Goodwill and Other Intangible Assets - Summary of Changes in Carrying Amount of Goodwill (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Goodwill [Line Items]
Goodwill, Beginning Balance	$ 227,959
Impairment	(83,895)	$ 0
Translation adjustments	1,203
Goodwill, Ending Balance	145,267
Research Segment [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance	219,814
Impairment	(83,895)
Translation adjustments	1,160
Goodwill, Ending Balance	137,079
Consulting Segment Member
Goodwill [Line Items]
Goodwill, Beginning Balance	8,145
Impairment	0
Translation adjustments	43
Goodwill, Ending Balance	$ 8,188