Pension and Other Postretirement Benefits - Net Periodic Benefit Cost and Changes in Other Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss) [Abstract]
Net Loss (Gain) Arising During The Period			$ 210
Recognition of amortization in net periodic benefit cost Prior service credit (cost)			116
Actuarial Loss			(3,159)
Effect of exchange rates on amounts Included in AOCI			(890)
Total Recognized in Other Comprehensive (Income) Loss			(4,143)
Total Recognized In Net Periodic Benefit Cost And Other Comprehensive Loss Or (Income)			1,779
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service Cost	$ 4,831	$ 3,941	3,809
Interest Cost	6,339	6,359	4,101
Expected Return on Plan Assets	(9,072)	(6,895)	(5,031)
Settlement Loss	22,579	258	2
Curtailment Charge	(1,155)	0
Actuarial Loss Amortization	2,996	3,105	(3,157)
Prior Service (Credit) Cost Amortization	(167)	(165)	(116)
Net Periodic Benefit Cost	26,351	6,603	5,922
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss) [Abstract]
Net Loss (Gain) Arising During The Period	(58)	7,752
Recognition of amortization in net periodic benefit cost Prior service credit (cost)	1,375	196
Actuarial Loss	3,209	(3,362)
Other comprehensive income loss plan settlement	(22,706)	0
Other Comprehensive Income Loss Plan Curtailments	(3)	0
Effect of exchange rates on amounts Included in AOCI	1,535	(61)
Total Recognized in Other Comprehensive (Income) Loss	(16,648)	4,525
Total Recognized In Net Periodic Benefit Cost And Other Comprehensive Loss Or (Income)	9,703	11,128
Other Postretirement Benefit Plans Defined Benefit [Member]
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss) [Abstract]
Total Recognized in Other Comprehensive (Income) Loss	(859)	395	(485)
Foreign [Member]
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss) [Abstract]
Net Loss (Gain) Arising During The Period			663
Recognition of amortization in net periodic benefit cost Prior service credit (cost)			175
Actuarial Loss			(883)
Effect of exchange rates on amounts Included in AOCI			(890)
Total Recognized in Other Comprehensive (Income) Loss			(2,261)
Total Recognized In Net Periodic Benefit Cost And Other Comprehensive Loss Or (Income)			1,899
Foreign [Member] | Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service Cost	4,340	3,507	3,426
Interest Cost	3,416	3,046	2,254
Expected Return on Plan Assets	(4,262)	(3,668)	(2,228)
Settlement Loss	(88)	258	2
Curtailment Charge	(1,155)	0
Actuarial Loss Amortization	886	757	881
Prior Service (Credit) Cost Amortization	(167)	(165)	(175)
Net Periodic Benefit Cost	2,970	3,735	4,160
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss) [Abstract]
Net Loss (Gain) Arising During The Period	(1,594)	3,826	(663)
Recognition of amortization in net periodic benefit cost Prior service credit (cost)	1,325	196	175
Actuarial Loss	(758)	(1,015)	(883)
Other comprehensive income loss plan settlement	(39)	0
Other Comprehensive Income Loss Plan Curtailments	(3)	0
Effect of exchange rates on amounts Included in AOCI	1,535	(61)	890
Total Recognized in Other Comprehensive (Income) Loss	466	2,946
Total Recognized In Net Periodic Benefit Cost And Other Comprehensive Loss Or (Income)	3,436	6,681	1,899
U.S. [Member]
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss) [Abstract]
Net Loss (Gain) Arising During The Period			(453)
Recognition of amortization in net periodic benefit cost Prior service credit (cost)			(59)
Actuarial Loss			(2,276)
Effect of exchange rates on amounts Included in AOCI			0
Total Recognized in Other Comprehensive (Income) Loss			(1,882)
Total Recognized In Net Periodic Benefit Cost And Other Comprehensive Loss Or (Income)			(120)
U.S. [Member] | Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service Cost	491	434	383
Interest Cost	2,923	3,313	1,847
Expected Return on Plan Assets	(4,810)	(3,227)	(2,803)
Settlement Loss	22,667	0	0
Curtailment Charge	0	0
Actuarial Loss Amortization	2,110	2,348	2,276
Prior Service (Credit) Cost Amortization	0	0	59
Net Periodic Benefit Cost	23,381	2,868	1,762
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss) [Abstract]
Net Loss (Gain) Arising During The Period	1,536	3,926	453
Recognition of amortization in net periodic benefit cost Prior service credit (cost)	50	0	(59)
Actuarial Loss	3,967	(2,347)	(2,276)
Other comprehensive income loss plan settlement	(22,667)	0
Other Comprehensive Income Loss Plan Curtailments	0	0
Effect of exchange rates on amounts Included in AOCI	0	0	0
Total Recognized in Other Comprehensive (Income) Loss	(17,114)	1,579
Total Recognized In Net Periodic Benefit Cost And Other Comprehensive Loss Or (Income)	6,267	4,447	(120)
U.S. [Member] | Other Postretirement Benefit Plans Defined Benefit [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service Cost	5	6	7
Interest Cost	77	143	130
Prior Service (Credit) Cost Amortization	(5)	0	42
Net Periodic Benefit Cost	77	149	179
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss) [Abstract]
Net Loss (Gain) Arising During The Period	(864)	395	(443)
Actuarial Loss	5	0	(42)
Total Recognized In Net Periodic Benefit Cost And Other Comprehensive Loss Or (Income)	$ (782)	$ 544	$ (306)