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Employee Benefits - Fair Value of Plan Assets (Details) - Combined Pension Plan - USD ($) $ in Millions | Dec. 31, 2024 | Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
--- | --- | --- | --- | ---
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | $ 4,201 | $ 4,476 | $ 4,715 | $ 8,531
Level 3 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 6 | 5 | 5 |
Investments valued at NAV |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 2,359 | 2,192 |  |
Total investments, excluding investments valued at NAV | Total |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 2,183 | 2,660 |  |
Total investments, excluding investments valued at NAV | Level 1 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 722 | 728 |  |
Total investments, excluding investments valued at NAV | Level 2 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 1,455 | 1,927 |  |
Total investments, excluding investments valued at NAV | Level 3 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 6 | 5 |  |
Investment grade bonds | Total |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 1,763 | 2,228 |  |
Investment grade bonds | Level 1 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 372 | 390 |  |
Investment grade bonds | Level 2 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 1,391 | 1,838 |  |
Investment grade bonds | Level 3 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 0 | 0 |  |
Investment grade bonds | Investments valued at NAV |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 72 | 105 |  |
High yield bonds | Total |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 30 | 36 |  |
High yield bonds | Level 1 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 0 | 0 |  |
High yield bonds | Level 2 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 26 | 32 |  |
High yield bonds | Level 3 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 4 | 4 | 4 |
High yield bonds | Investments valued at NAV |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 340 | 110 |  |
Emerging market bonds | Total |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 104 | 114 |  |
Emerging market bonds | Level 1 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 70 | 57 |  |
Emerging market bonds | Level 2 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 34 | 57 |  |
Emerging market bonds | Level 3 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 0 | 0 |  |
Emerging market bonds | Investments valued at NAV |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 69 | 0 |  |
U.S. stocks | Total |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 263 | 248 |  |
U.S. stocks | Level 1 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 260 | 247 |  |
U.S. stocks | Level 2 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 2 | 0 |  |
U.S. stocks | Level 3 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 1 | 1 | 1 |
U.S. stocks | Investments valued at NAV |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 6 | 51 |  |
Non-U.S. stocks | Total |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 15 | 6 |  |
Non-U.S. stocks | Level 1 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 14 | 6 |  |
Non-U.S. stocks | Level 2 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 0 | 0 |  |
Non-U.S. stocks | Level 3 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 1 | 0 | $ 0 |
Non-U.S. stocks | Investments valued at NAV |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 529 | 412 |  |
Cash equivalents and short-term investments | Total |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 8 |  |  |
Cash equivalents and short-term investments | Level 1 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 6 |  |  |
Cash equivalents and short-term investments | Level 2 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 2 |  |  |
Cash equivalents and short-term investments | Level 3 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 0 |  |  |
Cash equivalents and short-term investments | Investments valued at NAV |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 277 | 318 |  |
Multi-asset strategies | Total |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 28 |  |
Multi-asset strategies | Level 1 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 28 |  |
Multi-asset strategies | Level 2 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 0 |  |
Multi-asset strategies | Level 3 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 0 |  |
Multi-asset strategies | Investments valued at NAV |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 0 | 27 |  |
Other receivables | Total |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 27 |  |  |
Repurchase agreements & other obligations | Total |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | (361) | (375) |  |
Repurchase agreements & other obligations | Level 1 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 0 | 0 |  |
Repurchase agreements & other obligations | Level 2 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | (361) | (375) |  |
Repurchase agreements & other obligations | Level 3 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 0 | 0 |  |
Derivatives | Total |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | (7) | (1) |  |
Derivatives | Level 1 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | (1) | (1) |  |
Derivatives | Level 2 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | (6) | 0 |  |
Derivatives | Level 3 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 0 | 0 |  |
Emerging market stocks | Investments valued at NAV |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 4 | 10 |  |
Private equity | Investments valued at NAV |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 253 | 272 |  |
Private debt | Investments valued at NAV |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 398 | 421 |  |
Market neutral hedge funds | Investments valued at NAV |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 85 | 77 |  |
Directional hedge funds | Investments valued at NAV |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | 108 | 124 |  |
Real estate | Investments valued at NAV |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | $ 218 | $ 265 |  |

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