Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Impact of Adopting ASU 2017-07 ASC 715 Compensation-Retirement Benefits	$ 2,500	$ 3,000
Defined Benefit Plan, Service Cost	5,319	4,843
Defined Benefit Plan, Interest Cost	1,400	2,075
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	(10,466)	(9,609)
Defined Benefits Plan Net amortization and deferral	(471)	(1,725)
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	7,000	6,272
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	2,782	1,856
Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year	27,900
Pension Plan [Member] | Foreign Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Service Cost	4,945	4,517
Defined Benefit Plan, Interest Cost	850	1,180
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	(8,972)	(8,085)
Defined Benefits Plan Net amortization and deferral	(471)	(1,725)
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	6,299	5,654
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	2,651	1,541
Pension Plan [Member] | UNITED STATES
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Service Cost	374	326
Defined Benefit Plan, Interest Cost	548	889
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	(1,494)	(1,524)
Defined Benefits Plan Net amortization and deferral	0	0
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	729	644
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	157	335
Other Postretirement Benefits Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Service Cost	0	0
Defined Benefit Plan, Interest Cost	2	6
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	0	0
Defined Benefits Plan Net amortization and deferral	0	0
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	(28)	(26)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	(26)	$ (20)
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year	$ 200