v3.25.4
Employee benefit plans - Actuarial Assumptions (Details)
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Pension plans      
Actuarial assumptions used to determine annual benefit expense      
Weighted average discount rate 5.56% 4.85% 5.20%
Weighted average rate of compensation increases 3.20% 3.20% 3.00%
Weighted average expected long-term rate of return on plan assets 4.97% 5.80% 6.30%
Actuarial assumptions used to determine benefit obligations at end of year      
Weighted average discount rate 5.35% 5.55% 4.85%
Weighted average rate of compensation increases 3.20% 3.20% 3.00%
Post-retirement healthcare plan      
Actuarial assumptions used to determine annual benefit expense      
Weighted average discount rate 5.67% 5.16% 5.37%
Actuarial assumptions used to determine benefit obligations at end of year      
Weighted average discount rate 5.48% 5.67% 5.16%
Post-retirement healthcare plan | Maximum      
Actuarial assumptions used to determine annual benefit expense      
Weighted average annual medical cost increase rate 6.60% 6.80% 6.90%
Actuarial assumptions used to determine benefit obligations at end of year      
Weighted average annual medical cost increase rate 6.50% 6.60% 6.80%
Post-retirement healthcare plan | Minimum      
Actuarial assumptions used to determine annual benefit expense      
Weighted average annual medical cost increase rate 4.50% 4.50% 4.50%
Actuarial assumptions used to determine benefit obligations at end of year      
Weighted average annual medical cost increase rate 4.50% 4.50% 4.50%