Components of Net Periodic Benefit Cost (Details 2) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Net pension cost of plans
Service cost	$ 0	$ 0	$ 0	$ 100
Interest cost	1,931	1,916	5,793	5,771
Expected return on plan assets	(2,159)	(2,109)	(6,478)	(6,327)
Recognized actuarial loss	1,556	892	4,671	2,734
Net periodic benefit cost	$ 1,328	$ 699	$ 3,986	$ 2,278