v3.26.1
Components of Net Periodic Benefit Cost (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]        
Net periodic benefit cost     $ 9.5 $ 5.5
Pension Benefits        
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]        
Service cost $ 1.1 $ 0.6 4.7 1.3
Interest cost 4.9 3.5 16.5 6.8
Expected return on plan assets (5.4) (4.0) (14.7) (7.9)
Amortization of prior service benefit 0.2 0.0 0.3 0.1
Amortization of net (gain) loss 0.7 1.5 2.5 2.9
Net periodic benefit cost 1.5 1.6 9.3 3.2
Other Postretirement Benefits        
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]        
Service cost 0.1 0.1 0.2 0.1
Interest cost   0.9 1.2 1.9
Interest cost (0.1)      
Amortization of net (gain) loss (1.4) 0.1 (1.1) 0.3
Net periodic benefit cost $ (1.4) $ 1.1 $ 0.3 $ 2.3