v3.26.1
Share based payments - Stock options Narrative (Details)
$ in Millions
6 Months Ended
Jun. 30, 2026
USD ($)
shares
Jun. 30, 2025
USD ($)
Disclosure of terms and conditions of share-based payment arrangement [line items]    
Number of shares on conversion (in shares) | shares 1  
Total share based payment expense | $ $ 52 $ 55
Non-executive director | Stock options    
Disclosure of terms and conditions of share-based payment arrangement [line items]    
Vesting period 3 years  
Executive directors | Stock options | January 1, 2026 Grants    
Disclosure of terms and conditions of share-based payment arrangement [line items]    
Vesting period 3 years  
Share based compensation award tranche one    
Disclosure of terms and conditions of share-based payment arrangement [line items]    
Vesting percentage 0.3333  
Share based compensation award tranche two    
Disclosure of terms and conditions of share-based payment arrangement [line items]    
Vesting percentage 0.0278