Segment Information - Reconciliation of Segment Gross Contribution to Net Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total segment gross contribution	$ 273,885	$ 407,957
Costs and expenses:
Cost of services and product development - unallocated	459,441	435,139
Selling, general and administrative	689,833	657,090
Acquisition and integration charges	460	1,368
Gain from sale of divested operation	0	139,316
Operating income	273,885	407,957
Interest expense and other, net	(14,328)	(29,757)
Gain on event cancellation insurance claims	0	3,077
Less: Provision for income taxes	49,012	85,494
Net income	$ 210,545	295,783
Maximum
Costs and expenses:
Percent of target bonus charges allocated to segments	100.00%
Operating Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total segment gross contribution	$ 1,022,112	977,110
Costs and expenses:
Operating income	1,022,112	977,110
Corporate and Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total segment gross contribution	(748,227)	(569,153)
Costs and expenses:
Cost of services and product development - unallocated	8,627	3,380
Selling, general and administrative	689,833	657,090
Depreciation and amortization	49,307	46,631
Acquisition and integration charges	460	1,368
Operating income	$ (748,227)	$ (569,153)