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Stock-Based Incentive Compensation Plans and Employee Benefit Plans - Plan Assets (Details) $ in Millions | 12 Months Ended |  |
--- | --- | --- | ---
Dec. 31, 2023 USD ($) shares | Dec. 31, 2022 USD ($) | Dec. 31, 2021 USD ($) | Jan. 01, 2022 plan | Jan. 01, 2020 plan
Savings Plan [Abstract] |  |  |  |  |
Defined contribution plan cost | $ 67 | $ 72 | $ 58 |  |
Postemployment Benefits [Abstract] |  |  |  |  |
Postemployment Benefits, Period Expense | (1) | 4 | 3 |  |
Benefit expense related to deferred compensation plans | $ (1) | 1 | 3 |  |
Savings Plan |  |  |  |  |
Savings Plan [Abstract] |  |  |  |  |
Number of defined benefit plans to be merged | plan |  |  |  | 1 | 1
Number of Common stock held by the savings plan (in shares) | shares | 6,589,241 |  |  |  |
Percentage of investment in common stocks (in hundredths) | 7.00% |  |  |  |
Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | $ 1,204 | 1,212 | 2,072 |  |
Obligation to return cash received as collateral from securities lending | (94) | (47) |  |  |
Financial instruments | (4) | 0 |  |  |
Defined benefits plan, fair value of plan assets, excluding investments measured at net asset value | $ 744 | $ 708 |  |  |
Discount rate (as a percent) | 4.95% | 5.15% |  |  |
Contributions in 2023 | $ 32 | $ 35 |  |  |
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract] |  |  |  |  |
2024 | 141 |  |  |  |
2025 | 143 |  |  |  |
2026 | 137 |  |  |  |
2027 | 135 |  |  |  |
2028 | 133 |  |  |  |
2029-2033 | 606 |  |  |  |
Pension Plan | Qualified Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Contributions in 2023 | 24 |  |  |  |
Expected Minimum Contributions in 2024 | 2 |  |  |  |
Pension Plan | Nonqualified Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Contributions in 2023 | 8 |  |  |  |
Expected Minimum Contributions in 2024 | 7 |  |  |  |
Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | $ 112 | $ 109 | 132 |  |
Discount rate (as a percent) | 4.95% | 5.15% |  |  |
Contributions in 2023 | $ 7 | $ 8 |  |  |
Expected Minimum Contributions in 2024 | 8 |  |  |  |
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract] |  |  |  |  |
2024 | 14 |  |  |  |
2025 | 16 |  |  |  |
2026 | 17 |  |  |  |
2027 | 19 |  |  |  |
2028 | 20 |  |  |  |
2029-2033 | 107 |  |  |  |
Level 1 | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 229 | 199 |  |  |
Obligation to return cash received as collateral from securities lending | (94) | (47) |  |  |
Financial instruments | 0 | 0 |  |  |
Level 2 | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 515 | 509 |  |  |
Obligation to return cash received as collateral from securities lending | 0 | 0 |  |  |
Financial instruments | (4) | 0 |  |  |
Level 3 | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 0 | 0 |  |  |
Obligation to return cash received as collateral from securities lending | 0 | 0 |  |  |
Financial instruments | 0 | 0 |  |  |
U.S. equity | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 30 | 29 |  |  |
U.S. equity | Level 1 | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 30 | 29 |  |  |
U.S. equity | Level 2 | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 0 | 0 |  |  |
U.S. equity | Level 3 | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 0 | 0 |  |  |
Cash | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 21 | 7 |  |  |
Cash | Level 1 | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 21 | 7 |  |  |
Cash | Level 2 | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 0 | 0 |  |  |
Cash | Level 3 | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 0 | 0 |  |  |
Investment grade or above | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 469 | 467 |  |  |
Investment grade or above | Level 1 | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 0 | 0 |  |  |
Investment grade or above | Level 2 | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 469 | 467 |  |  |
Investment grade or above | Level 3 | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 0 | 0 |  |  |
Cash received as collateral from securities lending | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 94 | 47 |  |  |
Cash received as collateral from securities lending | Level 1 | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 94 | 47 |  |  |
Cash received as collateral from securities lending | Level 2 | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 0 | 0 |  |  |
Cash received as collateral from securities lending | Level 3 | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 0 | 0 |  |  |
U.S. treasuries and government agencies | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 178 | 163 |  |  |
U.S. treasuries and government agencies | Level 1 | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 178 | 163 |  |  |
U.S. treasuries and government agencies | Level 2 | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 0 | 0 |  |  |
U.S. treasuries and government agencies | Level 3 | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 0 | 0 |  |  |
Mortgage backed securities | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 15 | 6 |  |  |
Mortgage backed securities | Level 1 | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 0 | 0 |  |  |
Mortgage backed securities | Level 2 | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 15 | 6 |  |  |
Mortgage backed securities | Level 3 | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 0 | 0 |  |  |
Asset backed securities | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 1 | 2 |  |  |
Asset backed securities | Level 1 | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 0 | 0 |  |  |
Asset backed securities | Level 2 | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 1 | 2 |  |  |
Asset backed securities | Level 3 | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 0 | 0 |  |  |
Municipal bonds | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 25 | 24 |  |  |
Municipal bonds | Level 1 | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 0 | 0 |  |  |
Municipal bonds | Level 2 | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 25 | 24 |  |  |
Municipal bonds | Level 3 | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 0 | 0 |  |  |
Mutual funds | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | $ 113 | $ 109 |  |  |
Mutual funds | International equities | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, actual allocation (as a percent) | 8.00% | 8.00% |  |  |
Mutual funds | U.S. equity | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, actual allocation (as a percent) | 20.00% | 18.00% |  |  |
Mutual funds | Fixed income | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, actual allocation (as a percent) | 72.00% | 74.00% |  |  |
Mutual funds | Level 1 | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | $ 113 | $ 109 |  |  |
Mutual funds | Level 2 | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 0 | 0 |  |  |
Mutual funds | Level 3 | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 0 | 0 |  |  |
International government bonds | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 9 | 10 |  |  |
International government bonds | Level 1 | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 0 | 0 |  |  |
International government bonds | Level 2 | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 9 | 10 |  |  |
International government bonds | Level 3 | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 0 | 0 |  |  |
Common Collective Trust Funds | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | $ 460 | $ 504 |  |  |
Common Collective Trust Funds | International equities | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, actual allocation (as a percent) | 40.00% | 40.00% |  |  |
Common Collective Trust Funds | U.S. equity | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, actual allocation (as a percent) | 59.00% | 56.00% |  |  |
Common Collective Trust Funds | Fixed income | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, actual allocation (as a percent) | 1.00% | 4.00% |  |  |
Benefit Obligation |  |  |  |  |
Postemployment Benefits [Abstract] |  |  |  |  |
Postemployment benefit obligations | $ 5 | $ 9 |  |  |
Other non-qualified plans benefit obligations deferred compensation | 26 | 28 |  |  |
Benefit obligations related to split-dollar life insurance arrangements | $ 46 | 22 |  |  |
Minimum | U.S. equity | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Target allocation (as a percent) | 17.00% |  |  |  |
Minimum | U.S. equity | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Target allocation (as a percent) | 14.00% |  |  |  |
Minimum | International equity | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Target allocation (as a percent) | 9.00% |  |  |  |
Minimum | International equity | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Target allocation (as a percent) | 3.00% |  |  |  |
Minimum | Real estate | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Target allocation (as a percent) | 2.00% |  |  |  |
Minimum | Fixed income | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Target allocation (as a percent) | 54.00% |  |  |  |
Minimum | Fixed income | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Target allocation (as a percent) | 69.00% |  |  |  |
Minimum | Cash | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Target allocation (as a percent) | 0.00% |  |  |  |
Minimum | Cash | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Target allocation (as a percent) | 0.00% |  |  |  |
Maximum | U.S. equity | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Target allocation (as a percent) | 27.00% |  |  |  |
Maximum | U.S. equity | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Target allocation (as a percent) | 24.00% |  |  |  |
Maximum | International equity | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Target allocation (as a percent) | 19.00% |  |  |  |
Maximum | International equity | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Target allocation (as a percent) | 13.00% |  |  |  |
Maximum | Real estate | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Target allocation (as a percent) | 11.00% |  |  |  |
Maximum | Fixed income | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Target allocation (as a percent) | 64.00% |  |  |  |
Maximum | Fixed income | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Target allocation (as a percent) | 79.00% |  |  |  |
Maximum | Cash | Pension Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Target allocation (as a percent) | 2.00% |  |  |  |
Maximum | Cash | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Target allocation (as a percent) | 2.00% |  |  |  |
Common Stock | CenterPoint Energy | Savings Plan |  |  |  |  |
Savings Plan [Abstract] |  |  |  |  |
Maximum limit of account balance in company stock (as a percent) | 25.00% |  |  |  |
Houston Electric |  |  |  |  |
Savings Plan [Abstract] |  |  |  |  |
Defined contribution plan cost | $ 23 | 23 | 20 |  |
Postemployment Benefits [Abstract] |  |  |  |  |
Postemployment Benefits, Period Expense | 0 | 1 | 1 |  |
Benefit expense related to deferred compensation plans | 0 | 0 | 0 |  |
Houston Electric | Pension Plan | Qualified Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Contributions in 2023 | 0 |  |  |  |
Expected Minimum Contributions in 2024 | 0 |  |  |  |
Houston Electric | Pension Plan | Nonqualified Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Contributions in 2023 | 0 |  |  |  |
Expected Minimum Contributions in 2024 | 0 |  |  |  |
Houston Electric | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | $ 86 | $ 84 | 104 |  |
Discount rate (as a percent) | 4.95% | 5.15% |  |  |
Contributions in 2023 | $ 0 | $ 1 |  |  |
Expected Minimum Contributions in 2024 | 1 |  |  |  |
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract] |  |  |  |  |
2024 | 6 |  |  |  |
2025 | 6 |  |  |  |
2026 | 7 |  |  |  |
2027 | 8 |  |  |  |
2028 | 9 |  |  |  |
2029-2033 | 49 |  |  |  |
Houston Electric | Mutual funds | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | $ 86 | $ 84 |  |  |
Houston Electric | Mutual funds | International equities | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, actual allocation (as a percent) | 9.00% | 8.00% |  |  |
Houston Electric | Mutual funds | U.S. equity | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, actual allocation (as a percent) | 19.00% | 17.00% |  |  |
Houston Electric | Mutual funds | Fixed income | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, actual allocation (as a percent) | 72.00% | 74.00% |  |  |
Houston Electric | Mutual funds | Level 1 | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | $ 86 | $ 84 |  |  |
Houston Electric | Mutual funds | Level 2 | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 0 | 0 |  |  |
Houston Electric | Mutual funds | Level 3 | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 0 | 0 |  |  |
Houston Electric | Benefit Obligation |  |  |  |  |
Postemployment Benefits [Abstract] |  |  |  |  |
Postemployment benefit obligations | 2 | 3 |  |  |
Other non-qualified plans benefit obligations deferred compensation | 3 | 4 |  |  |
Benefit obligations related to split-dollar life insurance arrangements | $ 1 | 1 |  |  |
Houston Electric | Minimum | U.S. equity | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Target allocation (as a percent) | 13.00% |  |  |  |
Houston Electric | Minimum | International equity | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Target allocation (as a percent) | 3.00% |  |  |  |
Houston Electric | Minimum | Fixed income | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Target allocation (as a percent) | 69.00% |  |  |  |
Houston Electric | Minimum | Cash | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Target allocation (as a percent) | 0.00% |  |  |  |
Houston Electric | Maximum | U.S. equity | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Target allocation (as a percent) | 23.00% |  |  |  |
Houston Electric | Maximum | International equity | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Target allocation (as a percent) | 13.00% |  |  |  |
Houston Electric | Maximum | Fixed income | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Target allocation (as a percent) | 79.00% |  |  |  |
Houston Electric | Maximum | Cash | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Target allocation (as a percent) | 2.00% |  |  |  |
CERC Corp |  |  |  |  |
Savings Plan [Abstract] |  |  |  |  |
Defined contribution plan cost | $ 20 | 22 | 23 |  |
Postemployment Benefits [Abstract] |  |  |  |  |
Postemployment Benefits, Period Expense | 0 | 1 | 2 |  |
Benefit expense related to deferred compensation plans | 0 | 0 | 0 |  |
CERC Corp | Pension Plan | Qualified Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Contributions in 2023 | 0 |  |  |  |
Expected Minimum Contributions in 2024 | 0 |  |  |  |
CERC Corp | Pension Plan | Nonqualified Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Contributions in 2023 | 0 |  |  |  |
Expected Minimum Contributions in 2024 | 0 |  |  |  |
CERC Corp | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | $ 26 | $ 25 | $ 29 |  |
Discount rate (as a percent) | 4.95% | 5.15% |  |  |
Contributions in 2023 | $ 4 | $ 4 |  |  |
Expected Minimum Contributions in 2024 | 4 |  |  |  |
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract] |  |  |  |  |
2024 | 5 |  |  |  |
2025 | 6 |  |  |  |
2026 | 6 |  |  |  |
2027 | 7 |  |  |  |
2028 | 7 |  |  |  |
2029-2033 | 36 |  |  |  |
CERC Corp | Mutual funds | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | $ 26 | $ 25 |  |  |
CERC Corp | Mutual funds | International equities | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, actual allocation (as a percent) | 6.00% | 6.00% |  |  |
CERC Corp | Mutual funds | U.S. equity | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, actual allocation (as a percent) | 22.00% | 20.00% |  |  |
CERC Corp | Mutual funds | Fixed income | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, actual allocation (as a percent) | 71.00% | 74.00% |  |  |
CERC Corp | Mutual funds | Level 1 | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | $ 26 | $ 25 |  |  |
CERC Corp | Mutual funds | Level 2 | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 0 | 0 |  |  |
CERC Corp | Mutual funds | Level 3 | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Plan assets, fair value | 0 | 0 |  |  |
CERC Corp | Benefit Obligation |  |  |  |  |
Postemployment Benefits [Abstract] |  |  |  |  |
Postemployment benefit obligations | 3 | 4 |  |  |
Other non-qualified plans benefit obligations deferred compensation | 1 | 1 |  |  |
Benefit obligations related to split-dollar life insurance arrangements | $ 0 | $ 0 |  |  |
CERC Corp | Minimum | U.S. equity | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Target allocation (as a percent) | 15.00% |  |  |  |
CERC Corp | Minimum | International equity | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Target allocation (as a percent) | 2.00% |  |  |  |
CERC Corp | Minimum | Fixed income | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Target allocation (as a percent) | 68.00% |  |  |  |
CERC Corp | Minimum | Cash | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Target allocation (as a percent) | 0.00% |  |  |  |
CERC Corp | Maximum | U.S. equity | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Target allocation (as a percent) | 25.00% |  |  |  |
CERC Corp | Maximum | International equity | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Target allocation (as a percent) | 12.00% |  |  |  |
CERC Corp | Maximum | Fixed income | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Target allocation (as a percent) | 78.00% |  |  |  |
CERC Corp | Maximum | Cash | Other Postretirement Benefits Plan |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |
Target allocation (as a percent) | 2.00% |  |  |  |

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