XML 41 R30.htm IDEA: XBRL DOCUMENT v3.4.0.3
Benefit Plans and Other Postretirement Benefits (Tables)
 3 Months Ended
Mar. 31, 2016
Compensation and Retirement Disclosure [Abstract]  
Components of Net Periodic Benefit Cost
Components of Net Periodic Benefit Cost
 
 
Three Months Ended March 31
 
 
2016
 
2015
 
2016
 
2015
(Thousands of Dollars)
 
Pension Benefits
 
Postretirement Health
Care Benefits
Service cost
 
$
1,104

 
$
1,190

 
$
6

 
$
7

Interest cost
 
1,704

 
1,630

 
163

 
163

Expected return on plan assets
 
(2,289
)
 
(2,371
)
 
(6
)
 
(8
)
Amortization of prior service cost (credit)
 
28

 
28

 
(88
)
 
(88
)
Amortization of net loss
 
1,348

 
1,701

 
83

 
114

Net benefit cost recognized for financial reporting
 
$
1,895

 
$
2,178

 
$
158

 
$
188