Pension Plan (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Compensation and Retirement Disclosure [Abstract]
Service cost	$ 113	$ 52	$ 226	$ 120
Interest cost on projected benefit obligation	719	810	1,438	1,697
Expected return on plan assets	(1,297)	(1,380)	(2,594)	(2,849)
Net amortization and deferral	695	805	1,390	1,617
Net periodic pension cost	$ 230	$ 287	$ 460	$ 585