v3.26.1
Revenue and Related Matters - Schedule of Disaggregation of Revenue by Geographic Area (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Disaggregation of Revenue [Line Items]        
Total revenues $ 1,675,943 $ 1,686,454 $ 3,186,984 $ 3,220,584
United States and Canada        
Disaggregation of Revenue [Line Items]        
Total revenues 1,024,251 1,056,422 1,948,556 2,050,251
Europe, Middle East and Africa        
Disaggregation of Revenue [Line Items]        
Total revenues 458,169 427,908 858,300 791,053
Other International        
Disaggregation of Revenue [Line Items]        
Total revenues 193,523 202,124 380,128 379,280
Insights        
Disaggregation of Revenue [Line Items]        
Total revenues 1,289,870 1,263,505 2,584,065 2,519,074
Insights | United States and Canada        
Disaggregation of Revenue [Line Items]        
Total revenues 769,525 780,245 1,540,893 1,572,078
Insights | Europe, Middle East and Africa        
Disaggregation of Revenue [Line Items]        
Total revenues 355,022 322,523 712,178 636,030
Insights | Other International        
Disaggregation of Revenue [Line Items]        
Total revenues 165,323 160,737 330,994 310,966
Conferences        
Disaggregation of Revenue [Line Items]        
Total revenues 244,157 211,407 322,482 284,004
Conferences | United States and Canada        
Disaggregation of Revenue [Line Items]        
Total revenues 162,259 138,285 219,559 193,869
Conferences | Europe, Middle East and Africa        
Disaggregation of Revenue [Line Items]        
Total revenues 64,910 55,295 76,237 64,437
Conferences | Other International        
Disaggregation of Revenue [Line Items]        
Total revenues 16,988 17,827 26,686 25,698
Consulting        
Disaggregation of Revenue [Line Items]        
Total revenues 141,916 155,594 261,045 295,300
Consulting | United States and Canada        
Disaggregation of Revenue [Line Items]        
Total revenues 92,467 91,779 173,551 182,743
Consulting | Europe, Middle East and Africa        
Disaggregation of Revenue [Line Items]        
Total revenues 38,237 42,796 66,527 75,099
Consulting | Other International        
Disaggregation of Revenue [Line Items]        
Total revenues $ 11,212 21,019 20,967 37,458
Other        
Disaggregation of Revenue [Line Items]        
Total revenues   55,948 19,392 122,206
Other | United States and Canada        
Disaggregation of Revenue [Line Items]        
Total revenues   46,113 14,553 101,561
Other | Europe, Middle East and Africa        
Disaggregation of Revenue [Line Items]        
Total revenues   7,294 3,358 15,487
Other | Other International        
Disaggregation of Revenue [Line Items]        
Total revenues   $ 2,541 $ 1,481 $ 5,158