XML 52 R34.htm IDEA: XBRL DOCUMENT v3.8.0.1
Pension and Other Postretirement Benefit Plans (Tables)
 3 Months Ended
Mar. 31, 2018
Retirement Benefits [Abstract]  
Components of Net Periodic Benefit Expense (Income) [Table Text Block]
 
Pension
 
Other
Postretirement
Components of Net Periodic Benefit Cost
2018
 
2017
 
2018
 
2017
Millions
 
 
 
 
 
 
 
Three Months Ended March 31,
 
 
 
 
 
 
 
Service Cost

$2.7

 

$2.5

 

$1.2

 

$1.1

Interest Cost (a)
7.4

 
8.1

 
1.8

 
1.9

Expected Return on Plan Assets (a)
(11.0
)
 
(10.6
)
 
(2.7
)
 
(2.6
)
Amortization of Prior Service Credits (a)
—

 
—

 
(0.4
)
 
(0.5
)
Amortization of Net Loss (a)
3.0

 
2.5

 
0.2

 
0.1

Net Periodic Benefit Cost

$2.1

 

$2.5

 

$0.1

 
—


(a)
These components of net periodic benefit cost are included in the line item “Other” under Other Income (Expense) on the Consolidated Statement of Income.