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Retirement Benefits (Reconciliation of Net Actuarial Loss) (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
Pension Benefits |  |  |
Recognized as component of net benefit (credit) cost: |  |  |
Total recognized as component of net benefit (credit) cost | $ (214) | $ (209) | $ (240)
Post-retirement Benefits |  |  |
Recognized as component of net benefit (credit) cost: |  |  |
Total recognized as component of net benefit (credit) cost | (2) | 2 | 2
Net actuarial losses |  |  |
Recognized as component of net benefit (credit) cost: |  |  |
Amortization of net loss (gain) | 20 | 150 | 208
U.S. | Net actuarial losses | Pension Benefits |  |  |
Reconciliation of unrecognized net actuarial gain loss [Roll Forward] |  |  |
Beginning balance | (1,419) | (1,777) |
Recognized as component of net benefit (credit) cost: |  |  |
Amortization of net loss (gain) | 19 | 74 |
Changes in plan assets and benefit obligations recognized in other comprehensive income (loss): |  |  |
Other | (7) | 0 |
Liability experience | 20 | 1,625 |
Asset experience | 40 | (1,341) |
Total amount recognized as change in plan assets and benefit obligations | 53 | 284 |
Ending balance | (1,347) | (1,419) | (1,777)
U.S. | Net actuarial losses | Post-retirement Benefits |  |  |
Reconciliation of unrecognized net actuarial gain loss [Roll Forward] |  |  |
Beginning balance | 8 | 3 |
Recognized as component of net benefit (credit) cost: |  |  |
Amortization of net loss (gain) | (2) | 0 |
Changes in plan assets and benefit obligations recognized in other comprehensive income (loss): |  |  |
Other | 0 | 2 |
Liability experience | (2) | 3 |
Asset experience | 0 | 0 |
Total amount recognized as change in plan assets and benefit obligations | (2) | 5 |
Ending balance | 4 | 8 | 3
Non-U.S. | Pension Benefits |  |  |
Recognized as component of net benefit (credit) cost: |  |  |
Total recognized as component of net benefit (credit) cost | (182) | (140) | (187)
Non-U.S. | Post-retirement Benefits |  |  |
Recognized as component of net benefit (credit) cost: |  |  |
Total recognized as component of net benefit (credit) cost | (1) | 1 | 2
Non-U.S. | Net actuarial losses | Pension Benefits |  |  |
Reconciliation of unrecognized net actuarial gain loss [Roll Forward] |  |  |
Beginning balance | (2,610) | (2,904) |
Recognized as component of net benefit (credit) cost: |  |  |
Amortization of net loss (gain) | 3 | 75 |
Effect of settlement | 2 | 2 |
Total recognized as component of net benefit (credit) cost | 5 | 77 |
Changes in plan assets and benefit obligations recognized in other comprehensive income (loss): |  |  |
Liability experience | (226) | 3,953 |
Asset experience | (191) | (4,051) |
Total amount recognized as change in plan assets and benefit obligations | (417) | (98) |
Exchange rate adjustments | (197) | 315 |
Ending balance | (3,219) | (2,610) | (2,904)
Non-U.S. | Net actuarial losses | Post-retirement Benefits |  |  |
Reconciliation of unrecognized net actuarial gain loss [Roll Forward] |  |  |
Beginning balance | 6 | (10) |
Recognized as component of net benefit (credit) cost: |  |  |
Amortization of net loss (gain) | (1) | 1 |
Effect of settlement | 0 | 0 |
Total recognized as component of net benefit (credit) cost | (1) | 1 |
Changes in plan assets and benefit obligations recognized in other comprehensive income (loss): |  |  |
Liability experience | 10 | 14 |
Asset experience | 0 | 0 |
Total amount recognized as change in plan assets and benefit obligations | 10 | 14 |
Exchange rate adjustments | 2 | 1 |
Ending balance | $ 17 | $ 6 | $ (10)

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