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Pension and Other Postretirement Benefits - Schedule of Fair Value of Pension Plan Assets (Details) - USD ($) $ in Millions | Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
--- | --- | --- | ---
Defined Benefit Plan Disclosure [Line Items] |  |  |
Net payable | $ 35 |  |
Net receivable |  | $ 8 |
Pension benefits |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Net plan assets | 925 | 970 | $ 1,531
Net plan assets excluding certain net receivables | 960 | 962 |
Pension benefits | Equities |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 436 | 541 |
Pension benefits | Equity securities |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 310 | 416 |
Pension benefits | Long/short equity hedge funds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 18 | 18 |
Pension benefits | Private equity |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 108 | 107 |
Pension benefits | Fixed income |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 419 | 320 |
Pension benefits | Intermediate and long duration government/credit |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 350 | 255 |
Pension benefits | Other |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 69 | 65 |
Pension benefits | Other investments |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 105 | 101 |
Pension benefits | Real estate |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 73 | 65 |
Pension benefits | Discretionary and systematic macro hedge funds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 29 | 29 |
Pension benefits | Other |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 3 | 7 |
Pension benefits | Level 1 |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Net plan assets | 205 | 113 |
Pension benefits | Level 1 | Equities |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 0 | 0 |
Pension benefits | Level 1 | Equity securities |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 0 | 0 |
Pension benefits | Level 1 | Long/short equity hedge funds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 0 | 0 |
Pension benefits | Level 1 | Private equity |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 0 | 0 |
Pension benefits | Level 1 | Fixed income |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 205 | 113 |
Pension benefits | Level 1 | Intermediate and long duration government/credit |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 199 | 107 |
Pension benefits | Level 1 | Other |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 6 | 6 |
Pension benefits | Level 1 | Other investments |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 0 | 0 |
Pension benefits | Level 1 | Real estate |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 0 | 0 |
Pension benefits | Level 1 | Discretionary and systematic macro hedge funds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 0 | 0 |
Pension benefits | Level 1 | Other |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 0 | 0 |
Pension benefits | Level 2 |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Net plan assets | 304 | 343 |
Pension benefits | Level 2 | Equities |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 85 | 133 |
Pension benefits | Level 2 | Equity securities |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 85 | 133 |
Pension benefits | Level 2 | Long/short equity hedge funds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 0 | 0 |
Pension benefits | Level 2 | Private equity |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 0 | 0 |
Pension benefits | Level 2 | Fixed income |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 214 | 207 |
Pension benefits | Level 2 | Intermediate and long duration government/credit |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 151 | 148 |
Pension benefits | Level 2 | Other |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 63 | 59 |
Pension benefits | Level 2 | Other investments |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 5 | 3 |
Pension benefits | Level 2 | Real estate |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 5 | 3 |
Pension benefits | Level 2 | Discretionary and systematic macro hedge funds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 0 | 0 |
Pension benefits | Level 2 | Other |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 0 | 0 |
Pension benefits | Net Asset Value |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Net plan assets | 451 | 506 |
Pension benefits | Net Asset Value | Equities |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 351 | 408 |
Pension benefits | Net Asset Value | Equity securities |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 225 | 283 |
Pension benefits | Net Asset Value | Long/short equity hedge funds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 18 | 18 |
Pension benefits | Net Asset Value | Private equity |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 108 | 107 |
Pension benefits | Net Asset Value | Fixed income |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 0 | 0 |
Pension benefits | Net Asset Value | Intermediate and long duration government/credit |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 0 | 0 |
Pension benefits | Net Asset Value | Other |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 0 | 0 |
Pension benefits | Net Asset Value | Other investments |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 100 | 98 |
Pension benefits | Net Asset Value | Real estate |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 68 | 62 |
Pension benefits | Net Asset Value | Discretionary and systematic macro hedge funds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | 29 | 29 |
Pension benefits | Net Asset Value | Other |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of pension and other postretirement plans' assets | $ 3 | $ 7 |

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