Revenue Recognition - Schedule of Revenue Recognition (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Disaggregation of Revenue [Line Items]
Total revenues	$ 3,666	$ 3,229
Transaction-based expenses	689	756
Total revenues, less transaction-based expenses	2,977	2,473
Data services revenues
Disaggregation of Revenue [Line Items]
Total revenues	277	246
Services transferred at a point in time
Disaggregation of Revenue [Line Items]
Total revenues, less transaction-based expenses	1,446	1,076
Services transferred over time
Disaggregation of Revenue [Line Items]
Total revenues, less transaction-based expenses	1,531	1,397
Exchanges Segment
Disaggregation of Revenue [Line Items]
Total revenues	2,470	2,123
Transaction-based expenses	689	756
Total revenues, less transaction-based expenses	1,781	1,367
Exchanges Segment | Data services revenues
Disaggregation of Revenue [Line Items]
Total revenues	277	246
Exchanges Segment | Net Interest Income
Disaggregation of Revenue [Line Items]
Total revenues		25
Revenue related to net interest income earned	28
Exchanges Segment | Services transferred at a point in time
Disaggregation of Revenue [Line Items]
Total revenues, less transaction-based expenses	1,182	852
Exchanges Segment | Services transferred over time
Disaggregation of Revenue [Line Items]
Total revenues, less transaction-based expenses	599	515
Exchanges Segment | Services transferred over time | Data services revenues
Disaggregation of Revenue [Line Items]
Total revenues, less transaction-based expenses	277	246
Exchanges Segment | Services transferred over time | Services transferred over time related to risk management of open interest performance obligations
Disaggregation of Revenue [Line Items]
Total revenues, less transaction-based expenses	161	109
Exchanges Segment | Services transferred over time | Services transferred over time related to listings
Disaggregation of Revenue [Line Items]
Total revenues, less transaction-based expenses	128	122
Exchanges Segment | Services transferred over time | Services transferred over time related to regulatory fees, trading permits, and software licenses
Disaggregation of Revenue [Line Items]
Total revenues, less transaction-based expenses	33	38
Fixed Income and Data Services Segment
Disaggregation of Revenue [Line Items]
Total revenues	657	596
Transaction-based expenses	0	0
Total revenues, less transaction-based expenses	657	596
Fixed Income and Data Services Segment | Data services revenues
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Fixed Income and Data Services Segment | Net Interest Income
Disaggregation of Revenue [Line Items]
Total revenues		26
Revenue related to net interest income earned	26
Fixed Income and Data Services Segment | Services transferred at a point in time
Disaggregation of Revenue [Line Items]
Total revenues, less transaction-based expenses	129	114
Fixed Income and Data Services Segment | Services transferred over time
Disaggregation of Revenue [Line Items]
Total revenues, less transaction-based expenses	528	482
Fixed Income and Data Services Segment | Services transferred over time | Services transferred over time related to risk management of open interest performance obligations
Disaggregation of Revenue [Line Items]
Total revenues, less transaction-based expenses	14	11
Fixed Income and Data Services Segment | Services transferred over time | Data services revenues
Disaggregation of Revenue [Line Items]
Total revenues, less transaction-based expenses	514	471
Mortgage Technology Segment
Disaggregation of Revenue [Line Items]
Total revenues	539	510
Transaction-based expenses	0	0
Total revenues, less transaction-based expenses	539	510
Mortgage Technology Segment | Data services revenues
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Mortgage Technology Segment | Services transferred at a point in time
Disaggregation of Revenue [Line Items]
Total revenues, less transaction-based expenses	135	110
Mortgage Technology Segment | Services transferred over time
Disaggregation of Revenue [Line Items]
Total revenues, less transaction-based expenses	404	400
Mortgage Technology Segment | Services transferred over time | Recurring revenues
Disaggregation of Revenue [Line Items]
Total revenues, less transaction-based expenses	401	397
Mortgage Technology Segment | Services transferred over time | Other
Disaggregation of Revenue [Line Items]
Total revenues, less transaction-based expenses	$ 3	$ 3