Restructuring Costs - Restructuring Charges (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 29,420	$ 2,043	$ 4,468
Lease restructuring costs
Restructuring Cost and Reserve [Line Items]
Restructuring costs	24,330	0	0
ROU assets write down
Restructuring Cost and Reserve [Line Items]
Restructuring costs	13,938	0	0
Abandonment of property and equipment
Restructuring Cost and Reserve [Line Items]
Restructuring costs	5,147	0	0
Other lease restructuring costs
Restructuring Cost and Reserve [Line Items]
Restructuring costs	5,245	0	0
Severance and other associated costs
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 5,090	$ 2,043	$ 4,468