v3.25.4
Pensions and other postretirement benefits (Weighted-average Assumptions Used) (Details)
12 Months Ended
Dec. 31, 2026
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Pensions        
To determine projected benefit obligation        
Discount rate   4.88% 4.65% 4.64%
Rate of compensation increase   2.75% 2.75% 2.75%
To determine net periodic benefit cost (income)        
Rate to determine current service cost   4.80% 4.62% 5.25%
Rate to determine interest cost   4.30% 4.61% 5.21%
Rate of compensation increase   2.75% 2.75% 2.75%
Expected return on plan assets   7.10% 7.30% 7.60%
Expected return on plan asset assumption to be used in future year (in hundredths)   7.10%    
Pensions | Forecast        
To determine net periodic benefit cost (income)        
Expected return on plan asset assumption to be used in future year (in hundredths) 7.10%      
Pensions | Change In Methodology Of Net Periodic Pension Cost (Income)        
To determine net periodic benefit cost (income)        
Period in years over which realized and unrealized gains/losses and appreciation/depreciation in the value of the investments are recognized based on the companies election to use market related value   5 years    
Corridor percentage   10.00%    
Pensions | Maximum | Change In Methodology Of Net Periodic Pension Cost (Income)        
To determine net periodic benefit cost (income)        
Market-related value, as a percentage   110.00%    
Pensions | Minimum | Change In Methodology Of Net Periodic Pension Cost (Income)        
To determine net periodic benefit cost (income)        
Market-related value, as a percentage   90.00%    
Other postretirement benefits        
To determine projected benefit obligation        
Discount rate   4.95% 4.85% 4.71%
Rate of compensation increase   2.75% 2.75% 2.75%
To determine net periodic benefit cost (income)        
Rate to determine current service cost   5.03% 4.73% 5.17%
Rate to determine interest cost   4.52% 4.68% 5.23%
Rate of compensation increase   2.75% 2.75% 2.75%