Restructuring - Summary of Restructuring Charges (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Restructuring Cost and Reserve [Line Items]
Total Restructuring Expenses	$ 6,991	$ 18,738	$ 29,277	$ 32,019
Right-of-Use Asset Impairment
Restructuring Cost and Reserve [Line Items]
Total Restructuring Expenses	2,456	14,287	18,634	23,010
Operating Lease Charges
Restructuring Cost and Reserve [Line Items]
Total Restructuring Expenses	1,557	979	2,570	1,778
Severance
Restructuring Cost and Reserve [Line Items]
Total Restructuring Expenses	2,694	1,856	4,725	2,992
Fixed Asset Impairment
Restructuring Cost and Reserve [Line Items]
Total Restructuring Expenses	263	1,072	2,952	2,569
Other Expenses
Restructuring Cost and Reserve [Line Items]
Total Restructuring Expenses	$ 21	$ 544	$ 396	$ 1,670