Retirement Plans - Reconciliation of Benefit Obligation, Plan Assets, and Funded Status (Details 2) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Change in plan assets:
Beginning Balance	$ 259,752
Ending Balance	282,696	$ 259,752
Defined Benefit Plan, Benefit Obligation, Benefits Paid	$ (145)	$ (157)
Post-Retirement Life Insurance Plan
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.09%	4.26%	3.59%
Retirement Plans
Defined Benefit Plan, Accumulated Benefit Obligation	$ 4,766	$ 4,595
Change in projected benefit obligation:
Beginning Balance	4,595	5,134
Service cost	1	2	$ 2
Interest cost	170	156	161
Actuarial loss (gain)	145	(540)
Ending Balance	4,766	4,595	5,134
Change in plan assets:
Beginning Balance	0	0
Actual return on assets	0	0
Company contributions	145	157
Foreign exchange impact	0	0
Ending Balance	0	0	$ 0
Funded status (plan assets less projected benefit obligations)	(4,766)	(4,595)
Defined Benefit Plan, Benefit Obligation, Benefits Paid	$ (145)	$ (157)
UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.15%	4.30%	3.63%
Retirement Plans
Defined Benefit Plan, Accumulated Benefit Obligation	$ 220,339	$ 205,319
Change in projected benefit obligation:
Beginning Balance	205,319	228,934
Service cost	0	0	$ 0
Interest cost	7,724	7,123	8,273
Actuarial loss (gain)	22,130	(15,957)
Foreign exchange impact	0	0
Ending Balance	220,339	205,319	228,934
Change in plan assets:
Beginning Balance	258,327	284,762
Actual return on assets	37,680	(11,757)
Company contributions	103	103
Foreign exchange impact	0	0
Ending Balance	281,276	258,327	$ 284,762
Funded status (plan assets less projected benefit obligations)	60,937	53,008
Defined Benefit Plan, Benefit Obligation, Benefits Paid	$ (14,834)	$ (14,781)
Foreign Plan
Defined Benefit Plan Disclosure [Line Items]
Discount rate	1.00%	1.13%	1.38%
Retirement Plans
Defined Benefit Plan, Accumulated Benefit Obligation	$ 1,854	$ 1,936
Change in projected benefit obligation:
Beginning Balance	2,756	3,140
Service cost	37	43	$ 48
Interest cost	31	42	34
Actuarial loss (gain)	153	287
Foreign exchange impact	64	(87)
Ending Balance	2,633	2,756	3,140
Change in plan assets:
Beginning Balance	1,425	1,777
Actual return on assets	73	67
Company contributions	295	300
Foreign exchange impact	34	(50)
Ending Balance	1,419	1,425	$ 1,777
Funded status (plan assets less projected benefit obligations)	(1,214)	(1,331)
Defined Benefit Plan, Benefit Obligation, Benefits Paid	$ (408)	$ (669)