Statement of Stockholders' Equity [Abstract] Statement [Table] Statement [Table] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Duke Energy Carolinas [Member] Duke Energy Carolinas [Member] Duke Energy Carolinas Progress Energy [Member] Progress Energy [Member] Progress Energy Duke Energy Progress [Member] Duke Energy Progress [Member] Duke Energy Progress Duke Energy Florida [Member] Duke Energy Florida [Member] Duke Energy Florida Duke Energy Ohio [Member] Duke Energy Ohio [Member] Duke Energy Ohio Duke Energy Indiana [Member] Duke Energy Indiana [Member] Duke Energy Indiana Piedmont Natural Gas [Member] Piedmont Natural Gas [Member] Piedmont Natural Gas Statement, Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Common Stock [Member] Common Stock [Member] Additional Paid-in Capital [Member] Additional Paid-in Capital [Member] Retained Earnings [Member] Retained Earnings [Member] Members Equity [Member] Members Equity [Member] Members Equity Net Gains (Losses) on Cash Flow Hedges [Member] Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] Net Unrealized Gains (Losses) on Available for Sale Securities [Member] Accumulated Net Investment Gain (Loss) Attributable to Parent [Member] Pension and OPEB Adjustments [Member] Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Common Stockholders' Equity [Member] Parent [Member] Noncontrolling Interest [Member] Noncontrolling Interest [Member] Statement [Line Items] Statement [Line Items] Beginning Balance Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Beginning Balance, in shares Common Stock, Shares, Outstanding Beginning Balance (member's equity) Members' Equity Beginning Balance (parent) Stockholders' Equity Attributable to Parent Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Net income (attributable to parent) Net Income (Loss) Attributable to Parent Other comprehensive income (loss) Other Comprehensive Income (Loss), Net of Tax Common stock issuances, including dividend reinvestment and employee benefits, shares Stock Issued During Period, Shares, New Issues Common stock issuances, including dividend reinvestment and employee benefits Stock Issued During Period, Value, New Issues Distributions to noncontrolling interest in subsidiaries Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Distributions/dividends to parent Dividends Equitization of certain notes payable to affiliates Equitization Of Notes Payable Due to Affiliates The equitization of certain notes payable to affiliates. Other Stockholders' Equity, Other Ending Balance Ending Balance, in shares Ending Balance (member's equity) Ending Balance (parent) Variable Interest Entities [Abstract] Variable Interest Entities [Abstract] Schedule of Variable Interest Entities [Table] Schedule of Variable Interest Entities [Table] Counterparty Name [Axis] Counterparty Name [Axis] Counterparty Name [Domain] Counterparty Name [Domain] Pipeline Investments [Member] Pipeline Investments [Member] Pipeline Investments [Member] Commercial Renewables [Member] Commercial Renewables [Member] Commercial Renewables Other VIEs [Member] Other Vies [Member] Other VIEs Variable Interest Entities [Axis] Variable Interest Entities [Axis] Variable Interest Entity, Classification [Domain] Variable Interest Entity, Classification [Domain] Variable Interest Entity, Not Primary Beneficiary [Member] Variable Interest Entity, Not Primary Beneficiary [Member] Variable Interest Entities [Line Items] Variable Interest Entity [Line Items] Receivables from affiliated companies Due from Related Parties, Current Investments in equity method unconsolidated affiliates Equity Method Investments Other noncurrent assets Other Assets, Noncurrent Total assets Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets Taxes accrued Taxes Payable, Current Current Liabilities: Other Other Liabilities, Current Deferred income taxes Deferred Income Taxes and Other Tax Liabilities, Noncurrent Noncurrent Liabilities: Other Deferred Credits and Other Liabilities Total liabilities Variable Interest Entity, Nonconsolidated, Carrying Amount, Liabilities Net assets Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets and Liabilities, Net Investments, Debt and Equity Securities [Abstract] Schedule of Available-for-sale Securities [Table] Schedule of Available-for-sale Securities [Table] Schedule of Available-for-sale Securities [Line Items] Schedule of Available-for-sale Securities [Line Items] Debt Securities, Trading, and Equity Securities, FV-NI Debt Securities, Trading, and Equity Securities, FV-NI [Table Text Block] [Table Text Block] for Disclosure of information about investment in debt security measured at fair value with change in fair value recognized in net income (trading) and investment in equity security with change in fair value recognized in net income (FV-NI). Debt Securities, Available-for-sale Debt Securities, Available-for-sale [Table Text Block] [Table Text Block] for Disclosure of information about investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). Available-for-sale Securities Available-for-sale Securities [Table Text Block] Investments Classified by Contractual Maturity Date Investments Classified by Contractual Maturity Date [Table Text Block] Schedule of Realized Gain (Loss) Schedule of Realized Gain (Loss) [Table Text Block] Derivative Instruments and Hedging Activities Disclosure [Abstract] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Hedging Designation [Axis] Hedging Designation [Axis] Hedging Designation [Domain] Hedging Designation [Domain] Designated As Hedging Instrument [Member] Designated as Hedging Instrument [Member] Not Designated as Hedging Instrument [Member] Not Designated as Hedging Instrument [Member] Derivative Instrument [Axis] Derivative Instrument [Axis] Derivative Contract [Domain] Derivative Contract [Domain] Commodity Contracts [Member] Commodity Contract [Member] Interest Rate Contracts [Member] Interest Rate Contract [Member] Balance Sheet Location [Axis] Balance Sheet Location [Axis] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Current Assets, Other [Member] Other Current Assets [Member] Noncurrent Assets, Other [Member] Other Noncurrent Assets [Member] Current Liabilities, Other [Member] Other Current Liabilities [Member] Other Noncurrent Liabilities [Member] Other Noncurrent Liabilities [Member] Derivatives, Fair Value [Line Items] Derivatives, Fair Value [Line Items] Location and fair value amounts of derivatives (Asset) Derivative Asset, Fair Value, Gross Asset Location and fair value amounts of derivatives (Liability) Derivative Liability, Fair Value, Gross Liability Derivative [Table] Derivative [Table] Variable Interest Entity, Primary Beneficiary [Member] Variable Interest Entity, Primary Beneficiary [Member] Designated as Hedging Instrument [Member] Commodity Contracts [Member] Price Risk Derivative [Member] Public Utility [Axis] Public Utility [Axis] Utility Plant [Domain] Utility Plant [Domain] Electricity [Member] Electric Transmission [Member] Natural Gas [Member] Gas Distribution [Member] Derivative [Line Items] Derivative [Line Items] Notional amount Derivative, Notional Amount Notional amount, energy measure, in gigawatt-hours Derivative, Nonmonetary Notional Amount, Energy Measure Notional amount, volume, in millions of decatherms Derivative, Nonmonetary Notional Amount, Volume Statement of Financial Position [Abstract] Variable Interest Entity [Member] Variable Interest Entity [Member] Variable Interest Entity [Member] Allowance for doubtful accounts - receivables Allowance for Doubtful Accounts and Other Receivables, Current Amount of allowance related to receivables from customers, clients, or other third-parties, and receivables classified as other due within one year or the normal operating cycle, if longer, that are expected to be uncollectible. Allowance for doubtful accounts - receivables of VIEs Allowance for Doubtful Accounts Receivable, Current Regulatory assets, current Regulatory Assets, Current Other, current assets Prepaid Expense and Other Assets, Current Regulatory assets, noncurrent Regulatory Assets, Noncurrent Current maturities of long-term debt Long-term Debt, Current Maturities Long-Term Debt Long-term Debt, Excluding Current Maturities Common stock, par value Common Stock, Par or Stated Value Per Share Common stock, shares authorized Common Stock, Shares Authorized Common stock, shares outstanding Subsequent Events [Abstract] Subsequent Events Subsequent Events [Text Block] Statement of Comprehensive Income [Abstract] Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest [Abstract] Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest [Abstract] Other Comprehensive Income, net of tax Other Comprehensive Income (Loss), Net of Tax [Abstract] Pension and OPEB adjustments Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax Net unrealized gains on cash flow hedges Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax Reclassification into earnings from cash flow hedges Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax Unrealized (losses) gains on available-for-sale securities Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax Other Comprehensive Income, net of tax Comprehensive Income Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Less: Comprehensive Income Attributable to Noncontrolling Interests Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Comprehensive Income Attributable to Parent Comprehensive Income (Loss), Net of Tax, Attributable to Parent Balance Sheet Related Disclosures [Abstract] Public Utilities, Inventory [Table] Public Utilities, Inventory [Table] Inventory [Axis] Inventory [Axis] Inventory [Domain] Inventory [Domain] Materials and supplies [Member] Supplies [Member] Coal [Member] Coal [Member] Natural gas, oil and other fuel [Member] Public Utilities, Inventory, Fuel [Member] Public Utilities, Inventory [Line Items] Public Utilities, Inventory [Line Items] Inventory Public Utilities, Inventory Regulated Operations [Abstract] Schedule of Potential Plant Retirements Public Utility Property, Plant, and Equipment [Table Text Block] Revenue from Contract with Customer [Abstract] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Cinergy Receivables [Member] Cinergy Receivables [Member] Cinergy Receivables Accounts, Notes, Loans and Financing Receivable [Line Items] Accounts, Notes, Loans and Financing Receivable [Line Items] Unbilled receivables Unbilled Receivables, Current Segment Reporting [Abstract] Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Investment, Name [Axis] Investment, Name [Axis] Investment, Name [Domain] Investment, Name [Domain] National Methanol Company [Member] National Methanol Company [Member] National Methanol Company [Member] Nonregulated Retired Facility Sale [Axis] Nonregulated Retired Facility Sale [Axis] Sale of a nonregulated retired facility. Nonregulated Retired Facility Sale [Domain] Nonregulated Retired Facility Sale [Domain] [Domain] for Sale of a nonregulated retired facility. Beckjord [Member] Beckjord [Member] Beckjord nonregulated facility. Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Equity Method Investment, Ownership Percentage Equity Method Investment, Ownership Percentage Loss on Sales of Other Assets and Other, net Gain (Loss) on Disposition of Assets Operation, maintenance and other Utilities Operating Expense, Maintenance, Operations, and Other Costs and Expenses Number of Reportable Segments Number of Reportable Segments Equity Securities Offering [Abstract] Equity Securities Offering [Abstract] Forward Contract Indexed to Issuer's Equity [Table] Forward Contract Indexed to Issuer's Equity [Table] Forward Contract Indexed to Issuer's Equity, Type [Axis] Forward Contract Indexed to Issuer's Equity, Type [Axis] Forward Contract Indexed to Issuer's Equity, Type [Domain] Forward Contract Indexed to Issuer's Equity, Type [Domain] Forward Contract Indexed to Issuer's Equity [Line Items] Forward Contract Indexed to Issuer's Equity [Line Items] Maximum Value Of Shares To Be Issued Under ATM Program Maximum Value Of Shares To Be Issued Under ATM Program Maximum value of shares to be issued under ATM program of its common stock through an at-the-market offering program, including an equity forward sales component. Shares offered Forward Contract Indexed to Issuer's Equity, Indexed Shares Settlement Alternatives, Shares Forward Contract Indexed to Issuer's Equity, Settlement Alternatives, Shares, at Fair Value Forward Contract Indexed to Issuer's Equity, Forward Rate Per Share Forward Contract Indexed to Issuer's Equity, Forward Rate Per Share Forward Contract Indexed to Issuer's Equity, Shares Forward Contract Indexed to Issuer's Equity, Shares Accounting Policies [Abstract] Organization And Basis Of Presentation [Table] Organization And Basis Of Presentation [Table] Schedule reflecting the orgnaization and basis of presentation. Organization And Basis Of Presentation [Line Items] Organization And Basis Of Presentation [Line Items] Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Schedule of Cash, Cash Equivalents and Restricted Cash Schedule of Cash and Cash Equivalents [Table Text Block] Schedule of Utility Inventory Schedule of Utility Inventory [Table Text Block] Schedule of Excise Taxes Schedule Of Excise Taxes [Table Text Block] Schedule of excise taxes accounted for on a gross basis during the reporting period. Commitments and Contingencies Disclosure [Abstract] Loss Contingencies [Table] Loss Contingencies [Table] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum [Member] Minimum [Member] Maximum [Member] Maximum [Member] Loss Contingency Nature [Axis] Loss Contingency Nature [Axis] Loss Contingency, Nature [Domain] Loss Contingency, Nature [Domain] Coal Ash Insurance Coverage Litigation [Member] Coal Ash Insurance Coverage Litigation [Member] Coal Ash Insurance Coverage Litigation [Member] NCDEQ State Enforcement Actions [Member] NCDEQ State Enforcement Actions [Member] North Carolina Department of Environmental Quality State Enforcement Actions [Member] Groundwater Contamination Claims [Member] Groundwater Contamination Claims [Member] Groundwater Contamination Claims [Member] Asbestos-related Injuries and Damages Claims [Member] Asbestos Issue [Member] Spent Nuclear Fuels [Member] Spent Nuclear Fuels [Member] Spent Nuclear Fuels Gypsum Supply Agreements [Member] Gypsum Supply Agreements [Member] Gypsum Supply Agreements [Member] Westinghouse Electric Company Litigation [Member] Westinghouse Electric Company Litigation [Member] Westinghouse Electric Company Litigation MGP Cost Recovery Action [Member] MGP Cost Recovery Action [Member] MGP Cost Recovery Action [Member] Litigation Case [Axis] Litigation Case [Axis] Litigation Case Type [Domain] Litigation Case [Domain] Non-Malignant Asbestos Claim [Member] Non Malignant Asbestos Claim [Member] Asbestos claims that relate to a non-malignant diagnosis Malignant Asbestos Claim [Member] Malignant Asbestos Claim [Member] Asbestos claims that relate to a malignant diagnosis Loss Contingencies [Line Items] Loss Contingencies [Line Items] Valuation and Qualifying Accounts [Abstract] Valuation and Qualifying Accounts [Abstract] Number of NC and SC Plants with Ash Basins Number of NC and SC Plants with Ash Basins Number of NC and SC Plants with Ash Basins with insurance claims being sought Number of Plants with No Disputed Facts Number of Plants with No Disputed Facts Number of Plants with No Disputed Facts due to litigation being concluded Number of NC Plants with Ash Basins Number of NC Plants with Ash Basins Number of NC Plants with Ash Basins requiring additional monitoring and assessment Number of Plants with Disputed Facts Number of Plants with Disputed Facts Number of Plants with Disputed Facts Goodwill Payment Goodwill Payment Goodwill Payment to neighbors of ash basins Water Bill Stipend Period Water Bill Stipend Period Water Bill Stipend Period for ash basin neighbors Loss Contingency Accrual Loss Contingency Accrual Loss contingency, pending claims, number Loss Contingency, Pending Claims, Number Asbestos-related injuries and damages reserves Liability for Asbestos and Environmental Claims, Gross Reinsurance retention policy, excess retention, amount reinsured Reinsurance Retention Policy, Excess Retention, Amount Reinsured Probable insurance recoveries Loss Contingency, Receivable, Noncurrent Minimum Amount of Gypsum To Be Supplied Minimum Amount of Gypsum To Be Supplied Minimum Amount of Gypsum To Be Supplied Monthly To Third Party Under Supply Agreement Gain Contingency, Unrecorded Amount Gain Contingency, Unrecorded Amount Litigation Settlement, Amount Awarded from Other Party Litigation Settlement, Amount Awarded from Other Party Loss Contingency, Damages Sought, Original Amount Loss Contingency, Damages Sought, Original Amount Loss Contingency, Damages Sought, Original Amount Loss Contingency, Damages Awarded, Value Loss Contingency, Damages Awarded, Value Gain Contingency, Dismissed Amount Gain Contingency, Dismissed Amount Gain Contingency, Dismissed Amount Loss Contingency Damages Awarded and Interest, Value Loss Contingency Damages Awarded and Interest, Value Loss Contingency Damages Awarded and Interest, Value Public Utilities General Disclosures [Table] Public Utilities General Disclosures [Table] Allen Steam Station Units 1-3 [Member] Allen Steam Station Units 1-3 [Member] Allen Steam Station Units 1-3 [Member] Crystal River Units 1 and 2 [Member] Crystal River Units 1 and 2 [Member] Crystal River Units 1 and 2 [Member] Gallagher Units 2 and 4 [Member] Gallagher Units 2 and 4 [Member] Gallagher Units 2 and 4 [Member] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Type [Domain] Generation Facilities To Be Retired [Member] Generation Facilities To Be Retired [Member] Generation Facilities To Be Retired [Member] Public Utilities, General Disclosures [Line Items] Public Utilities, General Disclosures [Line Items] Capacity (in MW) Coal-Fired Generation Capacity Potential Plants To Be Retired, in Megawatts Coal-Fired Generation Capacity, in Megawatts Public Utilities, Property, Plant and Equipment, Net Public Utilities, Property, Plant and Equipment, Net Derivatives and Hedging Derivative Instruments and Hedging Activities Disclosure [Text Block] Business Segments Segment Reporting Disclosure [Text Block] Variable Interest Entities Variable Interest Entity Disclosure [Text Block] Investments In Debt And Equity Securities Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] ASSETS Assets [Abstract] Current Assets Assets, Current [Abstract] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Receivables (net of allowance for doubtful accounts) Accounts and Other Receivables, Net, Current Receivables of VIEs (net of allowance for doubtful accounts) Accounts Receivable, Net, Current Notes receivable from affiliated companies Notes Receivable, Related Parties, Current Regulatory assets Income taxes receivable Income Taxes Receivable, Current Other Total current assets Assets, Current Property, Plant and Equipment Property, Plant and Equipment [Abstract] Cost Public Utilities, Property, Plant and Equipment, Plant in Service Accumulated depreciation and amortization Public Utilities, Property, Plant and Equipment, Accumulated Depreciation Generation facilities to be retired, net Generation Facilities To Be Retired Net Generation facilities to be retired, net Net property, plant and equipment Other Noncurrent Assets Assets, Noncurrent [Abstract] Goodwill Goodwill Regulatory assets Nuclear decommissioning trust funds Decommissioning Fund Investments Other Total other noncurrent assets Investments and Other Noncurrent Assets Total Assets Assets LIABILITIES AND EQUITY Liabilities and Equity [Abstract] Current Liabilities Liabilities, Current [Abstract] Accounts payable Accounts Payable, Current Accounts payable to affiliated companies Due to Related Parties, Current Notes payable and commercial paper Short-term Debt Notes payable to affiliated companies Notes Payable, Related Parties, Current Taxes accrued Interest accrued Interest Payable, Current Current maturities of long-term debt Asset retirement obligations Asset Retirement Obligation, Current Regulatory liabilities Regulatory Liability, Current Other Total current liabilities Liabilities, Current Long-Term Debt Payable to Affiliated Companies Notes Payable, Related Parties, Noncurrent Other Noncurrent Liabilities Other Liabilities, Noncurrent [Abstract] Asset retirement obligations Asset Retirement Obligations, Noncurrent Regulatory liabilities Regulatory Liability, Noncurrent Accrued pension and other post-retirement benefit costs Liability, Defined Benefit Plan, Noncurrent Investment tax credits Accumulated Deferred Investment Tax Credit Other Total other noncurrent liabilities Liabilities, Other than Long-term Debt, Noncurrent Commitments and Contingencies Commitments and Contingencies Equity Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Member's equity Members' Capital Common stock Common Stock, Value, Issued Additional paid-in capital Additional Paid in Capital, Common Stock Retained earnings Retained Earnings (Accumulated Deficit) Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Total Parent stockholders' equity Noncontrolling interests Stockholders' Equity Attributable to Noncontrolling Interest Total member's equity Total equity Total Liabilities and Equity Liabilities and Equity Long-term Debt, Current Maturities [Abstract] Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Consolidated Entities [Axis] Consolidated Entities [Axis] Consolidated Entities [Domain] Consolidated Entities [Domain] Parent Company [Member] Parent Company [Member] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Unsecured Debt [Member] Unsecured Debt [Member] First Mortgage Bonds [Member] First Mortgage [Member] Other Debt Obligations [Member] Other Debt Obligations [Member] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument Name [Domain] Debt Instrument, Name [Domain] Debt Maturing June 2018, 6.250% Coupon [Member] Unsecured Debt Maturing June 2018, 6.250% Coupon [Member] Unsecured Debt Maturing June 2018, 6.250% Coupon [Member] Debt Maturing June 2018, 2.100% Coupon [Member] Unsecured Debt Maturing June 2018, 2.100% Coupon [Member] Unsecured Debt Maturing June 2018, 2.100% Coupon [Member] Debt Maturing December 2018, Floating Rate [Member] Debt Maturing December 2018, Floating Rate [Member] Debt Maturing December 2018, Floating Rate [Member] Debt Maturing March 2019, 7.050% Coupon [Member] Debt Maturing March 2019, 7.050% Coupon [Member] Debt Maturing March 2019, 7.050% Coupon [Member] Bonds Maturing April 2018, 5.100% Coupon [Member] First Mortgage Bonds Maturing April 2018, 5.100% Coupon [Member] First Mortgage Bonds Maturing April 2018, 5.100% Coupon [Member] Bonds Maturing June 2018, 5.650% Coupon [Member] First Mortgage Bonds Maturing June 2018, 5.650% Coupon [Member] First Mortgage Bonds Maturing June 2018, 5.650% Coupon [Member] Bonds Maturing November 2018, 7.000% Coupon [Member] First Mortgage Bonds Maturing November 2018 7.000% Coupon [Member] First Mortgage Bonds Maturing November 2018 7.000% Coupon [Member] Bonds Maturing January 2019, 5.300% Coupon [Member] Bonds Maturing January 2019, 5.300% Coupon [Member] Bonds Maturing January 2019, 5.300% Coupon [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Interest rate Debt Instrument, Interest Rate, Stated Percentage Valuation and Qualifying Accounts Disclosure [Table] Valuation and Qualifying Accounts Disclosure [Table] Valuation Allowances and Reserves Type [Axis] Valuation Allowances and Reserves Type [Axis] Valuation Allowances and Reserves [Domain] Valuation Allowances and Reserves [Domain] Reserve for Environmental Costs [Member] Reserve for Environmental Costs [Member] Legal Reserve [Member] Legal Reserve [Member] Valuation and Qualifying Accounts Disclosure [Line Items] Valuation and Qualifying Accounts Disclosure [Line Items] Schedule of Additional Possible Losses in Excess of Recorded Environmental Reserves Environmental Exit Costs by Cost [Table Text Block] Schedule of Legal Reserves Schedule of Loss Contingencies by Contingency [Table Text Block] Excise Taxes [Abstract] Information related to company's excise taxes. Excise taxes collected Excise Taxes Collected Revenue, Initial Application Period Cumulative Effect Transition [Table] Revenue, Initial Application Period Cumulative Effect Transition [Table] Initial Application Period Cumulative Effect Transition [Axis] Initial Application Period Cumulative Effect Transition [Axis] Initial Application Period Cumulative Effect Transition [Domain] Initial Application Period Cumulative Effect Transition [Domain] Difference between Revenue Guidance in Effect before and after Topic 606 [Member] Difference between Revenue Guidance in Effect before and after Topic 606 [Member] Adjustments for New Accounting Pronouncements [Axis] Adjustments for New Accounting Pronouncements [Axis] Type of Adoption [Domain] Type of Adoption [Domain] Accounting Standards Update 2014-09 [Member] Accounting Standards Update 2014-09 [Member] Revenue, Initial Application Period Cumulative Effect Transition [Line Items] Revenue, Initial Application Period Cumulative Effect Transition [Line Items] Revenue from Contract with Customer, Excluding Assessed Tax Revenue from Contract with Customer, Excluding Assessed Tax Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Stock-Based Compensation Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Revenue Revenue from Contract with Customer [Text Block] Significant Accounting Policies Registrants [Table] Significant Accounting Policies Registrants [Table] Presents significant accounting policies information by registrant. Policy Text Block [Line Items] Policy Text Block [Line Items] Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Consolidation Consolidation, Policy [Policy Text Block] Use of Estimates Use of Estimates, Policy [Policy Text Block] Cash and Cash Equivalents, Restricted Cash and Cash Equivalents Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block] Inventory Inventory, Policy [Policy Text Block] Excise Taxes Excise Taxes [Policy Text Block] Disclosure of accounting policy for excise taxes, including in which circumstances excise taxes are accounted for on a gross basis or on a net basis. New Accounting Standards New Accounting Pronouncements, Policy [Policy Text Block] Environmental Costs Environmental Costs, Policy [Policy Text Block] Derivatives Derivatives, Policy [Policy Text Block] Investments Investment, Policy [Policy Text Block] Earnings Per Share Earnings Per Share, Policy [Policy Text Block] Stock-based Compensation Compensation Related Costs, Policy [Policy Text Block] Revenue Revenue Recognition, Policy [Policy Text Block] Fair Value Disclosures [Abstract] Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Major Types of Debt and Equity Securities [Axis] Major Types of Debt and Equity Securities [Axis] Major Types of Debt and Equity Securities [Domain] Major Types of Debt and Equity Securities [Domain] Equity Securities [Member] Equity Securities [Member] Debt Securities [Member] Debt Securities [Member] Investment Secondary Categorization [Axis] Investment Secondary Categorization [Axis] Investments by Secondary Categorization [Domain] Investments by Secondary Categorization [Domain] Ndtf [Member] Ndtf [Member] NDTF [Member] Other Classification [Member] Other Classification [Member] Other Investment Classification. This includes all investments not held within the Nuclear decomissioning trust fund and the Duke Energy Indiana Grantor Trust. Fair Value, Hierarchy [Axis] Fair Value, Hierarchy [Axis] Fair Value Hierarchy [Domain] Fair Value Hierarchy [Domain] Level 1 [Member] Fair Value, Inputs, Level 1 [Member] Level 2 [Member] Fair Value, Inputs, Level 2 [Member] Level 3 [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Equity Securities, FV-NI Equity Securities, FV-NI Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). Alternative Investment, Fair Value Disclosure Alternative Investment, Fair Value Disclosure Available-for-sale Securities, Debt Securities Available-for-sale Securities, Debt Securities Investments, Fair Value Disclosure Investments, Fair Value Disclosure Derivative assets Derivative Asset Total assets Assets, Fair Value Disclosure Derivative liabilities Derivative Liability Net assets (liabilities) Fair Value, Net Asset (Liability) Earnings Per Share [Abstract] Common Stock Earnings Per Share [Text Block] Common Stock Stockholders' Equity Note Disclosure [Text Block] Available-for-sale Securities, Gross Realized Gain (Loss) [Abstract] Available-for-sale Securities, Gross Realized Gain (Loss) [Abstract] Realized gains Available-for-sale Securities, Gross Realized Gains Realized losses Available-for-sale Securities, Gross Realized Losses Debt Disclosure [Abstract] First Mortgage [Member] March 2018 Debt Issuance 3.950% Coupon Due 2025 [Member] March 2018 Debt Issuance 3.950% Coupon [Member] March 2018 Debt Issuance 3.950% Coupon Due 2025 [Member] March 2018 Debt Issuance 3.050% Coupon [Member] March 2018 Debt Issuance 3.050% Coupon [Member] March 2018 Debt Issuance 3.050% Coupon [Member] March 2018 Debt Issuance 3.950% Coupon Due 2048 [Member] March 2018 Debt Issuance 3.950% Coupon Due 2048 [Member] March 2018 Debt Issuance 3.950% Coupon Due 2048 [Member] Debt issuances Debt Instrument, Face Amount Retirement Benefits [Abstract] Schedule of Defined Benefit Plans Disclosures [Table] Schedule of Defined Benefit Plans Disclosures [Table] Retirement Plan Type [Axis] Retirement Plan Type [Axis] Retirement Plan Type [Domain] Retirement Plan Type [Domain] Qualified Pension Plan [Member] Pension Plan [Member] Non-Qualified Pension Plan [Member] Other Pension Plan [Member] Other Post-Retirement Benefit Plans [Member] Other Postretirement Benefits Plan [Member] Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan Disclosure [Line Items] Schedule of Defined Benefit Plans Disclosures Schedule of Defined Benefit Plans Disclosures [Table Text Block] Components of Net Periodic Pension Costs Schedule of Net Benefit Costs [Table Text Block] Defined Contribution Plan Disclosures Defined Contribution Plan Disclosures [Table Text Block] Income Tax Disclosure [Abstract] Summary of Effective Tax Rates Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Income from continuing operations attributable to Duke Energy common stockholders excluding impact of participating securities Income (Loss) from Continuing Operations, Net of Tax, Excluding Participating Securities Amount after tax of income (loss) from continuing operations attributable to parent, excluding the impact of participating securities. Average shares, basic Weighted Average Number of Shares Outstanding, Basic Incremental Common Shares Attributable to Dilutive Effect of Equity Forward Agreements Incremental Common Shares Attributable to Dilutive Effect of Equity Forward Agreements Average shares, diluted Weighted Average Number of Shares Outstanding, Diluted EPS, basic (usd per share) Income (Loss) from Continuing Operations, Per Basic Share EPS, diluted (usd per share) Income (Loss) from Continuing Operations, Per Diluted Share Number of stock options and performance and unvested stock awards excluded from the dilutive securities calculation Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Dividends declared per share (usd per share) Common Stock, Dividends, Per Share, Declared Offsetting Assets [Table] Offsetting Assets [Table] Other Current Liabilities [Member] Offsetting Assets [Line Items] Offsetting Assets [Line Items] Offsetting Derivative Assets [Abstract] Offsetting Derivative Assets [Abstract] Gross amounts recognized Gross amounts offset Derivative Asset, Fair Value, Gross Liability Net amounts recognized on the Condensed Consolidated Balance Sheet Income Taxes Income Tax Disclosure [Text Block] DERF [Member] DERF [Member] Wholly owned limited liability company named Duke Energy Receivables Finance Company, LLC. DEPR [Member] DEPR [Member] Duke Energy Progress Receivables, LLC DEFR [Member] Defr [Member] Duke Energy Flordia Receivables, LLC DEFPF [Member] DEFPF [Member] Duke Energy Florida Project Finance LLC [Member] Duke American Transmission Company [Member] Duke American Transmission Company [Member] Duke American Transmission Company [Member] Pioneer Transmission [Member] Pioneer Transmission [Member] Pioneer Transmission, LLC OVEC [Member] OVEC [Member] OVEC [Member] Variable Interest Entity, Financial or Other Support, Amount Variable Interest Entity, Financial or Other Support, Amount Percent of proceeds received as cash Percent of proceeds received as cash Percent of proceeds from accounts receivable securitization received as cash. Percent of proceeds received as subordinated note Percent of proceeds received as subordinated note Percent of proceeds from accounts receivable securitization received as subordinated note. Minimum equity balance required by Cinergy Receivables Receivables To Maintain Minimum equity Balance Minimum equity Balance required by Cinergy Receivables Variable Interest Entity Ownership Interest Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage Fixed interest rate added to LIBOR to compute variable rate Debt Instrument, Basis Spread on Variable Rate Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table Text Block] Disaggregation of Revenue Disaggregation of Revenue [Table Text Block] Schedule Of Unbilled Revenues With Restricted Receivables Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block] Cash and Cash Equivalents [Member] Cash and Cash Equivalents [Member] Corporate Debt Securities [Member] Corporate Debt Securities [Member] Municipal Bonds [Member] Municipal Bonds [Member] US Treasury and Government [Member] US Treasury and Government [Member] Gross Unrealized Holding Gains Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax Gross Unrealized Holding Losses Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax Estimated Fair Value Available-for-sale Securities Employee Benefit Plans Pension and Other Postretirement Benefits Disclosure [Text Block] Related Party Transactions [Abstract] Related Party Transactions Related Party Transactions Disclosure [Text Block] Notional Amounts of Outstanding Derivative Positions Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block] Location And Fair Value Of Derivatives Recognized in the Condensed Consolidated Balance Sheets Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block] Offsetting Assets Offsetting Assets [Table Text Block] Offsetting Liabilities Offsetting Liabilities [Table Text Block] Derivative Contracts with Contingent Credit Features Disclosure of Credit Derivatives [Table Text Block] Receivables sold Continuing Involvement with Transferred Financial Assets, Principal Amount Outstanding Less: Retained interests Continuing Involvement with Continued to be Recognized Transferred Financial Assets, Amount Outstanding Net receivables sold Continuing Involvement with Derecognized Transferred Financial Assets, Amount Outstanding Accounting Changes and Error Corrections [Abstract] New Accounting Pronouncements or Change in Accounting Principle [Table] New Accounting Pronouncements or Change in Accounting Principle [Table] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Operating Expense [Member] Operating Expense [Member] Nonoperating Income (Expense) [Member] Nonoperating Income (Expense) [Member] Accounting Standards Update 2017-07 (1) [Member] Accounting Standards Update 2017-07 (1) [Member] Accounting Standards Update 2017-07 Compensation-Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost. New Accounting Pronouncements or Change in Accounting Principle [Line Items] New Accounting Pronouncements or Change in Accounting Principle [Line Items] New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification Debt Securities, Trading, and Equity Securities, FV-NI [Table] Debt Securities, Trading, and Equity Securities, FV-NI [Table] Disclosure of information about investment in debt security measured at fair value with change in fair value recognized in net income (trading) and investment in equity security with change in fair value recognized in net income (FV-NI). Debt Securities, Trading, and Equity Securities, FV-NI [Line Items] Debt Securities, Trading, and Equity Securities, FV-NI [Line Items] [Line Items] for Disclosure of information about investment in debt security measured at fair value with change in fair value recognized in net income (trading) and investment in equity security with change in fair value recognized in net income (FV-NI). EquitySecuritiesFvNiAccumulatedUnrealizedGainLoss [Abstract] EquitySecuritiesFvNiAccumulatedUnrealizedGainLoss [Abstract] Equity Securities, FV-NI, Accumulated Unrealized Gain (Loss) [Abstract] Equity Securities, FV-NI, Unrealized Gain Equity Securities, FV-NI, Accumulated Unrealized Gain Amount of accumulated unrealized gain on investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). Substantially all of the associated unrealized gains and losses on these investments are deferred as a regulatory asset or liability. Equity Securities, FV-NI, Unrealized Loss Equity Securities, FV-NI, Accumulated Unrealized Loss Amount of accumulated unrealized loss on investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). Substantially all of the associated unrealized gains and losses on these investments are deferred as a regulatory asset or liability. Equity Securities, FV-NI, Realized Gain (Loss) [Abstract] EquitySecuritiesFvNiRealizedGainLoss1 [Abstract] Equity Securities, FV-NI, Realized Gain (Loss) [Abstract] Equity Securities, FV-NI, Realized Gain Equity Securities, FV-NI, Realized Gain Amount of realized gain from sale of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). Equity Securities, FV-NI, Realized Loss Equity Securities, FV-NI, Realized Loss Amount of realized loss from sale of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). Defined Contribution Plan [Table] Defined Contribution Plan [Table] Defined Contribution Plan Disclosure [Line Items] Defined Contribution Plan Disclosure [Line Items] Employer contributions Defined Contribution Plan, Cost Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Award Type [Axis] Award Type [Axis] Equity Award [Domain] Equity Award [Domain] Restricted Stock Units Awards [Member] Restricted Stock Units (RSUs) [Member] Performance Awards [Member] Performance Shares [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Pretax stock-based compensation cost Allocated Share-based Compensation Expense Tax benefit associated with stock-based compensation expense Employee Service Share-based Compensation, Tax Benefit from Compensation Expense Stock-based compensation costs capitalized Employee Service Share-based Compensation, Allocation of Recognized Period Costs, Capitalized Amount Reserves for legal matters Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Revenue, Remaining Performance Obligation Revenue, Remaining Performance Obligation Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period Regulatory Liability [Axis] Regulatory Liability [Axis] Regulatory Liability [Domain] Regulatory Liability [Domain] Storm Costs [Member] Storm Costs [Member] Public Utilities, Regulatory Proceeding [Axis] Public Utilities, Regulatory Proceeding [Axis] Public Utilities, Regulatory Proceeding [Domain] Public Utilities, Regulatory Proceeding [Domain] 2017 North Carolina Rate Case [Member] 2017 NC Rate Case [Member] 2017 NC Rate Case [Member] FERC Formula Rate Matter [Member] FERC Formula Rate Matter [Member] FERC Formula Rate Matter [Member] 2016 South Carolina Rate Case Settlement [Member] 2016 South Carolina Rate Case Settlement [Member] 2016 South Carolina Rate Case Settlement [Member] 2016 South Carolina Rate Case Settlement Year 1 Increase [Member] 2016 South Carolina Rate Case Settlement Year 1 Increase [Member] 2016 South Carolina Rate Case Settlement Year 1 Increase [Member] 2016 South Carolina Rate Case Settlement Year 2 Increase [Member] 2016 South Carolina Rate Case Settlement Year 2 Increase [Member] 2016 South Carolina Rate Case Settlement Year 2 Increase [Member] Western Carolinas Modernization Plan [Member] Western Carolinas Modernization Plan [Member] Western Carolinas Modernization Plan [Member] Shearon Harris Nuclear Expansion [Member] Shearon Harris Nuclear Expansion [Member] Shearon Harris Nuclear Expansion [Member] Storm Restoration Cost Recovery [Member] Storm Restoration Cost Recovery [Member] Storm Restoration Cost Recovery [Member] Citrus County Combined Cycle Facility [Member] Citrus County Combined Cycle Facility [Member] Citrus County Combined Cycle Facility [Member] 2017 Ohio Electric Base Rate Case [Member] 2017 Ohio Base Rate Case [Member] 2017 Ohio Base Rate Case [Member] Energy Efficiency Cost Recovery [Member] Energy Efficiency Cost Recovery Program [Member] Energy Efficiency Cost Recovery Program [Member] Natural Gas Pipeline Extension [Member] Natural Gas Pipeline Extension [Member] Natural Gas Pipeline Extension [Member] Duke Energy Kentucky Rate Case [Member] Duke Energy Kentucky Rate Case [Member] Duke Energy Kentucky Rate Case [Member] FERC Transmission Rates [Member] FERC Transmission Rates [Member] FERC Transmission Rates [Member] FERC Complaint [Member] FERC Complaint [Member] FERC Complaint regarding return on equity percentage FERC Complaint 1 [Member] FERC Complaint 1 [Member] FERC Complaint 1 [Member] FERC Complaint 2 [Member] FERC Complaint 2 [Member] FERC Complaint 2 [Member] TPUC IMR Petition Filed November 2017 [Member] TPUC IMR Petition Filed November 2017 [Member] TPUC IMR Petition Filed November 2017 [Member] William States Lee Combined Cycle Facility [Member] William States Lee Combined Cycle Facility [Member] William States Lee Combined Cycle Facility [Member] William State Lee III Nuclear Station [Member] William State Lee Iii Nuclear Station [Member] William State Lee III Nuclear Station Asheville Plant [Member] Asheville Plant [Member] Asheville Plant [Member] Citrus County Station [Member] Citrus County Station [Member] Citrus County Station [Member] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event [Member] Subsequent Event [Member] Benton County Wind Farm Dispute [Member] Benton County Wind Farm Dispute [Member] Benton County Wind Farm Dispute [Member] Regulatory Agency [Axis] Regulatory Agency [Axis] Regulatory Agency [Domain] Regulatory Agency [Domain] NCUC [Member] NCUC [Member] NCUC [Member] FERC [Member] Federal Energy Regulatory Commission [Member] Federal Energy Regulatory Commission [Member] PSCSC [Member] PSCSC [Member] Public Service Commission of South Carolina [Member] FPSC [Member] FPSC [Member] Florida Public Service Commission [Member] PUCO [Member] Public Utilities Commission Of Ohio [Member] Public Utilities Commission of Ohio regulatory body. OPSB [Member] Ohio Power Siting Board [Member] Ohio Power Siting Board [Member] KPSC [Member] KPSC [Member] KPSC [Member] TPUC [Member] TPUC [Member] The Tennessee Regulatory Authority (TRA) is charged with the responsibility of setting the rates and service standards of privately owned telephone, natural gas, electric and water utilities. Regulatory Asset [Axis] Regulatory Asset [Axis] Regulatory Asset [Domain] Regulatory Asset [Domain] Asset retirement obligations - coal ash [Member] Asset retirement obligations - coal ash [Member] Asset retirement obligations - coal ash [Member] Related Party [Axis] Related Party [Axis] Related Party [Domain] Related Party [Domain] Dominion Resources [Member] Dominion Resources [Member] Dominion Resources [Member] Southern Company Gas [Member] Southern Company Gas [Member] Southern Company Gas Spectra Energy Partners [Member] EnbridgeInc [Member] Enbridge Inc (formerly Spectra Energy) [Member] NextEra Energy [Member] NextEra Energy [Member] NextEra Energy [Member] Williams Partners L.P. [Member] Williams Partners L.P. [Member] Williams Partners L.P. [Member] Jointly Owned Utility Plant [Axis] Jointly Owned Utility Plant [Axis] Jointly Owned Utility Plant [Domain] Jointly Owned Utility Plant [Domain] NCEMC [Member] NCEMC [Member] North Carolina Electric Membership Corporation [Member] Atlantic Coast Pipeline (ACP) [Member] Atlantic Coast Pipeline (ACP) [Member] Atlantic Coast Pipeline (ACP) [Member] Sabal Trail Transmission Pipeline [Member] Sabal Trail Transmission Pipeline [Member] Sabal Trail Transmission Pipeline [Member] Constitution Pipeline [Member] Constitution Pipeline [Member] Constitution Pipeline [Member] Requested Rate Increase (Decrease), Amount Public Utilities, Requested Rate Increase (Decrease), Amount Requested Rate Increase, Percentage Public Utilities, Requested Rate Increase (Decrease), Percentage Requested Return on Equity, Percentage Public Utilities, Requested Return on Equity, Percentage Public Utilities, Requested Equity Capital Structure, Percentage Public Utilities, Requested Equity Capital Structure, Percentage Public Utilities, Requested Debt Capital Structure, Percentage Public Utilities, Requested Debt Capital Structure, Percentage Utilities Operating Expense, Maintenance, Operations, and Other Costs and Expenses Requested Rate Increase (Decrease), Amended, Amount Public Utilities, Requested Rate Increase (Decrease), Amended, Amount Customer Refundable Fees, Refund Payments Customer Refundable Fees, Refund Payments Estimated capital cost of new utility plant, including AFUDC Estimated Capital Cost Including Afudc Estimated capital cost of new utility plant including AFUDC. Joint owner ownership percentage Jointly Owned Utility Plant, Proportionate Ownership Share Requested Rate Increase (Decrease), Amended, Percentage Public Utilities, Requested Rate Increase (Decrease), Amended, Percentage Estimated Storm Costs - Capital and Operation Maintenance Estimated Storm Costs - Capital and Operation Maintenance Estimated Storm Costs - Capital and Operation Maintenance Utilities Operating Expense, Impairments Utilities Operating Expense Deferred coal ash costs Deferred coal ash costs Deferred coal ash costs Regulatory Asset, Amortization Period Regulatory Asset, Amortization Period Excluded deferred coal ash costs Excluded Deferred Coal Ash Costs Amount of excluded deferred coal ash costs. Penalty assessed Penalty assessed Penalty assessed Estimated future coal ash costs Estimated future coal ash costs Estimated future coal ash costs Approved Rate Increase (Decrease), Amount Public Utilities, Approved Rate Increase (Decrease), Amount Approved Rate Increase (Decrease), One Time Waiver Amount Approved Rate Increase (Decrease), One Time Waiver, Amount Approved Rate Increase (Decrease) One Time Waiver, Amount Asset Retirement Obligation, Accretion Expense Asset Retirement Obligation, Accretion Expense Loss Before Income Taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Approved return on equity percentage Public Utilities, Approved Return on Equity, Percentage Estimated capital cost Estimated capital cost Estimated capital cost of new project Wholesale Debt Return Amortization Period Wholesale Debt Return Amortization Period Wholesale Debt Return Amortization Period Customers Experiencing Outages Customers Experiencing Outages Customers Experiencing Outages Allowed Storm Reserve Regulatory Liabilities Regulatory Assets Regulatory Assets Requested Rider Revenue Increase Requested Rider Revenue Increase Requested Rider Revenue Increase Electric Domestic Regulated Revenue Electric Domestic Regulated Revenue Estimated Capital Cost Excluding AFUDC Estimated Capital Cost Excluding AFUDC Estimated Capital Cost Excluding AFUDC Public Utilities, Approved Equity Capital Structure, Percentage Public Utilities, Approved Equity Capital Structure, Percentage Total Allocable Capitalization Total Allocable Capitalization Kentucky Capital Structure consists of LTD + STD + Preferred Stock + Common Equity = Total Allocable Capitalization Costs recovered through existing riders Costs recovered through existing riders Costs recovered through existing riders Incremental Rider Revenue Incremental Rider Revenue Incremental Rider Revenue Approved Return on Equity Percentage Adder Approved Return on Equity Percentage Adder Approved Return on Equity Percentage Adder Litigation Settlement, Amount Awarded to Other Party Litigation Settlement, Amount Awarded to Other Party Long-term Purchase Commitment, Period Long-term Purchase Commitment, Period Original estimated capital cost Original estimated capital cost Original estimated capital cost Estimated Contributions Estimated Contributions The estimated cash outflow associated with contributions to an equity method investment (EMI) to fund the EMI's development and construction of a new natural gas pipeline. Equity Method Investment, Other than Temporary Impairment Equity Method Investment, Other than Temporary Impairment Anticipated credit loss ratio Assumption for Fair Value of Assets or Liabilities that relate to Transferor's Continuing Involvement, Expected Credit Losses Discount rate Assumption for Fair Value of Assets or Liabilities that relate to Transferor's Continuing Involvement, Discount Rate Receivable turnover rate Receivable Turnover Rate The ratio of total receivables to total monthly billings, as related to total receivables. Cash and Cash Equivalents [Abstract] Schedule of Cash and Cash Equivalents [Table] Schedule of Cash and Cash Equivalents [Table] Cash and Cash Equivalents [Line Items] Cash and Cash Equivalents [Line Items] Cash and Cash Equivalents, at Carrying Value Restricted Cash and Cash Equivalents, Current Restricted Cash and Cash Equivalents, Current Restricted Cash and Cash Equivalents, Noncurrent Restricted Cash and Cash Equivalents, Noncurrent Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Schedule Of Stock-Based Compensation Expense Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Plan [Table Text Block] Defined Benefit Plan, Expected Future Employer Contributions, Current Fiscal Year Defined Benefit Plan, Expected Future Employer Contributions, Current Fiscal Year Contributions by Employer Defined Benefit Plan, Plan Assets, Contributions by Employer Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year Fair Value Inputs, Assets, Quantitative Information [Table] Fair Value Inputs, Assets, Quantitative Information [Table] Asset Class [Axis] Asset Class [Axis] Asset Class [Domain] Asset Class [Domain] Financial Transmission Rights [Member] Derivative Financial Instruments Liabilities Financial Transmission Rights [Member] This item represents derivative instrument obligations related to financial transmission rights meeting the definition of a liability which are reported as of the balance sheet date. Valuation Technique [Axis] Valuation Technique [Axis] Valuation Technique [Domain] Valuation Technique [Domain] Market Approach Valuation Technique [Member] Market Approach Valuation Technique [Member] Fair Value Inputs, Assets, Quantitative Information [Line Items] Fair Value Inputs, Assets, Quantitative Information [Line Items] Net derivative asset (liability) Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs Fair Value Input Price Per Unit Fair Value Unobservable Input Price Per Unit Price per unit, used as an input to measure unobservable input, such as fair value for financial transmission rights agreements or natural gas contracts. Line of Credit Facility [Table] Line of Credit Facility [Table] Proceeds Loaned To Subsidiary Registrants [Member] Proceeds Loaned To Subsidiary Registrants [Member] Proceeds Loaned To Subsidiary Registrants Credit Facility [Axis] Credit Facility [Axis] Credit Facility [Domain] Credit Facility [Domain] Revolving Credit Facility [Member] Revolving Credit Facility [Member] Line of Credit Facility [Line Items] Line of Credit Facility [Line Items] Facility size Line of Credit Facility, Maximum Borrowing Capacity Commercial paper Long-term Commercial Paper Outstanding letters of credit Letters of Credit Outstanding, Amount Tax exempt bonds Long-term Pollution Control Bond Coal ash set-aside Line of Credit Facility, Capacity Available for Specific Purpose Other than for Trade Purchases Available capacity Line of Credit Facility, Remaining Borrowing Capacity Schedule of Related Party Transactions, by Related Party [Table] Schedule of Related Party Transactions, by Related Party [Table] Affiliated Entity [Member] Affiliated Entity [Member] Related Party Transaction [Line Items] Related Party Transaction [Line Items] Income tax payable Accrued Income Taxes, Current Equity Method Investments [Abstract] Equity Method Investments [Abstract] Cardinal Pipeline Company, LLC [Member] Cardinal Pipeline Company, LLC [Member] Cardinal Pipeline Company, LLC [Member] Pine Needle LNG Company, LLC [Member] Pine Needle LNG Company, LLC [Member] Pine Needle LNG Company, LLC [Member] Hardy Storage Company, LLC [Member] Hardy Storage Company, LLC [Member] Hardy Storage Company, LLC [Member] Equity Method Investee [Member] Equity Method Investee [Member] Related party transaction, expenses from transactions with related party Related Party Transaction, Expenses from Transactions with Related Party Accounts Payable, Related Parties, Current Accounts Payable, Related Parties, Current Fair Value Measurements Fair Value Disclosures [Text Block] Debt Securities, Available-for-sale [Table] Debt Securities, Available-for-sale [Table] Disclosure of information about investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). Financial Instrument [Axis] Financial Instrument [Axis] Financial Instruments [Domain] Financial Instruments [Domain] Debt Securities, Available-for-sale [Line Items] Debt Securities, Available-for-sale [Line Items] [Line Items] for Disclosure of information about investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract] Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract] Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax1 Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax1 Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). Debt Securities, Available-for-sale, Realized Gain (Loss) [Abstract] AvailableForSaleSecuritiesGrossRealizedGainLoss1 [Abstract] Debt Securities, Available-for-sale, Realized Gain (Loss) [Abstract] Debt Securities, Available-for-Sale, Realized Gain Debt Securities, Available-for-Sale, Realized Gain Amount of realized gain on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). Debt Securities, Available-for-sale, Realized Loss Debt Securities, Available-for-sale, Realized Loss Amount of realized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract] Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract] Service cost Defined Benefit Plan, Service Cost Interest cost on projected benefit obligation Defined Benefit Plan, Interest Cost Expected return on plan assets Defined Benefit Plan, Expected Return (Loss) on Plan Assets Amortization of actuarial loss (gain) Defined Benefit Plan, Amortization of Gain (Loss) Amortization of prior service credit Defined Benefit Plan, Amortization of Prior Service Cost (Credit) Other Defined Benefit Plan, Other Cost (Credit) Net periodic costs Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Litigation Case [Domain] USDOJ [Member] USDOJ [Member] United States Department of Justice [Member] North Carolina Ash Basins [Member] North Carolina Ash Basins [Member] North Carolina Ash Basins Three Year Revolving Credit Facility [Member] June 2017 Three Year Revolving Credit Facility [Member] June 2017 Three Year Revolving Credit Facility [Member] Minimum Master Credit Facility Balance Required Minimum Master Credit Facility Balance Required Minimum Master Credit Facility Balance Required to be maintained to meet obligations outlined in Plea Agreements Long-term Line of Credit Long-term Line of Credit Line of Credit Facility, Expiration Date Line of Credit Facility, Expiration Date Schedule Of Earnings Per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Goodwill and Intangible Assets Disclosure [Abstract] Goodwill Goodwill and Intangible Assets Disclosure [Text Block] Schedule of Goodwill [Table] Schedule of Goodwill [Table] Segments [Axis] Segments [Axis] Segments [Domain] Segments [Domain] Electric Utilities and Infrastructure [Member] Electric Utilities and Infrastructure [Member] Electric Utilities and Infrastructure Segment Gas Utilities and Infrastructure [Member] Gas Utilities and Infrastructure [Member] Gas Utilities and Infrastructure [Member] Goodwill [Line Items] Goodwill [Line Items] Goodwill balance Goodwill, Gross Accumulated impairment charges Goodwill, Impaired, Accumulated Impairment Loss Goodwill, adjusted for accumulated impairment charges Schedule of Information Regarding Derivative Instruments That Contain Credit-Risk Related Contingent Features Description of Credit Risk Related Contingent Features [Abstract] Aggregate fair value amounts of derivative instruments in a net liability position Derivative, Net Liability Position, Aggregate Fair Value Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered Additional Collateral, Aggregate Fair Value Cinergy Receivables [Member] Accounts Receivable from Securitization Accounts Receivable from Securitization Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract] Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract] Receivables of VIEs Property, plant and equipment, cost Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Investments [Member] Investments [Member] 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] Fair Value Measurement Transfers Between Activity Levels Fair Value Measurement Transfers Between Activity Levels Transfers into and out of fair value hierarchy levels for assets or liabilities measured at fair value. Investments Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Beginning balance Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value Total pretax gains (losses) included in earnings Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings Total pretax realized or unrealized gains included in comprehensive income Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss) Purchases Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases Sales Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales Settlements Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements Total gains (losses) included on the Condensed Consolidated Balance Sheet Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Deferred Gains Or Losses As Regulatory Assets And Liabilities Net, Asset This element represents deferred gains or losses as regulatory assets and liabilities [net] measured at fair value on a recurring basis using unobservable inputs (Level 3) which have taken place during the period. Ending balance Derivatives (net) Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward] Beginning balance Total pretax gains (losses) included in earnings Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Earnings Purchases Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Purchases Sales Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Sales Settlements Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Settlements Total gains (losses) included on the Condensed Consolidated Balance Sheet Fair Value Net Derivative Asset Liability Measured On Recurring Basis Unobservable Inputs Deferred Gains Or Losses As Regulatory Asset Or Liability Total amount, including deferred gains or losses, recorded as regulatory assets and liabilities [net] measured at fair value on a recurring basis using unobservable inputs (Level 3) which have taken place during the period. Total gains (losses) and settlements Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Period Increase (Decrease) Ending balance Investments and Derivatives, Net Investments and Derivatives, Net [Abstract] Investments and Derivatives, Net [Abstract] Beginning balance Fair Value Measurement Unobservable Inputs Reconciliation Net Fair value of financial instrument classified as asset (liability) after deduction of liability (asset), measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. Total pretax realized or unrealized gains included in comprehensive income Fair Value Measurement Unobservable Inputs Reconciliation Net Gain Loss Included In Other Comprehensive Income Loss Amount of gain (loss) recognized in other comprehensive income (loss) for financial instrument classified as an asset (liability) measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would be using. Purchases Fair Value Net Financial Instrument Unobservable Inputs Reconciliation Purchases Amount of purchases of financial instrument classified as an asset (liability) measured using unobservable inputs that reflect the entity's own assumption oabout the assumptions market participants would use in pricing. Sales Fair Value Net Financial Instrument Measure On Recurring Basis Unobservable Inputs Reconciliation Sales Amount of sales of financial instrument classified as an asset (liability) after deduction of liability (asset), measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. Settlements Fair Value Net Financial Asset Liability Measured On Recurring Basis Unobservable Inputs Reconciliation Settlements Amount of settlements of financial instrument classified as an asset (liability) after deduction of liability (asset), measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. Total gains (losses) included on the Condensed Consolidated Balance Sheet Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Deferred Gains Or Losses As Regulatory Assets And Liabilities Net This element represents the total amount included on the consolidated balance sheet as regulatory assets and liabilities [net] measured at fair value on a recurring basis using unobservable inputs (Level 3) which have taken place during the period. Ending balance Schedule Of Variable Interest Entities Schedule of Variable Interest Entities [Table Text Block] Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Other [Member] Other [Member] Other [Member] Products and Services [Axis] Products and Services [Axis] Products and Services [Domain] Products and Services [Domain] Electricity, US Regulated [Member] Electricity, US Regulated [Member] Generation, transmission, and distribution of electric energy regulated by government or agency in the US Other Revenues [Member] Other Revenues [Member] Other Revenues Natural Gas, US Regulated [Member] Natural Gas, US Regulated [Member] Generation, transmission and distribution of flammable gas occurring naturally underground regulated by government or agency in the US Customer [Axis] Customer [Axis] Customer [Domain] Customer [Domain] Residential [Member] Residential [Member] Residential Customer Class [Member] General [Member] General [Member] General service customers Industrial [Member] Industrial [Member] Industrial Customer [Member] Wholesale [Member] Wholesale [Member] Wholesale Customer [Member] Commercial [Member] Commercial [Member] Commercial Customer [Member] Power Generation [Member] Power Generation [Member] Power Generation [Member] Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Revenue from Sources other than Contracts with Customers Revenue from sources other than contracts with customers Revenue from sources other than contracts with customers Operating revenues Regulated and Unregulated Operating Revenue Statement of Cash Flows [Abstract] CASH FLOWS FROM OPERATING ACTIVITIES Net Cash Provided by (Used in) Operating Activities [Abstract] Adjustments to reconcile net income to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Depreciation, amortization and accretion (including amortization of nuclear fuel) Depreciation, Depletion and Amortization Equity component of AFUDC Public Utilities, Allowance for Funds Used During Construction, Capitalized Cost of Equity Losses (gains) on sales of other assets Gain (Loss) on Disposition of Other Assets Impairment charges Other Asset Impairment Charges Deferred income taxes Deferred Income Taxes and Tax Credits Equity in losses (earnings) of unconsolidated affiliates Income (Loss) from Equity Method Investments Accrued pension and other post-retirement benefit costs Pension and Other Postretirement Benefits Cost (Reversal of Cost) Contributions to qualified pension plans Payment for Pension Benefits Payments for asset retirement obligations Asset Retirement Obligation, Cash Paid to Settle Payment for disposal of other assets Payment For Disposal Of Other Assets The cash outflow associated with the payment for the disposal of other assets. Other rate case adjustments Other Operating Activities, Cash Flow Statement Provision for rate refunds Provision For Rate Refunds Provision for rate refunds resulting from impacts of the federal statutory tax rate changing as a result of the Tax Cut and Jobs Act. (Increase) decrease in Increase (Decrease) in Operating Assets [Abstract] Net realized and unrealized mark-to-market and hedging transactions Unrealized Gain (Loss) on Derivatives Receivables Increase (Decrease) in Receivables Receivable from affiliated companies Increase (Decrease) in Accounts Receivable, Related Parties Inventory Increase (Decrease) in Inventories Other current assets Increase (Decrease) in Other Current Assets Increase (decrease) in Increase (Decrease) in Operating Liabilities [Abstract] Accounts payable Increase (Decrease) in Accounts Payable Accounts payable to affiliated companies Increase (Decrease) in Accounts Payable, Related Parties Taxes accrued Increase (Decrease) in Accrued Taxes Payable Other current liabilities Increase (Decrease) in Other Current Liabilities Other assets Increase (Decrease) in Other Operating Assets Other liabilities Increase (Decrease) in Other Operating Liabilities Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities CASH FLOWS FROM INVESTING ACTIVITIES Net Cash Provided by (Used in) Investing Activities [Abstract] Capital expenditures Payments to Acquire Property, Plant, and Equipment Cost of removal, net of salvage Payments for (Proceeds from) Removal Costs Contributions to equity method investments Payments to Acquire Interest in Subsidiaries and Affiliates Purchases of debt and equity securities Payments to Acquire Investments Proceeds from sales and maturities of debt and equity securities Proceeds from Sale, Maturity and Collection of Investments Notes receivable from affiliated companies Proceeds Or Payments From Collection Or Advance To Affiliate The cash inflow (outflow) from the collection (advancement) of money to an affiliated entity. Other Payments for (Proceeds from) Other Investing Activities Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities CASH FLOWS FROM FINANCING ACTIVITIES Net Cash Provided by (Used in) Financing Activities [Abstract] Proceeds from the issuance of long-term debt Proceeds from Issuance of Long-term Debt Proceeds from the issuance of common stock Proceeds from Issuance or Sale of Equity Payments for the redemption of long-term debt Repayments of Long-term Debt Proceeds from issuance of short-term debt with original maturities greater than 90 days Proceeds from Short-term Debt, Maturing in More than Three Months Payments for the redemption of short-term debt with original maturities greater than 90 days Repayments of Short-term Debt, Maturing in More than Three Months Notes payable and commercial paper Proceeds from (Repayments of) Short-term Debt Notes payable to affiliated companies Proceeds from (Repayments of) Related Party Debt Dividends to parent Payments of Distributions to Affiliates Distributions to parent Distribution Made to Limited Liability Company (LLC) Member, Cash Distributions Paid Dividends paid Payments of Ordinary Dividends, Common Stock Other Proceeds from (Payments for) Other Financing Activities Net cash provided by financing activities Net Cash Provided by (Used in) Financing Activities Net increase in cash, cash equivalents and restricted cash Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect Net increase (decrease) in cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease) Cash, cash equivalents and restricted cash at beginning of period Cash, cash equivalents and restricted cash at end of period Cash and cash equivalents at beginning of period Cash and cash equivalents at end of period Significant non-cash transactions: Noncash Investing and Financing Items [Abstract] Accrued capital expenditures Capital Expenditures Incurred but Not yet Paid Non-cash dividends Dividends, Common Stock, Stock Fair Value Inputs, Quantitative Information [Abstract] Fair Value Inputs, Liabilities, Quantitative Information [Table] Fair Value Inputs, Liabilities, Quantitative Information [Table] Liability Class [Axis] Liability Class [Axis] Fair Value by Liability Class [Domain] Fair Value by Liability Class [Domain] Derivative Financial Instruments, Liabilities [Member] Derivative Financial Instruments, Liabilities [Member] Discounted Cash Flow [Member] Discounted Cash Flow [Member] Discounted Cash Flow [Member] Fair Value Inputs, Liabilities, Quantitative Information [Line Items] Fair Value Inputs, Liabilities, Quantitative Information [Line Items] Document And Entity Information [Abstract] Document and Entity Information [Abstract] Document Information [Table] Document Information [Table] Document Information [Line Items] Document Information [Line Items] Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Document Type Document Type Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Amendment Flag Amendment Flag Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Trading Symbol Trading Symbol Environmental Matters Details [Line Items] Environmental Exit Costs, Reasonably Possible Additional Loss Environmental Exit Costs, Reasonably Possible Additional Loss Accrual for Environmental Loss Contingencies [Roll Forward] Accrual for Environmental Loss Contingencies [Roll Forward] Beginning balance Accrual for Environmental Loss Contingencies Provisions/adjustments Accrual for Environmental Loss Contingencies, Period Increase (Decrease) Cash reductions Accrual for Environmental Loss Contingencies, Payments Ending balance Debt And Credit Facilities Debt Disclosure [Text Block] Schedule of Long-term Debt Instruments Schedule of Long-term Debt Instruments [Table Text Block] Schedule Of Line Of Credit Facilities Schedule of Line of Credit Facilities [Table Text Block] Offsetting Liabilities [Table] Offsetting Liabilities [Table] Offsetting Liabilities [Line Items] Offsetting Liabilities [Line Items] Offsetting Derivative Liabilities [Abstract] Offsetting Derivative Liabilities [Abstract] Gross amounts recognized Gross amounts offset Derivative Liability, Fair Value, Gross Asset Net amounts recognized on the Condensed Consolidated Balance Sheet Schedule of Related Party Transactions, Other Revenue and Expense Schedule of Related Party Transactions [Table Text Block] Income Tax Disclosure [Table] Income Tax Disclosure [Table] Schedule reflecting income tax information. Income Tax Disclosure [Line Items] Income Tax Disclosure [Line Items] Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Tax Cuts and Jobs Act of 2017 Incomplete Accounting Provisional Income Tax Expense Benefit TaxCutsAndJobsActOf2017IncompleteAccountingProvisionalIncomeTaxExpenseBenefit Provisional Income Tax Expense (Benefit) associated with the Tax Cuts and Jobs Act of 2017. Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract] Effective Income Tax Rate Reconciliation, Amount [Abstract] Effective tax rate Effective Income Tax Rate Reconciliation, Percent Schedule Of Available For Sale Securities And Other Trading Assets [Table] Schedule Of Available For Sale Securities And Other Trading Assets [Table] Disclosure of information about investment in debt security measured at fair value with change in other comprehensive income and investment in equity security with change in fair value recognized in net income (FV-NI). Schedule Of Available For Sale Securities And Other Trading Assets [Line Items] Schedule Of Available For Sale Securities And Other Trading Assets [Line Items] [Line Items] for Disclosure of information about investment in debt security measured at fair value with change in other comprehensive income and investment in equity security with change in fair value recognized in net income (FV-NI). Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Gain Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Gain Amount of unrealized gain on investments in debt securities measured at fair value with change in fair value recognized in OCI and equity securities measured at fair value with change in fair value recognized in net income (FV-NI). Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Loss Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Loss Amount of unrealized loss on investments in debt securities measured at fair value with change in fair value recognized in OCI and equity securities measured at fair value with change in fair value recognized in net income (FV-NI) Cash and cash equivalents Cash And Cash Equivalent Investments Amount of cash and cash equivalents held in a trust fund or other type of investment. Debt Securities, Available-for-sale, and Equity Securities, FV-NI Debt Securities, Available-for-sale, and Equity Securities, FV-NI Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading Income Statement [Abstract] Operating Revenues Revenues [Abstract] Regulated electric Regulated natural gas Gas Domestic Regulated Revenue Nonregulated electric and other Unregulated Operating Revenue Total operating revenues Operating Expenses Costs and Expenses [Abstract] Fuel used in electric generation and purchased power Cost of Domestic Regulated Electric Fuel used in electric generation and purchased power – nonregulated Cost of Worldwide Unregulated Electric Cost of natural gas Utilities Operating Expense, Gas and Petroleum Purchased Depreciation and amortization Cost of Goods Sold, Depreciation, Depletion and Amortization Property and other taxes Taxes, Miscellaneous Impairment charges Asset Impairment Charges Total operating expenses Costs and Expenses (Loss) Gains on Sales of Other Assets and Other, net Operating Income Operating Income (Loss) Other Income and Expenses Nonoperating Income (Expense) [Abstract] Equity in (losses) earnings of unconsolidated affiliates Other income and expenses, net Other Nonoperating Income (Expense) Total other income and expenses Nonoperating Income (Expense) Interest Expense Interest Expense Income Before Income Taxes Income Tax Expense Income Tax Expense (Benefit) Income from Continuing Operations Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest (Loss) Income From Discontinued Operations, net of tax Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest Net income Less: Net Income Attributable to Noncontrolling Interests Net Income (Loss) Attributable to Noncontrolling Interest Net Income Attributable to Parent Other Comprehensive Income (Loss), net of tax Net unrealized gain on cash flow hedges Reclassification into earnings from cash flow hedges Unrealized gains on available-for-sale securities Other Comprehensive Income, net of tax Less: Comprehensive Income Attributable to Noncontrolling Interests Earnings Per Share – Basic and Diluted Earnings Per Share, Basic and Diluted [Abstract] Net income attributable to Duke Energy Corporation common stockholders Basic (usd per share) Earnings Per Share, Basic Diluted (usd per share) Earnings Per Share, Diluted Weighted average shares outstanding Weighted Average Number of Shares Outstanding, Diluted [Abstract] Basic (shares) Diluted (shares) Organization and Basis of Presentation Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block] Pipeline Investments [Abstract] Pipeline Investments [Abstract] Atlantic Coast Pipeline [Member] Atlantic Coast Pipeline [Member] Atlantic Coast Pipeline [Member] Equity Method Investment Line Of Credit Facility Maximum Borrowing Capacity Equity Method Investment Line Of Credit Facility Maximum Borrowing Capacity Maximum borrowing capacity, for the equity method investment that is not consolidated, under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility. Variable Interest Entity Entity Maximum Loss Exposure Percent Variable Interest Entity Entity Maximum Loss Exposure Percent The reporting entity's maximum percentage of exposure to loss as a result of its involvement with the Variable Interest Entity (VIE). Variable Interest Entity, Nonconsolidated, Carrying Amount, Liabilities Equity Method Investment Long Term Debt Equity Method Investment Long Term Debt Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt issued by the equity method investment that is not consolidated. Proceeds from Equity Method Investment, Distribution, Return of Capital Proceeds from Equity Method Investment, Distribution, Return of Capital Investments in Joint Ventures Regulatory Matters Public Utilities Disclosure [Text Block] Fair Value Measurement Amounts For Assets And Liabilities Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Reconciliation Of Assets And Liabilities Measured At Fair Value On A Recurring Basis Using Unobservable Inputs Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Quantitative Information Table - Level 3 Fair Value, Assets and Liabilities Measured on Nonrecurring Basis, Valuation Techniques [Table Text Block] Schedule Of Long Term Debt Fair Value Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block] Related Party Transaction [Axis] Related Party Transaction [Axis] Related Party Transaction [Domain] Related Party Transaction [Domain] Corporate Governance And Shared Service Expenses [Member] Corporate Governance And Shared Service Expenses [Member] Proportionate share of corporate governance and other costs, primarily related to human resources, employee benefits, legal and accounting fees, as well as other third party costs. Indemnification Coverages [Member] Indemnification Coverages [Member] Certain indemnification coverages incurred through captive insurance subsidiary Joint Dispatch Agreement [Member] Joint Dispatch Agreement [Member] Revenues or expenses from the joint dispatch agreement between Duke Energy Carolinas and Progress Energy Carolinas Intercompany Natural Gas Transactions [Member] Intercompany Natural Gas Transactions [Member] Intercompany Natural Gas Transactions between Piedmont Natural Gas and Duke Energy Carolinas/Duke Energy Progress Related party transaction, other revenues from transactions with related party Related Party Transaction, Other Revenues from Transactions with Related Party Business Segment Data Schedule of Segment Reporting Information, by Segment [Table Text Block] Due in one year or less Available-for-sale Securities, Debt Maturities, Next Twelve Months, Fair Value Due after one through five years Available-for-sale Securities, Debt Maturities, Year Two Through Five, Fair Value Due after five through 10 years Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Fair Value Due after 10 years Available-for-sale Securities, Debt Maturities, after Ten Years, Fair Value Total Goodwill By Reportable Operating Segment Schedule of Goodwill [Table Text Block] Consolidation Items [Axis] Consolidation Items [Axis] Consolidation Items [Domain] Consolidation Items [Domain] Operating Segments [Member] Operating Segments [Member] Intersegment Eliminations [Member] Intersegment Eliminations [Member] Corporate, Non-Segment [Member] Corporate, Non-Segment [Member] Total Reportable Segments [Member] Total Reportable Segments [Member] Total Reportable Segments Other Segments [Member] Other Segments [Member] Segment income (loss) Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent Net Income (Loss) Attributable to Noncontrolling Interest (Loss) Income From Discontinued Operations, net of tax Segment assets Commitments And Contingencies Commitments and Contingencies Disclosure [Text Block] Receivables sold Financing Receivable Sales The amount of any sales of receivables during the reporting period. Loss recognized on sale Gain (Loss) on Sale of Accounts Receivable Cash proceeds from receivables sold Cash Flows Between Transferor and Transferee, Proceeds from New Transfers Collection fees received Cash Flows Between Transferor and Transferee, Servicing Fees Return received on retained interests Proceeds from Collection of Retained Interest in Securitized Receivables Long-term debt, book value Long-term Debt Long-term debt, fair value Long-term Debt, Fair Value