v3.25.2
Retirement benefits - Summary of Assumptions for Sensitivity Analysis (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Rate of increase in pensionable remuneration    
Disclosure of sensitivity analysis for actuarial assumptions [line items]    
Percentage assumptions used 3.90% 4.00%
Range of assumptions, possible decrease 1.00%  
Range of assumptions, possible increase 1.00%  
Rate of increase in pensionable remuneration | of which the Netherlands    
Disclosure of sensitivity analysis for actuarial assumptions [line items]    
Percentage assumptions used 3.30% 3.30%
Rate of increase in pensionable remuneration | of which UK    
Disclosure of sensitivity analysis for actuarial assumptions [line items]    
Percentage assumptions used 4.10% 4.10%
Rate of increase in pensionable remuneration | of which USA    
Disclosure of sensitivity analysis for actuarial assumptions [line items]    
Percentage assumptions used 4.60% 4.60%
Rate of increase in pensionable remuneration | Bottom of range    
Disclosure of sensitivity analysis for actuarial assumptions [line items]    
Increase/(decrease) in defined benefit obligations $ 828 $ 833
Rate of increase in pensionable remuneration | Top of range    
Disclosure of sensitivity analysis for actuarial assumptions [line items]    
Increase/(decrease) in defined benefit obligations $ (915) $ (921)
Rate of increase in pensions in payment    
Disclosure of sensitivity analysis for actuarial assumptions [line items]    
Percentage assumptions used 1.90% 2.10%
Range of assumptions, possible decrease 1.00%  
Range of assumptions, possible increase 1.00%  
Rate of increase in pensions in payment | of which the Netherlands    
Disclosure of sensitivity analysis for actuarial assumptions [line items]    
Percentage assumptions used 2.40% 2.60%
Rate of increase in pensions in payment | of which UK    
Disclosure of sensitivity analysis for actuarial assumptions [line items]    
Percentage assumptions used 2.80% 3.00%
Rate of increase in pensions in payment | of which USA    
Disclosure of sensitivity analysis for actuarial assumptions [line items]    
Percentage assumptions used 0.00% 0.00%
Rate of increase in pensions in payment | Bottom of range    
Disclosure of sensitivity analysis for actuarial assumptions [line items]    
Increase/(decrease) in defined benefit obligations $ 5,599 $ 5,542
Rate of increase in pensions in payment | Top of range    
Disclosure of sensitivity analysis for actuarial assumptions [line items]    
Increase/(decrease) in defined benefit obligations $ (6,713) $ (6,657)
Discount rate for pension plans    
Disclosure of sensitivity analysis for actuarial assumptions [line items]    
Percentage assumptions used 4.10% 4.50%
Range of assumptions, possible decrease 1.00%  
Range of assumptions, possible increase 1.00%  
Discount rate for pension plans | of which the Netherlands    
Disclosure of sensitivity analysis for actuarial assumptions [line items]    
Percentage assumptions used 3.30% 3.70%
Discount rate for pension plans | of which UK    
Disclosure of sensitivity analysis for actuarial assumptions [line items]    
Percentage assumptions used 4.60% 4.80%
Discount rate for pension plans | of which USA    
Disclosure of sensitivity analysis for actuarial assumptions [line items]    
Percentage assumptions used 4.90% 5.00%
Discount rate for pension plans | Bottom of range    
Disclosure of sensitivity analysis for actuarial assumptions [line items]    
Increase/(decrease) in defined benefit obligations $ (10,560) $ (10,522)
Discount rate for pension plans | Top of range    
Disclosure of sensitivity analysis for actuarial assumptions [line items]    
Increase/(decrease) in defined benefit obligations $ 8,472 $ 8,328
Inflation rate for defined benefit obligation    
Disclosure of sensitivity analysis for actuarial assumptions [line items]    
Weighted average inflation rate used in the calculation of the defined benefit obligation 2.00% 2.20%
Range of assumptions, possible decrease 1.00%  
Range of assumptions, possible increase 1.00%  
Inflation rate for defined benefit obligation | of which the Netherlands    
Disclosure of sensitivity analysis for actuarial assumptions [line items]    
Weighted average inflation rate used in the calculation of the defined benefit obligation 2.40% 2.60%
Inflation rate for defined benefit obligation | of which UK    
Disclosure of sensitivity analysis for actuarial assumptions [line items]    
Weighted average inflation rate used in the calculation of the defined benefit obligation 2.90% 3.10%
Inflation rate for defined benefit obligation | Bottom of range    
Disclosure of sensitivity analysis for actuarial assumptions [line items]    
Increase/(decrease) in defined benefit obligations $ 6,034 $ 6,002
Inflation rate for defined benefit obligation | Top of range    
Disclosure of sensitivity analysis for actuarial assumptions [line items]    
Increase/(decrease) in defined benefit obligations $ (7,300) $ (7,271)
Rate of increase in health-care costs    
Disclosure of sensitivity analysis for actuarial assumptions [line items]    
Percentage assumptions used 7.00% 6.40%
Range of assumptions, possible decrease 1.00%  
Range of assumptions, possible increase 1.00%  
Rate of increase in health-care costs | Bottom of range    
Disclosure of sensitivity analysis for actuarial assumptions [line items]    
Increase/(decrease) in defined benefit obligations $ 338 $ 298
Rate of increase in health-care costs | Top of range    
Disclosure of sensitivity analysis for actuarial assumptions [line items]    
Increase/(decrease) in defined benefit obligations $ (422) $ (372)
Discount rate for health-care plans    
Disclosure of sensitivity analysis for actuarial assumptions [line items]    
Percentage assumptions used 5.60% 5.70%
Range of assumptions, possible decrease 1.00%  
Range of assumptions, possible increase 1.00%  
Discount rate for health-care plans | Bottom of range    
Disclosure of sensitivity analysis for actuarial assumptions [line items]    
Increase/(decrease) in defined benefit obligations $ (457) $ (401)
Discount rate for health-care plans | Top of range    
Disclosure of sensitivity analysis for actuarial assumptions [line items]    
Increase/(decrease) in defined benefit obligations $ 358 $ 309
Men    
Disclosure of sensitivity analysis for actuarial assumptions [line items]    
Expected age at death assumptions used 88 years 87 years
Range of assumptions, expected age at death decrease 1 year  
Range of assumptions, expected age at death increase 1 year  
Men | of which the Netherlands    
Disclosure of sensitivity analysis for actuarial assumptions [line items]    
Expected age at death assumptions used 88 years 88 years
Men | of which UK    
Disclosure of sensitivity analysis for actuarial assumptions [line items]    
Expected age at death assumptions used 87 years 87 years
Men | of which USA    
Disclosure of sensitivity analysis for actuarial assumptions [line items]    
Expected age at death assumptions used 87 years 85 years
Men | Bottom of range    
Disclosure of sensitivity analysis for actuarial assumptions [line items]    
Increase/(decrease) in defined benefit obligations $ 1,166 $ 1,130
Men | Top of range    
Disclosure of sensitivity analysis for actuarial assumptions [line items]    
Increase/(decrease) in defined benefit obligations $ (1,143) $ (1,103)
Women    
Disclosure of sensitivity analysis for actuarial assumptions [line items]    
Expected age at death assumptions used 89 years 89 years
Range of assumptions, expected age at death decrease 1 year  
Range of assumptions, expected age at death increase 1 year  
Women | of which the Netherlands    
Disclosure of sensitivity analysis for actuarial assumptions [line items]    
Expected age at death assumptions used 90 years 89 years
Women | of which UK    
Disclosure of sensitivity analysis for actuarial assumptions [line items]    
Expected age at death assumptions used 89 years 90 years
Women | of which USA    
Disclosure of sensitivity analysis for actuarial assumptions [line items]    
Expected age at death assumptions used 89 years 86 years
Women | Bottom of range    
Disclosure of sensitivity analysis for actuarial assumptions [line items]    
Increase/(decrease) in defined benefit obligations $ 1,006 $ 993
Women | Top of range    
Disclosure of sensitivity analysis for actuarial assumptions [line items]    
Increase/(decrease) in defined benefit obligations $ (1,041) $ (1,077)