v3.25.4
Retirement benefits - Summary of Defined Benefit Plan Obligations (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Disclosure of net defined benefit liability (asset) [line items]      
Beginning balance $ (3,251)    
Actuarial (gains) losses (2,871) $ (4,266) $ 2,375
Other movements (10) (7) (5)
Ending balance 2,084 (3,251)  
Defined benefit plan obligation      
Disclosure of net defined benefit liability (asset) [line items]      
Beginning balance 66,054 78,024  
Current service cost 693 826  
Interest expense 2,941 2,911  
Actuarial (gains) losses (2,871) (4,266)  
Benefit payments (4,109) (3,770)  
Other movements (30) (4,837)  
Currency translation differences 5,040 (2,834)  
Ending balance 67,718 66,054 78,024
Defined benefit plan obligation | The Netherlands      
Disclosure of net defined benefit liability (asset) [line items]      
Beginning balance 23,577 26,746  
Current service cost 168 186  
Interest expense 811 847  
Actuarial (gains) losses (2,636) (1,377)  
Benefit payments (1,158) (1,076)  
Other movements 0 (251)  
Currency translation differences 2,836 (1,498)  
Ending balance 23,598 23,577 26,746
Defined benefit plan obligation | UK      
Disclosure of net defined benefit liability (asset) [line items]      
Beginning balance 16,957 19,074  
Current service cost 102 148  
Interest expense 907 847  
Actuarial (gains) losses (248) (1,793)  
Benefit payments (1,151) (1,081)  
Other movements (8) (1)  
Currency translation differences 1,175 (237)  
Ending balance 17,734 16,957 19,074
Defined benefit plan obligation | USA      
Disclosure of net defined benefit liability (asset) [line items]      
Beginning balance 9,596 15,579  
Current service cost 199 239  
Interest expense 485 507  
Actuarial (gains) losses 282 (997)  
Benefit payments (732) (702)  
Other movements 1 (5,030)  
Currency translation differences 0 0  
Ending balance 9,831 9,596 15,579
Defined benefit plan obligation | Rest of the world      
Disclosure of net defined benefit liability (asset) [line items]      
Beginning balance 13,046 13,524  
Current service cost 193 215  
Interest expense 566 556  
Actuarial (gains) losses (294) (22)  
Benefit payments (912) (770)  
Other movements (14) 540  
Currency translation differences 985 (997)  
Ending balance 13,570 13,046 13,524
Defined benefit plan obligation | Germany      
Disclosure of net defined benefit liability (asset) [line items]      
Beginning balance 3,234    
Ending balance 3,260 3,234  
Defined benefit plan obligation | Canada (Federal)      
Disclosure of net defined benefit liability (asset) [line items]      
Beginning balance 3,641    
Ending balance 3,772 3,641  
Defined benefit plan obligation | Third-party insurance contract | USA      
Disclosure of net defined benefit liability (asset) [line items]      
Beginning balance 5,052    
Ending balance   5,052  
Defined benefit plan obligation | Pensions | Funded pension plans      
Disclosure of net defined benefit liability (asset) [line items]      
Beginning balance 59,915    
Ending balance $ 61,387 $ 59,915  
Duration of defined benefit obligation 13 years 13 years  
Defined benefit plan obligation | Pensions | Funded pension plans | The Netherlands      
Disclosure of net defined benefit liability (asset) [line items]      
Beginning balance $ 23,577    
Ending balance $ 23,598 $ 23,577  
Duration of defined benefit obligation 14 years 15 years  
Defined benefit plan obligation | Pensions | Funded pension plans | UK      
Disclosure of net defined benefit liability (asset) [line items]      
Beginning balance $ 16,638    
Ending balance $ 17,352 $ 16,638  
Duration of defined benefit obligation 12 years 12 years  
Defined benefit plan obligation | Pensions | Funded pension plans | USA      
Disclosure of net defined benefit liability (asset) [line items]      
Beginning balance $ 8,787    
Ending balance $ 9,089 $ 8,787  
Duration of defined benefit obligation 12 years 12 years  
Defined benefit plan obligation | Pensions | Funded pension plans | Rest of the world      
Disclosure of net defined benefit liability (asset) [line items]      
Beginning balance $ 10,913    
Ending balance $ 11,348 $ 10,913  
Duration of defined benefit obligation 13 years 13 years  
Defined benefit plan obligation | Pensions | Unfunded pension plans      
Disclosure of net defined benefit liability (asset) [line items]      
Beginning balance $ 3,261    
Ending balance $ 3,346 $ 3,261  
Duration of defined benefit obligation 11 years 11 years  
Defined benefit plan obligation | Pensions | Unfunded pension plans | UK      
Disclosure of net defined benefit liability (asset) [line items]      
Beginning balance $ 319    
Ending balance $ 382 $ 319  
Duration of defined benefit obligation 13 years 15 years  
Defined benefit plan obligation | Pensions | Unfunded pension plans | USA      
Disclosure of net defined benefit liability (asset) [line items]      
Beginning balance $ 809    
Ending balance $ 742 $ 809  
Duration of defined benefit obligation 8 years 8 years  
Defined benefit plan obligation | Pensions | Unfunded pension plans | Rest of the world      
Disclosure of net defined benefit liability (asset) [line items]      
Beginning balance $ 2,133    
Ending balance $ 2,222 $ 2,133  
Duration of defined benefit obligation 11 years 11 years  
Defined benefit plan obligation | OPEB      
Disclosure of net defined benefit liability (asset) [line items]      
Beginning balance $ 2,878 $ 3,101  
Current service cost 31 38  
Interest expense 172 154  
Actuarial (gains) losses 25 (77)  
Benefit payments (156) (141)  
Other movements (9) (95)  
Currency translation differences 44 (102)  
Ending balance 2,985 2,878 3,101
Defined benefit plan obligation | OPEB | Unfunded pension plans      
Disclosure of net defined benefit liability (asset) [line items]      
Beginning balance 2,878    
Ending balance $ 2,985 $ 2,878  
Duration of defined benefit obligation 14 years 12 years  
Defined benefit plan assets      
Disclosure of net defined benefit liability (asset) [line items]      
Beginning balance $ (69,707) $ (79,961)  
Interest expense (3,153) (2,999)  
Benefit payments 3,905 3,590  
Other movements (24) 4,452  
Currency translation differences (5,711) 3,337  
Ending balance (72,913) (69,707) (79,961)
Defined benefit plan assets | The Netherlands      
Disclosure of net defined benefit liability (asset) [line items]      
Beginning balance (28,330) (30,266)  
Interest expense (983) (946)  
Benefit payments 1,158 1,076  
Other movements 11 9  
Currency translation differences (3,428) 1,777  
Ending balance (29,703) (28,330) (30,266)
Defined benefit plan assets | UK      
Disclosure of net defined benefit liability (asset) [line items]      
Beginning balance (19,560) (22,320)  
Interest expense (1,052) (995)  
Benefit payments 1,151 1,081  
Other movements 22 22  
Currency translation differences (1,371) 270  
Ending balance (20,366) (19,560) (22,320)
Defined benefit plan assets | USA      
Disclosure of net defined benefit liability (asset) [line items]      
Beginning balance (9,425) (14,835)  
Interest expense (486) (487)  
Benefit payments 732 702  
Other movements 11 4,891  
Currency translation differences 0 0  
Ending balance (9,529) (9,425) (14,835)
Defined benefit plan assets | Rest of the world      
Disclosure of net defined benefit liability (asset) [line items]      
Beginning balance (12,392) (12,540)  
Interest expense (632) (571)  
Benefit payments 864 731  
Other movements (68) (470)  
Currency translation differences (912) 1,290  
Ending balance (13,315) (12,392) $ (12,540)
Defined benefit plan assets | Germany      
Disclosure of net defined benefit liability (asset) [line items]      
Beginning balance (2,705)    
Ending balance (3,123) (2,705)  
Defined benefit plan assets | Canada (Federal)      
Disclosure of net defined benefit liability (asset) [line items]      
Beginning balance (3,179)    
Ending balance (3,111) (3,179)  
Defined benefit plan assets | Third-party insurance contract | USA      
Disclosure of net defined benefit liability (asset) [line items]      
Beginning balance $ 4,920    
Ending balance   $ 4,920