v3.26.3
Pension and Postretirement Benefits - Components of Net Periodic Benefit Expense (Details) - USD ($)
$ in Millions
 1 Months Ended 3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Pension Plans            
Defined Benefit Plan Disclosure [Line Items]            
Service cost     $ 0.5 $ 0.4 $ 1.3 $ 1.1
Interest cost     40.4 47.8 120.5 140.2
Expected return on plan assets     (35.7) (57.2) (107.5) (152.8)
Amortization of prior service benefit     (1.2) (1.1) (3.6) (3.4)
Recognized net actuarial gain     27.7 25.1 80.8 73.6
Settlement losses     151.2 227.7 151.2 227.7
Net periodic postretirement benefit expense     182.9 242.7 242.7 286.4
Pension Plans | U.S. Plans            
Defined Benefit Plan Disclosure [Line Items]            
Service cost     0.0 0.0 0.0 0.0
Interest cost     22.2 28.6 65.1 84.4
Expected return on plan assets     (15.8) (34.6) (47.1) (87.2)
Amortization of prior service benefit     (0.6) (0.6) (1.9) (1.9)
Recognized net actuarial gain     18.6 18.7 53.6 54.8
Settlement losses     151.2 227.7 151.2 227.7
Net periodic postretirement benefit expense     175.6 239.8 220.9 277.8
Group annuity contract to transfer projected benefit obligations, purchase amount $ 200.0 $ 320.0        
Pension Plans | International Plans            
Defined Benefit Plan Disclosure [Line Items]            
Service cost     0.5 0.4 1.3 1.1
Interest cost     18.2 19.2 55.4 55.8
Expected return on plan assets     (19.9) (22.6) (60.4) (65.6)
Amortization of prior service benefit     (0.6) (0.5) (1.7) (1.5)
Recognized net actuarial gain     9.1 6.4 27.2 18.8
Settlement losses     0.0 0.0 0.0 0.0
Net periodic postretirement benefit expense     7.3 2.9 21.8 8.6
Postretirement Benefit Plans            
Defined Benefit Plan Disclosure [Line Items]            
Service cost     0.0 0.0 0.0 0.1
Interest cost     0.7 0.6 1.9 1.8
Expected return on plan assets     (0.1) 0.0 (0.1) (0.1)
Amortization of prior service benefit     0.2 0.1 0.5 0.2
Recognized net actuarial gain     (0.3) (0.5) (0.7) (1.6)
Net periodic postretirement benefit expense     $ 0.5 $ 0.2 $ 1.6 $ 0.4