Retirement Plans - Reconciliation of Benefit Obligation, Plan Assets, and Funded Status (Details 2) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Change in projected benefit obligation:
Benefits paid	$ (165)	$ (172)
Change in plan assets:
Beginning Balance	290,795
Benefits paid	(165)	(172)
Ending Balance	293,567	290,795
U.S.Pension Plans
Retirement Plans
Accumulated benefit obligation	247,276	256,924
Change in projected benefit obligation:
Beginning Balance	256,924	284,365
Service cost	87	171	$ 192
Interest cost	11,024	11,258	12,214
Benefits paid	(20,537)	(21,526)
Actuarial (gain) loss	(222)	(17,344)
Plan settlement	0	0
Foreign exchange impact	0	0
Ending Balance	247,276	256,924	284,365
Change in plan assets:
Beginning Balance	289,315	314,453
Actual return on assets	23,163	(3,723)
Company contributions	103	111
Benefits paid	(20,537)	(21,526)
Plan settlement	0	0
Foreign exchange impact	0	0
Ending Balance	292,044	289,315	314,453
Funded status (plan assets less projected benefit obligations)	44,768	32,391
Non-U.S. Pension Plans
Retirement Plans
Accumulated benefit obligation	2,295	2,247
Change in projected benefit obligation:
Beginning Balance	2,796	16,168
Service cost	51	63	83
Interest cost	46	465	608
Benefits paid	(289)	(691)
Actuarial (gain) loss	229	(131)
Plan settlement	0	12,786
Foreign exchange impact	33	(292)
Ending Balance	2,866	2,796	16,168
Change in plan assets:
Beginning Balance	1,480	15,128
Actual return on assets	11	(538)
Company contributions	303	1,275
Benefits paid	(289)	(691)
Plan settlement	0	(13,437)
Foreign exchange impact	18	(257)
Ending Balance	1,523	1,480	15,128
Funded status (plan assets less projected benefit obligations)	(1,343)	(1,316)
Post-Retirement Life Insurance Plan
Retirement Plans
Accumulated benefit obligation	4,952	4,885
Change in projected benefit obligation:
Beginning Balance	4,886	5,194
Service cost	3	5	4
Interest cost	207	204	230
Benefits paid	165	172
Actuarial (gain) loss	21	(345)
Ending Balance	4,952	4,886	5,194
Change in plan assets:
Beginning Balance	0	0
Actual return on assets	0	0
Company contributions	165	172
Benefits paid	165	172
Foreign exchange impact	0	0
Ending Balance	0	0	$ 0
Funded status (plan assets less projected benefit obligations)	$ (4,952)	$ (4,886)