v3.25.4
Income taxes - Income Tax Rate Reconciliation (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Income Tax Expense (Benefit), Effective Income Tax Rate Reconciliation, Amount [Abstract]      
Swiss federal statutory tax rate $ 127 $ 138 $ 111
Changes in unrecognized tax benefits (20) 15 43
OECD Pillar Two tax (6) 24  
Deferred tax adjustments 7    
Purchase price adjustments   (13)  
Repatriation cost 28    
Total income tax expense $ 326 $ 368 $ 361
Effective Income Tax Rate Reconciliation, Percent [Abstract]      
Swiss federal statutory tax rate 8.50% 8.50% 8.50%
Changes in unrecognized tax benefits (1.40%) 0.90% 3.30%
OECD Pillar Two tax (0.40%) 1.50%  
Deferred tax adjustments 0.50%    
Purchase price adjustments   (0.80%)  
Repatriation cost 1.80%    
Effective income tax rate 21.80% 22.60% 27.80%
SWITZERLAND      
Income Tax Expense (Benefit), Effective Income Tax Rate Reconciliation, Amount [Abstract]      
State and local income taxes $ 11 $ 14 $ 8
Other $ (3) $ (2)  
Effective Income Tax Rate Reconciliation, Percent [Abstract]      
State and local income taxes 0.70% 0.80% 0.60%
Other (0.10%) (0.10%)  
U.S.      
Income Tax Expense (Benefit), Effective Income Tax Rate Reconciliation, Amount [Abstract]      
State and local income taxes $ 33 $ 46 $ 46
Other (2) (8) 4
Effect of rates different than statutory 97 118 96
Nontaxable or nondeductible items     5
Percentage depletion $ (17) (18) (16)
Deferred tax adjustments   $ (18) $ 2
Effective Income Tax Rate Reconciliation, Percent [Abstract]      
State and local income taxes 2.20% 2.80% 3.60%
Other (0.10%) (0.50%) 0.30%
Effect of rates different than statutory 6.50% 7.20% 7.40%
Nontaxable or nondeductible items     0.40%
Percentage depletion (1.10%) (1.10%) (1.30%)
Deferred tax adjustments   (1.10%) 0.20%
Canada      
Income Tax Expense (Benefit), Effective Income Tax Rate Reconciliation, Amount [Abstract]      
State and local income taxes $ 1 $ 1 $ 1
Other (1) 6 3
Effect of rates different than statutory $ 70 58 51
Nontaxable or nondeductible items   $ 7 $ 7
Effective Income Tax Rate Reconciliation, Percent [Abstract]      
State and local income taxes 0.10% 0.10% 0.10%
Other (0.10%) 0.40% 0.10%
Effect of rates different than statutory 4.60% 3.50% 4.00%
Nontaxable or nondeductible items   0.50% 0.60%
Other foreign jurisdictions:      
Income Tax Expense (Benefit), Effective Income Tax Rate Reconciliation, Amount [Abstract]      
Other $ 1    
Effective Income Tax Rate Reconciliation, Percent [Abstract]      
Other 0.10%