XML 45 R33.htm IDEA: XBRL DOCUMENT v3.24.3
Benefit Plans and Other Postretirement Benefits (Tables)
9 Months Ended
Sep. 30, 2024
Benefit Plans and Other Postretirement Benefits  
Schedule of components of net pension expense

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

Three Months Ended September 30, 

​

Nine Months Ended September 30, 

​

    

2024

 

2023

  

2024

 

2023

Service cost

 

$

0.9

​

$

1.8

​

$

2.7

​

$

5.5

Interest cost

​

 

6.1

​

 

6.5

​

 

18.1

​

 

19.5

Expected return on plan assets

​

 

(7.2)

​

 

(7.3)

​

 

(21.5)

​

 

(21.8)

Amortization of prior service cost

​

 

0.3

​

 

0.4

​

 

0.9

​

 

1.3

Amortization of net actuarial losses

​

 

0.8

​

 

0.6

​

 

2.5

​

 

1.6

Net pension expense

 

$

0.9

​

$

2.0

​

$

2.7

​

$

6.1