Segment Information - Reconciliation of Income Statement Items from Reportable Segments (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Reportable segments reconciliations:
Total revenue		$ 365,899	$ 382,721	$ 947,001	$ 879,284
ON Services sale purchase price adjustment		0	0	(204)	0
Interest expense, net		(12,476)	(10,252)	(37,081)	(23,890)
Other expense, net		(554)	(280)	(1,533)	(1,530)
Restructuring charges		(480)	(1,387)	(1,125)	(3,467)
Income (loss) from continuing operations before income taxes		58,953	50,669	53,792	40,938
GES
Reportable segments reconciliations:
Total revenue		178,959	218,925	638,924	614,105
Pursuit
Reportable segments reconciliations:
Total revenue		186,940	163,796	308,077	265,179
Operating Segments
Reportable segments reconciliations:
Segment operating income (loss)		76,025	66,339	103,941	80,238
Operating Segments | GES
Reportable segments reconciliations:
Segment operating income (loss)		(5,350)	6,590	31,867	36,116
Operating Segments | Pursuit
Reportable segments reconciliations:
Total revenue		186,940	163,796	308,077	265,179
Segment operating income (loss)		81,375	59,749	72,074	44,122
Restructuring charges		(192)	0	(201)	0
Operating Segments | Spiro
Reportable segments reconciliations:
Total revenue		58,887	73,277	199,617	205,518
Segment operating income (loss)		179	3,720	11,632	18,328
Restructuring charges		(155)	(71)	(331)	(1,297)
Operating Segments | GES-Exhibitions
Reportable segments reconciliations:
Total revenue		122,115	147,872	446,146	414,303
Segment operating income (loss)		(5,529)	2,870	20,235	17,788
Restructuring charges		(125)	(1,316)	(585)	(2,140)
Impairment charges		0	0	0	(583)
Operating Segments | Corporate
Reportable segments reconciliations:
Restructuring charges		(8)	0	(8)	(30)
Operating Segments | GES intersegment eliminations [Member]
Reportable segments reconciliations:
Total revenue		(2,043)	(2,224)	(6,839)	(5,716)
Corporate Eliminations
Reportable segments reconciliations:
Segment operating income (loss)	[1]	17	17	49	51
Corporate
Reportable segments reconciliations:
Segment operating income (loss)		$ (3,579)	$ (3,768)	$ (10,255)	$ (9,881)

[1] Corporate eliminations represent the elimination of depreciation expense recorded by Pursuit associated with previously eliminated intercompany profit realized by GES for renovations to Pursuit’s Banff Gondola.