Restructuring - Expected Cost, Costs Recognized, and Costs to be Recognized (Details) - USD ($) $ in Thousands		12 Months Ended
	Sep. 17, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restructuring Cost and Reserve [Line Items]
Costs charged to expense		$ 37,013	$ 6,278	$ 77,183
2020 Projects [Member]
Restructuring Cost and Reserve [Line Items]
Total Expected Costs at December 31, 2020		59,677
Costs charged to expense	$ 43,200	43,232	0
Expected Remaining Costs to be Recognized at December 31, 2020		16,445
2018 Projects [Member]
Restructuring Cost and Reserve [Line Items]
Total Expected Costs at December 31, 2020		85,821
Costs charged to expense		(6,219)	87,395
Expected Remaining Costs to be Recognized at December 31, 2020		4,645
Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Costs charged to expense		27,265
Employee Severance [Member] | 2020 Projects [Member]
Restructuring Cost and Reserve [Line Items]
Total Expected Costs at December 31, 2020		36,225
Costs charged to expense		36,225	0
Expected Remaining Costs to be Recognized at December 31, 2020		0
Employee Severance [Member] | 2018 Projects [Member]
Restructuring Cost and Reserve [Line Items]
Total Expected Costs at December 31, 2020		63,173
Costs charged to expense		(8,960)	72,133
Expected Remaining Costs to be Recognized at December 31, 2020		0
Asset Impairment and Net (Gain) Loss on Sale or Disposal [Member]
Restructuring Cost and Reserve [Line Items]
Costs charged to expense		5,888
Asset Impairment and Net (Gain) Loss on Sale or Disposal [Member] | 2020 Projects [Member]
Restructuring Cost and Reserve [Line Items]
Total Expected Costs at December 31, 2020		6,944
Costs charged to expense		6,944	0
Expected Remaining Costs to be Recognized at December 31, 2020		0
Asset Impairment and Net (Gain) Loss on Sale or Disposal [Member] | 2018 Projects [Member]
Restructuring Cost and Reserve [Line Items]
Total Expected Costs at December 31, 2020		2,786
Costs charged to expense		(1,056)	3,842
Expected Remaining Costs to be Recognized at December 31, 2020		0
Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Costs charged to expense		3,860
Other Restructuring [Member] | 2020 Projects [Member]
Restructuring Cost and Reserve [Line Items]
Total Expected Costs at December 31, 2020		16,508
Costs charged to expense		63	0
Expected Remaining Costs to be Recognized at December 31, 2020		16,445
Other Restructuring [Member] | 2018 Projects [Member]
Restructuring Cost and Reserve [Line Items]
Total Expected Costs at December 31, 2020		19,862
Costs charged to expense		3,797	$ 11,420
Expected Remaining Costs to be Recognized at December 31, 2020		$ 4,645