Long-term Purchase Commitment [Table Text Block] Long-term Purchase Commitment [Table Text Block] Other comprehensive income (loss): Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract] Commitments and Contingencies [Text Block] Commitments and Contingencies Disclosure [Text Block] Related Party [Axis] Related Party [Axis] Series A Preferred Stock [Member] Series A Preferred Units [Member] Series A Preferred Stock [Member] Interest expense and other finance charges Interest and Debt Expense Other comprehensive income (loss) from unconsolidated affiliates OCI, Equity Method Investment, after Tax 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 Preferred units – unconsolidated affiliate Cost Method Investments Liabilities and Equity [Abstract] Liabilities and Equity [Abstract] Statistical Measurement [Domain] Statistical Measurement [Domain] 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] Preferred Stock [Member] Series A Preferred Units [Member] Preferred Stock [Member] Security Exchange Name Security Exchange Name Debt Instrument, Initial Interest Rate, Stated Percentage Debt Instrument, Initial Interest Rate, Stated Percentage Debt Instrument, Initial Interest Rate, Stated Percentage 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 Change in Accounts Receivable [Roll Forward] Change in Accounts Receivable [Roll Forward] Change in Accounts Receivable [Roll Forward] Proceeds from long-term debt, net Proceeds from Issuance of Long-term Debt Capital expenditures Capital Expenditure, Discontinued Operations Total current liabilities Current liabilities Liabilities, Current Prepaid expenses and other current assets Prepaid Expense and Other Assets, Current Variable Rate [Domain] Variable Rate [Domain] Assets [Abstract] Assets [Abstract] Investment, Name [Axis] Investment, Name [Axis] Issuances related to benefit and investment plans Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture Accounts and notes payable–affiliated companies Due to Related Parties, Current 9.15% First Mortgage Bonds due 2021 [Member] 9.15% First Mortgage Bonds due 2021 [Member] 9.15% First Mortgage Bonds due 2021 [Member] Chicago Stock Exchange [Member] Chicago Stock Exchange [Member] Chicago Stock Exchange [Member] Lease Income Lease Income Natural gas expenses, including transportation and storage costs Property, plant and equipment from parent Related Party Transaction, Purchases from Related Party 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] CenterPoint Energy’s basis difference (1) Equity Method Investment, Basis Difference This represents the basis difference of an equity method investment. Undistributed earnings allocated to preferred shareholders (1) Undistributed Earnings (Loss) Allocated to Participating Securities, Basic Change in Other Accrued Unbilled Revenues [Roll Forward] Change in Other Accrued Unbilled Revenues [Roll Forward] Change in Other Accrued Unbilled Revenues [Roll Forward] Guarantor obligations, maximum exposure, undiscounted Guarantor Obligations, Maximum Exposure, Undiscounted Preferred Stock, $0.01 par value Preferred Stock, Value, Issued Diluted earnings (loss) per common share - continuing operations Income (Loss) from Continuing Operations, Per Diluted Share Management rights ownership percentage Management Rights Ownership Percentage Represents the percentage of management rights in the general partner of Enable Regulatory liabilities Regulatory Liability, Noncurrent Diluted earnings (loss) per common share - discontinued operations Discontinued Operation, Income (Loss) from Discontinued Operation, Net of Tax, Per Diluted Share Common Stock, Par or Stated Value Per Share Common Stock, Par or Stated Value Per Share Benefit Plan Contributions [Table Text Block] Benefit Plan Contributions [Table Text Block] Benefit Plan Contributions [Table Text Block] Other Other Liabilities, Noncurrent Operating Activities [Axis] Operating Activities [Axis] Investment in marketable securities Marketable Securities, Current Percentage Reduction of Dividend or Distribution Amount Percentage Reduction of Dividend or Distribution Amount Percentage Reduction of Dividend or Distribution Amount Accrued unbilled revenues, less bad debt reserve Unbilled Receivables, Current VCC [Member] VCC [Member] Vectren Capital Corp Measurement Frequency [Domain] Measurement Frequency [Domain] Net income (loss) Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest CenterPoint Energy Houston Electric 2019 Rate Case [Member] CenterPoint Energy Houston Electric 2019 Rate Case [Member] CenterPoint Energy Houston Electric 2019 Rate Case [Member] Current portion of other long-term debt Other Long-term Debt, Current Statement [Line Items] Statement [Line Items] Class of Stock [Domain] Class of Stock [Domain] Statement [Table] Statement [Table] Statistical Measurement [Axis] Statistical Measurement [Axis] Interest cost (2) Defined Benefit Plan, Interest Cost Preferred equity Equity Method Investment, Summarized Financial Information, Preferred Equity Amount of preferred equity attributable to the equity method investment of the entity. 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 Interest Income Interest Income, Other Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax Loss from reclassification to held for sale Loss on assets held for sale Loss from reclassification to held for sale Loss from reclassification to held for sale Entity Small Business Entity Small Business 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 Ratio of indebtedness to net capital Ratio of Indebtedness to Net Capital Long-term Debt [Text Block] Debt Disclosure [Text Block] Fair Value, Assets Measured on Recurring Basis, Disclosure Items [Domain] Fair Value Hierarchy and NAV [Domain] Revenues Disposal Group, Including Discontinued Operation, Revenue First Mortgage [Member] First Mortgage [Member] Cost of sales, excluding depreciation and amortization Cost of Revenue Estimated capital expenditure to clean ash ponds Estimated capital expenditure to clean ash ponds Estimated Capital Expenditure to Clean Ash Ponds Amendment Flag Amendment Flag Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Reclassification of deferred loss from cash flow hedges realized in net income Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax Measurement Frequency [Axis] Measurement Frequency [Axis] Total non-current liabilities held for sale Total non-current liabilities held for sale Disposal Group, Including Discontinued Operation, Liabilities, Noncurrent Series B Preferred Stock [Member] Series B Preferred Stock [Member] Financial Instruments [Domain] Financial Instruments [Domain] Estimated fair value of financial instruments, debt instruments [Table Text Block] Fair Value, by Balance Sheet Grouping [Table Text Block] Expected return on plan assets (2) Defined Benefit Plan, Expected Return (Loss) on Plan Assets 2024 Purchase Obligation, to be Paid, Year Four Fair Value Measurement [Domain] Fair Value Measurement [Domain] Increase in short-term borrowings, net Proceeds from Short-term Debt Natural gas expense Discontinued Operation, Intra-Entity Amounts, Discontinued Operation after Disposal, Expense Accounts payable related to capital expenditures Capital Expenditures Incurred but Not yet Paid Subsequent Events (CenterPoint Energy) [Text Block] Subsequent Events [Text Block] Write-down of natural gas inventory Inventory Write-down, discontinued operations Inventory Write-down, discontinued operations Bad debt reserve Accounts Receivable, Allowance for Credit Loss, Current Interest expense on Securitization Bonds Interest on Transition and System Restoration Bonds Interest and debt related expenses associated with transition and system restoration bonds. Income Statement Location [Domain] Income Statement Location [Domain] Accounts payable related to capital expenditures Accounts payable related to capital expenditures, discontinued operations Accounts payable related to capital expenditures, discontinued operations 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. Unprotected excess deferred income tax Unprotected excess deferred income tax Unprotected excess deferred income tax resulting from the TCJA Preferred Stock Incremental Common Shares Attributable to Dilutive Effect of Conversion of Preferred Stock Unusual Risk or Uncertainty, Nature [Domain] Unusual Risk or Uncertainty, Nature [Domain] Exchange [Domain] Exchange [Domain] Other Other Assets, Noncurrent CenterPoint Energy’s ownership interest in Enable partners’ equity Equity Method Investment, Underlying Equity in Net Assets Financial Liabilities Fair Value Disclosure Financial Liabilities Fair Value Disclosure Benefit obligations Disposal Group, Including Discontinued Operation, Pension Plan Benefit Obligation, Noncurrent Income (Loss) from Continuing Operations Income (loss) from continuing operations Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent Total Assets Assets Assets Related Party Transactions (Houston Electric and CERC) [Text Block] Related Party Transactions Disclosure [Text Block] Maximum incentive distribution right Incentive Distribution Right, Maximum Maximum additional incentive right to the general partner with quarterly distribution per unit exceeding $0.330625 Public Utilities, Regulatory Proceeding [Axis] Public Utilities, Regulatory Proceeding [Axis] Construction Backlog [Member] Order or Production Backlog [Member] Amortization of prior service cost (2) Defined Benefit Plan, Amortization of Prior Service Cost (Credit) Infrastructure Services Disposal Group [Member] Infrastructure Services [Member] Infrastructure Services Disposal Group [Member] Infrastructure Services Disposal Group [Member] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Investments, Debt and Equity Securities [Abstract] Investments, Debt and Equity Securities [Abstract] Other Disposal Group, Including Discontinued Operation, Other Liabilities, Noncurrent Non-utility cost of revenues [Member] Cost of Sales [Member] Environmental Remediation Site [Domain] Environmental Remediation Site [Domain] Other [Member] Other Intangible Assets [Member] 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 Net uncertain tax liability Liability for Uncertainty in Income Taxes, Noncurrent Retirement Plan Type [Axis] Retirement Plan Type [Axis] 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. 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 Schedule of Related Party Transactions, by Related Party [Table] Schedule of Related Party Transactions, by Related Party [Table] 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 2025 Purchase Obligation, to be Paid, Year Five Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Fair Value, Inputs, Level 1 [Member] Fair Value, Inputs, Level 1 [Member] Inventory Increase (Decrease) in Inventories Weighted average interest rate of debt Debt, Weighted Average Interest Rate Environmental Improvement Revenue Bonds, Mount Vernon, 0.875%, Series 2015 [Member] Environmental Improvement Revenue Bonds, Mount Vernon, 0.875%, Series 2015 [Member] Environmental Improvement Revenue Bonds, Mount Vernon, 0.875%, Series 2015 Number of states in which entity operates Number of States in which Entity Operates Preferred Units by Name [Axis] Preferred Units by Name [Axis] Regulatory Agency [Axis] Regulatory Agency [Axis] Additional Paid-in Capital [Member] Additional Paid-in Capital [Member] Income allocated to preferred shareholders Total income allocated to preferred shareholders Preferred Stock Dividends and Other Adjustments Gains (Losses) in Other Income (Expense) [Member] Nonoperating Income (Expense) [Member] Other operating activities, net Other Operating Activities, Cash Flow Statement 2022 Purchase Obligation, to be Paid, Year Two Basic earnings (loss) per common share - continuing operations Income (Loss) from Continuing Operations, Per Basic Share Accrued unbilled revenues Disposal Group, Including Discontinued Operation, Accrued Unbilled Revenues Disposal Group, Including Discontinued Operation, Accrued Unbilled Revenues Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Non-trading derivative assets Disposal Group, Including Discontinued Operation, Non-trading derivative assets Disposal Group, Including Discontinued Operation, Non-trading derivative assets Common Stock, Shares, Outstanding Balance, beginning of period Balance, end of period Common Stock, Shares, Outstanding Investment in unconsolidated affiliates Equity Method Investments Income Tax Disclosure [Abstract] Income Tax Disclosure [Abstract] Loss on dilution, net of proportional basis difference recognition Dilution Loss, Equity Method Investment Dilution Loss, Equity Method Investment Revolving Credit Facility [Member] Revolving Credit Facility [Member] Schedule of Goodwill [Table] Schedule of Goodwill [Table] Income (Loss) from Continuing Operations before Income Taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest ERCOT Loan, COVID-19 ERP ERCOT Loan, COVID-19 ERP ERCOT Loan, COVID-19 ERP Number of days until commercial paper maturity Number of days until commercial paper maturity Number of days until commercial paper maturity. Acquisitions, net of cash acquired Payments to Acquire Businesses, Net of Cash Acquired Common Stock, Shares Authorized Common Stock, Shares Authorized Quarterly cash distribution, date of record Distribution Made to Limited Partner, Date of Record Restricted stock (4) Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements Years to resolve contingency Site Contingency, Years to Resolve Contingency This represents the estimated years necessary to resolve the contingency. Property, plant and equipment Property, Plant and Equipment, Gross Schedule of Segment Reporting Information, by Segment [Table Text Block] Schedule of Segment Reporting Information, by Segment [Table Text Block] Income Statement [Abstract] Income Statement [Abstract] AOCI Attributable to Parent [Member] AOCI Attributable to Parent [Member] Incentive distribution per unit Incentive Distribution, Distribution Per Unit Equity Method Investment's Impairment on an equity method investment Equity Method Investment's Impairment on an equity method investment Enable's Impairment on an equity method investment (Southeast Supply Header) SESH Second Quarter 2019 [Member] Second Quarter 2019 [Member] Second Quarter 2019 [Member] Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Variable Interest Entity, Primary Beneficiary [Member] Variable Interest Entity, Primary Beneficiary [Member] Disposal Groups, Including Discontinued Operations [Table] Disposal Groups, Including Discontinued Operations [Table] 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] Basis difference amortization (1) Basis Difference Accretion Gain Basis Difference Accretion Gain 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. Consolidated Entities [Axis] Consolidated Entities [Axis] 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. Finite-Lived Intangible Assets Amortization Expense Maturity Schedule [Abstract] Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract] Consolidation Items [Domain] Consolidation Items [Domain] 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. Goodwill and Other Intangibles (CenterPoint Energy and CERC) [Text Block] Goodwill and Intangible Assets Disclosure [Text Block] Accounts and notes receivable–affiliated companies Due from Related Parties, Current Guarantee exposure replaced by third party Guarantee exposure replaced by third party Guarantee exposure replaced by third party Property, Plant and Equipment: Property, Plant and Equipment [Abstract] Common Stock, Capital Shares Reserved for Future Issuance Common Stock, Capital Shares Reserved for Future Issuance Convertible Preferred Stock, Shares Issued upon Conversion Convertible Preferred Stock, Shares Issued upon Conversion Property, plant and equipment, net Disposal Group, Including Discontinued Operation, Property, Plant and Equipment, Noncurrent Equity in earnings (loss) of unconsolidated affiliates, net Equity in (earnings) losses of unconsolidated affiliates Equity in earnings of unconsolidated affiliate, net Equity in earnings from investment in Enable Income (Loss) from Equity Method Investments Indiana Gas Service Territory [Member] Indiana Gas Service Territory [Member] Represents the areas in Indiana serviced by Indiana Gas Service Hedging Designation [Axis] Hedging Designation [Axis] Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] 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 Receivables, net Disposal Group, Including Discontinued Operation, Accounts, Notes and Loans Receivable, Net Entity [Domain] Entity [Domain] Enable Midstream Partners [Member] Enable Midstream Partners [Member] Enable Midstream Partners, LP Discontinued Operation, Additional Disclosures [Abstract] Discontinued Operation, Additional Disclosures [Abstract] Goodwill [Line Items] Goodwill [Line Items] Contribution from parent Cash contribution from parent Proceeds from Contributions from Parent Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Pension contributions Payment for Pension Benefits Limited Partners' Capital Account, Class [Domain] Limited Partners' Capital Account, Class [Domain] Restricted cash Restricted Cash and Cash Equivalents Subsegments Consolidation Items [Axis] Subsegments Consolidation Items [Axis] Other current assets Increase (Decrease) in Other Current Assets Restricted Stock [Member] Restricted Stock [Member] Consolidated Entities [Domain] Consolidated Entities [Domain] Dividends, Distributions, Change [Domain] Dividends, Distributions, Change [Domain] [Domain] for Dividends, Distributions, Change [Axis] Recognized tax benefit from changes in tax laws, CARES act Recognized tax benefit from changes in tax laws Recognized tax benefit from changes in tax laws 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 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 Discontinued Operation, Alternative Cash Flow Information [Abstract] Discontinued Operation, Alternative Cash Flow Information [Abstract] Income Statement Impact of Derivative Activity [Table Text Block] Derivative Instruments, Gain (Loss) [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] Fair Value Measurements [Text Block] Fair Value Disclosures [Text Block] Regulatory assets Rate case expense Regulatory Assets, Noncurrent Limited partner ownership interest Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage Derivatives, Fair Value [Line Items] Derivatives, Fair Value [Line Items] Name of Major Customer [Domain] Customer [Domain] Current assets held for sale Total current assets held for sale Disposal Group, Including Discontinued Operation, Assets, Current 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. Common Stock, $0.01 Par Value [Member] Common Stock, $0.01 Par Value [Member] Common Stock, $0.01 Par Value [Member] Preferred stock aggregate liquidation preference Preferred Stock, Liquidation Preference, Value Entity Registrant Name Entity Registrant Name 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) Subsequent Event Type [Domain] Subsequent Event Type [Domain] Assets Assets, Fair Value Disclosure [Abstract] Non-current assets Assets, Noncurrent Estimated remediation costs for the Minnesota sites Site Contingency Loss Exposure Estimate of the reasonably possible loss exposure at an individual site. Discontinued Operation, Continuing Involvement [Abstract] Discontinued Operation, Continuing Involvement [Abstract] Payment of dividends on Common Stock Payments of Ordinary Dividends, Common Stock Receivable from sale of disposal group Receivable from sale of disposal group Receivable for working capital and other adjustments from sale of disposal group Remaining three months of 2020 Purchase Obligation, to be Paid, Remainder of Fiscal Year Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Record Date Dividends Payable, Date of Record Dividends Payable, Date of Record Preferred stock dividend requirement Preferred stock dividend requirement Preferred Stock Dividends, Income Statement Impact Preferred Stock dividends declared (see Note 19) Total dividends paid Dividends, Preferred Stock, Cash Shares Issued, Price Per Share Shares Issued, Price Per Share Contract Balances [Line Items] Contract Balances [Line Items] [Line Items] for Contract Balances [Table] Adjustments for New Accounting Pronouncements [Axis] Accounting Standards Update [Axis] Preferred Stock, Convertible, Conversion Limit Preferred Stock, Convertible, Conversion Limit Preferred Stock, Convertible, Conversion Limit Decrease (increase) in notes receivable–affiliated companies Increase (Decrease) in Notes Receivable, Related Parties Entity Address, Postal Zip Code Entity Address, Postal Zip Code Depreciation and amortization Disposal Group, Including Discontinued Operation, Depreciation and Amortization Goodwill Goodwill Goodwill Quarterly increase of fee received for retained CES guarantee exposure Annualized fee received for retained CES obligation guarantees Annualized fee received for retained CES obligation guarantees Total Net current period other comprehensive income (loss) Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Proceeds from (payments of) commercial paper, net Proceeds from (Repayments of) Commercial Paper Dividends declared per share Common Stock, Dividends, Per Share, Declared Principal amount of debt issued Principal amount of debt issued Debt Instrument, Face Amount VUHI [Member] VUHI [Member] VUHI [Member] Decrease in notes payable–affiliated companies Increase (Decrease) in Notes Payable, Related Parties Schedule of Goodwill [Table Text Block] Schedule of Goodwill [Table Text Block] Equity [Abstract] Equity [Abstract] Corporate service charges Related Party Transaction, Selling, General and Administrative Expenses from Transactions with Related Party Assets, Fair Value Disclosure Assets, Fair Value Disclosure Preferred Units, Class [Domain] Preferred Units, Class [Domain] Divestitures (CenterPoint Energy and CERC) [Text Block] Disposal Groups, Including Discontinued Operations, Disclosure [Text Block] Customer deposits Contract with Customer, Liability, Current Entities [Table] Entities [Table] 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] Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] Derivative Contract Type [Domain] Derivative Contract [Domain] Weighted Average Common Shares Outstanding, Diluted Weighted average common shares outstanding - diluted Weighted Average Number of Shares Outstanding, Diluted Letter of Credit [Member] Letter of Credit [Member] Variable rate term loan [Member] Variable rate term loan [Member] Variable rate term loan [Member] Debt Disclosure [Abstract] Debt Disclosure [Abstract] Operation and maintenance Utilities Operating Expense, Maintenance, Operations, and Other Costs and Expenses First Quarter 2020 [Member] First Quarter 2020 [Member] First Quarter 2020 [Member] Other Disposal Group, Including Discontinued Operation, Other Liabilities, Current Net cash provided by (used in) financing activities from continuing operations Net Cash Provided by (Used in) Financing Activities Payments of long-term debt Repayments of Long-term Debt Revenue expected to be recognized Revenue, Remaining Performance Obligation, Amount New Accounting Pronouncements and Changes in Accounting Principles [Abstract] Accounting Standards Update and Change in Accounting Principle [Abstract] Payment of dividends on Preferred Stock Payments of Ordinary Dividends, Preferred Stock and Preference Stock Minnesota and Indiana Gas Service Territories [Member] Minnesota and Indiana Gas Service Territories [Member] Minnesota and Indiana Gas Service Territories Common stock Common Stock, Value, Issued Document Fiscal Year Focus Document Fiscal Year Focus Tax expense Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent 2022 Finite-Lived Intangible Asset, Expected Amortization, Year Two Entity Current Reporting Status Entity Current Reporting Status Fair value of goodwill Goodwill, Fair Value Disclosure Related Party Transaction [Axis] Related Party Transaction [Axis] 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] Estimated Remaining Exposure Estimated Remaining Exposure Estimated Remaining Exposure Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Cash and Cash Equivalents, at Carrying Value Operation and maintenance agreements [Member] Operation and maintenance agreements [Member] Operation and maintenance agreements [Member] Total long-term debt, net Long-term Debt, Excluding Current Maturities Segment Reporting [Abstract] Segment Reporting [Abstract] Debt Instrument [Line Items] Debt Instrument [Line Items] Preferred Stock Dividends and Other Adjustments [Abstract] Preferred Stock Dividends and Other Adjustments [Abstract] Total shareholders’ equity Balance, beginning of period Balance, end of period Enable partners’ equity Stockholders' Equity Attributable to Parent Amortization of intangible assets in Non-utility cost of revenues Amortization of intangible assets, discontinued operations Amortization of intangible assets, discontinued operations Maximum contractual exposure under Securities Purchase Agreement Discontinued Operation, Amounts of Material Contingent Liabilities Remaining Weighted average interest rate Money Pool Investments Weighted Average Interest Rate Weighted average interest rate of outstanding investments in money pool. Entity Address, City or Town Entity Address, City or Town Fair Value, Assets Measured on Recurring Basis, Disclosure Items [Axis] Fair Value Hierarchy and NAV [Axis] Financial Instrument [Axis] Financial Instrument [Axis] Type of Adoption [Domain] Accounting Standards Update [Domain] Non-trading derivative liabilities Disposal Group, Discontinued Operation, Non-trading derivative liabilities Disposal Group, Discontinued Operation, Non-trading derivative liabilities Return on Equity Public Utilities, Requested Return on Equity, Percentage Limited partner interest units held Equity Method Investment, Ownership, Shares Equity Method Investment, Ownership, Shares 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. 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 Accrued Unbilled Revenues, Allowance for Credit Losses, Current Accrued Unbilled Revenues, Allowance for Credit Losses, Current Allowance for credit losses on accrued unbilled revenues Dividend to parent Cash dividends paid to parent Payments of Dividends Other assets Increase (Decrease) in Other Noncurrent Assets Money pool investments (borrowings) (1) Money Pool Investments Represents investments in the parent company's money pool. 2023 Finite-Lived Intangible Asset, Expected Amortization, Year Three Total assets held for sale Disposal Group, Including Discontinued Operation, Assets Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block] Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block] Debt Capital Structure Public Utilities, Requested Debt Capital Structure, Percentage Other Other Liabilities, Current Investment, Name [Domain] Investment, Name [Domain] Other comprehensive income (loss) Other Comprehensive Income (Loss), Net of Tax Regulatory Asset [Axis] Regulatory Asset [Axis] Accounts payable for natural gas purchases from Enable Accounts Payable, Related Parties, Current Taxes other than income taxes Taxes, Miscellaneous Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Total current assets Current assets Assets, Current Corporate and Other [Member] Corporate and Other [Member] Earnings Per Share [Abstract] Earnings Per Share [Abstract] Increase in defined benefit plan, plan assets Defined Benefit Plan, Plan Assets, Period Increase (Decrease) Long-term Debt: Long-term Debt, Excluding Current Maturities [Abstract] 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. Prior service cost (2) Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, before Tax Change in Contract Liability [Roll Forward] Change in Contract Liability [Roll Forward] Change in Contract Liability [Roll Forward] Disposal Group Name [Domain] Disposal Group Name [Domain] 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. Net deferred tax liabilities on sale recognized as deferred income tax benefit by CenterPoint Energy Disposal Group, Including Discontinued Operation, Deferred Tax Liabilities 2025 Finite-Lived Intangible Asset, Expected Amortization, Year Five Energy Related Derivative [Member] Energy Related Derivative [Member] Document Fiscal Period Focus Document Fiscal Period Focus Third Quarter 2019 Third Quarter 2019 [Member] Third Quarter 2019 Total contributions to the plans during the period Defined Benefit Plan, Plan Assets, Contributions by Employer Environmental Improvement Revenue Bonds, Warrick County, 0.875%, Series 2015 [Member] Environmental Improvement Revenue Bonds, Warrick County, 0.875%, Series 2015 [Member] Environmental Improvement Revenue Bonds, Warrick County, 0.875%, Series 2015 Debt Instrument, Redemption Price, Percentage Debt Instrument, Redemption Price, Percentage Entity Filer Category Entity Filer Category Houston electric stipulation and settlement agreement [Member] Houston electric stipulation and settlement agreement [Member] Houston electric stipulation and settlement agreement [Member] Common Stock [Member] Common Units [Member] Common Stock [Member] 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 Distributions from unconsolidated affiliate in excess of cumulative earnings Proceeds from Equity Method Investment, Distribution, Return of Capital Net regulatory assets and liabilities Increase (Decrease) in Regulatory Assets and Liabilities Other, net [Member] Other Nonoperating Income (Expense) [Member] Total other assets Assets Non current Other Than Property Plant And Equipment 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. Debt Instrument, Interest Rate, Stated Percentage Interest rate of debt Debt Instrument, Interest Rate, Stated Percentage Total contributions expected in current year Defined Benefit Plan, Expected Future Employer Contributions, Current Fiscal Year Quarterly cash distribution, declaration date Distribution Made to Limited Partner, Declaration Date Expected timing of satisfaction, period Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period Schedule of Related Party Transactions [Table Text Block] Schedule of Related Party Transactions [Table Text Block] Earnings Per Share, Diluted [Abstract] Diluted Earnings (Loss) Per Common Share Earnings Per Share, Diluted [Abstract] 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. Total Nonoperating Income (Expense) Loss Contingency, Nature [Domain] Loss Contingency, Nature [Domain] Distribution Made to Limited Partner, Distributions Declared, Per Unit Quarterly cash distribution declared per share Distribution Made to Limited Partner, Distributions Declared, Per Unit Expenses: Costs and Expenses [Abstract] Subsequent Events [Abstract] Subsequent Events [Abstract] Derivative liability Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement Subsegments Consolidation Items [Domain] Subsegments Consolidation Items [Domain] Adoption of ASU 2016-13 Effect Of Adoption Of New Accounting Standard Effect of adoption o a new accounting standard 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. 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. Taxes accrued Disposal Group, Including Discontinued Operation, Accrued Income Tax Payable Interest, net of capitalized interest Interest Paid, Excluding Capitalized Interest, Operating Activities Background and Basis of Presentation [Text Block] Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Rate case expense [Member] Rate case expense [Member] Rate case expense [Member] Additional paid-in capital Additional Paid in Capital 2021 Finite-Lived Intangible Asset, Expected Amortization, Year One Total Revenues Operating revenues Revenues Class of Stock [Axis] Class of Stock [Axis] Income tax payments, net Income Taxes Paid, Net Proceeds from divestitures (Note 3) Cash proceeds from sale Proceeds from Divestiture of Businesses 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] Gain (loss) on classification to held for sale, net (2) Gain (Loss) on Sale of Assets and Asset Impairment Charges Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, Tax Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, Tax Other comprehensive income (loss) from unconsolidated affiliates OCI, Equity Method Investment, before Tax Proceeds from issuance of Series C Preferred Stock, net Proceeds from Issuance of Preferred Stock and Preference Stock Diluted Earnings (Loss) Per Common Share Earnings Per Share, Diluted General mortgage bonds used as collateral General mortgage bonds used as collateral General mortgage bonds used as collateral Reclassification of net deferred losses from cash flow hedges Other Comprehensive Income (Loss), Cash Flow Hedge Gain (Loss) Reclassification To Regulatory Asset After Tax Reclassification of net deferred loss from cash flow hedges net of tax to regulatory assets or regulatory liabilities Fair Value Of Disposal Group Fair Value Of Disposal Group Fair Value Of Disposal Group Schedule of Stock by Class [Table] Schedule of Stock by Class [Table] Gain on marketable securities Marketable Securities, Gain (Loss) Pipeline construction and repair services capitalized Discontinued operation, Capitalized fees Represents fees incurred from discontinued operations and capitalized. Entity Address, Address Line One Entity Address, Address Line One Entity Emerging Growth Company Entity Emerging Growth Company Deferred income taxes Deferred Income Tax Expense (Benefit) Derivative Liabilities Fair Value Derivative Liability, Fair Value, Gross Liability 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. COVID-19 ERP Regulatory Liability COVID-19 ERP Regulatory Liability COVID-19 ERP Regulatory Liability Intangible assets accumulated amortization Finite-Lived Intangible Assets, Accumulated Amortization Maximum [Member] Maximum [Member] Preferred Stock, Shares Authorized Preferred Stock, Shares Authorized SIGECO 2020 First Mortgage Bonds Remarketing, 0.875%, Series 2015 [Member] SIGECO 2020 First Mortgage Bonds Remarketing, 0.875%, Series 2015 [Member] SIGECO 2020 First Mortgage Bonds Remarketing, 0.875%, Series 2015 Common Stock dividends declared (see Note 19) Total dividends paid Dividends, Common Stock, Cash Effective income tax rate Effective Income Tax Rate Reconciliation, Percent 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] Taxes receivable Increase (Decrease) in Income Taxes Receivable Other Postretirement Benefits Plan [Member] Other Postretirement Benefits Plan [Member] Trading Symbol Trading Symbol Public unitholders [Member] Public unitholders [Member] Public unitholders [Member] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table Text Block] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table Text Block] Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Consolidation and Presentation of Financial Statements [Abstract] Credit facility swing line sublimit Credit facility swing line sublimit Credit facility swing line sublimit. Other Assets: AssetsNoncurrentOtherThanPropertyPlantAndEquipment [Abstract] AssetsNoncurrentOtherThanPropertyPlantAndEquipment [Abstract] Incentive Distribution Right, Percentage Incentive Distribution Right, Percentage Entity's interest in incentive distribution rights held by the general partner. Entity Shell Company Entity Shell Company Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Fair Value, Recurring [Member] Fair Value, Recurring [Member] Regulatory Agency [Domain] Regulatory Agency [Domain] Document Type Document Type Other income (expense), net Other Nonoperating Income (Expense) Cost to sell Disposal Group, Including Discontinued Operation, Other Expense Proliance Holdings LLC [Member] Proliance Holdings LLC [Member] Proliance Holdings LLC [Member] Transportation revenue Discontinued Operation, Intra-Entity Amounts, Discontinued Operation after Disposal, Revenue Current tax expense (benefit) of cash taxes payable upon sale Current tax expense (benefit) of cash taxes payable upon sale Current tax expense (benefit) recognized as a result of the cash taxes payable upon sale of business Segments [Axis] Segments [Axis] Employee Benefit Plans [Text Block] Retirement Benefits [Text Block] Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Fair Value, Inputs, Level 3 [Member] Fair Value, Inputs, Level 3 [Member] Write-down of natural gas inventory Inventory Write-down Sales price of outstanding equity interests Sales price of outstanding equity interests Sales price of outstanding equity interests Line of Credit [Member] Line of Credit [Member] Other liabilities Increase (Decrease) in Other Noncurrent Liabilities Deferred income taxes, net Deferred Income Tax Liabilities, Net Derivative Instruments [Text Block] Derivative Instruments and Hedging Activities Disclosure [Text Block] Fuel cost recovery Increase (Decrease) in over (under) Energy Recovery Accounts receivable and unbilled revenues, net Increase (Decrease) in Accounts and Other Receivables Operating Income Operating income Operating Income (Loss) Payment of debt issuance costs Payments of Debt Issuance Costs 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 Regulatory Assets and Liabilities, Other Disclosures [Abstract] Regulatory Assets and Liabilities, Other Disclosures [Abstract] Other long-term debt, net Other Long-term Debt, Noncurrent Cumulative Preferred Stock Cumulative Preferred Stock [Member] Contract with Customer, Asset and Liability [Table Text Block] Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block] 2026 and beyond Purchase Obligation, to be Paid, after Year Five Variable Rate [Axis] Variable Rate [Axis] Indexed debt securities derivative Indexed debt securities derivative Commitments and Contingencies (Note 14) Commitments and Contingencies Equity Method Investment, Difference Between Carrying Amount and Underlying Equity [Abstract] Equity Method Investment, Difference Between Carrying Amount and Underlying Equity [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. Taxes accrued Taxes Payable, Current Entity Address, State or Province Entity Address, State or Province Schedule of Defined Benefit Plans Disclosures [Table Text Block] Schedule of Defined Benefit Plans Disclosures [Table Text Block] Accounts payable Accounts Payable, Current Retained earnings (accumulated deficit) Retained Earnings (Accumulated Deficit) Materials and supplies Public Utilities, Inventory Period [Domain] Period [Domain] [Domain] for Period of the transaction occurred [Axis] Shareholders’ Equity: Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Aggregate notional amount Derivative Liability, Notional Amount Major Customers [Axis] Customer [Axis] Gain (loss) on derivative instruments not designated as hedging instruments Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net Hedging Designation [Domain] Hedging Designation [Domain] 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. Other investing activities, net Payments for (Proceeds from) Other Investing Activities Natural gas inventory Energy Related Inventory, Natural Gas in Storage Houston Electric [Member] Houston Electric [Member] Houston Electric [Member] 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. Asset retirement obligation Asset Retirement Obligation Performance guarantee obligations outstanding face amount Performance guarantee obligations outstanding face amount Face amount of individual surety bonds the wholly-owned subsidiary has outstanding Revenue from contracts Revenue from Contract with Customer, Excluding Assessed Tax Unusual Risk or Uncertainty, Nature [Axis] Unusual Risk or Uncertainty, Nature [Axis] Business Acquisition [Axis] Business Acquisition [Axis] Settlement cost (2) (3) Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan Disclosure [Line Items] Equity Method Investments, Fair Value Disclosure Equity Method Investments, Fair Value Disclosure Common Units [Member] Common Units [Member] Common Units [Member] Continuing Operations Numerator: Earnings Per Share, Basic and Diluted [Abstract] Interest accrued Interest Payable, Current Opening balance as of December 31, 2019 Closing balance as of September 30, 2020 Accounts Receivable for Contracts with Customers Accounts Receivable for Contracts with Customers 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 Credit Facility [Axis] Credit Facility [Axis] Series C preferred stock Preferred Stock, Shares Issued 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. Non-trading derivative liabilities Derivative Liability, Noncurrent Accumulated Other Comprehensive Income (Loss) [Roll Forward] Accumulated Other Comprehensive Income (Loss) [Roll Forward] Accumulated Other Comprehensive Income (Loss) [Roll Forward] 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 SIGECO [Member] SIGECO [Member] SIGECO [Member] Revenue Recognition [Abstract] Revenue Recognition [Abstract] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] AT&T Common [Member] AT&T Common [Member] Common stock of AT&T Inc. Proceeds from issuance of Common Stock, net Proceeds from Issuance of Common Stock Proceeds from Issuance of Common Stock Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] CERC Senior notes 4.50% due 2021 [Member] CERC Senior notes 4.50% due 2021 [Member] CERC Senior notes 4.50% due 2021 Non-utility cost of revenues Disposal Group, Including Discontinued Operation, Costs of Goods Sold 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 6.625% Senior Notes due 2037 [Member] 6.625% Senior Notes due 2037 [Member] 6.625% Senior Notes due 2037 [Member] Long-term line of credit Long-term Line of Credit Accounts and notes receivable (payable) - affiliate companies [Member] Accounts and notes receivable (payable) - affiliate companies [Member] Accounts and notes receivable (payable) - affiliate companies [Member] Repayments of Debt Repayments of Debt Total other liabilities Liabilities, Other than Long-term Debt, Noncurrent Equity Method Investments [Table Text Block] Equity Method Investments [Table Text Block] Net cash provided by operating activities from continuing operations Net Cash Provided by (Used in) Operating Activities Entity Central Index Key Entity Central Index Key Related Party [Domain] Related Party [Domain] Dividends, Distributions, Change [Axis] Dividends, Distributions, Change [Axis] Dividends, Distributions, Change [Axis] Related Party Transaction [Line Items] Related Party Transaction [Line Items] Derivative Instrument [Axis] Derivative Instrument [Axis] Derivative Instrument [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Other Noncurrent Liabilities [Member] Other Noncurrent Liabilities [Member] Schedule of Finite-Lived Intangible Assets [Table Text Block] Schedule of Finite-Lived Intangible Assets [Table Text Block] Contract Balances [Table] Contract Balances [Table] Contract Balances [Table] Total liabilities held for sale Disposal Group, Including Discontinued Operation, Liabilities Materials and supplies Disposal Group, Including Discontinued Operation, Materials and Supplies Disposal Group, Including Discontinued Operation, Materials and Supplies Senior Notes [Member] Senior Notes [Member] Supplemental Disclosure of Cash Flow Information [Text Block] Cash Flow, Supplemental Disclosures [Text Block] Utility natural gas, fuel and purchased power Utilities Operating Expense, Gas and Petroleum Purchased Taxes receivable Income Taxes Receivable, Current Segments [Domain] Reporting Segment [Domain] Segments [Domain] Line of Credit Facility [Abstract] Line of Credit Facility [Abstract] Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax, Attributable to Parent Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax, Attributable to Parent Schedule of Line of Credit Facilities [Table Text Block] Schedule of Line of Credit Facilities [Table Text Block] Income Statement Location [Axis] Income Statement Location [Axis] Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Amortization of intangible assets in non-utility cost of revenues Amortization of Intangible Assets Amortization of Intangible Assets Investments [Member] Investments [Member] 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. Enable Partnership Interest [Abstract] Enable Partnership Interest [Abstract] Enable Partnership Interest [Abstract] Unconsolidated Affiliates (CenterPoint Energy and CERC) [Text Block] Equity Method Investments and Joint Ventures Disclosure [Text Block] Reportable Business Segments [Text Block] Segment Reporting Disclosure [Text Block] Issuances of stock, net of issuance costs Stock Issued During Period, Value, New Issues Quarterly cash distribution, distribution date Distribution Made to Limited Partner, Distribution Date Schedule of Environmental Loss Contingencies by Site [Table Text Block] Schedule of Environmental Loss Contingencies by Site [Table Text Block] Non-trading derivative liabilities Derivative Liability, Current Title of 12(b) Security Title of 12(b) Security Income (loss) from Discontinued Operations before income taxes Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax Net intangible assets Finite-Lived Intangible Assets, Net Affiliates of Vistra Energy Corp. [Member] Affiliates of Vistra Energy Corp. [Member] Affiliates of Vistra Energy Corp. [Member] Enable Distributions [Abstract] Enable Distributions [Abstract] Enable Distributions [Abstract] Depreciation and amortization Depreciation and amortization Depreciation, Depletion and Amortization Preferred Stock, Liquidation Preference Per Share Preferred Stock, Liquidation Preference Per Share Discontinued Operations [Member] CES natural gas related transactions [Member] Discontinued Operations [Member] Schedule of New Accounting Pronouncements and Changes in Accounting Principles [Table Text Block] Accounting Standards Update and Change in Accounting Principle [Table Text Block] Environmental Remediation Site [Axis] Environmental Remediation Site [Axis] 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. 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. Supplemental Cash Flow Elements [Abstract] Supplemental Cash Flow Elements [Abstract] New York Stock Exchange [Member] New York Stock Exchange [Member] New York Stock Exchange [Member] Contract with Customer, Liability, Revenue Recognized Contract with Customer, Liability, Revenue Recognized Income (Loss) Available to Common Shareholders Net income attributable to Enable common units Income (loss) available to common shareholders from continuing operations - basic and diluted Net Income (Loss) Available to Common Stockholders, Basic Fair Value, Assets Measured on Recurring Basis [Table] Fair Value, Recurring and Nonrecurring [Table] Accounts payable Increase (Decrease) in Accounts Payable Basic earnings (loss) per common share - discontinued operations Discontinued Operation, Income (Loss) from Discontinued Operation, Net of Tax, Per Basic Share Dividends paid per share Common Stock, Dividends, Per Share, Cash Paid Depreciation and amortization expense [Member] Depreciation and amortization expense [Member] Depreciation and amortization expense [Member] Debt Instrument [Axis] Debt Instrument [Axis] 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. Change in Contract Asset [Roll Forward] Change in Contract Asset [Roll Forward] Change in Contract Asset [Roll Forward] Partner Type [Axis] Partner Type [Axis] Second Quarter 2020 [Member] Second Quarter 2020 [Member] Second Quarter 2020 [Member] Operating Segments [Member] Operating Segments [Member] Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Class of Stock [Line Items] Class of Stock [Line Items] Derivative liabilities Derivative Liability Opening balance as of December 31, 2019 Closing balance as of September 30, 2020 Unbilled Contracts Receivable 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] Revenue from Contract with Customer [Abstract] Revenue from Contract with Customer [Abstract] Depreciation and amortization on assets held for sale Depreciation and Amortization Depreciation and Amortization, Discontinued Operations Operating Activities [Domain] Operating Activities [Domain] Entity Information [Line Items] Entity Information [Line Items] Margin deposits, net Increase (Decrease) in Margin Deposits Outstanding Utility revenues Regulated Operating Revenue Loss Contingency Nature [Axis] Loss Contingency Nature [Axis] Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract] Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract] Subsequent Event [Member] Subsequent Event [Member] Total Disposal Group, Including Discontinued Operation, Operating Expense 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. Proceeds from Issuance of Convertible Preferred Stock Proceeds from Issuance of Convertible Preferred Stock Affiliates of NRG Energy, Inc. [Member] Affiliates of NRG Energy, Inc. [Member] Affiliates of NRG Energy, Inc. [Member] Fair Value [Member] Estimate of Fair Value Measurement [Member] 2024 Finite-Lived Intangible Asset, Expected Amortization, Year Four PreferredStockSharesToBeConvertedToCommon PreferredStockSharesToBeConvertedToCommon PreferredStockSharesToBeConvertedToCommon Current Assets: Assets, Current [Abstract] Cash Flows from Investing Activities: Net Cash Provided by (Used in) Investing Activities, Continuing Operations [Abstract] Purchase Obligations Purchase Obligation, Fiscal Year Maturity [Abstract] Investments, including money market funds (1) Investments, Fair Value Disclosure Comprehensive income (loss) Comprehensive Income (Loss), Net of Tax, Attributable to Parent Preferred Stock, Convertible, Conversion Price Preferred Stock, Convertible, Conversion Price Preferred Stock, Convertible, Conversion Price Preferred stock par value (in dollars per share) Preferred Stock, Par or Stated Value Per Share Not Designated as Hedging Instrument, Economic Hedge [Member] Not Designated as Hedging Instrument, Economic Hedge [Member] Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Indexed debt, net Indexed Debt Current City Area Code City Area Code Legal Entity [Axis] Legal Entity [Axis] Document Period End Date Document Period End Date Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] Dividends Declared [Table Text Block] Dividends Declared [Table Text Block] Disaggregation of Revenue [Table Text Block] Disaggregation of Revenue [Table Text Block] Realized losses deferred to other comprehensive income Deferred gain (loss) from interest rate derivatives (1) Other Comprehensive Income (Loss), before Reclassifications, before Tax Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Capital expenditures Payments to Acquire Productive Assets Tax benefit (expense) on Other Comprehensive lncome (loss) from unconsolidated affiliates OCI, Equity Method Investment, Tax Other financing activities, net Proceeds from (Payments for) Other Financing Activities Period [Axis] Period [Axis] Period of the transaction occurred [Axis] Cover [Abstract] Cover [Abstract] Regulatory Asset [Domain] Regulatory Asset [Domain] Distributions from unconsolidated affiliates Expected cash distribution from equity method investment Proceeds from Equity Method Investment, Distribution 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 Increase (Decrease) in Contract with Customer, Liability Increase (Decrease) in Contract with Customer, Liability Pre-tax gain on sale Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax OGE [Member] OGE [Member] OGE [Member] Service cost (1) Defined Benefit Plan, Service Cost Interest income from Securitization Bonds Interest Income on Transition and System Restoration Bonds Interest Income on Transition and System Restoration Bonds Customer Relationships [Member] Customer Relationships [Member] Non-utility cost of revenues, including natural gas Cost of Goods and Services Sold Income (Loss) from Discontinued Operations Net income (loss) from Discontinued Operations Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent Total Costs and Expenses Equity Components [Axis] Equity Components [Axis] 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. Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Minimum [Member] Minimum [Member] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Equity Method Investment, Other than Temporary Impairment Impairment of CenterPoint Energy’s equity method investment in Enable Impairment of CenterPoint Energy's equity method investment in Enable Equity Method Investment, Other than Temporary Impairment Disposal Group, Including Discontinued Operation, Balance Sheet Disclosures [Abstract] Disposal Group, Including Discontinued Operation, Balance Sheet Disclosures [Abstract] Non-utility revenues Unregulated Operating Revenue Schedule of Cash Flow, Supplemental Disclosures [Table Text Block] Schedule of Cash Flow, Supplemental Disclosures [Table Text Block] Equity Method Investments and Joint Ventures [Abstract] Equity Method Investments and Joint Ventures [Abstract] Amortization of net loss (2) Defined Benefit Plan, Amortization of Gain (Loss) Outstanding obligation related to AMAs Discontinued operation after disposal, purchase obligation Discontinued operation after disposal, purchase obligation Entity Interactive Data Current Entity Interactive Data Current Net periodic cost (income) Defined Benefit Plan, Net Periodic Benefit Cost (Credit) First Quarter 2019 [Member] First Quarter 2019 [Member] First Quarter 2019 [Member] Revenues: Revenues [Abstract] Equity [Text Block] Stockholders' Equity Note Disclosure [Text Block] SharesIssuedUponConversion SharesIssuedUponConversion SharesIssuedUponConversion Remaining three months of 2020 Finite-Lived Intangible Asset, Expected Amortization, Remainder of Fiscal Year Preferred units held Preferred Units Held Preferred Units Held Represents the number of Series A Preferred Units held as of the balance sheet date. Distributions received from Enable cost method investment 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. Other Disposal Group, Including Discontinued Operation, Other Assets, Current 2023 Purchase Obligation, to be Paid, Year Three Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Entity Listings, Exchange [Axis] Entity Listings, Exchange [Axis] Legal, Environmental and Other Matters Environmental Remediation Obligations [Abstract] Retirement Plan Type [Domain] Retirement Plan Type [Domain] Consolidation Items [Axis] Consolidation Items [Axis] Denominator: Incremental Weighted Average Shares Attributable to Dilutive Effect [Abstract] Not Designated as Hedging Instrument [Member] Not Designated as Hedging Instrument [Member] Accounts receivable, less bad debt reserve Accounts Receivable, after Allowance for Credit Loss, Current Goodwill Impairment Goodwill, Impairment Loss Goodwill, Impairment Loss Beginning Balance Ending Balance Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax Regulatory Matters [Text Block] Public Utilities Disclosure [Text Block] Other Adjustments to Additional Paid in Capital, Other Capital distribution to parent associated with the sale of CES Capital Distribution to Parent Capital Distribution to Parent Capital Distribution to Parent Recognition of beneficial conversion feature Beneficial Conversion Feature Beneficial conversion feature Non-cash transaction beneficial conversion feature Non-cash transaction beneficial conversion feature Payment Date Dividends Payable, Date to be Paid Dividends Payable, Date to be Paid Declaration Date Dividends Payable, Date Declared Dividends Payable, Date Declared Accounts and notes receivable, less bad debt reserve Accounts and Financing Receivable, after Allowance for Credit Loss Schedule of Revenue by Major Customers by Reporting Segments [Table Text Block] Schedule of Revenue by Major Customers by Reporting Segments [Table Text Block] Document Transition Report Document Transition Report 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 Derivative Assets Fair Value Derivative Asset, Fair Value, Gross Asset Interest income (expense) (1) Interest Income (Expense) Net, Related Party Net interest income (expense) related to affiliate investments or borrowings Other Income (Expense): Nonoperating Income (Expense) [Abstract] Fair Value, Inputs, Level 2 [Member] Fair Value, Inputs, Level 2 [Member] Document Quarterly Report Document Quarterly Report Liabilities Liabilities, Fair Value Disclosure [Abstract] Accounts receivable for amounts billed for services provided to Enable Accounts Receivable, Related Parties Accounting Standards Update 2016-13 [Member] Accounting Standards Update 2016-13 [Member] Accumulated other comprehensive loss Equity Method Investment Summarized Financial Information Accumulated Other Comprehensive Income Loss EquityMethodInvestmentSummarizedFinancialInformationAccumulatedOtherComprehensiveIncomeLoss Subsequent Event [Line Items] Subsequent Event [Line Items] Enable GP, LLC [Member] Enable GP, LLC [Member] Enable GP, LLC [Member] Credit Facility [Domain] Credit Facility [Domain] Basic Earnings (Loss) Per Common Share Earnings Per Share, Basic Entity File Number Entity File Number Curtailment gain (2) (4) Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Curtailment Benefit obligations Liability, Defined Benefit Plan, Noncurrent Cash Flows from Operating Activities: Net Cash Provided by (Used in) Operating Activities, Continuing Operations [Abstract] Disposal Groups, Including Discontinued Operations [Table Text Block] Disposal Groups, Including Discontinued Operations [Table Text Block] Charter Common [Member] Charter Common [Member] Charter Common [Member] Goodwill Disposal Group, Including Discontinued Operation, Goodwill, Noncurrent Balance Sheet Location [Axis] Derivatives, Fair Value, by Balance Sheet Location [Axis] Balance Sheet Location [Axis] Contribution From Parent Contribution From Parent Contribution From Parent Goodwill and Intangible Assets Disclosure [Abstract] Goodwill and Intangible Assets Disclosure [Abstract] Disposal Group Name [Axis] Disposal Group Name [Axis] 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 Commercial Paper [Member] Commercial Paper [Member] IDS Derivative [Member] IDS Derivative [Member] Derivative instrument related to indexed debt securities Natural gas inventory Disposal Group, Including Discontinued Operation, Inventory, Current ERCOT Loan, COVID-19 ERP, Outstanding ERCOT Loan, COVID-19 ERP, Outstanding ERCOT Loan, COVID-19 ERP, Outstanding Retirement Benefits [Abstract] Retirement Benefits [Abstract] Subsequent Event [Table] Subsequent Event [Table] Other Disposal Group, Including Discontinued Operation, Other Assets, Noncurrent Issuances related to benefit and investment plans Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Non-controlling interest Stockholders' Equity Attributable to Noncontrolling Interest Increase (Decrease) in Contract with Customer, Asset Increase (Decrease) in Contract with Customer, Asset Short-term borrowings Short-term Debt Public Utility Commission of Texas [Member] Public Utility Commission of Texas [Member] Public Utility Commission of Texas [Member] Balance of investment owned (in shares) Investment Owned, Balance, Shares Enable Units [Abstract] Enable Units [Abstract] Enable Units [Abstract] Public Utilities, Regulatory Proceeding [Domain] Public Utilities, Regulatory Proceeding [Domain] Percent increase (decrease) change in Defined Benefit Plan Assets Increase (Decrease) Change In Defined Benefit Plan Assets Percentage Increase (decrease) change in Defined Benefit Plan Assets, percentage Schedule of Defined Benefit Plans Disclosures [Table] Schedule of Defined Benefit Plans Disclosures [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] Amortization of Beneficial Conversion Feature Amortization of Beneficial Conversion Feature Amortization of Beneficial Conversion Feature Amortization of Beneficial Conversion Feature Amortization of Beneficial Conversion feature of Series C Preferred Stock Statement of Comprehensive Income [Abstract] Statement of Comprehensive Income [Abstract] Current liabilities held for sale Total current liabilities held for sale Disposal Group, Including Discontinued Operation, Liabilities, Current Total Liabilities and Shareholders’ Equity Liabilities and Equity Accumulated other comprehensive income (loss) Accumulated Other Comprehensive Income (Loss), Net of Tax Income Taxes [Text Block] Income Tax Disclosure [Text Block] Non-current liabilities Liabilities, Noncurrent Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, Tax Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, Tax Portion at Fair Value Measurement [Member] Portion at Fair Value Measurement [Member] Accounts payable Disposal Group, Including Discontinued Operation, Accounts Payable Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations Hedging Relationship [Axis] Hedging Relationship [Axis] Series C Preferred Stock [Member] Series C Preferred Stock [Member] Amount of antidilutive shares excluded from computation of earnings per share Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Weather hedges term Weather Hedges Term Period of time used as the basis for weather hedges entered into by the company. CERC Senior notes 1.75% due 2030 [Member] CERC Senior notes 1.75% due 2030 [Member] Issued October 2020, CERC Senior notes 1.75% due 2030 Midstream Investments [Member] Midstream Investments [Member] Midstream Investments [Member] Equity Capital Structure Public Utilities, Requested Equity Capital Structure, Percentage Unrealized loss (gain) on marketable securities Marketable Securities, Unrealized Gain (Loss), Excluding Other-than-temporary Impairment Loss Equity Component [Domain] Equity Component [Domain] Equity Method Investment, Summarized Financial Information, Gross Profit (Loss) [Abstract] Equity Method Investment, Summarized Financial Information [Abstract] Property, plant and equipment, net Property, Plant and Equipment, Net 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. Entity Tax Identification Number Entity Tax Identification Number Cumulative Effect on Retained Earnings Cumulative Effect on Retained Earnings Cumulative effect on beginning retained earnings for the adoption of a new accounting standard Interest Rate Contract [Member] Interest Rate Contract [Member] Net Income (Loss) Net income (Loss) Net income (loss) Net Income (Loss) Attributable to Parent Changes in other assets and liabilities, excluding acquisitions: Increase (Decrease) in Operating Capital [Abstract] London Interbank Offered Rate (LIBOR) [Member] London Interbank Offered Rate (LIBOR) [Member] Trade Names [Member] Trade Names [Member] Non-trading derivatives, net Increase (Decrease) in Derivative Assets and Liabilities Incremental Uncollectible Receivables, Regulatory Asset Incremental Uncollectible Receivables, Regulatory Asset Incremental Uncollectible Receivables, Regulatory Asset 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 Current Fiscal Year End Date Current Fiscal Year End Date Minnehaha Academy Gas Explosion [Member] Damage from Fire, Explosion or Other Hazard [Member] New Accounting Pronouncements [Text Block] Description of New Accounting Pronouncements Not yet Adopted [Text Block] Transactions with Enable [Abstract] Transactions with Enable [Abstract] Transactions with Enable [Abstract] Enable Equity Summary [Abstract] Enable Equity Summary [Abstract] Enable Equity Summary [Abstract] Revised Dividend or Distribution [Member] Revised Dividend or Distribution [Member] Revised Dividend or Distribution [Member] Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Tax Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Tax Series A Preferred Units [Member] Series A Preferred Units [Member] Series A Preferred Units [Member] Goodwill and Intangible Asset Impairment Goodwill and Intangible Asset Impairment Parent Company [Member] Parent Company [Member] 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 Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] Energy Services [Member] Energy Services Disposal Group [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. Letters of credit swing line sublimit Letters of credit swing line sublimit Letters of credit swing line sublimit General Mortgage Bonds Due 2050 [Member] General Mortgage Bonds Due 2050 [Member] General Mortgage Bonds Due 2050 [Member] Dividend to parent Dividends, Cash Preferred Stock, Convertible, Percent Outstanding Shares To Amend Preferred Stock, Convertible, Percent Outstanding Shares To Amend Preferred Stock, Convertible, Percent Outstanding Shares To Amend Issuance of stock, shares Stock Issued During Period, Shares, New Issues Stock Issued During Period, Shares, New Issues Intangible assets gross carrying amount Finite-Lived Intangible Assets, Gross 6.95% General Mortgage Bonds due 2033 [Member] 6.95% General Mortgage Bonds due 2033 [Member] 6.95% General Mortgage Bonds due 2033 [Member] Finite-Live Intangible Assets [Abstract] Finite-Lived Intangible Assets, Net [Abstract] Dividends paid per share Preferred Stock, Dividends, Per Share, Cash Paid Less: accumulated depreciation and amortization Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Opening balance as of December 31, 2019 Closing balance as of September 30, 2020 Contract with Customer, Asset, after Allowance for Credit Loss, Current 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. Related Party Transactions [Abstract] Related Party Transactions [Abstract] Hedging Relationship [Domain] Hedging Relationship [Domain] Weighted Average Common Shares Outstanding, Basic Weighted average common shares outstanding - basic Weighted Average Number of Shares Outstanding, Basic Basis spread on LIBOR Debt Instrument, Basis Spread on Variable Rate 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. Contested amount of fines imposed Contested Amount Of Fines Imposed Contested amount of fines imposed by the Minnesota Office of Pipeline Safety. Total non-current assets held for sale Total non-current assets held for sale Disposal Group, Including Discontinued Operation, Assets, Noncurrent Carrying Amount [Member] Reported Value Measurement [Member] Revenue Recognition [Text Block] Revenue from Contract with Customer [Text Block] Ownership percentage of equity method investment Equity Method Investment, Ownership Percentage Third Quarter 2020 Third Quarter 2020 [Member] Third Quarter 2020 Other current liabilities Increase (Decrease) in Other Current Liabilities Actuarial losses (2) Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax Preferred stock dividends declared Preferred Stock, Dividends Per Share, Declared ROU assets obtained in exchange for lease liabilities (1) Right-of-Use Asset Obtained in Exchange for Operating Lease Liability Partner Type of Partners' Capital Account, Name [Domain] Partner Type of Partners' Capital Account, Name [Domain] Long-term Debt, Fair Value Long-term Debt, Fair Value Limited Partners' Capital Account by Class [Axis] Limited Partners' Capital Account by Class [Axis] Income tax expense (benefit) Income Tax Expense (Benefit) Percentage on limitation of debt to total capitalization under covenant (in hundredths) Percentage on limitation of debt to total capitalization under covenant (in hundredths) Percentage on limitation of debt to total capitalization under covenant. Cash, Cash Equivalents and Restricted Cash at Beginning of Period Cash, Cash Equivalents and Restricted Cash at End of Period Total cash, cash equivalents and restricted cash shown in Condensed Statements of Consolidated Cash Flows Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Requested revenue increase Public Utilities, Requested Rate Increase (Decrease), Amount Local Phone Number Local Phone Number Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Instruments and Hedging Activities Disclosure [Abstract] Finite-lived Intangible Assets Amortization Expense [Table Text Block] Finite-lived Intangible Assets Amortization Expense [Table Text Block] 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 Discontinued Operation, Tax Effect of Discontinued Operation Income tax expense (benefit) Discontinued Operation, Tax Effect of Discontinued Operation Liability recorded for environmental loss contingencies Accrual for Environmental Loss Contingencies Schedule of Subsequent Events [Table Text Block] Schedule of Subsequent Events [Table Text Block] Vectren [Member] Vectren [Member] Vectren [Member] Outstanding debt balance Long-term Debt Long-term Debt, Gross Previous Dividend or Distribution [Member] Previous Dividend or Distribution [Member] Previous Dividend or Distribution [Member] 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] Opening balance as of December 31, 2019 Closing balance as of September 30, 2020 Contract with Customer, Liability Related Party Transaction [Domain] Related Party Transaction [Domain] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table] 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. Size of credit facility Line of Credit Facility, Maximum Borrowing Capacity Reclassification of net deferred loss from cash flow hedges (3) Reclassification of net deferred loss from cash flow hedges (3) Reclassification of net deferred losses from cash flow hedges to regulatory asset and regulatory liability, before tax Award Type [Axis] Award Type [Axis] Performance Guarantees & Product Warranties [Abstract] Performance Guarantees & Product Warranties [Abstract] Performance Guarantees & Product Warranties [Abstract] Prepaid expenses and other current assets [Member] Prepaid Expenses and Other Current Assets [Member] 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. Amortization of deferred financing costs Amortization of Debt Issuance Costs 2021 Purchase Obligation, to be Paid, Year One Materials and supplies Inventory, Raw Materials and Supplies, Gross Retained Earnings [Member] Retained Earnings [Member] Preferred stock outstanding (in shares) Balance, beginning of period Balance, end of period Preferred Stock, Shares Outstanding 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. Measurement Basis [Axis] Measurement Basis [Axis] Net cash used in investing activities from continuing operations Net Cash Provided by (Used in) Investing Activities Award Type [Domain] Award Type [Domain] Other Liabilities: Liabilities, Noncurrent [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. Discontinued Operations and Disposal Groups [Abstract] Discontinued Operations and Disposal Groups [Abstract] Continuing Operations [Member] Continuing Operations [Member] Reportable Subsegments [Member] Reportable Subsegments [Member] Interest and taxes accrued Increase Decrease Interest and taxes accrued Increase (decrease) in interest and taxes accrued. Earnings Per Share (CenterPoint Energy) [Text Block] Earnings Per Share [Text Block] Pension Benefits [Member] Pension Plan [Member] Natural Gas Expenses [Member] Natural Gas Expenses [Member] Represents natural gas expenses, including transportation and storage costs. Current Liabilities: Liabilities, Current [Abstract] Cash Flows from Financing Activities: Net Cash Provided by (Used in) Financing Activities, Continuing Operations [Abstract] Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Earnings (loss) per common share: Earnings Per Share, Basic [Abstract] 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)