Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Revenues:
Total revenues	$ 1,534,130	$ 1,472,926
Costs and expenses:
Cost of services and product development	475,030	459,441
Selling, general and administrative	730,308	689,833
Depreciation	28,866	26,317
Amortization of intangibles	21,894	22,990
Acquisition and integration charges	0	460
Total costs and expenses	1,256,098	1,199,041
Operating income	278,032	273,885
Interest expense, net	(13,413)	(19,219)
Other income, net	2,389	4,891
Income before income taxes	267,008	259,557
Provision for income taxes	56,069	49,012
Net income	$ 210,939	$ 210,545
Net income per share:
Basic (in dollars per share)	$ 2.73	$ 2.69
Diluted (in dollars per share)	$ 2.71	$ 2.67
Weighted average shares outstanding:
Basic (in shares)	77,357	78,339
Diluted (in shares)	77,790	78,964
Research
Revenues:
Total revenues	$ 1,321,827	$ 1,268,172
Conferences
Revenues:
Total revenues	72,597	70,069
Consulting
Revenues:
Total revenues	$ 139,706	$ 134,685