v3.25.1

REVENUE RECOGNITION - Disaggregation of Operating Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Disaggregation Of Revenue [Line Items]
Operating revenues	$ 745,826	$ 679,965
Index
Disaggregation Of Revenue [Line Items]
Operating revenues	421,743	373,872
Analytics
Disaggregation Of Revenue [Line Items]
Operating revenues	172,185	163,966
Sustainability and Climate
Disaggregation Of Revenue [Line Items]
Operating revenues	84,619	77,884
All Other - Private Assets
Disaggregation Of Revenue [Line Items]
Operating revenues	67,279	64,243
Recurring subscriptions
Disaggregation Of Revenue [Line Items]
Operating revenues	552,641	513,055
Recurring subscriptions | Index
Disaggregation Of Revenue [Line Items]
Operating revenues	233,330	212,952
Recurring subscriptions | Analytics
Disaggregation Of Revenue [Line Items]
Operating revenues	169,755	160,551
Recurring subscriptions | Sustainability and Climate
Disaggregation Of Revenue [Line Items]
Operating revenues	82,737	76,418
Recurring subscriptions | All Other - Private Assets
Disaggregation Of Revenue [Line Items]
Operating revenues	66,819	63,134
Asset-based fees
Disaggregation Of Revenue [Line Items]
Operating revenues	177,415	150,259
Asset-based fees | Index
Disaggregation Of Revenue [Line Items]
Operating revenues	177,415	150,259
Asset-based fees | Analytics
Disaggregation Of Revenue [Line Items]
Operating revenues	0	0
Asset-based fees | Sustainability and Climate
Disaggregation Of Revenue [Line Items]
Operating revenues	0	0
Asset-based fees | All Other - Private Assets
Disaggregation Of Revenue [Line Items]
Operating revenues	0	0
Non-recurring
Disaggregation Of Revenue [Line Items]
Operating revenues	15,770	16,651
Non-recurring | Index
Disaggregation Of Revenue [Line Items]
Operating revenues	10,998	10,661
Non-recurring | Analytics
Disaggregation Of Revenue [Line Items]
Operating revenues	2,430	3,415
Non-recurring | Sustainability and Climate
Disaggregation Of Revenue [Line Items]
Operating revenues	1,882	1,466
Non-recurring | All Other - Private Assets
Disaggregation Of Revenue [Line Items]
Operating revenues	$ 460	$ 1,109

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