Retirement Benefits [Abstract] Schedule of Defined Benefit Plans Disclosures [Table] Schedule of Defined Benefit Plans Disclosures [Table] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Houston Electric [Member] Houston Electric [Member] Houston Electric [Member] CERC Corp [Member] CERC Corp [Member] Another company which is controlled, directly or indirectly, by its parent. The usual condition for control is ownership of a majority (over 50%) of the outstanding voting stock. The power to control may also exist with a lesser percentage of ownership, for example, by contract, lease, agreement with other stockholders or by court decree. Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Operation and maintenance expense [Member] Operation And Maintenance Expense Member Amount of share-based compensation cost reported in the period, allocated to operations and maintenance expense. Operations and maintenance expense are the costs associated with normal operations, including general and administrative expenses, and routine plant maintenance and repairs. Other, net [Member] Other Nonoperating Income (Expense) [Member] Retirement Plan Type [Axis] Retirement Plan Type [Axis] Retirement Plan Type [Domain] Retirement Plan Type [Domain] Pension Benefits [Member] Pension Plan [Member] Other Postretirement Benefits Plan [Member] Other Postretirement Benefits Plan [Member] Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan Disclosure [Line Items] Service cost (1) Defined Benefit Plan, Service Cost Interest cost (2) Defined Benefit Plan, Interest Cost Expected return on plan assets (2) Defined Benefit Plan, Expected Return (Loss) on Plan Assets Amortization of prior service cost (2) Defined Benefit Plan, Amortization of Prior Service Cost (Credit) Amortization of net loss (2) Defined Benefit Plan, Amortization of Gain (Loss) Curtailment gain (2) (3) Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Curtailment Net periodic cost (income) Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Total contributions expected in current year Defined Benefit Plan, Expected Future Employer Contributions, Current Fiscal Year Total contributions to the plans during the period Defined Benefit Plan, Plan Assets, Contributions by Employer Defined Benefit Plan, Plan Assets, Period Increase (Decrease) Defined Benefit Plan, Plan Assets, Period Increase (Decrease) Percent increase (decrease) change in Defined Benefit Plan Assets Percent increase (decrease) change in Defined Benefit Plan Assets Percent increase (decrease) change in Defined Benefit Plan Assets Equity [Abstract] Schedule of Stock by Class [Table] Schedule of Stock by Class [Table] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event [Member] Subsequent Event [Member] Period [Axis] Period [Axis] Period of the transaction occurred [Axis] Period [Domain] Period [Domain] [Domain] for Period of the transaction occurred [Axis] First Quarter 2020 [Member] First Quarter 2020 [Member] First Quarter 2020 [Member] First Quarter 2019 [Member] First Quarter 2019 [Member] First Quarter 2019 [Member] Derivative Instrument [Axis] Derivative Instrument [Axis] Derivative Contract Type [Domain] Derivative Contract [Domain] Interest Rate Contract [Member] Interest Rate Contract [Member] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Series C Preferred Stock [Member] Series C Preferred Stock [Member] Common Stock [Member] Common Stock [Member] Series A Preferred Stock [Member] Series A Preferred Stock [Member] Series B Preferred Stock [Member] Series B Preferred Stock [Member] Class of Stock [Line Items] Class of Stock [Line Items] Preferred Stock, Shares Issued Preferred Stock, Shares Issued Convertible Preferred Stock, Shares Issued upon Conversion Convertible Preferred Stock, Shares Issued upon Conversion Preferred Stock, Liquidation Preference Per Share Preferred Stock, Liquidation Preference Per Share Dividends declared per share Common Stock, Dividends, Per Share, Declared Preferred stock dividends declared Preferred Stock, Dividends Per Share, Declared Declaration Date Dividends Payable, Date Declared Record Date Dividends Payable, Date of Record Payment Date Dividends Payable, Date to be Paid Dividends paid per share Common Stock, Dividends, Per Share, Cash Paid Total dividends paid Dividends, Common Stock, Cash Dividends paid per share Preferred Stock, Dividends, Per Share, Cash Paid Total dividends paid Dividends, Preferred Stock, Cash Preferred stock dividend requirement Preferred Stock Dividends, Income Statement Impact Accumulated Other Comprehensive Income (Loss) [Roll Forward] Accumulated Other Comprehensive Income (Loss) [Roll Forward] Accumulated Other Comprehensive Income (Loss) [Roll Forward] Beginning Balance Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax Other comprehensive income (loss) before reclassifications Other Comprehensive Income (Loss), before Reclassifications, before Tax Other comprehensive loss from unconsolidated affiliates, net of tax Other comprehensive loss from unconsolidated affiliates, net of tax Other comprehensive loss from unconsolidated affiliates, net of tax Actuarial losses Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax Reclassification of deferred loss from cash flow hedges realized in net income Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax Tax expense Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent Net current period other comprehensive income (loss) Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Ending Balance Proceeds from Issuance of Convertible Preferred Stock Proceeds from Issuance of Convertible Preferred Stock Preferred Stock, Convertible, Conversion Price Preferred Stock, Convertible, Conversion Price Preferred Stock, Convertible, Conversion Price Preferred Stock, Convertible, Conversion Limit Preferred Stock, Convertible, Conversion Limit Preferred Stock, Convertible, Conversion Limit Preferred Stock, Convertible, Percent Outstanding Shares To Amend Preferred Stock, Convertible, Percent Outstanding Shares To Amend Preferred Stock, Convertible, Percent Outstanding Shares To Amend Stock Issued During Period, Shares, New Issues Stock Issued During Period, Shares, New Issues Shares Issued, Price Per Share Shares Issued, Price Per Share Proceeds from Issuance of Common Stock Proceeds from Issuance of Common Stock Commitments and Contingencies Disclosure [Abstract] Statement [Table] Statement [Table] Segments [Axis] Segments [Axis] Segments [Domain] Segments [Domain] Discontinued Operations [Member] Discontinued Operations [Member] Guarantor Obligations, Nature [Axis] Guarantor Obligations, Nature [Axis] Guarantor Obligations, Nature [Domain] Guarantor Obligations, Nature [Domain] CES natural gas related transactions [Member] CES natural gas related transactions [Member] CES natural gas related transactions [Member] Loss Contingency Nature [Axis] Loss Contingency Nature [Axis] Loss Contingency, Nature [Domain] Loss Contingency, Nature [Domain] Minnehaha Academy Gas Explosion [Member] Damage from Fire, Explosion or Other Hazard [Member] Indiana Electric Integrated [Member] Indiana Electric Integrated [Member] Segment information for the Indiana Electric Integrated reportable segment which consists of electric transmission and distribution services primarily to southwestern Indiana and includes power generation and wholesale power operations Environmental Remediation Site [Axis] Environmental Remediation Site [Axis] Environmental Remediation Site [Domain] Environmental Remediation Site [Domain] Minnesota and Indiana Gas Service Territories [Member] Minnesota and Indiana Gas Service Territories [Member] Minnesota and Indiana Gas Service Territories Indiana Gas Service Territory [Member] Indiana Gas Service Territory [Member] Represents the areas in Indiana serviced by Indiana Gas Service Statistical Measurement [Axis] Statistical Measurement [Axis] Statistical Measurement [Domain] Statistical Measurement [Domain] Minimum [Member] Minimum [Member] Maximum [Member] Maximum [Member] Statement [Line Items] Statement [Line Items] Purchase Obligations Purchase Obligation, Fiscal Year Maturity [Abstract] Remaining nine months of 2020 Purchase Obligation, Future Minimum Payments, Remainder of Fiscal Year 2021 Purchase Obligation, Due in Next Twelve Months 2022 Purchase Obligation, Due in Second Year 2023 Purchase Obligation, Due in Third Year 2024 Purchase Obligation, Due in Fourth Year 2025 Purchase Obligation, Due in Fifth Year 2026 and beyond Purchase Obligation, Due after Fifth Year Performance Guarantees & Product Warranties [Abstract] Performance Guarantees & Product Warranties [Abstract] Performance Guarantees & Product Warranties [Abstract] Number of surety bond obligations outstanding Number of surety bond obligations outstanding Represents the absolute number of surety bonds the wholly owned subsidiary has outstanding in its role as general contractor Performance guarantee obligations outstanding face amount Performance guarantee obligations outstanding face amount Face amount of individual surety bonds the wholly-owned subsidiary has outstanding Percentage of work yet to be completed on projects with open surety bonds Percentage of work yet to be completed on projects with open surety bonds Percentage of work yet to be completed by wholly owned subsidiary on projects with open surety bonds. Guarantor obligations, maximum exposure, undiscounted Guarantor Obligations, Maximum Exposure, Undiscounted Annualized fee received for retained CES obligation guarantees Annualized fee received for retained CES obligation guarantees Annualized fee received for retained CES obligation guarantees Quarterly increase of fee received for retained CES guarantee exposure Quarterly increase of fee received for retained CES guarantee exposure Quarterly increase of fee received for retained CES guarantee exposure Guarantor Obligations, Current Carrying Value Guarantor Obligations, Current Carrying Value Legal, Environmental and Other Matters Environmental Remediation Obligations [Abstract] Contested amount of fines imposed ContestedAmountOfFinesImposed Contested amount of fines imposed by the Minnesota Office of Pipeline Safety. Environmental remediation number of sites with potential remedial responsibility Environmental remediation number of sites with potential remedial responsibility Number of sites identified where the entity may potentially have some remedial responsibility Liability recorded for environmental loss contingencies Accrual for Environmental Loss Contingencies Estimated remediation costs for the Minnesota sites Site Contingency Loss Exposure Estimate of the reasonably possible loss exposure at an individual site. Years to resolve contingency Site Contingency, Years to Resolve Contingency This represents the estimated years necessary to resolve the contingency. Asset retirement obligation Asset Retirement Obligation Estimated capital expenditure to clean ash ponds Estimated capital expenditure to clean ash ponds Estimated Capital Expenditure to Clean Ash Ponds Segment Reporting [Abstract] Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Consolidation Items [Axis] Consolidation Items [Axis] Consolidation Items [Domain] Consolidation Items [Domain] Operating Segments [Member] Operating Segments [Member] Intersegment Eliminations [Member] Intersegment Eliminations [Member] Reporting Segment [Domain] Houston Electric T&D [Member] Electric Transmission & Distribution [Member] Segment information for the Electric Transmission & Distribution segment which engages in the electric transmission and distribution business in the Texas Gulf Coast area. Natural Gas Distribution [Member] Natural Gas Distribution [Member] Segment information for the Natural Gas Distribution segment which consists of intrastate natural gas sales to, and natural gas transportation and distribution for, residential, commercial, industrial and institutional customers. Midstream Investments [Member] Midstream Investments [Member] Midstream Investments [Member] Corporate and Other [Member] Corporate and Other [Member] Major Customers [Axis] Customer [Axis] Name of Major Customer [Domain] Customer [Domain] Affiliates of NRG Energy, Inc. [Member] Affiliates of NRG Energy, Inc. [Member] Affiliates of NRG Energy, Inc. [Member] Affiliates of Vistra Energy Corp. [Member] Affiliates of Vistra Energy Corp. [Member] Affiliates of Vistra Energy Corp. [Member] Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Number of States in which the Entity Performs Gas Delivery Services Number of States in which the Entity Performs Gas Delivery Services Number of States in which the Entity Performs Gas Delivery Services Revenues Revenues Equity in earnings from investment in Enable Income (Loss) from Equity Method Investments Depreciation and amortization Depreciation, Depletion and Amortization Interest Income Interest Income, Other Interest Expense Interest Expense, Other Income tax expense (benefit) Income Tax Expense (Benefit) Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest Net income (loss) from Discontinued Operations Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent Net income (loss) Net Income (Loss) Attributable to Parent Assets Assets Total Assets Classified as Held For Use, Current and Noncurrent Total Assets Classified as Held For Use, Current and Noncurrent Total Assets Classified as Held For Use, Current and Noncurrent Total Assets Classified as Held For Sale, Current and Noncurrent Total Assets Classified as Held For Sale, Current and Noncurrent Total Assets Classified as Held For Sale, Current and Noncurrent Interest income from Securitization Bonds Interest Income on Transition and System Restoration Bonds Interest Income on Transition and System Restoration Bonds Interest on Transition and System Restoration Bonds Interest on Transition and System Restoration Bonds Interest and debt related expenses associated with transition and system restoration bonds. Revenue from Contract with Customer [Abstract] Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Subsegments Consolidation Items [Axis] Subsegments Consolidation Items [Axis] Subsegments Consolidation Items [Domain] Subsegments Consolidation Items [Domain] Reportable Subsegments [Member] Reportable Subsegments [Member] Energy Services [Member] Energy Services [Member] Segment information for the Energy Services segment which offers variable and fixed price physical natural gas supplies primarily to commercial and industrial customers and electric and gas utilities. Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Revenue from contracts Revenue from Contract with Customer, Excluding Assessed Tax Other Other Revenue Excluding Assessed Tax Amount, excluding tax collected from customer, of alternative revenue programs and leases revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise. Lease Income Lease Income Revenue Recognition [Text Block] Revenue from Contract with Customer [Text Block] Subsequent Events [Abstract] Subsequent Event [Table] Subsequent Event [Table] Disposal Group Name [Axis] Disposal Group Name [Axis] Disposal Group Name [Domain] Disposal Group Name [Domain] Infrastructure Services [Member] Infrastructure Services Disposal Group [Member] Infrastructure Services Disposal Group [Member] Dividends, Distributions, Change [Axis] Dividends, Distributions, Change [Axis] Dividends, Distributions, Change [Axis] Dividends, Distributions, Change [Domain] Dividends, Distributions, Change [Domain] [Domain] for Dividends, Distributions, Change [Axis] Previous Dividend or Distribution [Member] Previous Dividend or Distribution [Member] Previous Dividend or Distribution [Member] Revised Dividend or Distribution [Member] Revised Dividend or Distribution [Member] Revised Dividend or Distribution [Member] Preferred Units by Name [Axis] Preferred Units by Name [Axis] Preferred Units, Class [Domain] Preferred Units, Class [Domain] Series A Preferred Units [Member] Series A Preferred Units [Member] Series A Preferred Units [Member] Limited Partners' Capital Account by Class [Axis] Limited Partners' Capital Account by Class [Axis] Limited Partners' Capital Account, Class [Domain] Limited Partners' Capital Account, Class [Domain] Common Units [Member] Common Units [Member] Common Units [Member] Investment, Name [Axis] Investment, Name [Axis] Investment, Name [Domain] Investment, Name [Domain] Enable Midstream Partners [Member] Enable Midstream Partners [Member] Enable Midstream Partners, LP Subsequent Event [Line Items] Subsequent Event [Line Items] Dividends payable, date declared Dividends payable, date of record Dividends payable, date to be paid Quarterly cash distribution, declaration date Distribution Made to Limited Partner, Declaration Date Quarterly cash distribution, date of record Distribution Made to Limited Partner, Date of Record Quarterly cash distribution, distribution date Distribution Made to Limited Partner, Distribution Date Quarterly cash distribution declared per share Distribution Made to Limited Partner, Distributions Declared, Per Unit Expected cash distribution from equity method investment Proceeds from Equity Method Investment, Distribution Expected cash distribution from cost method investment Cost Method Investment, Dividends Or Distributions This item represents disclosure of the amount of dividends or other distributions received from unconsolidated subsidiaries, certain corporate joint ventures, and certain noncontrolled corporation; these investments are accounted for under the cost method of accounting. This element excludes distributions that constitute a return of investment, which are classified as investing activities. Percentage Reduction of Dividend or Distribution Amount Percentage Reduction of Dividend or Distribution Amount Percentage Reduction of Dividend or Distribution Amount Sales price of outstanding equity interests Sales price of outstanding equity interests Sales price of outstanding equity interests ERCOT Loan, COVID-19 ERP ERCOT Loan, COVID-19 ERP ERCOT Loan, COVID-19 ERP Disaggregation of Revenue [Table Text Block] Disaggregation of Revenue [Table Text Block] Contract with Customer, Asset and Liability [Table Text Block] Contract with Customer, Asset and Liability [Table Text Block] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table Text Block] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table Text Block] Investments, Debt and Equity Securities [Abstract] Schedule of Indexed Debt Securities and Marketable Securities [Table Text Block] Schedule of Indexed Debt Securities and Marketable Securities [Table Text Block] Schedule of Indexed Debt Securities and Marketable Securities [Table Text Block] Dividends Declared [Table Text Block] Dividends Declared [Table Text Block] Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Fair Value Disclosures [Abstract] Fair value, assets and liabilities measured on a recurring basis [Table Text Block] Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs [Table Text Block] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Estimated fair value of financial instruments, debt instruments [Table Text Block] Fair Value, by Balance Sheet Grouping [Table Text Block] Income Statement [Abstract] Scenario [Axis] Scenario [Axis] Scenario [Domain] Scenario [Domain] Income tax expense associated with discontinued operations Discontinued Operation, Tax Effect of Discontinued Operation Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Instruments [Text Block] Derivative Instruments and Hedging Activities Disclosure [Text Block] Supplemental Cash Flow Elements [Abstract] Schedule of Cash Flow, Supplemental Disclosures [Table Text Block] Schedule of Cash Flow, Supplemental Disclosures [Table Text Block] Statement of Stockholders' Equity [Abstract] Adjustments for New Accounting Pronouncements [Axis] Adjustments for New Accounting Pronouncements [Axis] Type of Adoption [Domain] Type of Adoption [Domain] Accounting Standards Update 2016-13 [Member] Accounting Standards Update 2016-13 [Member] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Preferred Stock [Member] Preferred Stock [Member] Additional Paid-in Capital [Member] Additional Paid-in Capital [Member] Retained Earnings [Member] Retained Earnings [Member] AOCI Attributable to Parent [Member] AOCI Attributable to Parent [Member] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Balance, beginning of period Preferred Stock, Shares Outstanding Balance, end of period Balance, beginning of period Common Stock, Shares, Outstanding Issuances related to benefit and investment plans Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture Balance, end of period Balance, beginning of period Stockholders' Equity Attributable to Parent Issuances related to benefit and investment plans Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture Contribution From Parent Contribution From Parent Contribution From Parent Net income (Loss) Dividends, Common Stock, Cash Dividends, Preferred Stock, Cash Dividend to parent Dividends, Cash New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification Other comprehensive income (loss) Other Comprehensive Income (Loss), Net of Tax Balance, end of period Operating Activities [Axis] Operating Activities [Axis] Operating Activities [Domain] Operating Activities [Domain] Hedged Item [Axis] Hedged Item [Axis] The asset or liability (or portion thereof) being hedged. Hedged Item [Domain] Hedged Item [Domain] [Domain] for The asset or liability (or portion thereof) being hedged. Natural gas inventory [Member] Natural gas inventory [Member] Natural gas inventory [Member] Borrowed gas [Member] Borrowed gas [Member] Borrowed gas [Member] Gas Imbalance Receivable [Member] Gas Imbalance Receivable [Member] Gas Imbalance Receivable [Member] Gas Imbalance Payable [Member] Gas Imbalance Payable [Member] Gas Imbalance Payable [Member] Non-utility Natural Gas Expense [Member] Income (Loss) from discontinued operations [Member] Income (Loss) from discontinued operations [Member] Gains (Losses) in Other Income (Expense) [Member] Nonoperating Income (Expense) [Member] Hedging Relationship [Axis] Hedging Relationship [Axis] Hedging Relationship [Domain] Hedging Relationship [Domain] Fair Value Hedging [Member] Fair Value Hedging [Member] CenterPoint Energy [Member] CenterPoint Energy [Member] Another company which is controlled, directly or indirectly, by its parent. The usual condition for control is ownership of a majority (over 50%) of the outstanding voting stock. The power to control may also exist with a lesser percentage of ownership, for example, by contract, lease, agreement with other stockholders or by court decree. Derivative Instrument [Axis] Energy Related Derivative [Member] Energy Related Derivative [Member] IDS Derivative [Member] IDS Derivative [Member] Derivative instrument related to indexed debt securities Position [Axis] Position [Axis] Position [Domain] Position [Domain] Long [Member] Long [Member] Hedging Designation [Axis] Hedging Designation [Axis] Hedging Designation [Domain] Hedging Designation [Domain] Not Designated as Hedging Instrument, Economic Hedge [Member] Not Designated as Hedging Instrument, Economic Hedge [Member] Designated as Fair Value Hedge [Member] Designated as Hedging Instrument [Member] Not Designated as Hedging Instrument [Member] Not Designated as Hedging Instrument [Member] Derivatives, Fair Value, by Balance Sheet Location [Axis] Balance Sheet Location [Axis] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Current Assets Held for Sale [Member] Current Assets Held for Sale [Member] Current Assets Held for Sale Non-current assets held for sale [Member] Non-current assets held for sale [Member] Non-current assets held for sale Current Liabilities [Member] Current Liabilities [Member] Line item in the statement of financial position in which the fair value amounts of the derivative instruments are included. Current liabilities held for sale [Member] Current liabilities held for sale [Member] Current liabilities held for sale [Member] Other Noncurrent Liabilities [Member] Other Noncurrent Liabilities [Member] Non-current liabilities held for sale [Member] Non-current liabilities held for sale [Member] Non-current liabilities held for sale Derivatives, Fair Value [Line Items] Derivatives, Fair Value [Line Items] Derivative Assets Fair Value Derivative Asset, Fair Value, Gross Asset Derivative Liabilities Fair Value Derivative Liability, Fair Value, Gross Liability Derivative gross volume notional amount (in Bcf) Derivative, Nonmonetary Notional Amount, Volume Derivative Asset Derivative Asset Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of Hedged Item Deferred (Gain) Loss on Discontinuation of Fair Value Hedge Gross Amounts Recognized Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement Gross Amounts Recognized Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement Gross Amounts Recognized Derivative, Fair Value, Net Gross Amounts Offset Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset Gross Amounts Offset Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset Gross Amounts Offset in the Consolidated Balance Sheets Derivative, Fair Value, Offsets, Net Total of gross amounts offset, net. Derivative Liability Derivative Liability Net amount presented in the consolidated balance sheets Derivative Assets (Liabilities), at Fair Value, Net Total amounts presented in the statements of income in which the effects of hedges are recorded Cost of Goods and Services Sold Change in unrealized gain (loss) on fair value hedging instruments Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments Amounts excluded from effectiveness testing recognized in earnings immediately Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net Gain (loss) on derivative instruments not designated as hedging instruments Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net Aggregate fair value of derivatives containing material adverse change provisions in a net liability position Derivative, Net Liability Position, Aggregate Fair Value Fair value of collateral already posted Collateral Already Posted, Aggregate Fair Value Additional collateral required to be posted if credit risk contingent features triggered Additional Collateral, Aggregate Fair Value Fair Value, Assets Measured on Recurring Basis [Table] Fair Value, Recurring and Nonrecurring [Table] Measurement Frequency [Axis] Measurement Frequency [Axis] Measurement Frequency [Domain] Measurement Frequency [Domain] Fair Value, Recurring [Member] Fair Value, Recurring [Member] Fair Value, Assets Measured on Recurring Basis, Disclosure Items [Axis] Fair Value Hierarchy and NAV [Axis] Fair Value, Assets Measured on Recurring Basis, Disclosure Items [Domain] Fair Value Hierarchy and NAV [Domain] Fair Value, Inputs, Level 1 [Member] Fair Value, Inputs, Level 1 [Member] Fair Value, Inputs, Level 2 [Member] Fair Value, Inputs, Level 2 [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Inputs, Level 3 [Member] Forward Contracts [Member] Forward Contracts [Member] Measurement Basis [Axis] Measurement Basis [Axis] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Portion at Fair Value Measurement [Member] Portion at Fair Value Measurement [Member] Carrying Amount [Member] Reported Value Measurement [Member] Fair Value [Member] Estimate of Fair Value Measurement [Member] Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair value inputs (price per MMBtu) Fair Value Inputs, Price Per MMBtu Fair value inputs used for valuing physical forward contracts using a discounted cash flow model, including illiquid forward price curve locations. Volumetrically Weighted Average, Price Per MMBtu Volumetrically Weighted Average, Price Per MMBtu Volumetrically Weighted Average, Price Per MMBtu Assets Assets, Fair Value Disclosure [Abstract] Corporate equities Fair Value Assets Measured On Recurring Basis Corporate Equities This element represents a certain statement of financial position asset caption which represents a class of assets, or which may include an individual asset, measured at fair value on a recurring basis. Investments, including money market funds (2) Investments, Fair Value Disclosure Derivative asset Derivative asset, netting adjustment Derivative assets Hedged portion of natural gas inventory (5) Fair Value Hedge Assets Assets, Fair Value Disclosure Assets, Fair Value Disclosure Total derivative assets, netting adjustment Derivative Asset, Fair Value, Gross Liability Liabilities Liabilities, Fair Value Disclosure [Abstract] Derivative liability Derivative liabilities, netting adjustment Fair Value Hedge Liabilities Fair Value Hedge Liabilities Derivative liabilities Financial Liabilities Fair Value Disclosure Financial Liabilities Fair Value Disclosure Total derivative liabilities, netting adjustment Derivative Liability, Fair Value, Gross Asset Derivative fair value offsets, net Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward] Beginning balance Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs Total gains (losses) Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Earnings Total settlements Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Settlements Transfers into Level 3 Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Transfers into Level 3 Transfers out of Level 3 Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Transfers out of Level 3 Ending balance (1) The amount of total gains for the period included in earnings attributable to the change in unrealized gains or losses relating to assets still held at the reporting date: Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss) Equity Method Investment, Other than Temporary Impairment Equity Method Investment, Other than Temporary Impairment Equity Method Investments, Fair Value Disclosure Equity Method Investments, Fair Value Disclosure Goodwill, Impairment Loss Goodwill, Impairment Loss Loss on assets held for sale Loss from reclassification to held for sale Loss from reclassification to held for sale Fair Value Of Disposal Group Fair Value Of Disposal Group Fair Value Of Disposal Group Estimated Fair Value of Financial Instruments Additional Fair Value Elements [Abstract] Long-term debt, including current maturities Long-term Debt, Fair Value Regulatory Assets and Liabilities, Other Disclosures [Abstract] Amount Allowed equity return recognized in period [Table Text Block] Schedule of allowed equity return recognized [Table Text Block] [Table Text Block] Schedule of allowed equity return recognized[Table] Commitments and Contingencies [Text Block] Commitments and Contingencies Disclosure [Text Block] Schedule of Subsequent Events [Table Text Block] Schedule of Subsequent Events [Table Text Block] Related Party Transactions [Abstract] Related Party Transactions (Houston Electric and CERC) [Text Block] Related Party Transactions Disclosure [Text Block] Contract Balances [Table] Contract Balances [Table] Contract Balances [Table] Contract Balances [Line Items] Contract Balances [Line Items] [Line Items] for Contract Balances [Table] Change in Accounts Receivable [Roll Forward] Change in Accounts Receivable [Roll Forward] Change in Accounts Receivable [Roll Forward] Opening balance as of December 31, 2019 Accounts Receivable for Contracts with Customers Accounts Receivable for Contracts with Customers Closing balance as of March 31, 2020 Increase (Decrease) in Accounts Receivable on Contracts with Customers Increase (Decrease) in Accounts Receivable on Contracts with Customers Increase (Decrease) in Accounts Receivable on Contracts with Customers Change in Other Accrued Unbilled Revenues [Roll Forward] Change in Other Accrued Unbilled Revenues [Roll Forward] Change in Other Accrued Unbilled Revenues [Roll Forward] Opening balance as of December 31, 2019 Unbilled Contracts Receivable Closing balance as of March 31, 2020 Increase (Decrease) in Unbilled Receivables Increase (Decrease) In Contract With Customer, Asset, Other Accrued Unbilled Receivables Increase (Decrease) In Contract With Customer, Asset, Other Accrued Unbilled Receivables Change in Contract Asset [Roll Forward] Change in Contract Asset [Roll Forward] Change in Contract Asset [Roll Forward] Opening balance as of December 31, 2019 Contract with Customer, Asset, Net, Current Closing balance as of March 31, 2020 Increase (Decrease) in Contract with Customer, Asset Increase (Decrease) in Contract with Customer, Asset Change in Contract Liability [Roll Forward] Change in Contract Liability [Roll Forward] Change in Contract Liability [Roll Forward] Opening balance as of December 31, 2019 Contract with Customer, Liability Closing balance as of March 31, 2020 Increase (Decrease) in Contract with Customer, Liability Increase (Decrease) in Contract with Customer, Liability Contract with Customer, Liability, Revenue Recognized Contract with Customer, Liability, Revenue Recognized Income Tax Disclosure [Abstract] Unusual Risk or Uncertainty, Nature [Axis] Unusual Risk or Uncertainty, Nature [Axis] Unusual Risk or Uncertainty, Nature [Domain] Unusual Risk or Uncertainty, Nature [Domain] Coronavirus Aid Relief And Economic Security Act [Member] Coronavirus Aid Relief And Economic Security Act [Member] Coronavirus Aid Relief And Economic Security Act (CARES) [Member] Continuing Operations [Member] Continuing Operations [Member] Interest expense deductible limitation Interest expense deductible limitation Interest expense deductible limitation prior to the enactment of the CARES Act Increase in expense deductible limitation Increase in expense deductible limitation Interest expense limitation percentage after increase from the enactment of the CARES Act Recognized tax benefit from changes in tax laws Recognized tax benefit from changes in tax laws Recognized tax benefit from changes in tax laws Effective income tax rate Effective Income Tax Rate Reconciliation, Percent Net uncertain tax liability Liability for Uncertainty in Income Taxes, Noncurrent Unrecognized Tax Benefits Decrease Unrecognized Tax Benefits, Period Increase (Decrease) Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations Statement of Financial Position [Abstract] Cash Flows from Operating Activities: Net Cash Provided by (Used in) Operating Activities, Continuing Operations [Abstract] Adjustments to reconcile net income (loss) to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Depreciation and amortization Depreciation and amortization on assets held for sale Depreciation and Amortization, Discontinued Operations Amortization of deferred financing costs Amortization of Debt Issuance Costs Amortization of intangible assets in non-utility cost of revenues Amortization of Intangible Assets Deferred income taxes Deferred Income Tax Expense (Benefit) Goodwill impairment and loss from reclassification to held for sale Goodwill impairment and loss from reclassification to held for sale Goodwill impairment and loss from reclassification to held for sale Goodwill Impairment Unrealized loss (gain) on marketable securities Marketable Securities, Unrealized Gain (Loss), Excluding Other-than-temporary Impairment Loss Loss (gain) on indexed debt securities Indexed Debt Securities, Gain (Loss) This item represents the net total realized and unrealized gain (loss) included in earnings for the period related to indexed debt securities. Write-down of natural gas inventory Inventory Write-down Equity in (earnings) losses of unconsolidated affiliates Distributions from unconsolidated affiliates Pension contributions Payment for Pension Benefits Changes in other assets and liabilities, excluding acquisitions: Increase (Decrease) in Operating Capital [Abstract] Accounts receivable and unbilled revenues, net Increase (Decrease) in Accounts and Other Receivables Accounts receivable/payable–affiliated companies Increase decrease in Accounts receivable payable affiliates The increase (decrease) in net accounts receivables and payables due to/from affiliates. Inventory Increase (Decrease) in Inventories Taxes receivable Increase (Decrease) in Income Taxes Receivable Accounts payable Increase (Decrease) in Accounts Payable Fuel cost recovery Increase (Decrease) in over (under) Energy Recovery Non-trading derivatives, net Increase (Decrease) in Derivative Assets and Liabilities Margin deposits, net Increase (Decrease) in Margin Deposits Outstanding Interest and taxes accrued Increase Decrease Interest and taxes accrued Increase (decrease) in interest and taxes accrued. Net regulatory assets and liabilities Increase (Decrease) in Regulatory Assets and Liabilities Other current assets Increase (Decrease) in Other Current Assets Other current liabilities Increase (Decrease) in Other Current Liabilities Other assets Increase (Decrease) in Other Noncurrent Assets Other liabilities Increase (Decrease) in Other Noncurrent Liabilities Other operating activities, net Other Operating Activities, Cash Flow Statement Net cash provided by operating activities from continuing operations Net Cash Provided by (Used in) Operating Activities Cash Flows from Investing Activities: Net Cash Provided by (Used in) Investing Activities, Continuing Operations [Abstract] Capital expenditures Payments to Acquire Productive Assets Acquisitions, net of cash acquired Payments to Acquire Businesses, Net of Cash Acquired Distributions from unconsolidated affiliate in excess of cumulative earnings Proceeds from Equity Method Investment, Distribution, Return of Capital Increase in notes receivable–affiliated companies Increase (Decrease) in Notes Receivable, Related Parties Other investing activities, net Payments for (Proceeds from) Other Investing Activities Net cash used in investing activities from continuing operations Net Cash Provided by (Used in) Investing Activities Cash Flows from Financing Activities: Net Cash Provided by (Used in) Financing Activities, Continuing Operations [Abstract] Proceeds from (payments of) commercial paper, net Proceeds from (Repayments of) Commercial Paper Proceeds from long-term debt, net Proceeds from Issuance of Long-term Debt Payments of long-term debt Repayments of Long-term Debt Proceeds from (Repayments of) Lines of Credit Proceeds from (Repayments of) Lines of Credit Increase (decrease) in notes payable–affiliated companies Increase (Decrease) in Notes Payable, Related Parties Dividend to parent Payments of Dividends Contribution from parent Proceeds from Contributions from Parent Debt issuance costs Payments of Debt Issuance Costs Payment of dividends on Common Stock Payments of Ordinary Dividends, Common Stock Payment of dividends on Preferred Stock Payments of Ordinary Dividends, Preferred Stock and Preference Stock Other financing activities, net Proceeds from (Payments for) Other Financing Activities Net cash provided by (used in) financing activities from continuing operations Net Cash Provided by (Used in) Financing Activities Net Decrease in Cash, Cash Equivalents and Restricted Cash Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect Cash, Cash Equivalents and Restricted Cash at Beginning of Period Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Cash, Cash Equivalents and Restricted Cash at End of Period Schedule of Money Pool Investment and Borrowing [Table Text Block] Schedule of Money Pool Investment and Borrowing [Table Text Block] [Table Text Block] for Tabular disclosure the investments and borrowing within the money pool activities. Related Party Transactions Disclosure [Text Block] Schedule of Related Party Transactions [Table Text Block] Schedule of Related Party Transactions [Table Text Block] Goodwill and Intangible Assets Disclosure [Abstract] Goodwill and Other Intangibles (CenterPoint Energy and CERC) [Text Block] Goodwill and Intangible Assets Disclosure [Text Block] Debt Disclosure [Abstract] Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Revolving Credit Facility [Member] Revolving Credit Facility [Member] Commercial Paper [Member] Commercial Paper [Member] Credit Facility [Axis] Credit Facility [Axis] Credit Facility [Domain] Credit Facility [Domain] Line of Credit [Member] Line of Credit [Member] Letter of Credit [Member] Letter of Credit [Member] Vectren [Member] Vectren [Member] Vectren [Member] VUHI [Member] VUHI [Member] VUHI [Member] VCC [Member] VCC [Member] Vectren Capital Corp Consolidated Entities [Axis] Consolidated Entities [Axis] Consolidated Entities [Domain] Consolidated Entities [Domain] Parent Company [Member] Parent Company [Member] SIGECO [Member] SIGECO [Member] SIGECO [Member] Variable Rate [Axis] Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] London Interbank Offered Rate (LIBOR) [Member] London Interbank Offered Rate (LIBOR) [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Debt Instruments [Abstract] Debt Instruments [Abstract] General mortgage bonds used as collateral General mortgage bonds used as collateral General mortgage bonds used as collateral Maturities of Long-term Debt [Abstract] Maturities of Long-term Debt [Abstract] Line of Credit Facility [Abstract] Line of Credit Facility [Abstract] Size of credit facility Line of Credit Facility, Maximum Borrowing Capacity Basis spread on LIBOR Debt Instrument, Basis Spread on Variable Rate Percentage on limitation of debt to total capitalization under covenant Percentage on limitation of debt to total capitalization under covenant (in hundredths) Percentage on limitation of debt to total capitalization under covenant. Ratio of indebtedness to net capital Ratio of Indebtedness to Net Capital Percentage on limitation of debt to total capitalization under covenant amended (in hundredths) Percentage on limitation of debt to total capitalization under covenant amended (in hundredths) Temporary increased percentage on limitation of debt to total capitalization under covenant (in hundredths) System restoration costs threshold for increase in permitted debt to EBITDA covenant ratio Restoration Cost Expected Cost The minimum amount of estimated restoration cost in a calendar year in order for a temporary increase in debt to EBITDA covenant Consecutive period for system restoration costs to exceed $100 million (in months) Consecutive Period for System Restoration Costs to Exceed $100 million (in months) Consecutive Period for System Restoration Costs to Exceed $100 million (in months) Credit facility swing line sublimit Credit facility swing line sublimit Credit facility swing line sublimit. Letters of credit swing line sublimit Letters of credit swing line sublimit Letters of credit swing line sublimit Long-term line of credit Long-term Line of Credit Weighted average interest rate of debt Debt, Weighted Average Interest Rate Number of days until commercial paper maturity Number of days until commercial paper maturity Number of days until commercial paper maturity. Schedule of Defined Benefit Plans Disclosures [Table Text Block] Schedule of Defined Benefit Plans Disclosures [Table Text Block] Benefit Plan Contributions [Table Text Block] Benefit Plan Contributions [Table Text Block] Benefit Plan Contributions [Table Text Block] Statement of Comprehensive Income [Abstract] Tax benefit (expense) on adjustment related to pension and postretirement plans Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax, Attributable to Parent Tax expense (benefit) on net deferred gain (loss) from cash flow hedges Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, Tax Tax expense (benefit) on reclassification of deferred (gain) loss from cash flow hedges realized in net income Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Tax Tax benefit (expense) on Other comprehensive loss from unconsolidated affiliates Tax benefit (expense) on Other Comprehensive lncome (loss) from unconsolidated affiliates Tax benefit (expense) on Other Comprehensive lncome (loss) from unconsolidated affiliates Short-term Borrowings and Long-term Debt [Text Block] Debt Disclosure [Text Block] Schedule of Line of Credit Facilities [Table Text Block] Schedule of Line of Credit Facilities [Table Text Block] Cover [Abstract] Entities [Table] Entities [Table] Common Stock, $0.01 Par Value [Member] Common Stock, $0.01 Par Value [Member] Common Stock, $0.01 Par Value [Member] Depositary shares [Member] Depositary shares [Member] Depositary shares representing a 1/20th interest in a share of 7.00% Series B Mandatory Convertible Preferred Stock. 9.15% First Mortgage Bonds due 2021 [Member] 9.15% First Mortgage Bonds due 2021 [Member] 9.15% First Mortgage Bonds due 2021 [Member] 6.95% General Mortgage Bonds due 2033 [Member] 6.95% General Mortgage Bonds due 2033 [Member] 6.95% General Mortgage Bonds due 2033 [Member] 6.625% Senior Notes due 2037 [Member] 6.625% Senior Notes due 2037 [Member] 6.625% Senior Notes due 2037 [Member] Entity Listings, Exchange [Axis] Entity Listings, Exchange [Axis] Exchange [Domain] Exchange [Domain] New York Stock Exchange [Member] New York Stock Exchange [Member] New York Stock Exchange [Member] Chicago Stock Exchange [Member] Chicago Stock Exchange [Member] Chicago Stock Exchange [Member] Entity Information [Line Items] Entity Information [Line Items] Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Entity Shell Company Entity Shell Company Entity Interactive Data Current Entity Interactive Data Current Trading Symbol Trading Symbol Title of 12(b) Security Title of 12(b) Security Security Exchange Name Security Exchange Name 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 Entity Current Reporting Status Entity Current Reporting Status Entity Small Business Entity Small Business Entity Emerging Growth Company Entity Emerging Growth Company Document Quarterly Report Document Quarterly Report Document Transition Report Document Transition Report Entity File Number Entity File Number Entity Tax Identification Number Entity Tax Identification Number Entity Address, Address Line One Entity Address, Address Line One Entity Address, City or Town Entity Address, City or Town Entity Address, State or Province Entity Address, State or Province Entity Address, Postal Zip Code Entity Address, Postal Zip Code City Area Code City Area Code Local Phone Number Local Phone Number Other comprehensive income (loss): Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract] Adjustment to pension and other postretirement plans, net of tax Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax and Reclassification Adjustment, Attributable to Parent Net deferred gain (loss) from cash flow hedges, net of tax Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax, Parent Reclassification of deferred loss from cash flow hedges realized in net income, net of tax Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax Other comprehensive loss from unconsolidated affiliates, net of tax Total Comprehensive Income Net of Tax Before Preferred Stock Dividend Comprehensive Income Net of Tax Before Preferred Stock Dividend Comprehensive Income Net of Tax Before Preferred Stock Dividend Preferred stock dividend requirement Preferred Stock Dividends and Other Adjustments Comprehensive income (loss) Comprehensive Income (Loss), Net of Tax, Attributable to Parent Cumulative preferred stock par value (in dollars per share) Preferred Stock, Par or Stated Value Per Share Common stock shares par value (in dollars per share) Common Stock, Par or Stated Value Per Share Cumulative preferred stock shares authorized (in shares) Preferred Stock, Shares Authorized Common stock shares authorized (in shares) Common Stock, Shares Authorized Common stock dividends declared per share Financial Instrument [Axis] Financial Instrument [Axis] Financial Instruments [Domain] Financial Instruments [Domain] AT&T Common [Member] AT&T Common [Member] Common stock of AT&T Inc. Charter Common [Member] Charter Common [Member] Charter Common [Member] Subordinated Debt ZENS [Member] Subordinated Debt ZENS Member Issued debt obligation as zero-premium exchangeable subordinated notes. Obligation is bifurcated between a debt component and an embedded derivative component. Exchangeable for cash at any time at the option of the holder, and as such are classified as a current portion of long-term debt. Balance of investment owned (in shares) Investment Owned, Balance, Shares Principal amount of debt issued Debt Instrument, Face Amount Outstanding debt balance Long-term Debt, Gross Subordinated note cash exchangeable percentage of fair value Subordinated Note Cash Exchangeable Percentage Of Fair Value The percentage of the fair value of the referenced TW Common shares attributable to each note and the percentage of composite fair value each note can be exchanged for cash. Debt Instrument, Interest Rate, Stated Percentage Debt Instrument, Interest Rate, Stated Percentage Target Annual Yield On Reference Shares Target Annual Yield On Reference Shares The target annual yield from interest and cash dividends on reference shares, before any adjustment to increase or decrease principal amount of subordinated note is made. Number of shares referenced in exchangeable subordinated note Number Of Shares Referenced In Exchangeable Subordinated Note Number of shares attributable to each note and referenced in determining the fair value of the cash to be exchange at behest of note holder. Contingent principal amount outstanding Debt Instrument Contingent Principal Amount Outstanding Amount of outstanding contingent principal under the zero premium exchangeable subordinated notes contract contingent principal clause. Earnings Per Share [Abstract] Award Type [Axis] Award Type [Axis] Award Type [Domain] Award Type [Domain] Restricted Stock [Member] Restricted Stock [Member] Amount of antidilutive shares excluded from computation of earnings per share Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Preferred Stock Dividends, Income Statement Impact Continuing Operations Numerator: Earnings Per Share, Basic and Diluted [Abstract] Income (loss) from continuing operations Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent Income (loss) available to common shareholders - basic Net Income (Loss) Available to Common Stockholders, Basic Income (Loss) available to common shareholders from continuing operations - diluted Net Income (Loss) Available to Common Stockholders, Diluted Denominator: Incremental Weighted Average Shares Attributable to Dilutive Effect [Abstract] Weighted average common shares outstanding - basic Weighted Average Number of Shares Outstanding, Basic Restricted stock (1) Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements Series B Preferred Stock (2) Incremental Common Shares Attributable to Dilutive Effect of Conversion of Preferred Stock Weighted average common shares outstanding - diluted Weighted Average Number of Shares Outstanding, Diluted Earnings (loss) per common share: Earnings Per Share, Basic [Abstract] Basic earnings (loss) per common share - continuing operations Income (Loss) from Continuing Operations, Per Basic Share Basic earnings (loss) per common share - discontinued operations Discontinued Operation, Income (Loss) from Discontinued Operation, Net of Tax, Per Basic Share Basic Earnings (Loss) Per Common Share Earnings Per Share, Basic Diluted earnings (loss) per common share - continuing operations Income (Loss) from Continuing Operations, Per Diluted Share Diluted earnings (loss) per common share - discontinued operations Discontinued Operation, Income (Loss) from Discontinued Operation, Net of Tax, Per Diluted Share Diluted Earnings (Loss) Per Common Share Earnings Per Share, Diluted New Accounting Pronouncements and Changes in Accounting Principles [Abstract] Schedule of New Accounting Pronouncements and Changes in Accounting Principles [Table Text Block] Schedule of New Accounting Pronouncements and Changes in Accounting Principles [Table Text Block] Earnings Per Share (CenterPoint Energy) [Text Block] Earnings Per Share [Text Block] New Accounting Pronouncements [Text Block] Description of New Accounting Pronouncements Not yet Adopted [Text Block] Fair Value Measurements [Text Block] Fair Value Disclosures [Text Block] Variable Interest Entity, Primary Beneficiary [Member] Variable Interest Entity, Primary Beneficiary [Member] Cumulative Preferred Stock [Member] Cumulative Preferred Stock [Member] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Accounts receivable, less bad debt reserve Accounts Receivable, after Allowance for Credit Loss, Current Bad debt reserve Accounts Receivable, Allowance for Credit Loss, Current Accrued Unbilled Revenues, Allowance for Credit Losses, Current Accrued Unbilled Revenues, Allowance for Credit Losses, Current Allowance for credit losses on accrued unbilled revenues Prepaid expenses and other current assets Prepaid Expense and Other Assets, Current Regulatory assets Regulatory Assets, Noncurrent Preferred stock par value (in dollars per share) Cumulative preferred stock authorized (in shares) Preferred stock aggregate liquidation preference Preferred Stock, Liquidation Preference, Value Preferred stock outstanding (in shares) Common stock par value (in dollars per share) Common stock authorized (in shares) Common stock outstanding (in shares) Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Organization, Consolidation and Presentation of Financial Statements [Abstract] Background and Basis of Presentation [Text Block] Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Schedule of Related Party Transactions, by Related Party [Table] Schedule of Related Party Transactions, by Related Party [Table] Balance Sheet Location [Axis] Accounts and notes receivable (payable) - affiliate companies [Member] Accounts and notes receivable (payable) - affiliate companies [Member] Accounts and notes receivable (payable) - affiliate companies [Member] Related Party Transaction [Axis] Related Party Transaction [Axis] Related Party Transaction [Domain] Related Party Transaction [Domain] Investments [Member] Investments [Member] Related Party [Axis] Related Party [Axis] Related Party [Domain] Related Party [Domain] Related Party Transaction [Line Items] Related Party Transaction [Line Items] Money Pool Borrowings Money Pool Borrowings Represents borrowings from the parent company's money pool. Money pool investments (borrowings) (1) MoneyPoolInvestments Represents investments in the parent company's money pool. Weighted average interest rate Money Pool Investments Weighted Average Interest Rate Weighted average interest rate of outstanding investments in money pool. Interest income (expense) (1) Interest Income (Expense) Net, Related Party Net interest income (expense) related to affiliate investments or borrowings Corporate service charges Related Party Transaction, Selling, General and Administrative Expenses from Transactions with Related Party Net affiliate service charges (billings) Net affiliate service charges (billings) Amount of net service charges from (billings to) related party during the period, excluding transactions that are eliminated in consolidated or combined financial statements. Cash dividends paid to parent Cash contribution from parent Equity [Text Block] Stockholders' Equity Note Disclosure [Text Block] Designated as Hedging Instrument [Member] Aggregate notional amount Derivative Liability, Notional Amount Weather hedges term Weather Hedges Term Period of time used as the basis for weather hedges entered into by the company. Discontinued Operations and Disposal Groups [Abstract] Held for Sale and Discontinued Operations (CenterPoint Energy and CERC) [Text Block] Disposal Groups, Including Discontinued Operations, Disclosure [Text Block] Equity Method Investments and Joint Ventures [Abstract] Equity Method Investments [Table Text Block] Equity Method Investments [Table Text Block] Employee Benefit Plans [Text Block] Pension and Other Postretirement Benefits Disclosure [Text Block] Schedule of Goodwill [Table Text Block] Schedule of Goodwill [Table Text Block] Schedule of Finite-Lived Intangible Assets [Table Text Block] Schedule of Finite-Lived Intangible Assets [Table Text Block] Finite-lived Intangible Assets Amortization Expense [Table Text Block] Finite-lived Intangible Assets Amortization Expense [Table Text Block] Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] Prepaid expenses and other current assets [Member] Prepaid Expenses and Other Current Assets [Member] Interest, net of capitalized interest Interest Paid, Excluding Capitalized Interest, Operating Activities Income tax refunds, net Income Taxes Paid, Net Accounts payable related to capital expenditures Capital Expenditures Incurred but Not yet Paid ROU assets obtained in exchange for lease liabilities (1) Right-of-Use Asset Obtained in Exchange for Operating Lease Liability Restricted cash Restricted Cash and Cash Equivalents Total cash, cash equivalents and restricted cash shown in Condensed Statements of Consolidated Cash Flows Revenue Recognition [Abstract] Cumulative Effect on Retained Earnings, before Tax Cumulative Effect on Retained Earnings, before Tax Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Disposal Groups, Including Discontinued Operations Balance Sheet [Table Text Block] Disposal Groups, Including Discontinued Operations Balance Sheet [Table Text Block] Disposal Groups, Including Discontinued Operations Balance Sheet [Table Text Block] Disposal Groups, Including Discontinued Operations [Table Text Block] Disposal Groups, Including Discontinued Operations [Table Text Block] Disposal Groups, Including Discontinued Operations Cash Flow [Table Text Block] Disposal Groups, Including Discontinued Operations Cash Flow [Table Text Block] Disposal Groups, Including Discontinued Operations Cash Flow [Table Text Block] Revenues: Revenues [Abstract] Utility revenues Regulated Operating Revenue Non-utility revenues Unregulated Operating Revenue Total Expenses: Costs and Expenses [Abstract] Utility natural gas, fuel and purchased power Utilities Operating Expense, Gas and Petroleum Purchased Non-utility cost of revenues, including natural gas Operation and maintenance Utilities Operating Expense, Maintenance, Operations, and Other Costs and Expenses Taxes other than income taxes Taxes, Miscellaneous Total Costs and Expenses Operating Income Operating Income (Loss) Other Income (Expense): Nonoperating Income (Expense) [Abstract] Gain (loss) on marketable securities Marketable Securities, Gain (Loss) Gain (loss) on indexed debt securities Gain (loss) on Indexed Debt Securities This item represents the net total realized and unrealized gain (loss) included in earnings for the period related to indexed debt securities. Interest expense and other finance charges Interest and Debt Expense Interest expense on Securitization Bonds Equity in earnings (loss) of unconsolidated affiliates, net Interest Income Other income (expense), net Other Nonoperating Income (Expense) Total Nonoperating Income (Expense) Income (Loss) from Continuing Operations before Income Taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Income (Loss) from Continuing Operations Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent Net Income (Loss) Income (Loss) Available to Common Shareholders Earnings Per Share, Diluted [Abstract] Earnings Per Share, Diluted [Abstract] Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Diluted Share [Abstract] Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Diluted Share [Abstract] Weighted Average Common Shares Outstanding, Basic Weighted Average Common Shares Outstanding, Diluted Reportable Business Segments [Text Block] Segment Reporting Disclosure [Text Block] Indexed Debt Securities (ZENS) and Securities Related to ZENS (CenterPoint Energy) [Text Block] Indexed Debt Securities [Text Block] This item represents the entire disclosure related to Indexed Debt Securities (ZENS) and Time Warner Securities. Long-term Purchase Commitment [Table Text Block] Long-term Purchase Commitment [Table Text Block] Schedule of Environmental Loss Contingencies by Site [Table Text Block] Schedule of Environmental Loss Contingencies by Site [Table Text Block] Partner Type [Axis] Partner Type [Axis] Partner Type of Partners' Capital Account, Name [Domain] Partner Type of Partners' Capital Account, Name [Domain] Enable GP, LLC [Member] Enable GP, LLC [Member] Enable GP, LLC [Member] Natural Gas Expenses [Member] Natural Gas Expenses [Member] Represents natural gas expenses, including transportation and storage costs. Common Units [Member] Series A Preferred Units [Member] Proliance Holdings LLC [Member] Proliance Holdings LLC [Member] Proliance Holdings LLC [Member] OGE [Member] OGE [Member] OGE [Member] Public unitholders [Member] Public unitholders [Member] Public unitholders [Member] Series A Preferred Units [Member] Enable Equity Summary [Abstract] Enable Equity Summary [Abstract] Enable Equity Summary [Abstract] Enable Partnership Interest [Abstract] Enable Partnership Interest [Abstract] Enable Partnership Interest [Abstract] Ownership percentage of equity method investment Equity Method Investment, Ownership Percentage Limited partner ownership interest Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage Enable Units [Abstract] Enable Units [Abstract] Enable Units [Abstract] Limited partner interest units held Equity Method Investment, Ownership, Shares Equity Method Investment, Ownership, Shares Limited partner interest units held Variable Interest Entity, Ownership, Shares Represents the number of shares owned of the variable interest entity as of the balance sheet date Preferred Units Held Preferred Units Held Represents the number of Series A Preferred Units held as of the balance sheet date. Preferred units – unconsolidated affiliate Cost Method Investments Percentage of sales that trigger right of first refusal Sale of Units, Percentage, Trigger Right of First Refusal Sale of more than this percentage of aggregated common and subordinated units owned are subject to mutual rights of first offer and first refusal. Management rights ownership percentage Management Rights Ownership Percentage Represents the percentage of management rights in the general partner of Enable Incentive Distribution Right, Percentage Incentive Distribution Right, Percentage Entity's interest in incentive distribution rights held by the general partner. Incentive distribution per unit Incentive Distribution, Distribution Per Unit Maximum incentive distribution right Incentive Distribution Right, Maximum Maximum additional incentive right to the general partner with quarterly distribution per unit exceeding $0.330625 Enable Distributions [Abstract] Enable Distributions [Abstract] Enable Distributions [Abstract] Distribution per share of common units Distribution per share of common units Per share or per unit amount of distributions received from an equity method investment. Distributions received from Enable cost method investment Distribution per share of Series A preferred units Distribution per share of Series A preferred units Per share or per unit amount of distributions received from Enable Series A preferred units cost method investment. Total distributions received from Enable Total distributions received from Enable Represents the total amount of distributions received related to both equity method investments and cost method investments from Enable. Transactions with Enable [Abstract] Transactions with Enable [Abstract] Transactions with Enable [Abstract] Natural gas expenses, includes transportation and storage costs Related Party Transaction, Purchases from Related Party Accounts payable for natural gas purchases from Enable Accounts Payable, Related Parties, Current Equity Method Investment, Summarized Financial Information, Gross Profit (Loss) [Abstract] Equity Method Investment, Summarized Financial Information, Gross Profit (Loss) [Abstract] Operating revenues Equity Method Investment, Summarized Financial Information, Revenue Cost of sales, excluding depreciation and amortization Equity Method Investment, Summarized Financial Information, Cost of Sales Depreciation and amortization Equity Method Investment Summarized Financial Information Depreciation And Amortization The amount of the depreciation and amortization reported by an equity method investment of the entity. Equity Method Investment, Summarized Financial Information, Impairment of Goodwill and Long-Lived Assets Equity Method Investment, Summarized Financial Information, Impairment of Goodwill and Long-Lived Assets The amount of impairment of goodwill and long-lived assets reported by an equity method investment of the entity. Operating income Equity Method Investment, Summarized Financial Information, Operating Income (Loss) The amount of operating income (loss) reported by an equity method investment of the entity. Net income attributable to Enable common units Equity Method Investment, Summarized Financial Information, Net Income (Loss) CenterPoint Energy’s interest Equity Method Investment, Gross Equity In Earnings (Losses) This represents the gross equity in earnings (losses) of equity method investment, excluding any basis difference. Basis difference amortization (1) Basis Difference Accretion Gain Basis Difference Accretion Gain Dilution Loss, Equity Method Investment Dilution Loss, Equity Method Investment Dilution Loss, Equity Method Investment Impairment of CenterPoint Energy’s equity method investment in Enable Equity in earnings of unconsolidated affiliate, net Equity Method Investment, Summarized Financial Information, Assets and Liabilities [Abstract] Equity Method Investment, Summarized Financial Information, Assets [Abstract] Current assets Equity Method Investment, Summarized Financial Information, Current Assets Non-current assets Equity Method Investment, Summarized Financial Information, Noncurrent Assets Current liabilities Equity Method Investment, Summarized Financial Information, Current Liabilities Non-current liabilities Equity Method Investment, Summarized Financial Information, Noncurrent Liabilities Non-controlling interest Equity Method Investment, Summarized Financial Information, Noncontrolling Interest Preferred equity Equity Method Investment, Summarized Financial Information, Preferred Equity Amount of preferred equity attributable to the equity method investment of the entity. Accumulated other comprehensive loss Equity Method Investment Summarized Financial Information Accumulated Other Comprehensive Income Loss EquityMethodInvestmentSummarizedFinancialInformationAccumulatedOtherComprehensiveIncomeLoss Enable partners’ equity Equity Method Investment, Summarized Financial Information, Equity Excluding Noncontrolling Interests Equity Method Investment, Difference Between Carrying Amount and Underlying Equity [Abstract] Equity Method Investment, Difference Between Carrying Amount and Underlying Equity [Abstract] CenterPoint Energy’s ownership interest in Enable partners’ equity Equity Method Investment, Underlying Equity in Net Assets CenterPoint Energy’s basis difference (1) Equity Method Investment, Basis Difference This represents the basis difference of an equity method investment. Investment in unconsolidated affiliates Equity Method Investments Distribution Made to Limited Partner, Distributions Declared, Per Unit Regulatory Asset [Axis] Regulatory Asset [Axis] Regulatory Asset [Domain] Regulatory Asset [Domain] Rate case expense [Member] Rate case expense [Member] Rate case expense [Member] Public Utilities, Regulatory Proceeding [Axis] Public Utilities, Regulatory Proceeding [Axis] Public Utilities, Regulatory Proceeding [Domain] Public Utilities, Regulatory Proceeding [Domain] CenterPoint Energy Houston Electric 2019 Rate Case [Member] CenterPoint Energy Houston Electric 2019 Rate Case [Member] CenterPoint Energy Houston Electric 2019 Rate Case [Member] Houston electric stipulation and settlement agreement [Member] Houston electric stipulation and settlement agreement [Member] Houston electric stipulation and settlement agreement [Member] Amount of allowed equity return not recognized in the period Amount Of Allowed Equity Return Not Recognized In Period Amount Of Allowed Equity Return Not Recognized In Period Amount Of Allowed Equity Return Recognized In Period Amount Of Allowed Equity Return Recognized In Period Amount of allowed equity return on the true-up balance that was recognized in the period Requested revenue increase Public Utilities, Requested Rate Increase (Decrease), Amount Return on Equity Public Utilities, Requested Return on Equity, Percentage Debt Capital Structure Public Utilities, Requested Debt Capital Structure, Percentage Equity Capital Structure Public Utilities, Requested Equity Capital Structure, Percentage Unprotected excess deferred income tax Unprotected excess deferred income tax Unprotected excess deferred income tax resulting from the TCJA Rate case expense Subsequent Events (CenterPoint Energy) [Text Block] Subsequent Events [Text Block] Schedule of Goodwill [Table] Schedule of Goodwill [Table] Reporting Unit [Axis] Reporting Unit [Axis] Reporting Unit [Domain] Reporting Unit [Domain] Depreciation and amortization expense [Member] Depreciation and amortization expense [Member] Depreciation and amortization expense [Member] Non-utility cost of revenues [Member] Cost of Sales [Member] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Customer Relationships [Member] Customer Relationships [Member] Trade Names [Member] Trade Names [Member] Construction Backlog [Member] Order or Production Backlog [Member] Operation and maintenance agreements [Member] Operation and maintenance agreements [Member] Operation and maintenance agreements [Member] Other [Member] Other Intangible Assets [Member] Goodwill [Line Items] Goodwill [Line Items] Goodwill Goodwill Goodwill, Fair Value Disclosure Goodwill, Fair Value Disclosure Finite-Live Intangible Assets [Abstract] Finite-Lived Intangible Assets, Net [Abstract] Intangible assets gross carrying amount Finite-Lived Intangible Assets, Gross Intangible assets accumulated amortization Finite-Lived Intangible Assets, Accumulated Amortization Net intangible assets Finite-Lived Intangible Assets, Net Amortization of Intangible Assets Finite-Lived Intangible Assets Amortization Expense Maturity Schedule [Abstract] Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract] Remaining nine months of 2020 Finite-Lived Intangible Assets, Amortization Expense, Remainder of Fiscal Year 2021 Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months 2022 Finite-Lived Intangible Assets, Amortization Expense, Year Two 2023 Finite-Lived Intangible Assets, Amortization Expense, Year Three 2024 Finite-Lived Intangible Assets, Amortization Expense, Year Four 2025 Finite-Lived Intangible Assets, Amortization Expense, Year Five Unconsolidated Affiliate (CenterPoint Energy and CERC) [Text Block] Equity Method Investments and Joint Ventures Disclosure [Text Block] Supplemental Disclosure of Cash Flow Information [Text Block] Cash Flow, Supplemental Disclosures [Text Block] Disposal Groups, Including Discontinued Operations [Table] Disposal Groups, Including Discontinued Operations [Table] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Deferred Tax Liabilities, Net Deferred Tax Liabilities, Parent's Basis in Discontinued Operation Loss from reclassification to held for sale Cost to sell Disposal Group, Including Discontinued Operation, Other Expense Deferred Tax Asset Deferred Tax Asset, Parent's Basis in Discontinued Operation Disposal Group, Including Discontinued Operation, Balance Sheet Disclosures [Abstract] Disposal Group, Including Discontinued Operation, Balance Sheet Disclosures [Abstract] Receivables, net Disposal Group, Including Discontinued Operation, Accounts, Notes and Loans Receivable, Net Accrued unbilled revenues Disposal Group, Including Discontinued Operation, Accrued Unbilled Revenues Disposal Group, Including Discontinued Operation, Accrued Unbilled Revenues Natural gas inventory Disposal Group, Including Discontinued Operation, Inventory, Current Materials and supplies Disposal Group, Including Discontinued Operation, Materials and Supplies Disposal Group, Including Discontinued Operation, Materials and Supplies Non-trading derivative assets Disposal Group, Including Discontinued Operation, Non-trading derivative assets Disposal Group, Including Discontinued Operation, Non-trading derivative assets Property, plant and equipment, net Disposal Group, Including Discontinued Operation, Property, Plant and Equipment, Current Goodwill Disposal Group, Including Discontinued Operation, Goodwill, Current Loss on assets held for sale Loss on assets held for sale Loss recognized on discontinued operations classified as held for sale Other Disposal Group, Including Discontinued Operation, Other Assets, Current Total current assets held for sale Disposal Group, Including Discontinued Operation, Assets, Current Property, plant and equipment, net Disposal Group, Including Discontinued Operation, Property, Plant and Equipment, Noncurrent Goodwill Disposal Group, Including Discontinued Operation, Goodwill, Noncurrent Non-trading derivative assets Disposal Group, Including Discontinued Operation, Non-trading derivative assets, non-current Disposal Group, Including Discontinued Operation, Non-trading derivative assets, non-current Other Disposal Group, Including Discontinued Operation, Other Assets, Noncurrent Total non-current assets held for sale Disposal Group, Including Discontinued Operation, Assets, Noncurrent Total assets held for sale Disposal Group, Including Discontinued Operation, Assets Accounts payable Disposal Group, Including Discontinued Operation, Accounts Payable Taxes accrued Disposal Group, Including Discontinued Operation, Accrued Income Tax Payable Non-trading derivative liabilities Disposal Group, Discontinued Operation, Non-trading derivative liabilities Disposal Group, Discontinued Operation, Non-trading derivative liabilities Benefit obligations Disposal Group, Including Discontinued Operation, Pension Plan Benefit Obligation, Current Other Disposal Group, Including Discontinued Operation, Other Liabilities, Current Total current liabilities held for sale Disposal Group, Including Discontinued Operation, Liabilities, Current Non-trading derivative liabilities Disposal Group, Including Discontinued Operation, Non-trading derivative liabilities, non-current Disposal Group, Including Discontinued Operation, Non-trading derivative liabilities, non-current Benefit obligations Disposal Group, Including Discontinued Operation, Pension Plan Benefit Obligation, Noncurrent Other Disposal Group, Including Discontinued Operation, Other Liabilities, Noncurrent Total non-current liabilities held for sale Disposal Group, Including Discontinued Operation, Liabilities, Noncurrent Total liabilities held for sale Disposal Group, Including Discontinued Operation, Liabilities Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract] Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract] Revenues Disposal Group, Including Discontinued Operation, Revenue Non-utility cost of revenues Disposal Group, Including Discontinued Operation, Costs of Goods Sold Operation and maintenance Disposal Group, Including Discontinued Operation, Operation and Maintenance Expense The amount of operating expenses for the period that are associated with the discontinued operation's normal revenue producing operation; including selling, general, and administrative expenses, costs incurred for routine plant repairs and maintenance, and operations. Depreciation and amortization Disposal Group, Including Discontinued Operation, Depreciation and Amortization Taxes other than income taxes Disposal Group, Including Discontinued Operation, Taxes Other than Income Taxes Disposal Group, Including Discontinued Operation, Taxes Other than Income Taxes Total Disposal Group, Including Discontinued Operation, Operating Expense Income (loss) from Discontinued Operations before income taxes Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax Loss from reclassification to held for sale Loss from reclassification to held for sale, including impairment Loss from reclassification to held for sale, including impairment Income tax expense (benefit) Discontinued Operation, Alternative Cash Flow Information [Abstract] Discontinued Operation, Alternative Cash Flow Information [Abstract] Depreciation and Amortization Amortization of intangible assets in Non-utility cost of revenues Amortization of intangible assets, discontinued operations Amortization of intangible assets, discontinued operations Write-down of natural gas inventory Inventory Write-down, discontinued operations Inventory Write-down, discontinued operations Capital expenditures Capital Expenditure, Discontinued Operations Accounts payable related to capital expenditures Accounts payable related to capital expenditures, discontinued operations Accounts payable related to capital expenditures, discontinued operations Discontinued Operation, Continuing Involvement [Abstract] Discontinued Operation, Continuing Involvement [Abstract] Transportation revenue Discontinued Operation, Intra-Entity Amounts, Discontinued Operation after Disposal, Revenue Natural gas expense Discontinued Operation, Intra-Entity Amounts, Discontinued Operation after Disposal, Expense Pipeline construction and repair services charges Discontinued Operation, Intra-Entity Amounts, Discontinued Operation after Disposal, Pipeline construction and repair charges Discontinued Operation, Intra-Entity Amounts, Discontinued Operation after Disposal, Pipeline construction and repair charges Pipeline construction and repair services capitalized Discontinued operation, Capitalized fees Represents fees incurred from discontinued operations and capitalized. Regulatory Accounting [Text Block] Public Utilities Disclosure [Text Block] Number of states in which entity operates Number of States in which Entity Operates Preferred units held Revenue expected to be recognized Revenue, Remaining Performance Obligation, Amount 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] Expected timing of satisfaction, period Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period Current Assets: Assets, Current [Abstract] Investment in marketable securities Marketable Securities, Current Accounts and notes receivable, less bad debt reserve Accounts and Financing Receivable, after Allowance for Credit Loss Accounts and notes receivable–affiliated companies Due from Related Parties, Current Accrued unbilled revenues, less bad debt reserve Unbilled Receivables, Current Natural gas inventory Energy Related Inventory, Natural Gas in Storage Materials and supplies Public Utilities, Inventory Materials and supplies Inventory, Raw Materials and Supplies, Gross Taxes receivable Income Taxes Receivable, Current Current assets held for sale Total current assets Assets, Current Property, Plant and Equipment: Property, Plant and Equipment [Abstract] Property, plant and equipment Property, Plant and Equipment, Gross Less: accumulated depreciation and amortization Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Property, plant and equipment, net Property, Plant and Equipment, Net Other Assets: AssetsNoncurrentOtherThanPropertyPlantAndEquipment [Abstract] AssetsNoncurrentOtherThanPropertyPlantAndEquipment [Abstract] Goodwill Total non-current assets held for sale Other Other Assets, Noncurrent Total other assets AssetsNoncurrentOtherThanPropertyPlantAndEquipment Sum of the carrying amounts as of the balance sheet date of assets that are expected to be realized in cash, sold or consumed after one year or beyond the normal operating cycle, if longer, excluding property, plant and equipment. Total Assets Current Liabilities: Liabilities, Current [Abstract] Current portion of VIE Securitization Bonds long-term debt Transition And System Restoration Bonds Long Term Debt Current Long-term transition and system restoration bonds are securitization bonds issued to recover qualified stranded costs and qualified storm recovery costs. This represents the current portion. Indexed debt, net Indexed Debt Current Current portion of other long-term debt Other Long-term Debt, Current Indexed debt securities derivative Indexed debt securities derivative Accounts payable Accounts Payable, Current Accounts and notes payable–affiliated companies Due to Related Parties, Current Taxes accrued Taxes Payable, Current Interest accrued Interest Payable, Current Customer deposits Contract with Customer, Liability, Current Non-trading derivative liabilities Derivative Liability, Current Current liabilities held for sale Other Other Liabilities, Current Total current liabilities Liabilities, Current Other Liabilities: Liabilities, Noncurrent [Abstract] Deferred income taxes, net Deferred Income Tax Liabilities, Net Non-trading derivative liabilities Derivative Liability, Noncurrent Benefit obligations Liability, Defined Benefit Plan, Noncurrent Regulatory liabilities Regulatory Liability, Noncurrent Total non-current liabilities held for sale Other Other Liabilities, Noncurrent Total other liabilities Liabilities, Other than Long-term Debt, Noncurrent Long-term Debt: Long-term Debt, Excluding Current Maturities [Abstract] VIE Securitization Bonds, net Transition And System Restoration Bonds Long Term Debt Non Current Carrying value as of the balance sheet date of transition and system restoration bond debt (with maturities initially due after one year or beyond the operating cycle if longer), excluding current portion. Other long-term debt, net Other Long-term Debt, Noncurrent Total long-term debt, net Long-term Debt, Excluding Current Maturities Commitments and Contingencies (Note 14) Commitments and Contingencies Shareholders’ Equity: Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Cumulative preferred stock, $0.01 par value, 20,000,000 shares authorized Cumulative Preferred Stock Represents the caption on the face of the balance sheet represent total cumulative preferred stock presented in detail within the Shareholder's Equity section. Preferred Stock, $0.01 par value Preferred Stock, Value, Issued Common stock Common Stock, Value, Issued Additional paid-in capital Additional Paid in Capital Retained earnings (accumulated deficit) Retained Earnings (Accumulated Deficit) Accumulated other comprehensive income (loss) Accumulated Other Comprehensive Income (Loss), Net of Tax Total shareholders’ equity Total Liabilities and Shareholders’ Equity Liabilities and Equity Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block] Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block] Fair Value of Derivative Instruments [Table Text Block] Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block] Offsetting of Natural Gas Derivative Assets and Liabilities [Table Text Block] Derivative Instruments, Offsetting Assets and Liabilities [Table Text Block] Tabular disclosure of derivative assets and liabilities that are subject to offsetting, including master netting arrangements. Income Statement Impact of Derivative Activity [Table Text Block] Derivative Instruments, Gain (Loss) [Table Text Block] Disclosure of Credit Derivatives [Table Text Block] Disclosure of Credit Derivatives [Table Text Block] Schedule of Segment Reporting Information, by Segment [Table Text Block] Schedule of Segment Reporting Information, by Segment [Table Text Block] Schedule of Revenue by Major Customers by Reporting Segments [Table Text Block] Schedule of Revenue by Major Customers by Reporting Segments [Table Text Block] Income Taxes [Text Block] Income Tax Disclosure [Text Block]