v3.26.1
Pension and other postretirement benefits (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Other postretirement benefits plan        
Amortization of:        
Net periodic benefit cost $ 2 $ 1 $ 3 $ 2
U.S.        
Defined Benefit Plan Disclosure [Line Items]        
Service cost 1 1 1 1
Interest cost 6 6 12 12
Expected return on assets (6) (6) (12) (11)
Amortization of:        
Prior service credit 0 0 0 0
Actuarial loss 1 0 1 0
Curtailment gain 0 0 0 0
Settlement gain 0 0 0 0
Net periodic benefit cost 2 1 2 2
Non-U.S.        
Defined Benefit Plan Disclosure [Line Items]        
Service cost 8 10 17 20
Interest cost 23 22 46 42
Expected return on assets (25) (26) (51) (49)
Amortization of:        
Prior service credit (3) (3) (6) (6)
Actuarial loss 1 2 2 3
Curtailment gain (1) 0 (1) 0
Settlement gain (9) 0 (9) 0
Net periodic benefit cost $ (6) $ 5 $ (2) $ 10