Restructuring - Related Balance Sheet Activity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve - Beginning Balance	$ 56,107
Costs charged to expense	37,013	$ 6,278	$ 77,183
Cash (payments) receipts	(17,143)
Net assets disposed and impaired	8,102
Effect of change in exchange rates	4,751
Restructuring Reserve - Ending Balance	72,626	56,107
Employee severance costs
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve - Beginning Balance	53,741
Costs charged to expense	27,265
Cash (payments) receipts	(15,725)
Net assets disposed and impaired	0
Effect of change in exchange rates	4,724
Restructuring Reserve - Ending Balance	70,005	53,741
Asset Impairment and Net (Gain) Loss on Sale or Disposal [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve - Beginning Balance	0
Costs charged to expense	5,888
Cash (payments) receipts	(2,214)
Net assets disposed and impaired	8,102
Effect of change in exchange rates	0
Restructuring Reserve - Ending Balance	0	0
Other restructuring costs
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve - Beginning Balance	2,366
Costs charged to expense	3,860
Cash (payments) receipts	(3,632)
Net assets disposed and impaired	0
Effect of change in exchange rates	27
Restructuring Reserve - Ending Balance	$ 2,621	$ 2,366