v3.25.2
Pension and Postretirement Benefits - Components of Net Periodic Benefit Expense (Income) (Details)
$ in Millions
 1 Months Ended 3 Months Ended 6 Months Ended
Mar. 31, 2024
USD ($)
retiree
Jun. 30, 2025
USD ($)
Jun. 30, 2024
USD ($)
Jun. 30, 2025
USD ($)
Jun. 30, 2024
USD ($)
Pension Plans          
Defined Benefit Plan Disclosure [Line Items]          
Service cost   $ 0.3 $ 0.3 $ 0.7 $ 0.6
Interest cost   46.8 45.0 92.4 92.9
Expected return on plan assets   (48.5) (52.0) (95.6) (108.2)
Amortization of prior service benefit   (1.2) (1.1) (2.3) (2.3)
Recognized net actuarial loss (gain)   24.5 20.4 48.5 44.0
Settlement losses       0.0 132.3
Net periodic pension and postretirement expense (income)   21.9 12.6 43.7 159.3
Pension Plans | U.S. Plans          
Defined Benefit Plan Disclosure [Line Items]          
Service cost   0.0 0.0 0.0 0.0
Interest cost   27.9 28.3 55.8 59.3
Expected return on plan assets   (26.3) (30.2) (52.6) (64.6)
Amortization of prior service benefit   (0.7) (0.6) (1.3) (1.2)
Recognized net actuarial loss (gain)   18.1 15.2 36.1 33.6
Settlement losses       0.0 132.3
Net periodic pension and postretirement expense (income)   19.0 12.7 38.0 159.4
Group annuity contract to transfer projected benefit obligations, purchase amount $ 195.0        
Group annuity contract to transfer projected benefit obligations, number of retirees | retiree 3,800        
Pension Plans | International Plans          
Defined Benefit Plan Disclosure [Line Items]          
Service cost   0.3 0.3 0.7 0.6
Interest cost   18.9 16.7 36.6 33.6
Expected return on plan assets   (22.2) (21.8) (43.0) (43.6)
Amortization of prior service benefit   (0.5) (0.5) (1.0) (1.1)
Recognized net actuarial loss (gain)   6.4 5.2 12.4 10.4
Settlement losses       0.0 0.0
Net periodic pension and postretirement expense (income)   2.9 (0.1) 5.7 (0.1)
Postretirement Benefit Plans          
Defined Benefit Plan Disclosure [Line Items]          
Service cost   0.1 0.0 0.1 0.1
Interest cost   0.6 0.6 1.2 1.2
Expected return on plan assets   0.0 (0.1) (0.1) (0.1)
Amortization of prior service benefit   0.0 0.0 0.1 0.0
Recognized net actuarial loss (gain)   (0.6) (0.7) (1.1) (1.5)
Net periodic pension and postretirement expense (income)   $ 0.1 $ (0.2) $ 0.2 $ (0.3)