Goodwill and Intangible Assets - Schedule of Changes to the Carrying Amount of Goodwill by Segment (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2026 USD ($)
Goodwill [Roll Forward]
Beginning balance	$ 2,740,802
Foreign currency translation impact	(538)
Ending balance	2,740,264
Insights
Goodwill [Roll Forward]
Beginning balance	2,460,315
Foreign currency translation impact	(447)
Ending balance	2,459,868
Conferences
Goodwill [Roll Forward]
Beginning balance	184,052
Foreign currency translation impact	(10)
Ending balance	184,042
Consulting
Goodwill [Roll Forward]
Beginning balance	96,435
Foreign currency translation impact	(81)
Ending balance	$ 96,354