Pension and Severance Plans (Tables)
 3 Months Ended
Mar. 31, 2015
Compensation and Retirement Disclosure [Abstract]  
Components of net periodic pension cost
The components of net periodic pension cost for these defined benefit plans are as follows:
 
For the Three Months Ended
March 31,
 
2015
 
2014
 
(In thousands)
Service cost
$
1,219

 
$
1,424

Interest cost
766

 
779

Expected return on plan assets
(856
)
 
(766
)
Amortization of prior service cost
9

 
49

Recognized actuarial loss
21

 
92

Net periodic pension cost
$
1,159

 
$
1,578
Schedule of Korean severance obligation
The balance of our Korean severance obligation consists of the following:
 
March 31,
2015
 
December 31,
2014
 
(In thousands)
Current (Accrued expenses)
$
13,809

 
$
13,226

Non-current (Pension and severance obligations)
133,701

 
133,435

Total Korean severance obligation
$
147,510

 
$
146,661