Defined Benefit Plan (Tables)
 9 Months Ended
Sep. 30, 2016
Compensation and Retirement Disclosure [Abstract]  
Summary of Net Periodic Benefit Cost
Net periodic benefit cost consists of the following for the three and nine months ended September 30, 2016 and 2015 (in thousands):

 
Three months ended September 30,
 
Nine months ended September 30,
 
2016
 
2015
 
2016
 
2015
Service cost
$
111

 
$
121

 
$
325

 
$
455

Interest cost
35

 
34

 
103

 
132

Expected return on plan assets
5

 
(282
)
 
15

 
(416
)
Effect of curtailment
—

 
37

 
—

 
(864
)
Net periodic benefit cost
$
151

 
$
(90
)
 
$
443

 
$
(693
)