Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Revenues:
Total revenues	$ 1,262,740	$ 1,104,038
Costs and expenses:
Cost of services and product development	377,033	334,467
Selling, general and administrative	617,904	487,255
Depreciation	23,201	25,750
Amortization of intangibles	25,148	30,514
Acquisition and integration charges	2,207	640
Total costs and expenses	1,045,493	878,626
Operating income	217,247	225,412
Interest expense, net	(31,394)	(26,149)
Other income, net	29,206	15,490
Income before income taxes	215,059	214,753
Provision for income taxes	42,544	50,653
Net income	$ 172,515	$ 164,100
Net income per share:
Basic (in dollars per share)	$ 2.10	$ 1.86
Diluted (in dollars per share)	$ 2.08	$ 1.84
Weighted average shares outstanding:
Basic (in shares)	82,020	88,352
Diluted (in shares)	82,973	89,139
Research
Revenues:
Total revenues	$ 1,136,380	$ 979,732
Conferences
Revenues:
Total revenues	10,354	24,802
Consulting
Revenues:
Total revenues	$ 116,006	$ 99,504