Period [Axis] Period [Axis] Period [Axis] Estimated future employer contributions Defined Benefit Plan, Expected Future Employer Contributions, Current Fiscal Year Investments Investment, Policy [Policy Text Block] Commodity Commodity Contract [Member] Accrued taxes to affiliated companies Taxes Payable, Related Parties, Current Taxes Payable, Related Parties, Current Expected return on plan assets Defined Benefit Plan, Expected Return (Loss) on Plan Assets Award Timing Predetermined Award Timing Predetermined [Flag] Refined Fuels (gallons) Refined Fuels [Member] Refined fuels. Entity File Number Entity File Number Additional Paid-In Capital Additional Paid-in Capital [Member] UB deferral for uncollectible accounts receivable COVID-19 Deferral For Uncollectible Accounts Receivable [Member] COVID-19 Deferral For Uncollectible Accounts Receivable Tabular List, Table Tabular List [Table Text Block] Outstanding loans Outstanding Loan Outstanding Loan New Financial Accounting Standards New Accounting Pronouncements, Policy [Policy Text Block] Schedule of Costs of Administrative and Other Services Provided and Received Schedule of Related Party Transactions [Table Text Block] Fair Value Measurements Fair Value Measurement and Measurement Inputs, Recurring and Nonrecurring [Text Block] Proceeds from sale of Broken Bow II, net of cash and cash equivalents sold Proceeds from Divestiture of Businesses, Net of Cash Divested Capital expenditures in accounts payable Construction in Progress Expenditures Incurred but Not yet Paid Guarantee obligations maximum exposure Total guarantees, by type and term Guarantor Obligations, Maximum Exposure, Undiscounted Deferred derivative gains - long term Deferred Derivative Gains, Long Term [Member] Deferred Derivative Gains, Long Term Measurement Basis [Axis] Measurement Basis [Axis] Gas Oil and Gas, Purchased [Member] Adjustment to Compensation: Adjustment to Compensation [Axis] Related Party Transactions Related Party Transactions Disclosure [Text Block] Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] Annual gas revenue requirement amount Public Utilities, Annual Gas Revenue Requirement Amount Public Utilities, Annual Gas Revenue Requirement Amount Revenue Recognition Revenue from Contract with Customer [Text Block] Regulatory Matters Public Utilities Disclosure [Text Block] Schedule of Cash and Cash Equivalents Schedule of Cash and Cash Equivalents [Table Text Block] Pensions and retiree benefits contributions Payment for Pension and Other Postretirement Benefits Other deferred charges and noncurrent assets Other Assets, Miscellaneous, Noncurrent Adjustment to Compensation, Amount Adjustment to Compensation Amount Pension Benefits Pension Plan [Member] Amortizations to income of net liabilities Amortizations to income of net liabilities Utilities Operating Expense, Depreciation and Amortization Employee Stock Option Share-Based Payment Arrangement, Option [Member] Broken Bow II Broken Bow II [Member] Broken Bow II Changes in computed taxes resulting from: Effective Income Tax Rate Reconciliation, Percent [Abstract] Deferred tax assets Deferred Tax Assets, Tax Deferred Expense 0 – 3 years Guarantee Duration One To Three Years [Member] Guarantee Duration One To Three Years [Member] SHAREHOLDERS' EQUITY (See Consolidated Statement of Shareholders' Equity) Beginning balance Ending balance SHAREHOLDER’S EQUITY (See Consolidated Statement of Shareholder’s Equity) Common shareholders’ equity Equity, Attributable to Parent OTHER COMPREHENSIVE LOSS, NET OF TAXES Other Comprehensive Income (Loss), Net of Tax [Abstract] Insider Trading Policies and Procedures [Line Items] Issuance of common shares – public offering (shares) Number of shares of common stock issued (in shares) Stock Issued During Period, Shares, New Issues Total deferred gains (losses) Deferred Derivative Gains Losses Deferred Derivative Gains Losses Defer incremental preparation costs Deferred Storm and Property Reserve Deficiency, Current LIABILITIES AND SHAREHOLDERS’ EQUITY Liabilities and Equity [Abstract] Allowance for uncollectible accounts, net of regulatory recovery Effective Income Tax Rate Reconciliation, Change in Allowance For Uncollectible Accounts, Percent Effective Income Tax Rate Reconciliation, Change in Allowance For Uncollectible Accounts, Percent Cover [Abstract] Cover [Abstract] Portion at Fair Value Measurement Portion at Fair Value Measurement [Member] Dispositions Disposal Groups, Including Discontinued Operations, Disclosure [Text Block] Maximum Maximum Maximum [Member] NON-UTILITY PLANT Property, Plant and Equipment, Net [Abstract] Issuance of common shares for stock plans (shares) Shares Issued, Shares, Share-Based Payment Arrangement, before Forfeiture Income Tax Contingency [Line Items] Income Tax Contingency [Line Items] CET Electric Consolidated Edison Transmission Electric [Member] Consolidated Edison Transmission Electric [Member] Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount Makeup of net credit exposure with investment-grade counterparties Maximum Potential Future Exposure On Credit Risk Derivatives With Investment Grade Counterparties Maximum Potential Future Exposure On Credit Risk Derivatives With Investment Grade Counterparties Debt Instrument [Line Items] Debt Instrument [Line Items] Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] March 2022 Credit Agreement Variable Rate 364 Day Revolving Credit Agreement March 2022 Credit Agreement Variable Rate 364 Day Revolving Credit Agreement [Member] March 2022 Credit Agreement Variable Rate 364 Day Revolving Credit Agreement Retirement Benefits [Abstract] Retirement Benefits [Abstract] Forgone Recovery due to Disqualification of Tax Benefits, Amount Forgone Recovery due to Disqualification of Tax Benefits, Amount Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] Base rate changes Public Utilities, Property, Plant and Equipment, Rate Base Adjustments Public Utilities, Property, Plant and Equipment, Rate Base Adjustments Protected Portion Protected Portion [Member] Protected Portion [Member] INCOME BEFORE INCOME TAX EXPENSE Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Entity Shell Company Entity Shell Company Environmental Remediation Site [Domain] Environmental Remediation Site [Domain] Schedule of Carrying Amounts and Fair Values of Long-Term Debt Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block] Schedule of Long-term Debt Instruments [Table] Schedule of Long-Term Debt Instruments [Table] Balance Sheet Location [Axis] Statement of Financial Position Location, Activity, Accrual [Axis] Regulatory Assets [Line Items] Regulatory Asset [Line Items] Capacity (MW) Electric Capacity Derivative [Member] Electric Capacity Derivative [Member] Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Operating Segments Operating segment Operating Segments [Member] Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Schedule of Regulatory Liabilities [Table] Regulated Operation, Regulatory Liability [Table] Other receivables, net allowance for uncollectible accounts of $60 and $41 in 2025 and 2024, respectively Other receivables, net allowance for uncollectible accounts of $53 and $38 in 2025 and 2024, respectively Other Receivables Operating lease liabilities Operating Lease, Liability, Current Allowance for cost of removal less salvage Allowance for Cost of Removal Less Salvage [Member] Allowance for Cost of Removal Less Salvage Utility plant, at original cost Public Utilities, Property, Plant and Equipment, Transmission and Distribution Document Fiscal Period Focus Document Fiscal Period Focus Derivatives, Fair Value [Line Items] Derivatives, Fair Value [Line Items] Award Timing Method Award Timing Method [Text Block] Litigation Case [Domain] Litigation Case [Domain] Cost capitalized Cost capitalized Defined Benefit Plan Cost Capitalized Defined Benefit Plan Cost Capitalized Award Type Award Type [Axis] Utility Plant [Domain] Utility Plant [Domain] Estimated capitalization costs Public Utilities, Requested Capitalization Of Billing System Costs Public Utilities, Requested Capitalization Of Billing System Costs Investment, Name [Domain] Investment, Name [Domain] Trading Symbol Trading Symbol Environmental Remediation Obligations [Abstract] Environmental Remediation Obligations [Abstract] Entity Address, City or Town Entity Address, City or Town Regulatory Liabilities, Current Regulatory Liabilities Current [Member] Regulatory Liability for reserve of change in fair value of derivative instrument. TOTAL Public Utilities, Property, Plant and Equipment, Plant in Service Settlement of prudence proceeding Prudence Proceeding [Member] Prudence Proceeding [Member] Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount Net payment of short-term debt Net payment of short-term debt Proceeds from (Repayments of) Short-Term Debt Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Regulatory Agency [Axis] Regulatory Agency [Axis] Entity Emerging Growth Company Entity Emerging Growth Company Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year [Member] Total pre-tax gains (losses) recognized in income Derivative, Gain (Loss) on Derivative, Net Add: Incremental shares attributable to effect of potentially dilutive securities (shares) Incremental Common Shares Attributable to Dilutive Effect of Contingently Issuable Shares Beginning balance (shares) Ending balance (shares) Common Stock, Shares, Outstanding Reserve adjustments Accounts Receivable, Credit Loss Expense (Reversal) Schedule of Disaggregation of Revenue Disaggregation of Revenue [Table Text Block] Pension and retiree benefits Assets for Plan Benefits, Defined Benefit Plan Term loan Loans Payable to Bank, Current INCOME BEFORE INTEREST AND INCOME TAX EXPENSE INCOME BEFORE INTEREST AND INCOME TAX EXPENSE Income Before Interest Income Interest Expense And Income Taxes Income before interest income, interest expense and income taxes Purchased power Electricity, Purchased [Member] Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year [Member] Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Instruments and Hedging Activities Disclosure [Abstract] Entity Address, Postal Zip Code Entity Address, Postal Zip Code Restatement Determination Date Restatement Determination Date INCOME TAX EXPENSE INCOME TAX EXPENSE Effective tax rate Income Tax Expense (Benefit) Document Information [Line Items] Document Information [Line Items] Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] Related Party, Lending of Funds Related Party, Lending of Funds [Member] Related Party, Lending of Funds [Member] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Weighted average cost of capital (after-tax) (percent) Weighted Average Cost Of Capital Weighted Average Cost Of Capital Pre-tax gains (losses) deferred in accordance with accounting rules for regulated operations: Derivative Assets Liabilities At Fair Value By Balance Sheet Classification [Abstract] Derivative Assets Liabilities At Fair Value By Balance Sheet Classification [Abstract] Discontinued Operations and Disposal Groups [Abstract] Discontinued Operations and Disposal Groups [Abstract] Other receivables, allowance for uncollectible accounts Allowance for Credit Loss, Receivable, Other, Current Schedule of Guarantor Obligations [Table] Guarantor Obligation [Table] Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] All Trading Arrangements All Trading Arrangements [Member] Equity Awards Adjustments, Footnote Equity Awards Adjustments, Footnote [Text Block] Total Shareholder Return Vs Peer Group Total Shareholder Return Vs Peer Group [Text Block] STATUTORY TAX RATE Federal Statutory Income Tax Rate [Abstract] Federal Statutory Income Tax Rate [Abstract] TOTAL PERIODIC BENEFIT CREDIT Periodic Benefit Cost (Credit) After Amortization Of Regulatory Asset Total Periodic Benefit Cost (Credit) After Amortization of Regulatory Asset Other Effective Income Tax Rate Reconciliation, Other Adjustments, Amount Requested rate increase, amount Requested rate increase (decrease), amount Public Utilities, Requested Rate Increase (Decrease), Amount Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Earnings sharing (percent) Revenue Requirement Earnings Percentage Revenue Requirement Earnings Percentage NET CASH FLOWS FROM OPERATING ACTIVITIES Cash Provided by (Used in) Operating Activity, Including Discontinued Operation INVESTMENTS Long-Term Investments Debt instrument term (in years) Debt Instrument, Term Subsequent Event Subsequent Event [Member] Schedule of Equity Method Investments [Line Items] Schedule of Equity Method Investments [Line Items] Equity Valuation Assumption Difference, Footnote Equity Valuation Assumption Difference, Footnote [Text Block] PEO Total Compensation Amount PEO Total Compensation Amount Gross Amounts of Recognized Assets (Liabilities) Derivative Liability, Subject to Master Netting Arrangement, before Offset Equity Components [Axis] Equity Components [Axis] Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] Accounts receivable - customers Trade Accounts Receivable [Member] Dividend to Con Edison Payments of Ordinary Dividends Fair Value, Concentration of Risk, Disclosure Items [Domain] Fair Value, Concentration of Risk, Disclosure Items [Domain] Lease Expected To Commence In 3 Years With 15 Year Lease Term Lease Expected To Commence In 3 Years With 15 Year Lease Term [Member] Lease Expected To Commence In 3 Years With 15 Year Lease Term Regulatory liabilities Regulatory liabilities – noncurrent Accrued regulatory liability Regulatory Liability, Noncurrent Entity Address, State or Province Entity Address, State or Province Transmission Congestion Contracts Transmission Congestion Contracts [Member] Transmission Congestion Contracts [Member] Common stock dividends Common stock dividend to Con Edison Dividends, Common Stock Number of operating lease agreements Lessee, Operating Lease, Number of Contracts Lessee, Operating Lease, Number of Contracts TOTAL CURRENT LIABILITIES Liabilities, Current Deferred charges, noncurrent assets, leases, net and other regulatory assets Increase (Decrease) in Deferred Charges Individual: Individual [Axis] Other Postretirement Benefits Postemployment Benefits Disclosure [Text Block] MTA power reliability deferral MTA Power Reliability Deferral [Member] MTA Power Reliability Deferral [Member] Other receivables, net and other current assets Other receivables, net and other current assets Increase (Decrease) in Other Receivables Authorized return on common equity (percent) Return on common equity (as a percent) Public Utilities, Approved Return on Equity, Percentage System benefit charge System Benefits Charge Liability, Current System Benefits Charge Liability, Current Accounting Changes and Error Corrections [Abstract] Accounting Changes and Error Corrections [Abstract] Common stock dividends Payments of Ordinary Dividends, Common Stock Rate case amortization and accruals Amortization Forgone Recovery, Explanation of Impracticability Forgone Recovery, Explanation of Impracticability [Text Block] Environmental Remediation Contingency [Axis] Environmental Remediation Contingency [Axis] Entity Interactive Data Current Entity Interactive Data Current Mutual Funds Mutual Fund [Member] Lending period (not more than) (months) Lending Period Lending Period Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Current Expected Credit Losses Allowance for Credit Losses [Text Block] Capital contribution by Con Edison Proceeds from Contributions from Parent Property, Plant and Equipment, Type [Axis] Long-Lived Tangible Asset [Axis] Consolidated Edison Company of New York, Inc. And Orange And Rockland Consolidated Edison Company of New York, Inc. And Orange And Rockland Utilities, Inc. [Member] Consolidated Edison Company of New York, Inc. And Orange And Rockland Utilities, Inc. Year 3 Rate Plan for Year 3 [Member] Rate Plan for Year 3 [Member] Ownership [Domain] Ownership [Domain] Commercial paper, outstanding Commercial Paper TOTAL OTHER NONCURRENT ASSETS Other Assets, Noncurrent Accrued interest Interest Payable, Current Entity Central Index Key Entity Central Index Key Energy supply and hedging activities credit exposure total Credit Derivative, Maximum Exposure, Undiscounted PEO Name PEO Name TOTAL OPERATING REVENUES Total revenues Cost of services provided Revenues Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year [Member] Regulatory Liabilities [Line Items] Regulatory Liability [Line Items] Net utility plant reconciliations Net utility plant reconciliations Average Net Utility Plant Rates Deferred regulatory asset (liability) Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount Schedule of Defined Benefit Plans Disclosures [Table] Defined Benefit Plan [Table] Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Exercise Price Award Exercise Price Long-term Contract for Purchase of Electric Power [Domain] Long-Term Contract for Purchase of Electric Power [Domain] Entity Filer Category Entity Filer Category Reconciliation to rate level Effect of Reconciliation to Rate Level Effect of Reconciliation to Rate Level Federal Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Subsequent Event Type [Axis] Subsequent Event Type [Axis] Consideration from sale of business Disposal Group, Including Discontinued Operation, Consideration Nonrelated Party Nonrelated Party [Member] Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year [Member] Amortization of excess deferred federal income taxes Effective Income Tax Rate Reconciliation, Nondeductible Expense, Amortization Of Excess Deferred Federal Income Taxes, Amount Effective Income Tax Rate Reconciliation, Nondeductible Expense, Amortization Of Excess Deferred Federal Income Taxes, Amount Entity Address, Address Line One Entity Address, Address Line One Deferred storm costs Deferred Storm Costs [Member] Deferred Storm Costs [Member] Accumulated Other Comprehensive Income (Loss) AOCI Attributable to Parent [Member] Accounts receivable - customers, allowance for uncollectible accounts Accounts Receivable, Allowance for Credit Loss, Current Ownership [Axis] Ownership [Axis] Derivative Instruments and Hedging Activities Derivative Instruments and Hedging Activities Disclosure [Text Block] Recognition of prior service credit Recognition of prior service credit Defined Benefit Plan, Amortization of Prior Service Cost (Credit) Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Fair Value as of Grant Date Award Grant Date Fair Value Recovery period for deferred derivative losses (in years) Regulatory Assets, Deferred Derivative Losses, Noncurrent, Recovery Period Regulatory Assets, Deferred Derivative Losses, Noncurrent, Recovery Period Property tax reconciliation Property Tax Reconciliation [Member] Regulatory Asset for reconciliation of actual property tax expense to the level allowed in rates. Disposal Group, Held-for-sale, Not Discontinued Operations Disposal Group, Held-for-Sale, Not Discontinued Operations [Member] Accrued income taxes Accrued Income Taxes Related Party Transaction [Line Items] Related Party Transaction [Line Items] Electric base rate percentage Electric Base Rate Percentage Electric Base Rate Percentage Current Derivative Financial Instruments Current Liabilities [Member] Derivative Financial Instruments Current Liabilities [Member] Document Quarterly Report Document Quarterly Report Schedule of Commodity Derivatives Fair Value Measurement Inputs and Valuation Techniques [Table Text Block] LONG-TERM DEBT Long-term debt (including current portion) Long-Term Debt, Fair Value Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] Counterparty Name [Domain] Counterparty Name [Domain] Electric Electric Transmission [Member] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Title Trading Arrangement, Individual Title Peer Group Total Shareholder Return Amount Peer Group Total Shareholder Return Amount Interest Expense Interest and Debt Expense Non-PEO NEO Non-PEO NEO [Member] Capital Stock Expense Other Changes Stockholders Equity [Member] Other Changes Stockholders Equity Ending Balance Operating lease, not yet commenced, term of contract (in years) Lessee, Operating Lease, Lease Not yet Commenced, Term of Contract Schedule of Offsetting of Assets Offsetting Assets [Table Text Block] Schedule of Regulatory Liabilities Schedule of Regulatory Liabilities [Table Text Block] All Award Types Award Type [Domain] Equity Awards Adjustments Equity Awards Adjustments [Member] Other non-cash items, net Other Noncash Income (Expense) Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block] Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Other income Other Income Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan Disclosure [Line Items] Compensation Amount Outstanding Recovery Compensation Amount Contract term (years) Term Of Contract Term Of Contract Total fair value of derivative liabilities Derivative Financial Instruments, Liabilities [Member] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Recovery of Erroneously Awarded Compensation Disclosure [Line Items] Fair Value Estimate of Fair Value Measurement [Member] Retirement Plan Type [Domain] Retirement Plan Type [Domain] Schedule of Rollforward of Allowance for Credit Losses Accounts Receivable, Allowance for Credit Loss [Table Text Block] MNPI Disclosure Timed for Compensation Value MNPI Disclosure Timed for Compensation Value [Flag] Arrears Relief Program Deferral Arrears Relief Program Deferral [Member] Arrears Relief Program Deferral OPERATING REVENUES Revenues [Abstract] BALANCE AT END OF PERIOD EXCLUDING HELD FOR SALE Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Excluding Cash Held For Sale Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Excluding Cash Held For Sale Cash Value of Life Insurance Policies Fair Value Other [Member] Fair Value Other [Member] Maximum deferral (percent) Public Utilities, Maximum Deferral Percentage Public Utilities, Maximum Deferral Percentage O&R O&R Orange And Rockland Utilities Inc [Member] Orange And Rockland Utilities Inc. [Member] Capital expenditures Public Utilities, Property, Plant and Equipment, Capital Expenditures Public Utilities, Property, Plant and Equipment, Capital Expenditures Fuel oil, gas in storage, materials and supplies, at average cost Energy Related Inventory Fuel Oil Gas And Materials And Supplies Cost Energy related inventory, fuel oil, gas and materials and supplies, cost Weighted average interest rate of commercial paper (in percent) Weighted Average Interest Rate Of Commercial Paper Weighted Average Interest Rate Of Commercial Paper Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Carrying value of tax equity interest Carrying Value Of Tax Equity Interest Carrying Value Of Tax Equity Interest Environmental Remediation Site [Axis] Environmental Remediation Site [Axis] Minimum Minimum [Member] Accounts, Notes, Loans and Financing Receivable [Line Items] Accounts, Notes, Loans and Financing Receivable [Line Items] Company Selected Measure Name Company Selected Measure Name Accrued liability Accrual for Environmental Loss Contingencies Fair Value Measurement [Domain] Fair Value Measurement [Domain] Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Accounts payable Accounts Payable, Current Energy efficiency and other clean energy programs Energy Efficiency And Other Clean Energy Programs [Member] System Peak Reduction And Energy Efficiency Programs [Member] Operating lease cash flows Operating Lease, Payments Stock Appreciation Rights (SARs) Stock Appreciation Rights (SARs) [Member] Issuance of common shares for dividend reinvestment Dividends Payable Material Contingencies Commitments and Contingencies Disclosure [Text Block] Gross Amounts of Recognized Assets (Liabilities) Derivative Assets (Liabilities), at Fair Value, Net Schedule of Regulatory Assets [Table] Regulated Operation, Regulatory Asset [Table] OTHER NONCURRENT ASSETS Other Assets, Noncurrent [Abstract] AVERAGE NUMBER OF SHARES OUTSTANDING—DILUTED (shares) Adjusted weighted average common shares outstanding – diluted (shares) Weighted Average Number of Shares Outstanding, Diluted Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] Pre-tax gains (losses) recognized in income Pretax Effects Of Derivative Instruments On Consolidated Statements Of Operations [Abstract] Pretax Effects Of Derivative Instruments On Consolidated Statements Of Operations [Abstract] Entity Small Business Entity Small Business Income Tax Disclosure [Abstract] Income Tax Disclosure [Abstract] Unrecognized tax benefits, interest expenses Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense Income taxes due to Con Edison Related Party Tax Expense, Due to Affiliates, Current Amount of costs that will not recover from customers Loss Contingency, Loss in Period Document Transition Report Document Transition Report Steam Steam Steam Plant [Member] Deferred derivative gains - short term Deferred Derivative Gains Current [Member] Regulatory Liability for reserve of change in fair value of derivative instrument. Schedule of Reconciliation of Beginning and Ending Net Balances for Assets and Liabilities Measured at Level 3 Fair Value Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Underlying Securities Award Underlying Securities Amount Equity Component [Domain] Equity Component [Domain] Borrowing under term loan Proceeds From Borrowing Under Term Loan Proceeds From Borrowing Under Term Loan Document Period End Date Document Period End Date Derivatives in net asset position additional collateral Additional Collateral For Derivative Net Assets The additional collateral that would be required for derivative instruments that are net assets. Income Tax Income Tax Disclosure [Text Block] Beginning Balance Ending Balance Accounts Receivable, Allowance for Credit Loss Awards Close in Time to MNPI Disclosures, Table Awards Close in Time to MNPI Disclosures [Table Text Block] Gain on sale of subsidiary, after tax Gain (Loss) On Disposition Of Stock In Subsidiary, After Tax Gain (Loss) On Disposition Of Stock In Subsidiary, After Tax Investigation and remediation costs incurred Environmental Remediation Expense, before Recovery Document Type Document Type Level 3 Fair Value, Inputs, Level 3 [Member] Name Outstanding Recovery, Individual Name Loss Contingencies [Table] Loss Contingencies [Table] Product and Service [Axis] Product and Service [Axis] LESS: CHANGE IN CASH AND RESTRICTED CASH BALANCES HELD FOR SALE Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Held For Sale, Period Increase (Decrease), Including Exchange Rate Effect Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Held For Sale, Period Increase (Decrease), Including Exchange Rate Effect Revenues from contracts with customers Revenue from Contract with Customer, Excluding Assessed Tax Less: Accumulated depreciation Public Utilities, Property, Plant and Equipment, Accumulated Depreciation TOTAL CURRENT ASSETS Assets, Current Statistical Measurement [Axis] Statistical Measurement [Axis] Number of buildings destroyed by fire Number Of Buildings Destroyed By Fire Number Of Buildings Destroyed By Fire Loss contingency accrual Loss Contingency Accrual Regulatory Asset [Domain] Regulatory Asset [Domain] Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount Disposal Group Name [Axis] Disposal Group Name [Axis] Peer Group Issuers, Footnote Peer Group Issuers, Footnote [Text Block] Net deferred gains (losses) Net Deferred Gain Loss Net deferred gain/(loss) Regulatory assets Regulatory assets – current Regulatory Asset, Current Income Taxes Disclosure [Line Items] Income Taxes Disclosure [Line Items] Income Taxes Disclosure [Line Items] Insurance receivable Insurance Settlements Receivable CURRENT LIABILITIES Liabilities, Current [Abstract] TOTAL OTHER COMPREHENSIVE LOSS, NET OF TAXES Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Guarantor Obligations, Nature [Domain] Guarantor Obligations, Nature [Domain] Schedule of Realized and Unrealized Gains or Losses on Commodity Derivatives Derivative Instruments, Gain (Loss) [Table Text Block] TOTAL OPERATING EXPENSES Cost of services received Operating Expenses Level 1 Fair Value, Inputs, Level 1 [Member] Pre-tax loss on sale of the Clean Energy Businesses Gain (Loss) on Disposition of Assets Total cash, temporary cash investments and restricted cash Cash, Cash Equivalents, Restricted Cash, Excluding Held-For-Sale Cash, Cash Equivalents, Restricted Cash, Excluding Held-For-Sale Earnings from its equity investment, after tax OCI, Equity Method Investment, after Tax Schedule of Related Party Transactions, by Related Party [Table] Related Party Transaction [Table] Net income per common share - diluted (dollars per share) Net income per common share - diluted (dollars per share) Earnings Per Share, Diluted Accounts receivable – customers, net allowance for uncollectible accounts of $610 and $620 in 2025 and 2024, respectively Accounts receivable Accounts Receivable, after Allowance for Credit Loss, Current Beginning balance (shares) Ending balance (shares) Treasury Stock, Common, Shares Consolidation Items [Domain] Consolidation Items [Domain] General Business Description and Basis of Presentation [Text Block] Margin deposit liability Margin Deposit Liability Margin Deposit Liability Electric Energy (MWh) Electric Energy Derivative [Member] Electric Energy Derivative [Member] Prepayments Prepayments Increase (Decrease) in Prepaid Expense Superfund Sites Superfund Sites [Member] Superfund Sites [Member] Public Utilities General Disclosures [Table] Public Utilities General Disclosures [Table] Regulatory Liability [Domain] Regulatory Liability [Domain] Included in earnings Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Earnings Schedule of Aggregate Fair Value of Companies' Derivative Instruments with Credit-Risk-Related Contingent Features Disclosure of Credit Derivatives [Table Text Block] Cash and Cash Equivalents [Line Items] Cash and Cash Equivalents [Line Items] Deferred credits, noncurrent liabilities and other regulatory liabilities Increase (Decrease) in Deferred Liabilities Environmental Matters Environmental Loss Contingency Disclosure [Text Block] Income taxes Income Taxes Paid, Net Other Other Regulatory Liabilities [Member] Other regulatory liabilities. Assets held for sale Disposal Group, Including Discontinued Operation, Assets, Current Accrued wages Employee-related Liabilities, Current Subsidiaries Subsidiaries [Member] Unobservable Inputs Range (dollar per unit) Derivative Asset, Measurement Input Additional collateral (downgrade to below investment grade from current ratings) Additional Collateral For Non-Derivative Transactions Without Extended Unsecured Credit Additional Collateral For Non-Derivative Transactions Without Extended Unsecured Credit Inter-segment Intersegment Eliminations [Member] Expiration Date Trading Arrangement Expiration Date Other current liabilities Increase (Decrease) in Other Operating Liabilities NET PLANT Property, Plant and Equipment, Net Compensation Actually Paid vs. Net Income Compensation Actually Paid vs. Net Income [Text Block] Accounts receivable – customers, net Increase (Decrease) in Accounts Receivable Entity Current Reporting Status Entity Current Reporting Status Settlement of Gas Proceedings Settlement of Gas Proceedings [Member] Settlement of Gas Proceedings [Member] Awards Close in Time to MNPI Disclosures Awards Close in Time to MNPI Disclosures [Table] Consolidated Entities [Domain] Consolidated Entities [Domain] Downgrade to Below Investment Grade from Current Ratings Additional Collateral Aggregate Fair Value Down Below Investment Grade [Member] Additional Collateral Aggregate Fair Value Down Below Investment Grade [Member] Con Edison Transmission Con Edison Transmission [Member] Con Edison Transmission [Member] Federal Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Executive Category: Executive Category [Axis] Number of people injured in explosion and fire incident (more than) Number of People Injured in Explosion and Fire Incident Number of people injured in explosion and fire incident. Asset retirement obligations Asset Retirement Obligations, Noncurrent State income taxes, net of federal income taxes Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent Cost of removal Effective Income Tax Rate Reconciliation Cost Of Removal, Percent Effective Income Tax Rate Reconciliation, cost of removal Issuance of long-term debt Proceeds from Issuance of Long-Term Debt NET INTEREST EXPENSE Interest Expense, Operating and Nonoperating Current Fiscal Year End Date Current Fiscal Year End Date Percentage of revenue reserve Percentage of Revenue Reserve Percentage of Revenue Reserve RECO Rockland Electric Company (RECO) [Member] Rockland Electric Company (RECO) Schedule of Total Guarantees Schedule of Guarantor Obligations [Table Text Block] Net Amounts of Assets/ (Liabilities) Derivative liabilities: Derivative Liability Legacy meters Legacy Meters [Member] Legacy Meters Equity Awards Adjustments, Excluding Value Reported in Compensation Table Equity Awards Adjustments, Excluding Value Reported in the Compensation Table [Member] Unrecognized pension and other postretirement costs Unrecognized Pension And Other Postretirement Costs [Member] Regulatory Asset for difference between Liability to Fair Value of Plan Assets and Projected Benefit Obligation. Provision for injuries and damages Provision For Injuries And Damages Provision for injuries and damages. Distributions from equity investments Proceeds from Equity Method Investment, Distribution Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Estimated liability for uncertain tax positions Unrecognized Tax Benefits Site Contingency [Line Items] Site Contingency [Line Items] Anti-dilutive effect (shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Unrecorded unconditional purchase obligation Unrecorded Unconditional Purchase Obligation Deferred projects Number Of Deferred Projects Number Of Deferred Projects Inter-zonal forward price curves adjusted for historical zonal losses Measurement Input, Commodity Inter-Zonal Forward Price Curve [Member] Measurement Input, Commodity Inter-Zonal Forward Price Curve [Member] Leases Lessee, Operating Leases [Text Block] NET CASH FLOWS FROM (USED IN) FINANCING ACTIVITIES Cash Provided by (Used in) Financing Activity, Including Discontinued Operation Measure: Measure [Axis] Net Amounts of Assets/ (Liabilities) Derivative, Fair Value, Net Guarantor Obligations, Term [Domain] Guarantor Obligations, Term [Domain] [Domain] for Guarantor Obligations, Term [Axis] Stock awards Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures Property, Plant and Equipment, Type [Domain] Long-Lived Tangible Asset [Domain] Operating costs Cost of Product and Service Sold Disposal Group Classification [Domain] Disposal Group Classification [Domain] Downgrade One Level from Current Ratings Additional Collateral Aggregate Fair Value Down One Level [Member] Additional Collateral Aggregate Fair Value Down One Level [Member] Balance Sheet Location [Domain] Statement of Financial Position Location, Activity, Accrual [Domain] Con Edison Gas Pipeline and Storage, LLC Con Edison Gas Pipeline and Storage, LLC [Member] Con Edison Gas Pipeline and Storage, LLC [Member] Notional amount Derivative, Nonmonetary Notional Amount Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Public Utilities, General Disclosures [Line Items] Public Utilities, General Disclosures [Line Items] Entity Tax Identification Number Entity Tax Identification Number Increase (decrease) in allowance for uncollectible accounts resulting from COVID-19 pandemic Accounts Receivable, Allowance for Credit Loss, Period Increase (Decrease) Fair Value, Concentration of Risk, Financial Statement Captions [Line Items] Fair Value, Concentration of Risk, Financial Statement Captions [Line Items] Credit Availability Through March 2028 Credit Availability Through March 2028 [Member] Credit Availability Through December 2022 [Member] TOTAL NONCURRENT LIABILITIES Liabilities, Other than Long-Term Debt, Noncurrent Asbestos Suits Asbestos Suits [Member] Asbestos Suits [Member] Total Regulatory Liabilities Regulatory liabilities Regulatory Liability Regulatory Liabilities, Noncurrent Regulatory Liabilities Non Current [Member] Deferred Derivative Gains Non Current [Member] Trading Arrangement: Trading Arrangement [Axis] Fair value of derivative assets Derivative Asset, Current Total Shareholder Return Amount Total Shareholder Return Amount Clean Energy Businesses Clean Energy Businesses [Member] Clean Energy Businesses [Member] Loss Contingencies [Line Items] Loss Contingencies [Line Items] Security Exchange Name Security Exchange Name Superfund and other environmental costs, net Other Increase (Decrease) in Environmental Liabilities Late payment charge deferral 2022 And 2023 Late Payment Charge Deferral [Member] 2022 And 2023 Late Payment Charge Deferral Equipment acquired but unpaid as of end of period Capital Expenditures Incurred but Not yet Paid Maximum borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Issuance of common shares - public offering Proceeds from Issuance Initial Public Offering Prepayments Prepaid Expense, Current OPERATING EXPENSES Operating Expenses [Abstract] Other current liabilities Other Liabilities, Current Asset Class [Domain] Asset Class [Domain] Pensions and retiree benefits Liability, Defined Benefit Plan, Noncurrent Statement [Line Items] Statement [Line Items] Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] Cash and temporary cash investments Cash and Cash Equivalent Estimated project cost (in percent) Percentage Of Estimated Costs On Projects Percentage of estimated costs on projects. Common Stock Common Stock [Member] Deferred derivative losses - long term Derivative Losses Long Term [Member] Regulatory Asset for deferral of change in fair value of derivative instrument. Sale of natural gas Sales Of Natural Gas Propane Ngls And Condensate And Affiliates Sales Of Natural Gas Propane Ngls And Condensate And Affiliates Regulatory assets not earning return Regulatory Assets Not Earning Return Regulatory Assets Not Earning Return NET CHANGE FOR THE PERIOD Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Including Exchange Rate Effect and Discontinued Operation Repurchased Con Edison Stock Repurchased Con Edison Stock [Member] Repurchased Con Edison Stock Notes payable Notes Payable, Current Common stock dividends per share (dollars per share) Common Stock, Dividends, Per Share, Cash Paid Guarantor Obligations [Line Items] Guarantor Obligations [Line Items] Summary of Significant Accounting Policies and Other Matters Significant Accounting Policies [Text Block] MTA Surcredit amortization, net of federal taxes Effective Income Tax Rate Reconciliation, Nondeductible Expense, MTA Surcredit Amortization Of Excess Deferred Federal Income Taxes, Percent Effective Income Tax Rate Reconciliation, Nondeductible Expense, MTA Surcredit Amortization Of Excess Deferred Federal Income Taxes, Percent Other operations and maintenance Oil and Gas, Operation and Maintenance [Member] Statistical Measurement [Domain] Statistical Measurement [Domain] Other operations and maintenance Other Operations and Maintenance Other Operations and Maintenance Average rate base Regulatory Matters Average Base Rate Regulatory Matters Average Base Rate Related Party Transaction [Axis] Related Party Transaction [Axis] Asset Class [Axis] Asset Class [Axis] Earnings from its equity investment Income (Loss) from Equity Method Investments Leases [Abstract] Leases [Abstract] Aggregate project cost Aggregate Project Cost Aggregate Project Cost Accounts payable Increase (Decrease) in Accounts Payable Downward price adjustment, after tax Disposition Of Stock In Subsidiary, Downward Price Adjustment, After Tax Disposition Of Stock In Subsidiary, Downward Price Adjustment, After Tax Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Net income per common share - basic (dollars per share) Earnings Per Share, Basic Actual net expenses amount Actual Net Expenses Amount Actual Net Expenses Amount Additional collateral (downgrade one level from current ratings) Additional Collateral, Aggregate Fair Value Potential offsetting credit adjustments Potential Offsetting Credit Adjustments Potential Offsetting Credit Adjustments Other comprehensive (loss) income Other comprehensive loss Other Comprehensive Income (Loss), Net of Tax Financial Data for Business Segments Schedule of Segment Reporting Information, by Segment [Table Text Block] Gain on sale of subsidiary Gain (Loss) on Disposition of Stock in Subsidiary Long-term Contract for Purchase of Electric Power [Axis] Long-Term Contract for Purchase of Electric Power [Axis] Measurement Input Type [Domain] Measurement Input Type [Domain] Commodity Fair Value Commodity [Member] Fair Value Commodity [Member] Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] Fuel Fuel [Member] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Accounts and Financing Receivables [Table] NY Transco NY Transco [Member] NY Transco [Member] Cash contributions for equity method investments Payments to Acquire Equity Method Investments Issuance of common shares for stock plans Shares Issued, Value, Share-Based Payment Arrangement, before Forfeiture Impact in regulatory liability resulting from TCJA Tax Cuts And Jobs Act Of 2017, Change In Tax Rate, Regulatory Liabilities, Income Tax Benefit Tax Cuts And Jobs Act Of 2017, Change In Tax Rate, Regulatory Liabilities, Income Tax Benefit CURRENT ASSETS Assets, Current [Abstract] TOTAL LIABILITIES AND EQUITY Liabilities and Equity Common equity ratio (percent) Common equity ratio (percent) Common Equity Ratio, Percentage Common Equity Ratio, Percentage Pension and other postretirement benefits deferrals Pension And Other Post Retirement Benefits Deferrals [Member] Regulatory Asset for reconciliation of actual pension and other postretirement benefit expenses to the level allowed in rates. OTHER INCOME (DEDUCTIONS) Other Nonoperating Income (Expense) [Abstract] Electric average excluding AMI Electric Excluding AMI [Member] Electric Excluding AMI [Member] Fair value of derivative assets Offsetting Derivative Assets [Abstract] Changes in unrecognized tax benefits Effective Income Tax Rate Reconciliation, Changes in Unrecognized Tax Benefits Effective Income Tax Rate Reconciliation, Changes in Unrecognized Tax Benefits Investment Holdings [Table] Credit Derivative [Table] Recovery period (in years) Regulatory Assets, Recovery Period Regulatory Assets, Recovery Period Schedule of Equity Method Investments [Table] Equity Method Investment [Table] Capital expenditures Segment, Expenditure, Addition to Long-Lived Assets Accounting Policies [Abstract] Accounting Policies [Abstract] Public Utility [Axis] Public Utility [Axis] Accrued taxes Increase (Decrease) in Property and Other Taxes Payable Natural Gas (Dt) Natural Gas Derivative [Member] Natural Gas Derivative [Member] Treasury Stock Treasury Stock, Common [Member] Tax Credits Effective Income Tax Rate Reconciliation, Tax Credit, Renewable Energy Credits, Amount Effective Income Tax Rate Reconciliation, Tax Credit, Renewable Energy Credits, Amount Pay vs Performance Disclosure [Line Items] Depreciation and amortization Depreciation, Depletion and Amortization, Nonproduction Netting Adjustment Fair Value, Concentration of Risk, Market Risk Management, Reporting Date Value at Risk [Member] Site Contingency [Table] Site Contingency [Table] Period [Domain] Period [Domain] [Domain] for Period [Axis] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Non-utility property, net accumulated depreciation of $25 in 2025 and 2024 Non-utility property, net accumulated depreciation of $25 in 2025 and 2024 Disposal Group, Including Discontinued Operation, Property, Plant And Equipment, Non-Utility Plant, Net, Noncurrent Tangible assets that are held by an entity for use other than utility production; net of accumulated depreciation. Return on regulatory assets Return On Regulatory Assets Return On Regulatory Assets Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Company Selected Measure Amount Company Selected Measure Amount Contributions made by employer Defined Benefit Plan, Plan Assets, Contributions by Employer COMPREHENSIVE INCOME Comprehensive Income (Loss), Net of Tax, Attributable to Parent Measurement Input Type [Axis] Measurement Input Type [Axis] Disposal Group Name [Domain] Disposal Group Name [Domain] Name Measure Name Number of miles in pipeline construction Number Of Miles In Pipeline Construction Number Of Miles In Pipeline Construction Income Tax Contingency [Table] Income Tax Contingency [Table] Legal Entity [Axis] Legal Entity [Axis] TOTAL ASSETS Total assets Assets INVESTING ACTIVITIES Cash Provided by (Used in) Investing Activity, Continuing Operation [Abstract] Total deferred gains (losses) Deferred Gain Loss Liability Deferred gain/(loss), liability Capitalization Capitalization [Text Block] Capitalization [Text Block] Deferred derivative losses recovery period, current (in years) Regulatory Assets, Deferred Derivative Losses, Current, Recovery Period Regulatory Assets, Deferred Derivative Losses, Current, Recovery Period Fair Value, Concentration of Risk [Table] Fair Value, Concentration of Risk [Table] Cost of the program, recovery period (in years) Contract With Customer, Cost Of Program, Recovery Period Contract With Customer, Cost Of Program, Recovery Period Regulatory Liability [Axis] Regulatory Liability [Axis] Receivable Type [Axis] Receivable Type [Axis] SUPPLEMENTAL DISCLOSURE OF CASH INFORMATION Additional Cash Flow Elements and Supplemental Cash Flow Information [Abstract] Payment Guarantee by CET Electric of Contributions to New York Transco LLC Payment Guarantee by CET Electric of Contributions to New York Transco LLC [Member] Payment Guarantee by CET Electric of Contributions to New York Transco LLC [Member] 5.99 Percent Due 2055 5.99 Percent Due 2055 [Member] 5.99 Percent Due 2055 Variable Interest Entities Consolidation, Variable Interest Entity, Policy [Policy Text Block] Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Right-of-use assets Right-of-Use Asset Obtained in Exchange for Operating Lease Liability Pensions and retiree benefits obligations, net Increase (Decrease) in Obligation, Pension and Other Postretirement Benefits Revenue taxes Revenue Taxes [Member] Regulatory Asset for timing differences between taxes collected and paid by the Utilities to fund mass transportation. Level 2 Fair Value, Inputs, Level 2 [Member] State income taxes, net of federal income taxes Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount Schedule of Regulatory Assets Schedule of Regulatory Assets [Table Text Block] Short-Term Borrowing Short-Term Debt [Text Block] Equity method investments Equity Method Investments Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] Public Utilities General Disclosures Public Utilities General Disclosures [Table Text Block] Related Party Related Party [Member] Aggregate fair value – net liabilities Credit Risk Derivatives, at Fair Value, Net Document Information [Table] Document Information [Table] PEO PEO [Member] Net fair value derivative assets (liabilities) Offsetting Derivative Assets and Liabilities [Abstract] Offsetting Derivative Assets and Liabilities [Abstract] Lease Contractual Term [Domain] Lease Contractual Term [Domain] SUPPLEMENTAL DISCLOSURE OF NON-CASH INFORMATION Noncash Investing and Financing Items [Abstract] Write-offs Accounts Receivable, Allowance for Credit Loss, Writeoff, Net Of Adjustments Accounts Receivable, Allowance for Credit Loss, Writeoff, Net Of Adjustments New Jersey Board of Public Utilities New Jersey Board Of Public Utilities [Member] New Jersey Board Of Public Utilities CHANGES IN ASSETS AND LIABILITIES Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Increase (Decrease) in Operating Capital [Abstract] Recoverable energy costs Recoverable Energy Costs, Current Recoverable Energy Costs [Member] Recoverable Energy Costs [Member] Retained Earnings Retained Earnings [Member] BALANCE AT BEGINNING OF PERIOD BALANCE AT END OF PERIOD Total cash, temporary cash investments and restricted cash Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Income Statement [Abstract] Income Statement [Abstract] Net Amounts of Assets (Liabilities) Derivative assets: Fair Value of commodity derivatives Derivative Asset Estimated aggregate undiscounted potential liability related environmental contaminants (up to) Potential Undiscounted Liability For Environmental Loss Contingencies Gross Potential undiscounted liability for environmental loss contingencies gross. Potential earnings adjustment mechanism incentives Potential Earnings Adjustment Mechanism Incentive Revenue Potential Earnings Adjustment Mechanism Incentive Revenue Accrued taxes Taxes Payable, Current Fair value of derivative liabilities Derivative Liability, Noncurrent Accrued interest Increase (Decrease) in Interest Payable, Net Product and Service [Domain] Product and Service [Domain] Transfer out of level 3 Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Transfers out of Level 3 Allowance for uncollectible accounts, net of regulatory recovery Effective Income Tax Rate Reconciliation, Change in Allowance For Uncollectible Accounts, Amounts Effective Income Tax Rate Reconciliation, Change in Allowance For Uncollectible Accounts, Amounts Restatement does not require Recovery Restatement Does Not Require Recovery [Text Block] Deferred income taxes and unamortized investment tax credits Deferred Tax Liabilities And Accumulated Deferred Investment Tax Credit Represents the noncurrent portion of deferred tax liabilities and the reserve for accumulated deferred investment tax credits as of the balance sheet date, which result from applying the applicable tax rate to net taxable temporary differences pertaining to each jurisdiction to which the entity is obligated to pay income tax. A noncurrent taxable temporary difference is a difference between the tax basis and the carrying amount of a noncurrent asset or liability in the financial statements prepared in accordance with generally accepted accounting principles. In a classified statement of financial position, an enterprise shall separate deferred tax liabilities and assets into a current amount and a noncurrent amount. Deferred tax liabilities and assets shall be classified as current or noncurrent based on the classification of the related asset or liability for financial reporting. A deferred tax liability or asset that is not related to an asset or liability for financial reporting, including deferred tax assets related to carryforwards, shall be classified according to the expected reversal date of the temporary difference. This is the remaining investment credit, which will reduce the cost of services collected from ratepayers by a ratable portion over the investment's regulatory life. Allowance for equity funds used during construction Public Utilities, Allowance for Funds Used During Construction, Capitalized Cost of Equity Customer deposits Contract with Customer, Refund Liability, Current Schedule of Basic and Diluted Earnings Per Share Schedule of Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Table Text Block] City Area Code City Area Code CECONY CECONY Consolidated Edison Company of New York, Inc. [Member] Consolidated Edison Company of New York, Inc. [Member] Award Timing, How MNPI Considered Award Timing, How MNPI Considered [Text Block] Other Other Regulatory Assets [Member] Other Regulatory Assets [Member] Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Related Party Transactions [Abstract] Recognition of net actuarial gain Recognition of net actuarial gain Defined Benefit Plan, Amortization of Gain (Loss) Goodwill Goodwill Estimate of possible loss (up to) Loss Contingency, Estimate of Possible Loss Crane Project Crane Project [Member] Crane Project Unrecognized pension and other postretirement costs Unrecognized Other Postretirement Benefits Costs [Member] Unrecognized Other Postretirement Benefits Costs [Member] Schedule of Lease Costs, Cash Flows and Other Related Information Lease, Cost [Table Text Block] Schedule of Environmental Exit Cost [Table] Environmental Exit Cost [Table] Lease Contractual Term [Axis] Lease Contractual Term [Axis] Current Derivative Financial Instruments Current Assets [Member] Derivative Financial Instruments Current Assets [Member] Year 1 Rate Plan for Year 1 [Member] Rate Plan for Year 1 [Member] Forward energy prices Measurement Input, Commodity Forward Energy Price [Member] Measurement Input, Commodity Forward Energy Price [Member] Workers’ Compensation Workers Compensation [Member] Workers Compensation [Member] Equipment Equipment [Member] Construction work in progress Public Utilities, Property, Plant and Equipment, Construction Work in Progress Unprotected Portion Unprotected Portion [Member] Unprotected Portion [Member] Net regulatory assets Net Regulatory Assets Cash paid (received) during the period for: Supplemental Cash Flow Information [Abstract] Beginning balance Ending balance Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs Funding limit of CECONY to O&R (not to exceed) Maximum Amount Of Funding Maximum Amount Of Funding Other Performance Measure, Amount Other Performance Measure, Amount Noncurrent Derivative Financial Instruments Non Current Liabilities [Member] Derivative Financial Instruments Non Current Liabilities [Member] Schedule of Restrictions on Cash and Cash Equivalents Restrictions on Cash and Cash Equivalents [Table Text Block] Debt issuance costs Payments of Debt Issuance Costs Cost of removal Effective Income Tax Rate Reconciliation Cost Of Removal, Amount Effective Income Tax Rate Reconciliation Cost Of Removal, Amount Fair Value Measurements Fair Value Measurement, Policy [Policy Text Block] Related Party [Domain] Related and Nonrelated Parties [Domain] Net Net Utility Plant Tangible assets that are held by an entity for use in the production or supply of utilities and that are expected to provide economic benefit for more than one year; net of accumulated depreciation. Derivative Instrument [Axis] Derivative Instrument [Axis] Changes in computed taxes resulting from: Effective Income Tax Rate Reconciliation, Deduction, Amount [Abstract] Restricted cash Restricted Cash Leases Lessee, Finance Leases [Text Block] Makeup of net credit exposure with commodity exchange brokers Maximum Potential Future Exposure On Credit Risk Derivatives With Commodity Exchange Brokers Maximum Potential Future Exposure On Credit Risk Derivatives With Commodity Exchange Brokers Total credit recognized Defined Benefit Plan, Cost (Credit) Recognized Defined Benefit Plan, Cost (Credit) Recognized Other current assets Other Assets, Current Year 2 Rate Plan for Year 2 [Member] Rate Plan for Year 2 [Member] Entity [Domain] Entity [Domain] NET CASH FLOWS USED IN INVESTING ACTIVITIES Cash Provided by (Used in) Investing Activity, Including Discontinued Operation Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table [Member] Fair value of derivative assets Derivative Asset, Noncurrent Loss on sale of the Clean Energy Businesses Gain (Loss) on Disposition of Business Interest, net of capitalized interest Cash paid (received) during the period for: Interest Paid, Excluding Capitalized Interest, Operating Activity Document Fiscal Year Focus Document Fiscal Year Focus Operating lease right-of-use asset Operating Lease, Right-of-Use Asset Unrecognized tax benefits penalties Unrecognized Tax Benefits, Income Tax Penalties Expense Effective tax rate Effective Income Tax Rate Reconciliation, Percent Operating lease cost Operating Lease, Cost OPERATING ACTIVITIES Cash Provided by (Used in) Operating Activity, Continuing Operation [Abstract] Carrying Amount Reported Value Measurement [Member] Taxes, other than income taxes Taxes, Miscellaneous Gas Gas Gas Transmission [Member] Financial Information by Business Segment Segment Reporting Disclosure [Text Block] 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] Pension and other postretirement benefit deferrals Pension and Other Post Retirement Benefits Deferrals, Liabilities [Member] Pension and Other Post Retirement Benefits Deferrals, Liabilities [Member] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Schedule of Total Periodic Benefit Costs Schedule of Net Benefit Costs [Table Text Block] Compensation Actually Paid vs. Total Shareholder Return Compensation Actually Paid vs. Total Shareholder Return [Text Block] Average Market Price Weighted Average [Member] Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Restricted cash Restricted Cash and Cash Equivalent, Current Taxes receivable Increase (Decrease) in Income Taxes Receivable Other operating expense Other Operating Expenses Other Operating Expenses Revolving Credit Facility Revolving Credit Facility [Member] Arrangement Duration Trading Arrangement Duration Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] General Public Utilities, Property, Plant and Equipment, Common Regulatory Assets Non Current Regulatory Assets Non Current [Member] Regulatory Assets Non Current [Member] Segments [Axis] Segments [Axis] Fair Value by Liability Class [Domain] Fair Value by Liability Class [Domain] Local Phone Number Local Phone Number Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Other investing activities Payment for (Proceeds from) Other Investing Activity ASSETS Assets [Abstract] Recovery deferral (percent) Public Utilities, Recovery Deferral Percentage Public Utilities, Recovery Deferral Percentage Credit Facility [Axis] Credit Facility [Axis] Underlying Security Market Price Change Underlying Security Market Price Change, Percent Debt Instrument [Axis] Debt Instrument [Axis] Pension Benefits Retirement Benefits [Text Block] Credit Facility [Domain] Credit Facility [Domain] Fair value of derivative liabilities Derivative Liability, Current Short-term borrowings Proceeds from Short-Term Debt Allowance for borrowed funds used during construction Public Utilities, Allowance for Funds Used During Construction, Additions Interest rate (percent) Debt Instrument, Interest Rate, Stated Percentage Investment, Name [Axis] Investment, Name [Axis] Operating lease liabilities Operating Lease, Liability, Noncurrent Steam Steam [Member] Steam [Member] Net unbilled revenue deferrals Net Unbilled Revenue Deferrals [Member] Net Unbilled Revenue Deferrals [Member] Concentration of Credit or Market Risk [Axis] Concentration of Credit or Market Risk [Axis] Gross Amounts of Recognized Assets (Liabilities) Derivative Asset, Subject to Master Netting Arrangement, before Offset Schedule of Regulatory Assets Not Earning Return Schedule Of Regulatory Assets Not Earning Return [Table Text Block] Schedule Of Regulatory Assets Not Earning Return Entity Registrant Name Entity Registrant Name Retention of annual transmission congestion revenues Retention Of Annual Transmission Congestion Revenues Retention Of Annual Transmission Congestion Revenues Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] TOTAL PERIODIC OTHER POSTRETIREMENT CREDIT Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Regulated Operations [Abstract] Regulated Operations [Abstract] Future income tax Future Income Tax [Member] Future Income Tax Other Corporate And Reconciling Items [Member] Corporate And Reconciling Items [Member] Ratio of consolidated debt to consolidated total capital Ratio of Indebtedness to Net Capital Noncurrent Derivative Financial Instruments Non Current Assets [Member] Derivative Financial Instruments Non Current Assets [Member] Interest cost on projected benefit obligation Interest cost on projected other postretirement benefit obligation Defined Benefit Plan, Interest Cost Related Party [Axis] Related and Nonrelated Parties [Axis] Restatement Determination Date: Restatement Determination Date [Axis] Gross Amounts Offset Derivative Asset (Liability), Gross Amount Offset in Balance Sheet Derivative Asset (Liability), Gross Amount Offset in Balance Sheet Interest on long-term debt Interest Expense, Debt Regulatory Asset [Axis] Regulatory Asset [Axis] Name Trading Arrangement, Individual Name RWE Renewables Americas, LLC [Member] Renewables Americas, LLC Schedule of Short-term Debt [Table] Short-Term Debt [Table] Debt face amount Debt Instrument, Face Amount Statement of Comprehensive Income [Abstract] Statement of Comprehensive Income [Abstract] Amortization of excess deferred federal income taxes Effective Income Tax Rate Reconciliation, Nondeductible Expense, Amortization Of Excess Deferred Federal Income Taxes, Percent Effective Income Tax Rate Reconciliation, Nondeductible Expense, Amortization Of Excess Deferred Federal Income Taxes, Percent Name Awards Close in Time to MNPI Disclosures, Individual Name Unrecognized tax benefits, net Unrecognized Tax Benefits, Net Unrecognized Tax Benefits, Net Aggregate Erroneous Compensation Not Yet Determined Aggregate Erroneous Compensation Not Yet Determined [Text Block] Regulatory assets Regulatory assets – noncurrent Regulatory Asset, Noncurrent Manhattan Explosion and Fire Manhattan Explosion and Fire [Member] Manhattan Explosion and Fire [Member] Credit Loss [Abstract] Stock awards APIC, Share-Based Payment Arrangement, Increase for Cost Recognition Income Tax Expense Operating Income Tax Expense Benefit Operating Income Tax Expense Benefit Liability Class [Axis] Liability Class [Axis] Litigation Case [Axis] Litigation Case [Axis] Environmental Remediation Contingency [Domain] Environmental Remediation Contingency [Domain] Segments [Domain] Segments [Domain] Schedule of Cash and Cash Equivalents [Table] Cash and Cash Equivalent [Table] Amount of revenues retained Retained Earnings, Appropriated Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Loans payable Loans Payable, Current INTEREST EXPENSE (INCOME) Interest Expense, Operating and Nonoperating [Abstract] Earnings Per Share Earnings Per Share, Policy [Policy Text Block] Non-utility property, accumulated depreciation Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Utility capital expenditures Payments for Construction in Process Schedule of Environmental Remediation Costs Environmental Remediation Costs Incurred Related To Super Fund Sites [Table Text Block] Environmental Remediation Costs Incurred Related To Super Fund Sites [Table Text Block] Gross Amounts Offset Derivative Liability, Subject to Master Netting Arrangement, Asset Offset Billing system costs Public Utilities, Billing System Costs Public Utilities, Billing System Costs All Executive Categories All Executive Categories [Member] Changes in unrecognized tax benefits Effective Income Tax Rate Reconciliation, Changes in Unrecognized Tax Benefits, Percent Effective Income Tax Rate Reconciliation, Changes in Unrecognized Tax Benefits, Percent Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Over Three Years Over Three Years [Member] Over Three Years COMMITMENTS, CONTINGENCIES, AND GUARANTEES (Note B, Note G, and Note H) Commitments and Contingencies Maximum aggregate limit of failure to pay debt or derivative obligations Debt Instrument, Covenant Compliance, Maximum Aggregate Limit Of Failure To Pay Debt Or Derivative Obligations Debt Instrument, Covenant Compliance, Maximum Aggregate Limit Of Failure To Pay Debt Or Derivative Obligations Number of registrants Number Of Registrants Number Of Registrants Other Superfund Sites Other Superfund Sites [Member] Other Superfund Sites Unconditional charitable contribution, accrued amount Unconditional Charitable Contribution, Accrued Amount Unconditional Charitable Contribution, Accrued Amount Income Taxes Disclosure [Table] Income Taxes Disclosure [Table] Income Taxes Disclosure [Table] Equity method investment, ownership percent (in percent) Equity Method Investment, Ownership Percentage New Financial Accounting Standards Accounting Standards Update and Change in Accounting Principle [Text Block] Short-term Debt [Line Items] Short-Term Debt [Line Items] Revenue decoupling mechanism Revenue Decoupling Mechanism [Member] Revenue Decoupling Mechanism [Member] Rate adjustment mechanism Public Utilities, Rate Adjustment Mechanism Public Utilities, Rate Adjustment Mechanism Other deductions Other Nonoperating Expense PEO Actually Paid Compensation Amount PEO Actually Paid Compensation Amount Total fair value of derivative assets Derivative Financial Instruments, Assets [Member] Incremental costs Public Utilities, Incremental Costs Public Utilities, Incremental Costs Capital contribution by Con Edison Adjustments to Additional Paid in Capital, Contributions by Parent Adjustments to Additional Paid in Capital, Contributions by Parent Schedule of Accrued Liability for Asbestos Suits and Workers' Compensation Proceedings Accrued Liabilities For Asbestos Suits And Workers Compensation Proceedings [Table Text Block] Accrued liabilities for asbestos suits and workers compensation proceedings. Revenue from Contract with Customer [Abstract] Revenue from Contract with Customer [Abstract] Included in regulatory assets and liabilities Fair Value, Net Derivative Asset (Liability) Measured On Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included In Regulatory Assets And Liabilities Fair Value, Net Derivative Asset (Liability) Measured On Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included In Regulatory Assets And Liabilities Scenario [Axis] Scenario [Axis] March 2023 Credit Agreement Variable Rate 364 Day Revolving Credit Agreement March 2023 Credit Agreement Variable Rate 364 Day Revolving Credit Agreement [Member] March 2023 Credit Agreement Variable Rate 364 Day Revolving Credit Agreement CASH AND TEMPORARY CASH INVESTMENTS Cash and Cash Equivalent [Abstract] Derivative Contract [Domain] Derivative Contract [Domain] Net proceeds Proceeds from Issuance of Common Stock All Individuals All Individuals [Member] Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Name Forgone Recovery, Individual Name Other interest expense Interest Expense (Income), Other, Net Interest Expense (Income), Other, Net Regulatory Agency [Domain] Regulatory Agency [Domain] Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested [Member] Accounts payable from (to) affiliated companies Increase (Decrease) in Due to Affiliates Disposal Group Classification [Axis] Disposal Group Classification [Axis] Issuance of common shares for stock plans Proceeds, Issuance of Shares, Share-Based Payment Arrangement, Including Option Exercised CASH, TEMPORARY CASH INVESTMENTS, AND RESTRICTED CASH: Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation [Abstract] Equity Method Investee Equity Method Investee [Member] Guarantor Obligations, Term [Axis] Guarantor Obligations, Term [Axis] Guarantor Obligations, Term [Axis] Schedule of Hedged Volume of Derivative Transactions Schedule of Derivative Instruments [Table Text Block] Termination cost Lessee, Operating Lease, Termination Cost Lessee, Operating Lease, Termination Cost Customer account deferrals Customer Account Deferrals [Member] Electric Vehicle Make Ready Erroneous Compensation Analysis Erroneous Compensation Analysis [Text Block] Annual gas revenue requirement Annual Gas Revenue Requirement Annual Gas Revenue Requirement Mountain Valley Pipeline LLC Mountain Valley Pipeline LLC [Member] Mountain Valley Pipeline LLC [Member] Lessee, Lease, Description [Line Items] Lessee, Lease, Description [Line Items] Rule 10b5-1 Arrangement Terminated Rule 10b5-1 Arrangement Terminated [Flag] Pension and other postretirement benefit plan liability adjustments, net of taxes Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax and Reclassification Adjustment, Attributable to Parent Electricity Electricity Swaps [Member] Electricity Swaps [Member] Number of people died in explosion and fire incident Number of People Died in Explosion and Fire Incident Number of people died in explosion and fire incident. Forward capacity prices Measurement Input, Commodity Forward Capacity Price [Member] Measurement Input, Commodity Forward Capacity Price [Member] Refundable energy costs Refundable Energy Cost Current [Member] Refundable Energy Cost - Current [Member] Scenario, Forecast Forecast [Member] Erroneously Awarded Compensation Recovery Erroneously Awarded Compensation Recovery [Table] Title of 12(b) Security Title of 12(b) Security Lessee, Lease, Description [Table] Lessee, Lease, Description [Table] Disposal Groups, Including Discontinued Operations [Table] Disposal Groups, Including Discontinued Operations [Table] Superfund and other environmental costs Accrued liabilities Accrued Environmental Loss Contingencies, Noncurrent TOTAL OTHER INCOME Other Income (deductions) Nonoperating Income (Expense) Ownership interest (in percent) Subsidiary, Ownership Percentage, Parent MTA Surcredit amortization, net of federal taxes Effective Income Tax Rate Reconciliation, Nondeductible Expense, MTA Surcredit Amortization Of Excess Deferred Federal Income Taxes, Amount Effective Income Tax Rate Reconciliation, Nondeductible Expense, MTA Surcredit Amortization Of Excess Deferred Federal Income Taxes, Amount UTILITY PLANT, AT ORIGINAL COST Public Utilities, Property, Plant and Equipment [Abstract] Downward price adjustment Disposition Of Stock In Subsidiary, Downward Price Adjustment Disposition Of Stock In Subsidiary, Downward Price Adjustment Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Capital expenditures limit Public Utilities. Limit For Capitalization Public Utilities. Limit For Capitalization Award Timing Disclosures [Line Items] Service cost – including administrative expenses Service cost - including administrative expenses Defined Benefit Plan, Service Cost Recoveries Accounts Receivable, Allowance for Credit Loss, Recovery NET INCOME FOR COMMON STOCK NET INCOME Net income Net income for common stock Net Income (Loss) Attributable to Parent NONCURRENT LIABILITIES Liabilities, Noncurrent [Abstract] NET UTILITY PLANT Public Utilities, Property, Plant and Equipment, Net Potential charges Potential Penalty Expense Potential Penalty Expense Schedule of Income Tax Reconciliation Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Accounts Receivable, Allowance for Credit Loss [Roll Forward] Accounts Receivable, Allowance for Credit Loss [Roll Forward] Other Effective Income Tax Rate Reconciliation, Other Adjustments, Percent Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Number of regulated utility subsidiaries Number Of Regulated Utility Subsidiaries Number Of Regulated Utility Subsidiaries Adoption Date Trading Arrangement Adoption Date Reclassification Reclassification, Comparability Adjustment [Policy Text Block] Accrued unbilled revenue Contract with Customer, Asset, after Allowance for Credit Loss Regulatory Assets Current Regulatory Assets Current [Member] Deferred Derivative Losses [Member] Schedule of Accrued Liabilities and Regulatory Assets Accrued Liabilities And Regulatory Assets [Table Text Block] Accrued Liabilities And Regulatory Assets [Table Text Block] FINANCING ACTIVITIES Cash Provided by (Used in) Financing Activity, Continuing Operation [Abstract] OPERATING INCOME OPERATING INCOME Operating income (loss) Operating Income (Loss) Schedule of Offsetting of Liabilities Offsetting Liabilities [Table Text Block] Revenue decoupling mechanism receivable Revenue Decoupling Mechanism Receivable Revenue Decoupling Mechanism Receivable Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested [Member] System benefit charge carrying charge System Benefit Charge Carrying Charge [Member] System Benefit Charge Carrying Charge [Member] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table [Member] Liabilities held for sale Disposal Group, Including Discontinued Operation, Liabilities, Current Investment Holdings [Line Items] Credit Derivatives [Line Items] Retirement Plan Type [Axis] Retirement Plan Type [Axis] Statement [Table] Statement [Table] Deferred income taxes Deferred Income Tax Expense (Benefit) PRINCIPAL NON-CASH CHARGES (CREDITS) TO INCOME Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity [Abstract] Unbilled revenue and net unbilled revenue deferrals Contract With Customer, Liability, Unbilled Revenue Accruals And Deferrals Contract With Customer, Liability, Unbilled Revenue Accruals And Deferrals Other receivables Other Receivables [Member] Other Receivables [Member] Deferred derivative losses - short term Derivative Losses Current [Member] Regulatory Asset for deferral of change in fair value of derivative instrument. All Adjustments to Compensation All Adjustments to Compensation [Member] Electric Electricity [Member] Amendment Flag Amendment Flag Other deferred credits and noncurrent liabilities Deferred Credits and Other Liabilities, Noncurrent Other Postretirement Benefits Other Postretirement Benefits Plan [Member] Termination Date Trading Arrangement Termination Date Environmental Exit Cost [Line Items] Environmental Exit Cost [Line Items] Insider Trading Policies and Procedures Adopted Insider Trading Policies and Procedures Adopted [Flag] Receivable [Domain] Receivable [Domain] Reflects regulatory liability amortization Reflects Regulatory Liability Amortization Reflects Regulatory Liability Amortization AVERAGE NUMBER OF SHARES OUTSTANDING-BASIC (shares) Weighted average common shares outstanding – basic (shares) Weighted Average Number of Shares Outstanding, Basic Related Party Transaction [Domain] Related Party Transaction [Domain] Segment Reporting [Abstract] Segment Reporting [Abstract] Cost of long-term debt (percent) Long-Term Debt, Percentage Bearing Variable Interest, Percentage Rate Debt Disclosure [Abstract] Debt Disclosure [Abstract] Scenario [Domain] Scenario [Domain] Fair value of derivative liabilities Offsetting Derivative Liabilities [Abstract] Unamortized debt discount Debt Instrument, Unamortized Discount Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount Consolidated Entities [Axis] Consolidated Entities [Axis] Non-utility Non-Utility Products And Services [Member] Non-Utility Products And Services [Member] Other customer-provided capital rate (in percent) Other Customer Provided Capital Rate Other Customer Provided Capital Rate Taxes receivable Income Taxes Receivable, Current Cost of removal less salvage Payments for (Proceeds from) Removal Costs Guarantor Obligations, Nature [Axis] Guarantor Obligations, Nature [Axis] Total Regulatory Assets Regulatory assets Regulatory Asset Construction work in progress Construction in Progress, Gross Gross Amounts Offset Derivative Asset, Subject to Master Netting Arrangement, Liability Offset Insider Trading Arrangements [Line Items] Regulatory liabilities Regulatory liabilities – current Regulatory Liability, Current Other revenues Product and Service, Other [Member] Settlements Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Settlements Investment income Investment and other income Investment Income, Net Pension Adjustments Prior Service Cost Pension Adjustments Prior Service Cost [Member] Unrecognized tax benefits, increase resulting from current period tax positions Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions Material Terms of Trading Arrangement Material Terms of Trading Arrangement [Text Block] Tax Credits Effective Income Tax Rate Reconciliation, Tax Credit, Renewable Energy Credits, Percent Effective Income Tax Rate Reconciliation, Tax Credit, Renewable Energy Credits, Percent Defined benefit plan, expected future employer contributions, next fiscal year Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year Generating capacity per day (in dekatherms) Generating Capacity Per Day Generating Capacity Per Day Ratio of consolidated debt to consolidated total capital Debt Instrument, Covenant Compliance, Consolidated Debt To Consolidated Total Capital Ratio Debt Instrument, Covenant Compliance, Consolidated Debt To Consolidated Total Capital Ratio Issuance of common shares - public offering Stock Issued During Period, Value, New Issues Consolidation Items [Axis] Consolidation Items [Axis] Unamortized debt expense Unamortized Debt Issuance Expense Counterparty Name [Axis] Counterparty Name [Axis] Environmental investigation and remediation costs Environmental Restoration Costs [Member] Manufactured gas plant sites Manufactured Gas Plant Sites Natural Gas Processing Plant [Member] Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Non-NEOs Non-NEOs [Member] RECO Rockland Electric Company [Member] Rockland Electric Company Collateral posted Collateral Already Posted, Aggregate Fair Value