Related Inventory Regulatory assets - current Regulatory Assets, Current Other current assets Other Assets, Current Total current assets Assets, Current Electric utility plant, net Regulatory assets - noncurrent Regulatory Assets, Noncurrent Nuclear decommissioning trust Decommissioning Fund Investments Non-qualified benefit plan trust Assets Held-in-trust, Noncurrent Other noncurrent assets Other Assets, Noncurrent Total assets Assets LIABILITIES AND EQUITY Liabilities and Equity [Abstract] Current liabilities Liabilities, Current [Abstract] Accounts payable Accounts Payable, Current Liabilities from price risk mangement activities - current Derivative Liability, Current Current portion of long-term debt Long-term Debt, Current Maturities Accrued expenses and other current liabilities Total current liabilities Liabilities, Current Long-term debt, net of current portion Long-term Debt, Excluding Current Maturities Regulatory liabilities - noncurrent Regulatory Liability, Noncurrent Deferred income taxes Deferred Tax Liabilities, Net, Noncurrent Unfunded status of pension and postretirement plans Pension and Other Postretirement Defined Benefit Plans, Liabilities, Noncurrent Non-qualified benefit plan liabilities Other Postretirement Defined Benefit Plan, Liabilities, Noncurrent Asset retirement obligation Asset Retirement Obligation Liabilities from price risk mangement activities - noncurrent Derivative Liability, Noncurrent Other noncurrent liabilities Other Liabilities, Noncurrent Total liabilities Liabilities Commitments and contingencies (see notes) Commitments and Contingencies Equity: Portland General Electric Company shareholders' equity: Stockholders' Equity Attributable to Parent [Abstract] Preferred stock, no par value, 30,000,000 shares authorized; none issued and outstanding as of June 30, 2014 and December 31, 2013 Preferred Stock, Value, Issued Common stock, no par value, 160,000,000 shares authorized; 78,202,241 and 78,085,559 shares issued and outstanding as of June 30, 2014 and December 31, 2013, respectively Common Stock, Value, Issued Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Retained earnings Retained Earnings (Accumulated Deficit) Total Portland General Electric Company shareholders' equity Stockholders' Equity Attributable to Parent Noncontrolling interests' equity Stockholders' Equity Attributable to Noncontrolling Interest Total equity Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Total liabilities and equity Liabilities and Equity Concentration Risk [Table] Concentration Risk [Table] Concentration Risk Type [Axis] Concentration Risk Type [Axis] Concentration Risk Type [Domain] Concentration Risk Type [Domain] Assets from price risk management activities: Counterparty A Counterparty-A Individually significant counterparty of total assets arising from derivative instruments from price risk management activities. Counterparty B Counterparty B Individually significant counterparty of total assets arising from derivative instruments from price risk management activities. Counterparty C Counterparty C Individually significant counterparty of total assets arising from derivative instruments from price risk management activities. Concentration of Risk, Derivative Instruments, Assets Concentration of Risk, Derivative Instruments, Assets Represents aggregate of individually significant counterparties of total assets arising from derivative instruments from price risk management activities. Liabilities from price risk management activities: Counterparty D Counterparty D for PRM Liab Counterparty D for PRM Liab Counterparty E Counterparty E For PRM Liab Counterparty E For PRM Liab Concentration of Risk, Derivative Instruments, Liabilities Concentration of Risk, Derivative Instruments, Liabilities Represents aggregate of individually significant counterparties of total liabilities arising from derivative instruments from price risk management activities. BALANCE SHEET COMPONENTS Details of Certain Balance Sheet Accounts Disclosure [Text Block] Details of Certain Balance Sheet Accounts FAIR VALUE OF FINANCIAL INSTRUMENTS Fair Value Disclosures [Text Block] Price Risk Management assets and liabilities subject to master netting agreements [Table] Price Risk Management assets and liabilities subject to master netting agreements [Table] Price Risk Management assets and liabilities subject to master netting agreements [Table] Commodity [Axis] Commodity [Axis] Commodity [Axis] Commodity [Domain] Commodity [Domain] [Domain] for Commodity [Axis] Assets, Total [Member] Assets, Total [Member] Liabilities, Total [Member] Liabilities, Total [Member] Derivative Instrument Risk [Axis] Derivative Contract Type [Domain] Carrying (Reported) Amount, Fair Value Disclosure [Member] Reported Value Measurement [Member] Gross amounts offset [Member] Gross amounts offset [Member] Gross amounts offset [Member] net amount presented [Member] net amount presented [Member] net amount presented [Member] Derivative [Member] Derivative [Member] Securities Pledged as Collateral [Member] Securities Pledged as Collateral [Member] Commodity Contract [Member] Commodity Contract [Member] Price Risk Management assets and liabilities subject to master netting agreements [Line Items] Price Risk Management assets and liabilities subject to master netting agreements [Line Items] [Line Items] for Price Risk Management assets and liabilities subject to master netting agreements [Table] Derivative Asset, Fair Value, Amount Not Offset Against Collateral Derivative Asset, Fair Value, Amount Not Offset Against Collateral Derivative Liability, Fair Value, Net Derivative Liability, Fair Value, Amount Not Offset Against Collateral Schedule of Regulatory Assets [Table] Schedule of Regulatory Assets [Table] Regulatory Liability [Axis] Regulatory Liability [Axis] Regulatory Liability [Domain] Regulatory Liability [Domain] Current Regulatory Liabilities [Member] Current Regulatory Liabilities [Member] Current Regulatory Liabilities Noncurrent Regulatory Liabilities [Member] Noncurrent Regulatory Liabilities [Member] Noncurrent Regulatory Liabilities Regulatory Asset [Axis] Regulatory Asset [Axis] Regulatory Asset [Domain] Regulatory Asset [Domain] Current Regulatory Assets [Member] Regulatory Assets, Current [Member] Current Regulatory Assets Noncurrent Regulatory Assets [Member] Noncurrent Regulatory Assets Regulatory Assets and Liabilities [Line Items] Regulatory Assets [Line Items] Price risk management Regulatory assets related to price risk management activities Regulatory assets related to price risk management activities Pension and other postretirement plans Defined Benefit Plan, Assets for Plan Benefits, Noncurrent Deferred income taxes Deferred Tax Assets, Regulatory Assets and Liabilities Deferred broker settlements Broker settlements - deferred Deferred Broker settlements Debt reacquisition costs Deferred Finance Costs, Net Deferred capital projects Deferred capital project Deferred capital project. Other Other Deferred Costs, Net Total regulatory assets Regulatory Assets Asset retirement removal costs Asset retirement removal Asset retirement removal costs Trojan decommissioning activities regulatory liabilities - trojan decommissioning trust regulatory liabilities - Amounts held in trojan decommissioning trust that is to be returned to customers in future rate proceedings. Asset retirement obligations Asset Retirement Obligations, Noncurrent Other Regulatory liabilities - Other Other regulatory liabilities. Total regulatory liabilities Regulatory Liabilities Condensed Consolidated Balance Sheets (Unaudited) (Parentheticals) [Abstract] Condensed Consolidated Balance Sheets (Unaudited) (Parentheticals) [Abstract] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Preferred stock, no par value Preferred Stock, No Par Value Preferred stock, shares authorized Preferred Stock, Shares Authorized Preferred stock, issued Preferred Stock, Shares Issued Preferred stock, outstanding Preferred Stock, Shares Outstanding Common stock, no par value Common Stock, No Par Value Common stock, shares authorized Common Stock, Shares Authorized Common stock, shares issued Common Stock, Shares, Issued Common stock, shares outstanding Common Stock, Shares, Outstanding Derivatives, Policy [Policy Text Block] Derivatives, Policy [Policy Text Block] Commitments and Contingencies, Policy [Policy Text Block] Commitments and Contingencies, Policy [Policy Text Block] Equity Components [Axis] Equity Component [Domain] Common Stock [Member] Common Stock Including Additional Paid in Capital [Member] Accumulated Other Comprehensive Income (Loss) [Member] Retained Earnings [Member] Noncontrolling Interest [Member] Common Stock, Shares, Outstanding beginning of period Stock Issued During Period, Shares, New Issues Stock Issued During Period, Shares, New Issues Issuances of shares pursuant to equity-based plans Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Stock Issued During Period, Value, New Issues Stock Issued During Period, Value, New Issues Stock-based compensation Share-based Compensation Dividends declared Dividends, Common Stock Net Income (Loss) Attributable to Parent Net Income (Loss) Attributable to Parent Net Income (Loss) Attributable to Noncontrolling Interest Net Income (Loss) Attributable to Noncontrolling Interest Common Stock, Shares, Outstanding end of period Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Allowance for Uncollectible Accounts Accounts, Notes, Loans and Financing Receivable [Line Items] Balance as of begining of period Provision, net Provision for Doubtful Accounts Amounts written off, less recoveries Allowance for Doubtful Accounts Receivable, Write-offs Balance as of end of period Other Current Assets [Table] Other Current Assets [Table] Other Current Assets [Table] Other Current Assets [Line Items] other current assets [Line Items] [Line Items] other current assets [Line Items] [Line Items] Current deferred income tax asset Deferred Tax Assets, Net of Valuation Allowance, Current Prepaid expenses Prepaid Expense and Other Assets, Current Assets from price risk management activities Regulatory assets from price risk management activities Regulatory assets from price risk management activities Margin Deposit Assets Margin Deposit Assets Other Other Assets Other current assets Assets [Member] Assets [Member] Liabilities [Member] Derivative Financial Instruments, Liabilities [Member] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Low [Member] Minimum [Member] High [Member] Maximum [Member] Weighted Average [Member] Weighted Average [Member] Commodity Contracts Fair Value, Option, Quantitative Disclosures [Line Items] Electricity physical forward Electricity physical forward purchase Electricity physical forward purchase Natural gas financial swaps Natural gas financial swaps Natural gas financial swaps Electricity financial futures Fnancial swaps - electricity Fnancial swaps - electricity Total commodity contracts Total commodity contracts Total commodity contracts Inventory, Policy [Policy Text Block] Inventory, Policy [Policy Text Block] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Balance as of the beginning of the period Net Liabilities From Price Risk Management Activities Classified As Level 3 Net Liabilities From Price Risk Management Activities Classified as Level 3 Net realized and unrealized (gains) losses (1) Realized and Unrealized Gains and Losses, Net, Commodity Contract Realized and Unrealized Gains and Losses, Net, Commodity Contracts Purchases Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Purchases Transfers out of Level 3 to Level 2 Fair Value, Measurement with Unobservable Inputs Reconciliation, Liability, Transfers out of Level 3 Balance as of the end of the period Document and Entity Information [Abstract] Document and Entity Information [Abstract] Entities [Table] Entities [Table] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Entity Information [Line Items] Entity Information [Line Items] Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Document Type Document Type Document Period End Date Document Period End Date Amendment Flag Amendment Flag Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Trading Symbol Trading Symbol PRICE RISK MANAGEMENT Derivative Instruments and Hedging Activities Disclosure [Text Block] Electricity Realized and Unrealized Gains and Losses, Net, Commodity Contracts, Electricity 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. Natural Gas Realized and Unrealized Gains and Losses, Net, Commodity Contracts, Natural Gas 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. Guarantees, Indemnifications and Warranties Policies [Policy Text Block] Guarantees, Indemnifications and Warranties Policies [Policy Text Block] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Balance Sheet Location [Axis] Balance Sheet Location [Axis] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Derivatives, Fair Value [Line Items] Derivatives, Fair Value [Line Items] Current Assets, Commodity Contracts: Electricity Commodity Contract Asset, Current, Electricity Carrying amount as of the balance sheet date of the asset arising from commodity contracts related to electricity which are expected to be settled within a year or normal operating cycle, if longer. Natural gas Commodity Contract Asset, Current, Natural Gas Carrying amount as of the balance sheet date of the asset arising from commodity contracts related to natural gas which are expected to be settled within a year or normal operating cycle, if longer. Total current derivative assets Current Derivative Assets Fair valules as of the balance sheet date for all assets resulting from contracts that meet the criteria of being accounted for as derivative instruments, and which are expected to be settled within one year or the normal operating cycle, if longer. Noncurrent assets: Assets, Noncurrent [Abstract] Noncurrent Assets, Commodity Contracts: [Abstract] Noncurrent Assets, Commodity Contracts: [Abstract] Noncurrent Assets, Commodity Contracts: [Abstract] Electricity Commodity Contract Asset, Noncurrent, Electricity Carrying amount as of the balance sheet date of the asset arising from commodity contracts related to electricity which are expected to be settled after a year or beyond the normal operating cycle, if longer. Natural gas Commodity Contract Asset, Noncurrent, Natural Gas Carrying amount as of the balance sheet date of the asset arising from commodity contracts related to natural gas which are expected to be settled after a year or beyond the normal operating cycle, if longer. Total noncurrent derivative assets Derivative Asset, Noncurrent Total derivative assets not designated as hedging instruments Price Risk Derivative Instruments Not Designated as Hedging Instruments Asset, at Fair Value Total derivative assets Derivative Assets, Total Fair values as of the balance sheet date of all assets resulting from contracts that meet the criteria of being accounted for as derivative instruments. Current liabilities: Current Liabilities, Commodity Contracts: [Abstract] Current Liabilities, Commodity Contracts: [Abstract] Electricity Commodity Contract Liability, Current, Electricity Carrying amount as of the balance sheet date of the liability arising from commodity contracts related to electricity which are expected to be settled within a year or the normal operating cycle, if longer. Natural gas Commodity Contract Liability, Current, Natural Gas Carrying amount as of the balance sheet date of the liability arising from the commodity contracts related to natural gas which are expected to be settled within a year or normal operating cycle, if longer. Total current derivative liabilities Current Derivative Liabilities Fair values as of the balance sheet date for all liabilities resulting from contracts that meet the criteria of being accounted for as derivative instruments, and which are expected to be settled within one year of the normal operating cycle, if longer. Noncurrent liabilities: Liabilities, Noncurrent [Abstract] Noncurrent Liabilities, Commodity Contracts: [Abstract] Noncurrent Liabilities, Commodity Contracts: [Abstract] Electricity Commodity Contract Liability, Noncurrent, Electricity Carrying amount as of the balance sheet date of the liability arising from commodity contracts related to electricity which are expected to be settled after a year or beyond the normal operating cycle, if longer. Natural gas Commodity Contract Liability, Noncurrent, Natural Gas Carrying amount as of the balance sheet date of the liability arising from commodity contracts related to natural gas which are expected to be settled after a year or beyond the normal operating cycle, if longer. Total noncurrent derivative liabilities Noncurrent Derivative Liabilities Fair values as of the balance sheet date for all assets resulting from contracts that meet the criteria of being accounted for as derivative instruments, and which are expected to be settled after one year or normal operating cycle, if longer. Total derivative liabilities not designated as hedging instruments Price Risk Derivative Instruments Not Designated as Hedging Instruments Liability, at Fair Value Total derivative liabilities Derivative Liabilities, Total Fair values as of the balance sheet date of all liabilities resulting from contracts that meet the criteria of being accounted for as derivative instruments. Schedule of Valuation and Qualifying Accounts Disclosure [Text Block] Schedule of Valuation and Qualifying Accounts Disclosure [Text Block] Schedule of Other Current Assets [Table Text Block] Schedule of Other Current Assets [Table Text Block] Schedule of Public Utility Property, Plant, and Equipment [Table Text Block] Public Utility Property, Plant, and Equipment [Table Text Block] Schedule of Regulatory Assets and Liabilities [Text Block] Schedule of Regulatory Assets and Liabilities [Text Block] Other Liabilities Disclosure [Text Block] Other Liabilities Disclosure [Text Block] Pension and Other Postretirement Benefits Disclosure [Text Block] Pension and Other Postretirement Benefits Disclosure [Text Block] Service Area Sq Miles Service Area Sq Miles Approximate square miles of service area. Incorporated Cities Incorporated Cities Number of incorporated cities in service area. Number of Retail Customers Number of Retail Customers Includes residential, commercial and industrial. Service Area Population Service Area Population Service Area Population Percent of State's Population Percent of State's Population Service area population as a percent of the state's population. Margin Deposit Assets Cash received to be returned to customers pursuant to the Residential Exchange Program Cash Received from BPA Cash Received from BPA to be provided to customers. Power Cost Deferrals, Net Deferred Purchased Power Costs Other Comprehensive Income Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Revenue overstatement revenue overstatment Adjustment to revenue to reduce total for the overstatment of a prior customer billing. Price Risk Management Note [Abstract] Price risk management note. Electricity Volume Related to Derivative Instruments Held at Balance Sheet Date, Commodity Contracts, Electricity Net volume related to the reporting entity's derivative instruments as of the balance sheet date having arisen from price risk management activities. Natural gas Volume Related to Derivative Instruments at Balance Sheet Date, Commodity Contracts, Natural Gas 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. Foreign currency Volume Related to Derivative Instruments Held at Balance Sheet Date, Foreign Currency Net amount associated with the reporting entity's derivative instruments recorded as of the balance sheet date having arisen from price risk management activities related to foreign currency. Weighted Average Number of Shares Outstanding, Basic Weighted Average Number of Shares Outstanding, Basic Dilutive effect of potential common shares Weighted Average Number Diluted Shares Outstanding Adjustment Weighted Average Number of Shares Outstanding, Diluted Weighted Average Number of Shares Outstanding, Diluted Statement of Cash Flows [Abstract] Cash flows from operating activities: Net Cash Provided by (Used in) Operating Activities [Abstract] Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Adjustments to reconcile net income to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Depreciation and amortization Depreciation, Depletion and Amortization Cascade Crossing transmission project Decrease in net liabilities from price risk management activities Increase (Decrease) in Risk Management Assets and Liabilities Regulatory deferral - price risk management activities Regulatory deferral - price risk management activities Represents the increase or decrease in regulatory assets and liabilities, net related to price risk management activities Deferred income taxes Deferred Income Tax Expense (Benefit) Pension and other postretirement benefits Pension and Other Postretirement Benefit Expense Allowance for equity funds used during construction Public Utilities, Allowance for Funds Used During Construction, Capitalized Cost of Equity Regulatory deferral of settled derivative instruments Regulatory deferral of settled derivative instruments Regulatory deferral of settled derivative instruments Decoupling mechanism deferrals, net of amortization Decoupling Mechanism Deferrals, Net The deferral, which can be either a positive or negaitive amount depending on whether a collection from or refund to customers results, of the amounts recorded in net income for energy useage by customers on a weather adjusted basis that is different from base rates as determined under the Company's decoupling mechanism, expected to be recovered or refunded in future periods. Other non-cash income and expenses, net Other Noncash Income (Expense) Changes in working capital: Increase (Decrease) in Operating Capital [Abstract] Decrease in accounts receivable and unbilled revenues Increase (Decrease) in Receivables Decrease in margin deposits, net Increase (Decrease) in Margin Deposits Outstanding Decrease in accounts payable and accrued liabilities Increase (Decrease) in Accounts Payable Other working capital items, net Increase (Decrease) in Other Operating Assets and Liabilities, Net Other, net Increase (Decrease) in Other Operating Assets Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Cash flows from investing activities: Net Cash Provided by (Used in) Investing Activities [Abstract] Capital expenditures Payments to Acquire Property, Plant, and Equipment Sales of nuclear decommissioning trust securities Proceeds from Sale, Maturity and Collection of Investments Purchases of nuclear decommissioning trust securities Payments to Acquire Investments Proceeds from sale of property Proceeds from Sale of Property, Plant, and Equipment Other, net Payments for (Proceeds from) Other Investing Activities Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities Cash flows from financing activities: Net Cash Provided by (Used in) Financing Activities [Abstract] Proceeds from issuance of long-term debt Proceeds from Issuance of Long-term Debt Payments on long-term debt Repayments of Long-term Debt Proceeds from issuance of common stock, net of issuance costs Proceeds from Issuance of Common Stock Borrowings on short-term debt Proceeds from Short-term Debt Payments on short-term debt Repayments of Short-term Debt Maturities of commercial paper, net Repayments of Commercial Paper Dividends paid Payments of Dividends Debt issuance costs Debt Issuance Cost Net cash provided by financing activities Net Cash Provided by (Used in) Financing Activities Change in cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease) Cash and cash equivalents, beginning of period Cash and cash equivalents, end of period Supplemental cash flow information is as follows: Supplemental Cash Flow Information [Abstract] Cash paid for interest, net of amounts capitalized Interest Paid, Net Cash paid for income taxes Income Taxes Paid Non-cash investing and financing activities: Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract] Accrued dividends payable Dividends Payable Accrued capital additions Capital Expenditures Incurred but Not yet Paid Preliminary engineering costs transferred to Construction work-in-progress from Other noncurrent assets Preliminary engineering transferred to construction work in progress Preliminary engineering costs transferred to construction work in progress during the period Loss Contingencies [Table] Loss Contingencies [Table] Loss Contingency Nature [Axis] Loss Contingency Nature [Axis] Loss Contingency, Nature [Domain] Loss Contingency, Nature [Domain] Loss Contingencies [Line Items] Loss Contingencies [Line Items] Investment in Trojan investment in Trojan The portion of the Company's remaining investment in its Trojan plant that the OPUC allowed the Company to recover. Regulatory asset related to Trojan Regulatory asset related to Trojan Regulatory asset related to Trojan Refund to customers for Trojan Investment including interest refund to customers for Trojan Investment including interest refund to customers for Trojan Investment including interest Class action damages sought Class action lawsuit damages sought Class action lawsuit damages sought by plaintiffs against the Company. Contracts contracts Contracts that defendant in California proceeding had that are subject to possible refund. Site Contingency, Names of Other Potentially Responsible Parties Site Contingency, Names of Other Potentially Responsible Parties Lower estimate of range of cost of Portland Harbor cleanup in total Low estimate of range of cost of Portland Harbor cleanup in total Lower end estimate of the range of cost of Portland Harbor cleanup, in total. This represents the cost to all parties, not PGE portion. Upper estimated range of total cost of Portland Harbor cleanup Upper estimated range of total cost of Portland harbor cleanup Upper estimated range of total cost of Portland harbor cleanup. This is the estimated cost for all parties, not PGE portion. Remediation cost estimate lower range Loss Contingency, Range of Possible Loss, Minimum Remediation cost estimate upper range Loss Contingency, Range of Possible Loss, Maximum Loss Contingency, Estimate of Possible Loss Loss Contingency, Estimate of Possible Loss Regulatory asset for recovery of loss contingencies regulatory asset for recovery of loss contingencies regulatory asset for recovery of loss contingencies Civil Penalty Claim - Per day per violation through January 12, 2009 Civil Penalty Claim - Per day per violation through January 12, 2009 Civil Penalty Claim - Per Day Per Violation through January 12, 2009 Civil Penalty Claim - Per day per violation after January 12, 2009 Civil Penalty Claim - Per day per violation after January 12, 2009 Civil Penalty Claim - Per day per violation after January 12, 2009 projects added to plaintiff's suit projects added to plaintiff's suit projects added to plaintiff's suit Loss Contingency, Pending Claims, Number Loss Contingency, Pending Claims, Number Potential Income Tax Liability related to State Tax Court Ruling Possible Income Tax Liability Related to State Tax Court Ruling Potential Income Tax Liability Related to State Tax Court Ruling Income Statement [Abstract] Revenues, net Electric Revenue Operating expenses: Costs and Expenses [Abstract] Purchased power and fuel Cost of Purchased Power Production and distribution Electric Production Expense Administrative and other General and Administrative Expense Taxes other than income taxes Taxes, Miscellaneous Total operating expenses Costs and Expenses Income (loss) from operations Operating Income (Loss) Interest expense Interest Expense Other income: Other Income and Expenses [Abstract] Allowance for equity funds used during construction Miscellaneous income, net Other Nonoperating Income (Expense) Other income, net Nonoperating Income (Expense) Income (loss) before income tax expense (benefit) Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest Income tax expense (benefit) Income Tax Expense (Benefit) Net income (loss) and Comprehensive income (loss) Less: net loss attributable to noncontrolling interests Net income (loss) and Comprehensive income (loss) attributable to Portland General Electric Company Weighted-average shares outstanding (in thousands): Weighted Average Number of Shares Outstanding, Diluted [Abstract] Basic Diluted Earnings (loss) per share: Basic Earnings Per Share, Basic Diluted Earnings Per Share, Diluted Dividends declared per common share Common Stock, Dividends, Per Share, Declared Derivative, Collateral, Master Netting Arrangements, Letters of Credit Derivative, Collateral, Master Netting Arrangements, Letters of Credit The amount of collateral posted pursuant to derivative instruments with counterparties where a master netting arrangement exists, consisting of letters of credit. Derivative, Net Liability Position, Aggregate Fair Value Derivative, Net Liability Position, Aggregate Fair Value Collateral Already Posted, Aggregate Fair Value Collateral Already Posted, Aggregate Fair Value Collateral Aggregate Fair Value Collateral Aggregate Fair Value The aggregate fair value of assets that would be required to be posted as collateral for derviative instruments with credit-risk-related contingent features if the credit-risk-related contingent features were triggered at the end of the reporting period.