XML 37 R31.htm IDEA: XBRL DOCUMENT v2.4.0.8
EMPLOYEE BENEFIT PLANS (Tables)
 3 Months Ended
Mar. 31, 2014
Compensation and Retirement Disclosure [Abstract]  
Schedule of the components of net periodic benefit cost
The following table shows the components of net periodic benefit cost (including amounts capitalized to our balance sheets) for our benefit plans:
 
 
Pension Benefits
 
Other Postretirement Benefits
 
 
Three Months Ended March 31
 
Three Months Ended March 31
(Millions)
 
2014
 
2013
 
2014
 
2013
Service cost
 
$
2.4

 
$
2.7

 
$
2.5

 
$
2.7

Interest cost
 
8.7

 
7.8

 
3.9

 
3.3

Expected return on plan assets
 
(16.2
)
 
(14.4
)
 
(4.6
)
 
(3.7
)
Amortization of prior service cost (credit)
 
0.1

 
0.9

 
(1.1
)
 
(0.5
)
Amortization of net actuarial loss
 
3.7

 
5.8

 
0.6

 
1.8

Net periodic benefit cost (credit)
 
$
(1.3
)
 
$
2.8

 
$
1.3

 
$
3.6