Segment and Geographic Data, Operating Margin Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating margin reconciliation [Abstract]
Segment Operating Income	$ 455,942	$ 543,696	$ 755,888
Restructuring and Severance Costs	(743)	(24,139)	0
Impact of coronavirus outbreak	1,451	0	0
Consolidated Operating Income (Loss)	209,710	262,430	485,120
Unallocated Other Income (Expense)	(51,382)	(36,132)	(68,344)
Consolidated Income Before Taxes	158,328	226,298	416,776
Unallocated Amount to Segment [Member]
Operating margin reconciliation [Abstract]
Segment Operating Income	$ (246,940)	$ (257,127)	$ (270,768)