Pension Plan (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Compensation and Retirement Disclosure [Abstract]
Service cost	$ 113	$ 60	$ 339	$ 180
Interest cost on projected benefit obligation	719	849	2,158	2,546
Expected return on plan assets	(1,297)	(1,424)	(3,892)	(4,273)
Net amortization and deferral	695	808	2,085	2,425
Net periodic pension cost	$ 230	$ 293	$ 690	$ 878