Components of Net Periodic Benefit Cost (Details 2) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Net pension cost of plans
Interest cost	$ 1,950	$ 1,931
Expected return on plan assets	(2,061)	(2,159)
Recognized actuarial loss	597	1,557
Net periodic benefit cost	$ 486	$ 1,329