v3.26.1
Retirement benefit obligations - Assumptions (Details)
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Actuarial assumptions    
Discount rate 1.30% 1.00%
Salary growth rate 0.90% 1.00%
Pension growth rate 0.00% 0.00%
Discount rate    
Actuarial assumptions    
Percentage of reasonably possible increase in actuarial assumption 0.25% 0.25%
Increase (decrease) in defined benefit obligation due to reasonably possible increase in actuarial assumption, percentage (3.54%) (3.99%)
Percentage of reasonably possible decrease in actuarial assumption (0.25%) (0.25%)
Increase (decrease) in defined benefit obligation due to reasonably possible decrease in actuarial assumption, percentage 4.02% 4.64%
Interest rates on retirement savings capital    
Actuarial assumptions    
Percentage of reasonably possible increase in actuarial assumption 0.25% 0.25%
Increase (decrease) in defined benefit obligation due to reasonably possible increase in actuarial assumption, percentage 0.55% 0.09%
Percentage of reasonably possible decrease in actuarial assumption (0.25%) (0.25%)
Increase (decrease) in defined benefit obligation due to reasonably possible decrease in actuarial assumption, percentage (0.54%) (0.08%)
Salaries    
Actuarial assumptions    
Percentage of reasonably possible increase in actuarial assumption 0.25% 0.25%
Increase (decrease) in defined benefit obligation due to reasonably possible increase in actuarial assumption, percentage 0.01% 0.06%
Percentage of reasonably possible decrease in actuarial assumption (0.25%) (0.25%)
Increase (decrease) in defined benefit obligation due to reasonably possible decrease in actuarial assumption, percentage (0.01%) (0.03%)
Life expectancy    
Actuarial assumptions    
Period of reasonably possible increase in actuarial assumption 1 year 1 year
Increase (decrease) in defined benefit obligation due to reasonably possible increase in actuarial assumption, percentage 1.44% 1.54%
Period of reasonably possible decrease in actuarial assumption 1 year 1 year
Increase (decrease) in defined benefit obligation due to reasonably possible decrease in actuarial assumption, percentage (1.50%) (1.59%)