Restructuring Charges - Changes to Restructuring Liability by Major Restructuring Activity (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Restructuring Cost And Reserve [Line Items]
Beginning balance			$ 3,439
Restructuring charges	$ 192	$ 1,426	645	$ 2,080
Cash payments			(792)
Adjustment to liability			39
Ending balance	3,331		3,331
GES | Severance & Employee Benefits
Restructuring Cost And Reserve [Line Items]
Beginning balance			1,609
Restructuring charges			227
Cash payments			(297)
Adjustment to liability			0
Ending balance	1,539		1,539
GES | Facilities
Restructuring Cost And Reserve [Line Items]
Beginning balance			1,818
Restructuring charges			409
Cash payments			(481)
Adjustment to liability			46
Ending balance	1,792		1,792
Other Restructuring | Severance & Employee Benefits
Restructuring Cost And Reserve [Line Items]
Beginning balance			12
Restructuring charges			9
Cash payments			(14)
Adjustment to liability			(7)
Ending balance	$ 0		$ 0