Restructuring Charges - Changes to Restructuring Liability by Major Restructuring Activity (Details) - USD ($) $ in Thousands		3 Months Ended	9 Months Ended
		Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Restructuring Cost And Reserve [Line Items]
Beginning balance			$ 3,435
Restructuring charges		$ 2,186	3,467	$ 5,799
Cash payments			(1,641)
Non-cash items	[1]		(1,167)
Adjustment to liability			(8)
Ending balance			4,086
GES | Severance & Employee Benefits
Restructuring Cost And Reserve [Line Items]
Beginning balance			1,976
Restructuring charges			463
Cash payments			(869)
Non-cash items	[1]		0
Adjustment to liability			(3)
Ending balance			1,567
GES | Facilities
Restructuring Cost And Reserve [Line Items]
Beginning balance			1,433
Restructuring charges			2,974
Cash payments			(689)
Non-cash items	[1]		(1,167)
Adjustment to liability			(44)
Ending balance			2,507
Other Restructuring | Severance & Employee Benefits
Restructuring Cost And Reserve [Line Items]
Beginning balance			26
Restructuring charges			30
Cash payments			(83)
Adjustment to liability			39
Ending balance			$ 12

[1] Represents non-cash adjustments related to a write-down of certain ROU assets and leasehold improvements as a result of vacating certain facilities prior to the lease term.