Employee Pension Plans (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Summary of net periodic benefit cost
Interest cost	$ 1,053	$ 1,011	$ 2,106	$ 2,022
Expected return on plan assets	(1,203)	(1,256)	(2,406)	(2,512)
Amortization of net loss	427	1,460	854	2,920
Other	150		300
Net periodic benefit cost	$ 427	$ 1,215	854	2,430
Company contribution			800	$ 1,400
Expected contributions remainder of current fiscal year			$ 1,000