XML 61 R49.htm IDEA: XBRL DOCUMENT v3.22.2.2
Pension and Postretirement Benefit Costs - Schedule of Net Periodic Benefit (Benefit) Cost (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2022
Sep. 30, 2021
Sep. 30, 2022
Sep. 30, 2021
Defined Benefit Plan Disclosure [Line Items]        
Net periodic pension credit $ (12.2) $ (8.6) $ (36.7) $ (26.0)
Defined benefit pension plans        
Defined Benefit Plan Disclosure [Line Items]        
Service cost for benefits earned 0.1 0.0 0.1 0.1
Interest cost on projected benefit obligation 5.3 5.2 16.0 15.4
Expected return on plan assets (6.0) (5.8) (17.9) (17.2)
Net periodic pension credit (0.6) (0.6) (1.8) (1.7)
Postretirement benefit plans        
Defined Benefit Plan Disclosure [Line Items]        
Service cost for benefits earned 0.2 0.3 0.6 0.8
Interest cost on projected benefit obligation 1.7 2.9 5.2 8.7
Expected return on plan assets (0.2) (0.3) (0.6) (0.7)
Amortization of prior service credit (13.4) (11.0) (40.3) (33.0)
Net periodic pension credit $ (11.7) $ (8.1) $ (35.1) $ (24.2)