Employee Pension Plans (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Summary of net periodic benefit cost
Interest cost	$ 1,008	$ 1,030	$ 3,030	$ 3,090
Expected return on plan assets	(1,256)	(1,192)	(3,768)	(3,576)
Amortization of net loss	(1,417)	1,077	1,503	3,231
Net periodic benefit cost	$ (1,665)	$ 915	765	2,745
Company contribution			2,300	$ 4,100
Expected contributions remainder of current fiscal year			$ 500