Pension and Other Post-Retirement Benefit Plans - Components of Net Periodic Benefit Cost (Details) - Pension Plan - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
U.S. Pension and Other Post-Retirement Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 281	$ 217	$ 843	$ 1,107
Expected return on plan assets	(519)	(470)	(1,556)	(1,794)
Amortization of prior service cost	2	23	5	2,517
Recognized actuarial loss	74	75	223	262
Net (benefit) cost	(162)	(155)	(485)	2,092
Non-U.S. Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Interest cost	210	268	618	831
Expected return on plan assets	(277)	(268)	(806)	(834)
Amortization of prior service cost	151	12	437	36
Recognized actuarial loss	12	129	36	397
Net (benefit) cost	$ 96	$ 141	$ 285	$ 430