Goodwill and Intangible Assets - Schedule of Changes to the Carrying Amount of Goodwill by Segment (Details) $ in Thousands	9 Months Ended
Sep. 30, 2026 USD ($)
Goodwill [Roll Forward]
Beginning balance	$ 2,740,802
Foreign currency translation impact	(1,910)
Ending balance	2,738,892
Insights
Goodwill [Roll Forward]
Beginning balance	2,460,315
Foreign currency translation impact	(1,627)
Ending balance	2,458,688
Conferences
Goodwill [Roll Forward]
Beginning balance	184,052
Foreign currency translation impact	(34)
Ending balance	184,018
Consulting
Goodwill [Roll Forward]
Beginning balance	96,435
Foreign currency translation impact	(249)
Ending balance	$ 96,186

Amount, after accumulated impairment loss, of asset representing future economic benefit arising from other asset acquired in business combination or from joint venture formation or both, that is not individually identified and separately recognized.

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+ Details