v3.26.1
Employee benefit plans (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Healthcare benefits        
Defined Benefit Plan Disclosure [Line Items]        
Service cost $ 0 $ 0 $ 0 $ 0
Interest cost 1 1 2 2
Expected return on assets (3) (2) (5) (4)
Other 1 1 2 2
Net periodic benefit (credit) cost (1) 0 (1) 0
Domestic | Pension Benefits        
Defined Benefit Plan Disclosure [Line Items]        
Service cost 0 0 0 0
Interest cost 44 46 88 92
Expected return on assets (90) (91) (178) (182)
Other 14 8 28 16
Net periodic benefit (credit) cost (32) (37) (62) (74)
Foreign | Pension Benefits        
Defined Benefit Plan Disclosure [Line Items]        
Service cost 4 0 8 3
Interest cost 11 11 23 21
Expected return on assets (20) (20) (40) (39)
Other 0 (1) 0 (2)
Net periodic benefit (credit) cost $ (5) $ (10) $ (9) $ (17)