Pensions and Other Postemployment Benefits (OPEB)
 3 Months Ended
Mar. 31, 2015
Compensation and Retirement Disclosure [Abstract]  
Pensions and Other Postemployment Benefits (OPEB)
Pensions and Other Postemployment Benefits (OPEB)
The following table provides the components of net periodic benefit cost for the first quarters ended March 31, 2015 and 2014.
 
 
Pension Benefits
 
OPEB
 
Quarter Ended
 
Quarter Ended
 
March 31
 
March 31
 
2015
 
2014
 
2015
 
2014
Service cost
$
—

 
$
—

 
$
171

 
$
153

Interest cost
1,356

 
1,551

 
351

 
375

Expected return on plan assets
(2,480
)
 
(2,581
)
 
—

 
—

Amortization of:
 
 
 
 
 
 
 
Unrecognized actuarial net loss
600

 
429

 
118

 
22

Unrecognized prior service credit
—

 
—

 
(287
)
 
(287
)
Net periodic benefit cost (credit)
$
(524
)
 
$
(601
)
 
$
353

 
$
263