Portion at Fair Value Measurement [Member] Portion at Fair Value Measurement [Member] Cost [Member] Reported Value Measurement [Member] Subsequent Event Subsequent Event [Member] Document Fiscal Year Focus Document Fiscal Year Focus Revenue Type [Domain] Revenue Type [Domain] Revenue Type Segment Reporting [Abstract] Segment Reporting [Abstract] Gain (Loss) on Disposition of Business, Including Discontinued Operation Gain (Loss) on Disposition of Business, Including Discontinued Operation Gain (Loss) on Disposition of Business, Including Discontinued Operation Retail Revenue [Member] Retail Revenue [Member] Retail Revenue [Member] Common stock Common Stock, Value, Issued Common Stock, Value, Issued Public Utilities, General Disclosures [Line Items] Public Utilities, General Disclosures [Line Items] Schedule of Long-term Debt Instruments Schedule of Long-Term Debt Instruments [Table Text Block] Pension and Postretirement Benefits Retirement Benefits [Text Block] Line of Credit Line of Credit [Member] Expected return on assets Defined Benefit Plan, Expected Return (Loss) on Plan Assets 4.35% Senior Notes due 2029 [Member] 4.35% Senior Notes due 2029 [Member] 4.35% Senior Notes due 2029 [Member] Derivative Instrument [Axis] Derivative Instrument [Axis] Schedule of Effective Income Tax Rate Reconciliation Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Increase (Decrease) in Obligation, Pension and Other Postretirement Benefits Increase (Decrease) in Obligation, Pension and Other Postretirement Benefits Accounts Receivable, Allowance for Credit Loss Accounts Receivable, Allowance for Credit Loss Regulatory liabilities, non-current Regulatory Liability, Noncurrent Receivables from Contracts with Customers Receivables from Contracts with Customers [Table Text Block] Receivables from Contracts with Customers Amendment Flag Amendment Flag Current liabilities: Liabilities, Current [Abstract] Consolidated Entities [Axis] Consolidated Entities [Axis] Accounts Receivable, Credit Loss Expense (Reversal) Accounts Receivable, Credit Loss Expense (Reversal) Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding 4.25% Tax-exempt First Mortgage Bonds due 2027 4.25% Tax-exempt First Mortgage Bonds due 2027 [Member] 4.25% Tax-exempt First Mortgage Bonds due 2027 Public Utilities, Allowance for Funds Used During Construction, Capitalized Cost of Equity Public Utilities, Allowance for Funds Used During Construction, Capitalized Cost of Equity Governmental Revenue Governmental Revenue [Member] Governmental Revenue Disposal Group Classification [Axis] Disposal Group Classification [Axis] Tax Savings Credit Rider Tax Savings Credit Rider Tax Savings Credit Rider Risks and Uncertainties [Text Block] Risks and Uncertainties [Text Block] Risks and Uncertainties [Text Block] Total non-current liabilities Liabilities, Noncurrent Consolidated Entities [Domain] Consolidated Entities [Domain] Schedule of Cash and Cash Equivalents [Table Text Block] Schedule of Cash and Cash Equivalents [Table Text Block] Entity Address, City or Town Entity Address, State or Province Public Utility, Property, Plant and Equipment [Table] Public Utility, Property, Plant and Equipment [Table] Par value common shares (in USD per share) Common stock, par value (in USD per share) Common Stock, Par or Stated Value Per Share Segment Reporting, Long-Lived Asset, Expenditure for Addition Segment Reporting, Long-Lived Asset, Expenditure for Addition Reclassification out of Accumulated Other Comprehensive Income [Member] Reclassification out of Accumulated Other Comprehensive Income [Member] Cash and Cash Equivalents [Abstract] Cash and Cash Equivalents [Abstract] Intangible Asset, Excluding Goodwill, after Accumulated Amortization Intangible Asset, Excluding Goodwill, after Accumulated Amortization Non-current liabilities: Liabilities, Noncurrent [Abstract] Total long-term debt at subsidiary Total Long-term Debt At Subsidiary With Purchase Accounting Adjustments Total Long-term Debt At Subsidiary With Purchase Accounting Adjustments 5.19% First Mortgage Bonds due 2033 5.19% First Mortgage Bonds due 2033 [Member] 5.19% First Mortgage Bonds due 2033 Regulatory Asset, Noncurrent Regulatory Asset, Noncurrent Number of reportable segments Number of Reportable Segments Total current liabilities Liabilities, Current Liabilities, Current Subsegments Consolidation Items [Axis] Subsegments Consolidation Items [Axis] Taxes other than income taxes Taxes, Miscellaneous Tax-exempt First Mortgage Bonds due 2027 Tax-exempt First Mortgage Bonds due 2027 [Member] Tax-exempt First Mortgage Bonds due 2027 Entity Address, City or Town Entity Address, City or Town Taxes payable Taxes Payable Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Debt Instrument, Debt Covenant, Total Debt to EBITDA, Borrowing Limit Quarterly Reduction Debt Instrument, Debt Covenant, Total Debt to EBITDA, Quarterly Borrowing Limit Reduction Debt Instrument, Debt Covenant, Total Debt to EBITDA, Quarterly Borrowing Limit Reduction Financial Statement Presentation Basis of Accounting, Policy [Policy Text Block] Debt Instrument, Debt Covenant, Total Debt to EBITDA, New Borrowing Limit Debt Instrument, Debt Covenant, Total Debt to EBITDA, Maximum Borrowing Limit Debt Instrument, Debt Covenant, Total Debt to EBITDA, Maximum Borrowing Limit Covid-19 Deferral Write-Off Covid-19 Deferral Write-Off Covid-19 Deferral Write-Off Payments of Ordinary Dividends Payments of Ordinary Dividends Level 2 [Member] Fair Value, Inputs, Level 2 [Member] Line of Credit Facility, Maximum Borrowing Capacity Line of Credit Facility, Maximum Borrowing Capacity Other Comprehensive Income (Loss), Net of Tax, Total Other Comprehensive Income (Loss), Net of Tax Other Comprehensive Income (Loss), Net of Tax Long-Term Debt, Current Maturities Long-Term Debt, Current Maturities Proceeds from Insurance Settlement, Investing Activities Proceeds from Insurance Settlement, Investing Activities Other Expenses Other Expenses Subsequent Event Type [Axis] Subsequent Event Type [Axis] Total change in fair value of derivatives Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax Schedule of Long-term Debt Instruments [Table] Schedule of Long-Term Debt Instruments [Table] Non-cash capital contribution Non-cash capital contribution Non-cash capital contribution Recently Issued Accounting Standards New Accounting Pronouncements, Policy [Policy Text Block] New Accounting Pronouncements, Policy [Policy Text Block] Accruals for capital expenditures Capital Expenditures Incurred but Not yet Paid Financial Reporting for Reportable Business Segments Segment Reporting [Table Text Block] Estimated Smart Grid Phase 2 capital Estimated Smart Grid Phase 2 capital Estimated Smart Grid Phase 2 capital 4.13% Senior Notes due 2025 4.13% Senior Notes due 2025 [Member] 4.13% Senior Notes due 2025 Related Party, Type [Axis] Related and Nonrelated Parties [Axis] Repayments of Lines of Credit Repayments of Lines of Credit Long-term Debt Total long-term debt Long-Term Debt Revenue from Contracts with Customers Revenue from Contracts with Customers [Table Text Block] Revenue from Contracts with Customers Non-cash financing and investing activities: Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract] Increase (Decrease) in Income Taxes Payable Increase (Decrease) in Income Taxes Payable Document Period End Date Document Period End Date Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Increase (Decrease) in Operating Capital Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Increase (Decrease) in Operating Capital [Abstract] Cash Provided by (Used in) Investing Activity, Including Discontinued Operation Cash Provided by (Used in) Investing Activity, Including Discontinued Operation RSC Rider RSC Rider RSC Rider Unusual Risk or Uncertainty [Table] Unusual Risk or Uncertainty [Table] Subsidiaries [Member] Subsidiaries [Member] Equity ownership interest aggregate cost Equity Ownership Interest - Guaranteed Portion of Long-term Debt Obligation Equity ownership interest guaranteed portion of Long-term Debt Obligation Stockholders' Equity Note Disclosure Equity [Text Block] Debt Instrument, Interest Rate, Effective Percentage Debt Instrument, Interest Rate, Effective Percentage Deferral of Carrying Costs - ESP 4 Deferral of Carrying Costs - ESP 4 Deferral of Carrying Costs - ESP 4 Adjustments and Eliminations [Member] Consolidation, Eliminations [Member] Reclassification out of Accumulated Other Comprehensive Income [Domain] Reclassification out of Accumulated Other Comprehensive Income [Domain] Ohio Investments Ohio Investments [Member] Ohio Investments Accumulated other comprehensive income Accumulated Other Comprehensive Income (Loss), Net of Tax Entity Shell Company Entity Shell Company Consolidation Items [Domain] Consolidation Items [Domain] Cash and Cash Equivalent Cash and Cash Equivalent [Abstract] Accounts Receivable, Allowance for Credit Loss Accounts Receivable, Allowance for Credit Loss [Table Text Block] Accrued interest Interest Payable, Current Statement of Comprehensive Income [Abstract] Statement of Comprehensive Income [Abstract] Regulatory Matters [Abstract] Regulatory Matters [Abstract] Regulatory Matters Abstract Document Fiscal Period Focus Document Fiscal Period Focus Reclassification to earnings, net of income tax Other Comprehensive Income (Loss), Defined Benefit Plan, Transition Asset (Obligation), Reclassification Adjustment from AOCI, after Tax Other Comprehensive Income (Loss), Defined Benefit Plan, Transition Asset (Obligation), Reclassification Adjustment from AOCI, after Tax Other Comprehensive Income (Loss), Defined Benefit Plan, Transition Asset (Obligation), Reclassification Adjustment from AOCI, after Tax Liabilities Liabilities Liabilities RTO Revenue RTO Revenue RTO Revenue COVID-19 Deferral [Member] COVID-19 Deferral [Member] COVID-19 Deferral Purchased power Utilities Operating Expense, Purchased Power Customer receivables Customer receivables Amounts due from customers for billed utility services. Reclassification from AOCI, Current Period, Net of Tax, Attributable to Parent Reclassification from AOCI, Current Period, Net of Tax, Attributable to Parent Amortization of Debt Issuance Costs and Discounts Amortization of Debt Issuance Costs and Discounts 4.00% Tax-exempt First Mortgage Bonds due 2027 4.00% Tax-exempt First Mortgage Bonds due 2027 [Member] 4.00% Tax-exempt First Mortgage Bonds due 2027 Ohio Holdings Investment Percent Ohio Holdings Investment Percent Ohio Holdings Investment Percent Reclassifications Reclassifications [Text Block] Estimated Smart Grid Phase 2 costs Estimated Smart Grid Phase 2 costs Estimated Smart Grid Phase 2 costs Significant Accounting Policies [Table] Significant Accounting Policies [Table] Significant Accounting Policies [Table] Subsidiary, Ownership Percentage, Parent Subsidiary, Ownership Percentage, Parent Change in unfunded pension obligation [Member] Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Long-term Debt, Gross Long-Term Debt, Gross Debt Securities [Member] Debt Securities [Member] Increase (Decrease) in Other Accrued Liabilities Increase (Decrease) in Other Accrued Liabilities Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Asset Types [Domain] Asset Class [Domain] Unbilled Revenue Unbilled Revenue Amounts due from customers based upon an estimate of sales of power to customers since the last customer billing. Credit Facility [Domain] Credit Facility [Domain] Cash flows from operating activities: Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract] Gain (Loss) on Disposition of Intangible Assets Gain (Loss) on Disposition of Intangible Assets Shares, Issued Shares, Issued 5.49% Tax-exempt First Mortgage Bonds due 2028 5.49% Tax-exempt First Mortgage Bonds due 2028 [Member] 5.49% Tax-exempt First Mortgage Bonds due 2028 Entity Emerging Growth Company Entity Emerging Growth Company Related Party Transaction [Line Items] Related Party Transaction [Line Items] Pension, retiree and other benefits Liability, Defined Benefit Plan, Noncurrent Disposal Group Name [Domain] Disposal Group Name [Domain] Note to DPL Capital Trust II Maturing in September 2031 - 8.125% [Member] Eight Point One Two Five Percentage Of Note To Capital Trust II Maturing In September Two Thousand Thirty One [Member] Eight Point One Two Five Percentage Of Note To Capital Trust II Maturing In September Two Thousand Thirty One [Member] Proceeds from Lines of Credit Proceeds from Lines of Credit Entities [Table] Entities [Table] Regulatory Asset [Axis] Regulatory Asset [Axis] Ohio Holdings Ohio Holdings [Member] Ohio Holdings Utility [Member] Utility [Member] Utility [Member] Disposal Groups, Including Discontinued Operations [Table Text Block] Disposal Groups, Including Discontinued Operations [Table Text Block] Increase (Decrease) in Current Regulatory Assets and Liabilities Increase (Decrease) in Current Regulatory Assets and Liabilities The increase (decrease) during the reporting period in the value of assets that are created when regulatory agencies permit public utilities to defer costs (revenues) to the balance sheet. This element is the increase (decrease) of current regulatory assets and liabilities combined Contributions by employer Defined Benefit Plan, Plan Assets, Contributions by Employer Increase (Decrease) in Other Noncurrent Assets Increase (Decrease) in Other Noncurrent Assets Revenue [Abstract] Revenue [Abstract] Revenue [Abstract] Other Other Receivables Impairment of Long-Lived Assets Held-for-use Long-Lived Asset, Held and Used, Impairment Loss Increase (Decrease) in Other Operating Assets and Liabilities, Net Increase (Decrease) in Other Operating Assets and Liabilities, Net Cash Provided by (Used in) Operating Activity, Discontinued Operation Cash Provided by (Used in) Operating Activity, Discontinued Operation Level 1 [Member] Fair Value, Inputs, Level 1 [Member] Effective income tax rates Effective Income Tax Rate Reconciliation, Percent Proceeds from Contribution in Aid of Construction, Investing Activity Proceeds from Contribution in Aid of Construction, Investing Activity Debt Covenant, Debt to EBITDA Ratio, Maximum Debt Covenant, Debt to EBITDA Ratio, Maximum Debt Covenant, Debt to EBITDA Ratio, Maximum Total Assets Investments Other Than Derivatives The total of assets that are measured on a recurring basis. Debt Obligation on 4.9% Equity Ownership [Member] Debt Obligation On49 Equity Ownership [Member] Debt Obligation on 4.9% Equity Ownership in an electric generation company Interest expense Interest expense Interest and Debt Expense Scenario [Domain] Scenario [Domain] Pension and postretirement activity: Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax [Abstract] Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Business Segments Segment Reporting [Text Block] Long-term Line of Credit Long-Term Line of Credit Investments, Fair Value Disclosure Investments, Fair Value Disclosure Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Disaggregation of Revenue [Table Text Block] Disaggregation of Revenue [Table Text Block] Income Statement Location [Axis] Location, Statement of Income, Balance [Axis] Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Equity, Including Portion Attributable to Noncontrolling Interest Debt Instrument, Debt Covenant, Total Debt to EBITDA, Borrowing Limit Debt Instrument, Debt Covenant, Total Debt to EBITDA, Current Borrowing Limit Debt Instrument, Debt Covenant, Total Debt to EBITDA, Current Borrowing Limit Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Nonrelated Party Nonrelated Party [Member] Disposal Group, Including Discontinued Operations [Line Items] Disposal Group, Including Discontinued Operations [Line Items] Increase (Decrease) in Security Deposits Increase (Decrease) in Security Deposits Net periodic benefit cost Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Common Stock, Shares Authorized Common Stock, Shares Authorized Debt Instrument, Unamortized Discount (Premium), Net Debt Instrument, Unamortized Discount (Premium), Net Capital Structure - Equity - Distribution Rate Case Capital Structure - Equity - Distribution Rate Case Capital Structure - Equity - Distribution Rate Case Cash Provided by (Used in) Investing Activity, Including Discontinued Operation Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract] Related Party Transaction [Axis] Related Party Transaction [Axis] Segment Reporting [Line Items] Segment Reporting [Line Items] Document Quarterly Report Document Quarterly Report Disposal Groups, Including Discontinued Operations [Table] Disposal Groups, Including Discontinued Operations [Table] Segments [Domain] Segments [Domain] Industrial Revenue Industrial Revenue [Member] Industrial Revenue Electric Revenue, Including Discontinued Operations Electric Revenue, Including Discontinued Operations Electric Revenue, Including Discontinued Operations Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest Long-term Debt Debt Disclosure [Text Block] Scenario [Axis] Scenario [Axis] Disposal Group Classification [Domain] Disposal Group Classification [Domain] Unamortized deferred finance costs Debt Issuance Costs, Net Equity Component [Domain] Equity Component [Domain] Costs and Expenses Costs and Expenses 5.70% Senior Notes due 2033 5.70% Senior Notes due 2033 [Member] 5.70% Senior Notes due 2033 Inventory, Policy Inventory, Policy [Policy Text Block] Debt instrument interest percentage Debt Instrument, Interest Rate, Stated Percentage Equity, Attributable to Parent Equity, Attributable to Parent Nonoperating Income (Expense) Nonoperating Income (Expense) Nonoperating Income (Expense) Accounting Policies [Abstract] Accounting Policies [Abstract] TFR True-Up Liability TFR True-Up Liability TFR True-Up Liability Proceeds from (Payment for) Other Financing Activity Proceeds from (Payment for) Other Financing Activity Accounts Receivable, Allowance for Credit Loss, Current Accounts Receivable, Allowance for Credit Loss, Current Deferred Income Tax Expense (Benefit) Deferred Income Tax Expense (Benefit) Regulatory Asset, Current Regulatory Asset, Current TFR True-up Liability, Current TFR True-up Liability, Current TFR True-up Liability, Current Contractual Obligations, Commercial Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Number of Operating Segments Number of Operating Segments Short-Term Bank Loans and Notes Payable Short-Term Bank Loans and Notes Payable Debt Instrument, Debt Covenant, EBITDA to Interest Expense, EBITDA Minimum Debt Instrument, Debt Covenant, EBITDA to Interest Expense, EBITDA Minimum Debt Instrument, Debt Covenant, EBITDA to Interest Expense, EBITDA Minimum Rate Base - Distribution Rate Case Rate Base - Distribution Rate Case Rate Base - Distribution Rate Case Entity Central Index Key Entity Central Index Key Property, Plant, and Equipment, Accumulated Depreciation, Depletion, and Amortization Property, Plant, and Equipment, Accumulated Depreciation, Depletion, and Amortization Other paid-in capital Additional Paid in Capital, Common Stock Corporate, Non-Segment [Member] Segment Reporting, Reconciling Item, Corporate Nonsegment [Member] Equity [Abstract] DPL DPL [Member] DPL Cash Provided by (Used in) Operating Activity, Including Discontinued Operation Cash Provided by (Used in) Operating Activity, Including Discontinued Operation Stockholders' Equity, Other Stockholders' Equity, Other Stockholders' Equity, Other Income Statement [Abstract] Income Statement [Abstract] Document Transition Report Document Transition Report Ownership [Axis] Ownership [Axis] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Investment, Name [Axis] Investment, Name [Axis] Increase (Decrease) in Taxes Applicable to Subsequent Years Increase (Decrease) in Taxes Applicable to Subsequent Years The net change during the reporting period in the aggregate value of capitalized property and other taxes, associated with underlying transactions that are classified as operating activities. Intersegment Eliminations Intersegment Eliminations [Member] Revenue from external customers Revenue from external customers [Member] Revenue from external customers Capital Structure - Long-term Debt - Distribution Rate Case Capital Structure - Long-term Debt - Distribution Rate Case Capital Structure - Long-term Debt - Distribution Rate Case Interest Costs Capitalized Adjustment Interest Costs Capitalized Adjustment City Area Code City Area Code 5.49% Senior Notes due 2028 5.49% Senior Notes due 2028 [Member] 5.49% Senior Notes due 2028 AOCI Attributable to Parent [Member] AOCI Attributable to Parent [Member] Payments for (Proceeds from) Businesses and Interest in Affiliates Payments for (Proceeds from) Businesses and Interest in Affiliates Debt Debt Instrument, Fair Value Disclosure Ohio Holdings Purchase price Ohio Holdings Purchase price Ohio Holdings Purchase price Payments of Dividends Payments of Dividends Payments of Dividends Assets, Noncurrent Assets, Noncurrent Statement [Line Items] Statement [Line Items] Total assets Assets, Total Assets Schedule of Defined Benefit Plans Disclosures [Table] Defined Benefit Plan [Table] Ohio Investments Purchase price Ohio Investments Purchase price Ohio Investments Purchase price Entity [Domain] Entity [Domain] Approximate number of retail customers Number Of Retail Customers This element represents the approximate number of retail customers that electricity is generated and distributed within the company's service territory. Recovery - ESP 4 Recovery - ESP 4 Recovery - ESP 4 Effective Income Tax Rate Reconciliation [Line Items] Effective Income Tax Rate Reconciliation [Line Items] Prior service cost Defined Benefit Plan, Amortization of Prior Service Cost (Credit) Operating Segments [Member] Operating Segments [Member] Unrecovered OVEC Charges Unrecovered OVEC Charges [Member] Unrecovered OVEC Charges Disposal Group, Including Discontinued Operation, Revenue Disposal Group, Including Discontinued Operation, Revenue Description of Business Nature of Operations [Text Block] Current Income Tax Expense (Benefit), Continuing Operations [Abstract] Current Income Tax Expense (Benefit), Continuing Operations [Abstract] Increase (Decrease) in Prepaid Expense Increase (Decrease) in Prepaid Expense Measurement Basis [Axis] Measurement Basis [Axis] Other deferred credits Other Liabilities, Noncurrent Retirement Plan Type [Axis] Retirement Plan Type [Axis] Equity Contribution From Parent Equity Contribution From Parent Equity Contribution From Parent Debt Covenant, Total Debt to Total Capitalization Ratio, Maximum Debt Covenant, Total Debt to Total Capitalization Ratio, Maximum Debt Covenant, Total Debt to Total Capitalization Ratio, Maximum Subsequent Event Type [Domain] Subsequent Event Type [Domain] Accrued taxes Taxes Payable, Current Retained Earnings [Member] Retained Earnings [Member] Revolving Credit Facility [Member] Revolving Credit Facility [Member] Money Market Funds [Member] Money Market Funds [Member] Payment against tax receivable balance from Parent Payment against tax receivable balance from Parent Payment against tax receivable balance from Parent Public Utilities, Allowance for Funds Used During Construction, Additions Public Utilities, Allowance for Funds Used During Construction, Additions Fair Value Measurement Inputs and Valuation Techniques Fair Value Measurement Inputs and Valuation Techniques [Table Text Block] Common Stock, Shares, Outstanding Common Stock, Shares, Outstanding 4.55% First Mortgage Bond Due 2030 4.55% First Mortgage Bond Due 2030 [Member] 4.55% First Mortgage Bond Due 2030 Entity Current Reporting Status Entity Current Reporting Status Net cash provided by financing activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation Interest Costs Capitalized Interest Costs Capitalized Number of prior quarters included in EBITDA to interest calculation Debt Instrument, Debt Covenant, EBITDA to Interest Calculation, Number of Quarters Debt Instrument, Debt Covenant, EBITDA to Interest Calculation, Number of Quarters Unrealized Gain (Loss) on Investments Unrealized Gain (Loss) on Investments Intangible Asset, Finite-Lived [Line Items] Intangible Asset, Finite-Lived [Line Items] Ownership [Domain] Ownership [Domain] Operation and maintenance Utilities Operating Expense, Maintenance and Operations Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity [Abstract] Accounts Receivable, Allowance for Credit Loss, Writeoff Accounts Receivable, Allowance for Credit Loss, Writeoff Electric Generation Company [Member] Electric Generation Company [Member] The Electric Generation Company DP&L holds a 4.9% interest. Revenue from Contract with Customer, Excluding Assessed Tax Revenue from Contract with Customer, Excluding Assessed Tax Cash flows from financing activities: Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract] Property, Plant, and Equipment, after Accumulated Depreciation, Depletion, and Amortization Property, Plant, and Equipment, after Accumulated Depreciation, Depletion, and Amortization Interest cost Defined Benefit Plan, Interest Cost Schedule of New Accounting Pronouncements Accounting Standards Update and Change in Accounting Principle [Table Text Block] Estimate of Fair Value Measurement [Member] Fair Value [Member] Estimate of Fair Value Measurement [Member] Revenue from Contract with Customer [Text Block] Revenue from Contract with Customer [Text Block] Due from PJM transmission settlement Due from PJM transmission settlement Amount due from PJM transmission settlement Subsegments [Domain] Subsegments [Domain] Increase (Decrease) in Interest Payable, Net Increase (Decrease) in Interest Payable, Net Debt Covenant, Interest Coverage Ratio, Minimum Debt Covenant, Interest Coverage Ratio, Minimum Debt Covenant, Interest Coverage Ratio, Minimum Subsegments [Axis] Subsegments [Axis] Payment for (Proceeds from) Other Investing Activity Payment for (Proceeds from) Other Investing Activity Increase (Decrease) in Inventories Increase (Decrease) in Inventories Cash Contribution from Parent Company Cash Contribution from Parent Company Cash Contribution from Parent Company Segment Reporting [Table] Segment Reporting [Table] Schedule of Related Party Transactions, by Related Party [Table] Related Party Transaction [Table] Other Assets, Current Other Assets, Current Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, Tax Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, Tax Operating Income (Loss) Operating Income (Loss) Current Fiscal Year End Date Current Fiscal Year End Date Derivative activity: Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax [Abstract] Related Party Transaction [Domain] Related Party Transaction [Domain] Unusual Risk or Uncertainty, Nature [Domain] Unusual Risk or Uncertainty, Nature [Domain] Entity File Number Entity File Number Service cost Defined Benefit Plan, Service Cost Equity Securities [Member] Equity Securities [Member] Allowance for Funds Used During Construction, Capitalized Interest Allowance for Funds Used During Construction, Capitalized Interest Cost of Long-term Debt - Distribution Rate Case Cost of Long-term Debt - Distribution Rate Case Cost of Long-term Debt - Distribution Rate Case Common stock, shares issued Common Stock, Shares, Issued Entity Information [Line Items] Entity Information [Line Items] Long-term Debt, Current and Noncurrent [Abstract] Long-Term Debt, Current and Noncurrent [Abstract] Deferral of Purchased Power Costs Deferral of Purchased Power Costs - ESP 4 Deferral of Purchased Power Costs - ESP 4 Payments for (Proceeds from) Removal Costs Payments for (Proceeds from) Removal Costs Equity Components [Axis] Equity Components [Axis] Product and Service [Domain] Product and Service [Domain] Related Party Related Party [Member] Income Tax Paid, after Refund Received Income Tax Paid, after Refund Received Increase (Decrease) in Regulatory Assets and Liabilities Increase (Decrease) in Regulatory Assets and Liabilities Entity Interactive Data Current Entity Interactive Data Current Deferred Tax Liabilities, Net Deferred Income Tax Liabilities, Net Net Cost Deferral - Distribution Rate Case Net Cost Deferral - Distribution Rate Case Net Cost Deferral - Distribution Rate Case Proceeds from Contributions from Parent Proceeds from Contributions from Parent Equity ownership interest Public utilities equity interest, cost method, percentage The noncontrolling equity interest in an electric generation company, accounted for under the cost method of accounting. Debt Covenant, Total Debt to Total Capitalization Ratio, Maximum Upper Debt Covenant, Total Debt to Total Capitalization Ratio, Maximum Upper Range Debt Covenant, Total Debt to Total Capitalization Ratio, Maximum Upper Range Entity Small Business Entity Small Business Comprehensive Income (Loss), Net of Tax, Attributable to Parent Comprehensive Income (Loss), Net of Tax, Attributable to Parent Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, Tax Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, Tax Property, Plant, and Equipment [Line Items] Property, Plant, and Equipment [Line Items] Effective Income Tax Rate Reconciliation [Table] Effective Income Tax Rate Reconciliation [Table] Excise taxes collected Excise Taxes Collected Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Discontinued Operations Disposal Groups, Including Discontinued Operations, Disclosure [Text Block] Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Total change in unfunded pension obligation Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax Depreciation and amortization Depreciation, Depletion and Amortization, Including Discontinued Operation Depreciation, Depletion and Amortization, Including Discontinued Operation Other current liabilities Other Liabilities, Current Other Assets, Noncurrent Other Assets, Noncurrent Document Type Document Type 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] Gain (Loss) on Extinguishment of Debt Gain (Loss) on Extinguishment of Debt External customer revenues External customer revenues External customer revenues Overview and Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Accounting for Taxes Collected from Customers and Remitted to Governmental Authorities Regulatory Income Taxes, Policy [Policy Text Block] Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Proceeds from Issuance of Long-term Debt Proceeds from Issuance of Long-Term Debt Local Phone Number Local Phone Number Postretirement [Member] Other Postretirement Benefits Plan [Member] Consolidation Items [Axis] Consolidation Items [Axis] Entity Address, Postal Zip Code Entity Address, Postal Zip Code Entity Registrant Name Entity Registrant Name Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Commitments and contingencies Commitments and Contingencies Revenues Revenues Cash Provided by (Used in) Investing Activity, Discontinued Operation Cash flows from investing activities for discontinued operations Cash Provided by (Used in) Investing Activity, Discontinued Operation Reclassification out of Accumulated Other Comprehensive Income [Axis] Reclassification out of Accumulated Other Comprehensive Income [Axis] Number of financial covenants Debt Instrument, Number of Financial Covenants Debt Instrument, Number of Financial Covenants Adjustments and Eliminations Adjustments and Eliminations [Member] Adjustments and Eliminations Revenue Increase - Distribution Rate Case Revenue Increase - Distribution Rate Case Revenue Increase - Distribution Rate Case LIABILITIES AND SHAREHOLDER'S EQUITY Liabilities and Equity [Abstract] Debt Covenant, Leverage Ratio, Maximum Debt Covenant, Leverage Ratio, Maximum Debt Covenant, Leverage Ratio, Maximum Fair Value of Assets and Liabilities Measured on Recurring Basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Inventories Inventory, Net Revenue Type [Axis] Revenue Type [Axis] Information by type of revenue Fair Value Fair Value Disclosures [Text Block] Level 3 [Member] Fair Value, Inputs, Level 3 [Member] Deferred Finance Costs, Net, Including Acquisition Adjustments Unamortized deferred finance costs Deferred Finance Costs, Net, Including Acquisition Adjustments Deferred Finance Costs, Net, Including Acquisition Adjustments Supplemental Cash Flow Information Supplemental Cash Flow Information [Abstract] Reclassification of earnings, net of income tax Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax Taxes Applicable to Subsequent Years Taxes Applicable to Subsequent Years Carrying amount as of the balance sheet date of capitalized property and other taxes which will be charged against earnings within one year or the normal operating cycle, if longer. Loss from discontinued operations before income taxes Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax DPL Revolving Credit Agreement and Term Loan Maturing July 2020 [Member] DPL Revolving Credit Agreement and Term Loan Maturing July 2020 [Member] DPL Revolving Credit Agreement and Term Loan Maturing July 2020 [Member] Restricted Cash Restricted Cash First Mortgage Bonds due 2033 First Mortgage Bonds due 2033 [Member] First Mortgage Bonds due 2033 Significant Accounting Policies [Line Items] Significant Accounting Policies [Line Items] [Line Items] for Significant Accounting Policies [Table] Intersegment revenue Intersegment revenue [Member] Intersegment revenue Long-Lived Asset, Class [Axis] Long-Lived Asset, Class [Axis] Segment Reporting, Other Segment Item, Amount Segment Reporting, Other Segment Item, Amount U.S. Government note maturing in February 2061 - 4.20% [Member] Four Point Two Zero Percentage Of U S Government Note Maturing In February Two Thousand Sixty One [Member] Four Point Two Zero Percentage Of U S Government Note Maturing In February Two Thousand Sixty One [Member] Entity Tax Identification Number Entity Tax Identification Number Legal Entity [Axis] Legal Entity [Axis] Mutual Fund Mutual Fund [Member] Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Schedule of Finite-Lived Intangible Assets [Table] Intangible Asset, Finite-Lived [Table] Increase (Decrease) in Accounts Payable Increase (Decrease) in Accounts Payable Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code CDPQ Investment percent CDPQ Investment percent CDPQ Investment percent Reclassification out of Accumulated Other Comprehensive Income Reclassification out of Accumulated Other Comprehensive Income [Table Text Block] Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest, Total Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Debt Instrument [Axis] Debt Instrument [Axis] Disposal Group Name [Axis] Disposal Group Name [Axis] Subsegments Consolidation Items [Domain] Subsegments Consolidation Items [Domain] Investment, Name [Domain] Investment, Name [Domain] Non-cash Proceeds from Sale of Business Non-cash Proceeds from Sale of Business Non-cash Proceeds from Sale of Business Effective Income Tax Rate Reconciliation, Including Discontinued Operations, Percent Effective Income Tax Rate Reconciliation, Including Discontinued Operations, Percent Effective Income Tax Rate Reconciliation, Including Discontinued Operations, Percent Estimated Smart Grid Phase 2 O&M Estimated Smart Grid Phase 2 O&M Estimated Smart Grid Phase 2 O&M Contract with Customer, Liability, Current Contract with Customer, Liability, Current Assets, Current Assets, Current Long-term debt Long-Term Debt, Excluding Current Maturities Interest Rate Contract [Member] Interest Rate Contract [Member] Accounts Receivable, after Allowance for Credit Loss, Current Accounts Receivable, after Allowance for Credit Loss, Current Retained Earnings (Accumulated Deficit) Retained Earnings (Accumulated Deficit) 3.95% Senior Notes due 2049 [Member] 3.95% Senior Notes due 2049 [Member] 3.95% Senior Notes due 2049 [Member] 3.25% First Mortgage Bonds due 2040 [Member] 3.20% First Mortgage Bonds due 2040 [Member] 3.20% First Mortgage Bonds due 2040 Product and Service [Axis] Product and Service [Axis] Residential Revenue Residential Revenue [Member] Residential Revenue Pension [Member] Pension Plan [Member] Common Stock [Member] Common Stock [Member] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Cover [Abstract] Cover [Abstract] Commercial Revenue Commercial Revenue [Member] Commercial Revenue Derivative Contract Type [Domain] Derivative Contract [Domain] Public Utilities General Disclosures [Table] Public Utilities General Disclosures [Table] Property Plant And Equipment, Net of Depreciation Property Plant And Equipment, Net of Depreciation Total net property plant and equipment which was in service as of the balance sheet date. Allowance For Funds Used During Construction / Capitalized Interest Allowance For Funds Used During Construction / Capitalized Interest [Table Text Block] Allowance For Funds Used During Construction / Capitalized Interest Defined Benefit Plan, Funded (Unfunded) Status of Plan Defined Benefit Plan, Funded (Unfunded) Status of Plan Total liabilities and shareholder's equity Liabilities and Equity Regulatory Asset [Domain] Regulatory Asset [Domain] Current portion of long-term debt Debt, Current Segments [Axis] Segments [Axis] Asset Class [Axis] Asset Class [Axis] Related Party, Type [Domain] Related and Nonrelated Parties [Domain] Schedule of Supplemental Financial Information Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block] Unrealized Gain (Loss) on Investments Unrealized Gain (Loss) on Investments [Table Text Block] Estimated annual effective income tax rate Estimated Annual Effective Income Tax Rate, Continuing Operations A ratio calculated by dividing the estimated amount of annual income tax expense attributable to continuing operations by GAAP-basis estimated annual pretax income from continuing operations. Fixed-asset Impairment [Abstract] Fixed-asset Impairment [Abstract] Fixed-asset Impairment [Abstract] Payments to Acquire Intangible Assets Payments to Acquire Intangible Assets Other Nonoperating Income (Expense) Other Nonoperating Income (Expense) Other Revenues [Member] Other Revenues [Member] Other Revenues [Member] Unusual Risk or Uncertainty, Nature [Axis] Unusual Risk or Uncertainty, Nature [Axis] Contractual Obligations, Commercial Commitments And Contingencies [Abstract] Contractual Obligations, Commercial Commitments And Contingencies [Abstract] Contractual Obligations, Commercial Commitments and Contingencies [Abstract] Income Taxes Receivable, Current Income Taxes Receivable, Current Common shareholder's equity: Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Long-Lived Asset, Class [Domain] Long-Lived Asset, Class [Domain] Regulatory Liability Regulatory Liability Property, Plant, and Equipment [Table] Property, Plant, and Equipment [Table] Unusual Risk or Uncertainty [Line Items] Unusual Risk or Uncertainty [Line Items] Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax Payments of Deferred Finance Costs Payments of Deferred Finance Costs Payments of Deferred Finance Costs Other non-606 revenue Other non-606 revenue Other non-606 revenue Return on Equity - Distribution Rate Case Return on Equity - Distribution Rate Case Return on Equity - Distribution Rate Case Interest Paid, Excluding Capitalized Interest, Operating Activity Interest Paid, Excluding Capitalized Interest, Operating Activity Payments to Acquire Productive Assets Payments to Acquire Productive Assets Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Conesville [Member] Conesville [Member] Conesville Credit Facility [Axis] Credit Facility [Axis] Total Assets Assets, Fair Value Disclosure Schedule of Regulatory Assets and Liabilities [Text Block] Schedule of Regulatory Assets and Liabilities [Text Block] Debt obligation Long-Term Debt and Lease Obligation Discontinued Operations and Disposal Groups [Abstract] Discontinued Operations and Disposal Groups [Abstract] Fixed-asset Impairment (Narrative) [Abstract] Fixed-asset Impairment (Narrative) [Abstract] Fixed-asset Impairment (Narrative) [Abstract] Income Taxes Income Tax Disclosure [Text Block] Accounts payable Accounts Payable, Current Debt [Member] Debt [Member] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Schedule of Net Periodic Benefit Cost / (Income) Schedule of Net Periodic Benefit Cost / (Income) [Table Text Block] Schedule of Net Periodic Benefit Cost / (Income) [Table Text Block] Debt Instrument [Line Items] Debt Instrument [Line Items] Other Additional Capital [Member] Other Additional Capital [Member] Retirement Benefits, Description [Abstract] Retirement Benefits, Description [Abstract] Corporate and Other Corporate Segment and Other Operating Segment [Member] Retirement Plan Type [Domain] Retirement Plan Type [Domain] Additional Paid-in Capital Additional Paid-in Capital [Member] Entity Filer Category Entity Filer Category CDPQ Investment total CDPQ Investment total CDPQ Investment total Repayments of Short-Term Debt Repayments of Short-Term Debt Service area, square miles Service Area Square Miles Service area square miles Distribution Investment Rider Distribution Investment Rider Distribution Investment Rider Allowance for Funds Used During Construction, Equity Portion Allowance for Funds Used During Construction, Equity Portion Allowance for Funds Used During Construction, Equity Portion Cash and Cash Equivalent Cash and Cash Equivalent Cash and Cash Equivalent Fair Value and Cost Of Non-Derivative Instruments Schedule Of Fair Value And Cost Of Non-Derivative Instruments [Table Text Block] Schedule Of Fair Value And Cost Of Non-Derivative Instruments [Table Text Block] Depreciation and amortization Depreciation, Depletion and Amortization Return on Equity - ESP 4 Return on Equity - ESP 4 Return on Equity - ESP 4 Net income Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Entity Address, Address Line One Entity Address, Address Line One RTO Capacity Revenue RTO Capacity Revenue RTO Capacity Revenue Income Tax Expense (Benefit) Income Tax Expense (Benefit) Income Tax Expense (Benefit) Risks and Uncertainties [Abstract] Risks and Uncertainties [Abstract] 5.70% Tax-exempt First Mortgage Bonds due 2033 5.70% Tax-exempt First Mortgage Bonds due 2033 [Member] 5.70% Tax-exempt First Mortgage Bonds due 2033 Ohio Investment Percent Ohio Investment Percent Ohio Investment Percent Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Including Exchange Rate Effect and Discontinued Operation Disposal Group, Including Discontinued Operation, Operating and Other Expenses Disposal Group, Including Discontinued Operation, Operating and Other Expenses Disposal Group, Including Discontinued Operation, Operating and Other Expenses Forecast [Member] Forecast [Member] Actuarial loss / (gain) Defined Benefit Plan, Amortization of Gain (Loss) Wholesale Revenue [Member] Wholesale Revenue [Member] Wholesale Revenue [Member] Net Income (Loss) Attributable to Parent Net Income (Loss) Attributable to Parent Statement [Table] Statement [Table] Regulatory liabilities, current Regulatory Liability, Current Schedule of Accumulated Other Comprehensive Income (Loss) Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Uncommitted Accordion Feature Uncommitted Accordion Feature Uncommitted Accordion Feature Public Utility, Property, Plant and Equipment [Line Items] Public Utility, Property, Plant and Equipment [Line Items] Increase (Decrease) in Receivables Increase (Decrease) in Receivables Proceeds from Short-Term Debt Proceeds from Short-Term Debt Contract with Customer, Asset, before Allowance for Credit Loss Contract with Customer, Asset, before Allowance for Credit Loss Reserve for Regulatory Asset Reserve for Regulatory Asset Reserve for Regulatory Asset Accounts Receivable, Allowance for Credit Loss, Recovery Accounts Receivable, Allowance for Credit Loss, Recovery