v3.25.2
Retirement benefits - Summary of Remeasurements (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Actuarial gains/(losses) on obligations:      
Total $ 4,266 $ (2,375) $ 27,943
Return on plan assets in (shortage)/excess of interest income (2,319) 1,243 (20,612)
Other movements (93) 44 (349)
Total remeasurements 1,854 (1,088) 6,982
Pensions      
Actuarial gains/(losses) on obligations:      
Due to changes in financial assumptions 4,445 (1,513) 28,840
Due to experience adjustments (701) (491) (2,956)
Due to changes in demographic assumptions 445 (299) 27
OPEB      
Actuarial gains/(losses) on obligations:      
Due to changes in financial assumptions 249 (264) 527
Due to experience adjustments (259) 230 1,480
Due to changes in demographic assumptions 87 $ (38) $ 25
Adjustments for prescription drug rebates $ 782