Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Service Cost	$ 4,843	$ 3,952
Defined Benefit Plan, Interest Cost	2,075	3,720
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	(9,609)	(8,773)
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	(1,725)	(1,702)
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	6,272	5,591
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	1,856	2,788
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	25,600
Pension Plan [Member] | UNITED STATES
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Service Cost	326	266
Defined Benefit Plan, Interest Cost	889	1,146
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	(1,524)	(1,472)
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	0	0
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	644	593
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	335	533
Pension Plan [Member] | Foreign Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Service Cost	4,517	3,686
Defined Benefit Plan, Interest Cost	1,180	2,558
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	(8,085)	(7,301)
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	(1,725)	(1,702)
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	5,654	5,171
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	1,541	2,412
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	6	16
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	0	0
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	0	0
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	(26)	(173)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	(20)	$ (157)
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year	$ 200