XML 48 R36.htm IDEA: XBRL DOCUMENT v3.8.0.1
Pension Benefits and Other Postretirement Benefit Plans (Tables)
 3 Months Ended
Mar. 31, 2018
Defined Benefit Plan [Abstract]  
Components of net periodic benefit cost
The components of net periodic (benefit) cost for the periods indicated were:
(Dollars in thousands)
Pension Benefits
 
Retirement Health and
Life Insurance Benefits
Three Months Ended March 31,
 
Three Months Ended March 31,
Change in benefit obligation:
2018
 
2017
 
2018
 
2017
Service cost
$
—

 
$
—

 
$
20

 
$
39

Interest cost
1,680

 
1,841

 
15

 
18

Expected return on plan assets
(2,169
)
 
(2,309
)
 
—

 
—

Amortization of prior service cost (credit)
—

 
—

 
(400
)
 
(373
)
Amortization of net loss (gain)
456

 
433

 
—

 
(14
)
Net periodic (benefit) cost
$
(33
)
 
$
(35
)
 
$
(365
)
 
$
(330
)