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Share-based Compensation and Employee Benefits - Fair Value of Pension and OPEB Assets by Level of Assets (Details) - USD ($) $ in Millions | Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
--- | --- | --- | ---
Pension Benefits |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Total plan assets fair value | $ 1,562 | $ 1,741 | $ 2,231
Pension Benefits | Total |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Total plan assets fair value | 585 | 600 |
Pension Benefits | Level 1 |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Total plan assets fair value | 143 | 152 |
Pension Benefits | Level 2 |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Total plan assets fair value | 442 | 448 |
Pension Benefits | Measured at NAV |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Total plan assets fair value | 977 | 1,141 |
Pension Benefits | Short-term Investment Funds | Total |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Total plan assets fair value | 32 | 27 |
Pension Benefits | Short-term Investment Funds | Level 1 |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Total plan assets fair value | 0 | 0 |
Pension Benefits | Short-term Investment Funds | Level 2 |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Total plan assets fair value | 32 | 27 |
Pension Benefits | Equities | Total |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Total plan assets fair value | 143 | 152 |
Pension Benefits | Equities | Level 1 |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Total plan assets fair value | 143 | 152 |
Pension Benefits | Equities | Level 2 |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Total plan assets fair value | 0 | 0 |
Pension Benefits | Fixed Income Securities | Total |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Total plan assets fair value | 410 | 421 |
Pension Benefits | Fixed Income Securities | Level 1 |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Total plan assets fair value | 0 | 0 |
Pension Benefits | Fixed Income Securities | Level 2 |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Total plan assets fair value | 410 | 421 |
Pension Benefits | Common/Collective Trusts | Measured at NAV |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Total plan assets fair value | $ 976 | $ 1,138 |
Pension Benefits | Common/Collective Trusts Invested in Equity Securities | Measured at NAV |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Percentage of category allocated to investments | 64.00% | 66.00% |
Pension Benefits | Common/Collective Trusts Invested in Fixed Income Securities | Measured at NAV |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Percentage of category allocated to investments | 23.00% | 22.00% |
Pension Benefits | Common/Collective Trusts Invested in Real Estate | Measured at NAV |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Percentage of category allocated to investments | 13.00% | 12.00% |
Pension Benefits | Private Limited Partnerships | Measured at NAV |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Total plan assets fair value | $ 1 | $ 3 |
OPEB |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Total plan assets fair value | 323 | 302 | $ 382
OPEB | Short-term Investment Funds | Total |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Total plan assets fair value | 5 | 3 |
OPEB | Short-term Investment Funds | Level 1 |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Total plan assets fair value | 0 | 0 |
OPEB | Short-term Investment Funds | Level 2 |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Total plan assets fair value | 5 | 3 |
OPEB | Common/Collective Trusts | Measured at NAV |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Total plan assets fair value | $ 318 | $ 299 |
OPEB | Common/Collective Trusts Invested in Equity Securities | Measured at NAV |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Percentage of category allocated to investments | 62.00% | 61.00% |
OPEB | Common/Collective Trusts Invested in Fixed Income Securities | Measured at NAV |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Percentage of category allocated to investments | 38.00% | 39.00% |
Class P | Pension Benefits | Equities | Level 1 |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Amount of KMI securities invested in | $ 107 | $ 110 |

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