XML 77 R59.htm IDEA: XBRL DOCUMENT v3.23.2
Components of Net Periodic Benefit Cost (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2023
Jun. 30, 2022
Jun. 30, 2023
Jun. 30, 2022
Pension benefits        
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]        
Service cost $ 0.1 $ 1.0 $ 1.1 $ 2.1
Interest cost 4.4 2.6 7.0 5.1
Expected return on plan assets (1.7) (5.9) (7.5) (11.7)
Amortization of prior service costs 0.0 0.1 0.1 0.1
Amortization of net loss 2.4 1.0 3.2 1.7
Net periodic benefit cost (income) 5.2 (1.2) 3.9 (2.7)
Other postretirement benefits        
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]        
Service cost 0.0 0.0 0.1 0.1
Interest cost 1.2 0.6 1.9 1.3
Amortization of prior service costs 0.0 (0.5) 0.0 (1.0)
Amortization of net loss (0.2) 0.3 0.1 0.8
Net periodic benefit cost (income) $ 1.0 $ 0.4 $ 2.1 $ 1.2