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Stock-Based Incentive Compensation Plans and Employee Benefit Plans - Plan Assets (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2024 | Dec. 31, 2023 | Dec. 31, 2022
Savings Plan [Abstract] |  |  |
Savings plan benefit expenses | $ 72 | $ 67 | $ 72
Postemployment Benefits [Abstract] |  |  |
Deferred compensation plans | $ 3 | (1) | 1
Savings Plan |  |  |
Savings Plan [Abstract] |  |  |
Number of Common stock held by the savings plan (in shares) | 7,136,941 |  |
Percentage of investment in common stocks (in hundredths) | 6.00% |  |
Pension Plan |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Plan assets, fair value | $ 1,132 | 1,204 | 1,212
Obligation to return cash received as collateral from securities lending | (88) | (94) |
Financial instruments | (3) | (4) |
Defined benefits plan, fair value of plan assets, excluding investments measured at net asset value | 690 | 744 |
Contributions in 2024 | 30 | 32 |
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract] |  |  |
2025 | 144 |  |
2026 | 144 |  |
2027 | 141 |  |
2028 | 138 |  |
2029 | 134 |  |
2030-2034 | 609 |  |
Pension Plan | Qualified pension plans |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Contributions in 2024 | 23 |  |
Expected Minimum Contributions in 2025 | 105 |  |
Pension Plan | Non-qualified pension plans |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Contributions in 2024 | 7 |  |
Expected Minimum Contributions in 2025 | 7 |  |
Other Postretirement Benefits Plan |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Plan assets, fair value | 103 | 112 | 109
Contributions in 2024 | 9 | 7 |
Expected Minimum Contributions in 2025 | 8 |  |
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract] |  |  |
2025 | 16 |  |
2026 | 18 |  |
2027 | 19 |  |
2028 | 20 |  |
2029 | 21 |  |
2030-2034 | 102 |  |
Level 1 | Pension Plan |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Plan assets, fair value | 220 | 229 |
Obligation to return cash received as collateral from securities lending | (88) | (94) |
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 | 470 | 515 |
Obligation to return cash received as collateral from securities lending | 0 | 0 |
Financial instruments | (3) | (4) |
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 | 28 | 30 |
U.S. equity | Level 1 | Pension Plan |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Plan assets, fair value | 28 | 30 |
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 | 36 | 21 |
Cash | Level 1 | Pension Plan |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Plan assets, fair value | 36 | 21 |
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 |
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 | 88 | 94 |
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 | 88 | 94 |
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 | 156 | 178 |
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 | 156 | 178 |
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 |
Investment grade or above | Pension Plan |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Plan assets, fair value | 428 | 469 |
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 | 428 | 469 |
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 |
Mortgage-backed securities | Pension Plan |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Plan assets, fair value | 12 | 15 |
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 | 12 | 15 |
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 | 1 |
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 | 1 |
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 | 19 | 25 |
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 | 19 | 25 |
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 |
International government bonds | Pension Plan |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Plan assets, fair value | 13 | 9 |
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 | 13 | 9 |
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 | $ 442 | $ 460 |
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) | 38.00% | 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) | 61.00% | 59.00% |
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% | 1.00% |
Mutual funds | Other Postretirement Benefits Plan |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Plan assets, fair value | $ 103 | $ 113 |
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) | 7.00% | 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) | 19.00% | 20.00% |
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) | 74.00% | 72.00% |
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 | $ 103 | $ 113 |
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 |
Benefit Obligation |  |  |
Postemployment Benefits [Abstract] |  |  |
Deferred compensation plans | 22 | 26 |
Split-dollar life insurance arrangements | $ 46 | 46 |
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) | 8.00% |  |
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] |  |  |
Savings plan benefit expenses | $ 27 | 23 | 23
Postemployment Benefits [Abstract] |  |  |
Deferred compensation plans | 0 | 0 | 0
Houston Electric | Pension Plan | Qualified pension plans |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Contributions in 2024 | 0 |  |
Expected Minimum Contributions in 2025 | 0 |  |
Houston Electric | Pension Plan | Non-qualified pension plans |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Contributions in 2024 | 0 |  |
Expected Minimum Contributions in 2025 | 0 |  |
Houston Electric | Other Postretirement Benefits Plan |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Plan assets, fair value | 77 | 86 | 84
Contributions in 2024 | 1 | 0 |
Expected Minimum Contributions in 2025 | 1 |  |
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract] |  |  |
2025 | 7 |  |
2026 | 8 |  |
2027 | 8 |  |
2028 | 9 |  |
2029 | 9 |  |
2030-2034 | 46 |  |
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 | $ 77 | $ 86 |
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) | 8.00% | 9.00% |
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) | 18.00% | 19.00% |
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) | 74.00% | 72.00% |
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 | $ 77 | $ 86 |
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] |  |  |
Deferred compensation plans | 3 | 3 |
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 |  |  |
Savings Plan [Abstract] |  |  |
Savings plan benefit expenses | $ 23 | 20 | 22
Postemployment Benefits [Abstract] |  |  |
Deferred compensation plans | 0 | 0 | 0
CERC | Pension Plan | Qualified pension plans |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Contributions in 2024 | 0 |  |
Expected Minimum Contributions in 2025 | 0 |  |
CERC | Pension Plan | Non-qualified pension plans |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Contributions in 2024 | 0 |  |
Expected Minimum Contributions in 2025 | 0 |  |
CERC | Other Postretirement Benefits Plan |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Plan assets, fair value | 26 | 26 | $ 25
Contributions in 2024 | 5 | 4 |
Expected Minimum Contributions in 2025 | 5 |  |
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract] |  |  |
2025 | 6 |  |
2026 | 6 |  |
2027 | 7 |  |
2028 | 7 |  |
2029 | 7 |  |
2030-2034 | 35 |  |
CERC | Mutual funds | Other Postretirement Benefits Plan |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |
Plan assets, fair value | $ 26 | $ 26 |
CERC | 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) | 7.00% | 6.00% |
CERC | 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) | 21.00% | 22.00% |
CERC | 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% | 71.00% |
CERC | 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 | $ 26 |
CERC | 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 | 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 | Benefit Obligation |  |  |
Postemployment Benefits [Abstract] |  |  |
Deferred compensation plans | 1 | 1 |
Split-dollar life insurance arrangements | $ 0 | $ 0 |
CERC | 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 | 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 | 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 | 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 | 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 | 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 | 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 | 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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- Definition Represents the fair value of an obligation to return cash received as collateral from securities lending + References No definition available. + Details
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- Definition Fair value of assets that have been segregated and restricted to provide pension or postretirement benefits, excluding investments measured at net asset value per share or its equivalent. + References No definition available. + Details
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Namespace Prefix: | cnp_
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- Definition Represents the maximum percentage allowed of total account balance invested in company stock. + References No definition available. + Details
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Namespace Prefix: | cnp_
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