Revenue Recognition - Schedule of Revenue Recognition (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Disaggregation of Revenue [Line Items]
Total revenues	$ 2,897	$ 2,336	$ 5,698	$ 4,808
Transaction-based expenses	580	448	1,091	1,024
Total revenues, less transaction-based expenses	2,317	1,888	4,607	3,784
Data services revenues
Disaggregation of Revenue [Line Items]
Total revenues	240	231	475	463
Listings
Disaggregation of Revenue [Line Items]
Total revenues	122	126	244	252
Exchanges Segment
Disaggregation of Revenue [Line Items]
Total revenues	1,826	1,541	3,560	3,214
Transaction-based expenses	580	448	1,091	1,024
Total revenues, less transaction-based expenses	1,246	1,093	2,469	2,190
Exchanges Segment \| Data services revenues
Disaggregation of Revenue [Line Items]
Total revenues	240	231	475	463
Exchanges Segment \| Net Interest Income
Disaggregation of Revenue [Line Items]
Total revenues	23	20	47	44
Exchanges Segment \| Listings
Disaggregation of Revenue [Line Items]
Total revenues	122	126	244	252
Fixed Income and Data Services Segment
Disaggregation of Revenue [Line Items]
Total revenues	565	546	1,133	1,109
Transaction-based expenses	0	0	0	0
Total revenues, less transaction-based expenses	565	546	1,133	1,109
Fixed Income and Data Services Segment \| Data services revenues
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0	0
Fixed Income and Data Services Segment \| Net Interest Income
Disaggregation of Revenue [Line Items]
Total revenues	34	41	72	78
Fixed Income and Data Services Segment \| Listings
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0	0
Mortgage Technology Segment
Disaggregation of Revenue [Line Items]
Total revenues	506	249	1,005	485
Transaction-based expenses	0	0	0	0
Total revenues, less transaction-based expenses	506	249	1,005	485
Mortgage Technology Segment \| Data services revenues
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0	0
Mortgage Technology Segment \| Listings
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0	0
Services transferred at a point in time
Disaggregation of Revenue [Line Items]
Total revenues, less transaction-based expenses	972	815	1,931	1,640
Services transferred at a point in time \| Exchanges Segment
Disaggregation of Revenue [Line Items]
Total revenues, less transaction-based expenses	757	628	1,499	1,263
Services transferred at a point in time \| Fixed Income and Data Services Segment
Disaggregation of Revenue [Line Items]
Total revenues, less transaction-based expenses	101	106	212	229
Services transferred at a point in time \| Mortgage Technology Segment
Disaggregation of Revenue [Line Items]
Total revenues, less transaction-based expenses	114	81	220	148
Services transferred over time
Disaggregation of Revenue [Line Items]
Total revenues, less transaction-based expenses	1,345	1,073	2,676	2,144
Services transferred over time \| Exchanges Segment
Disaggregation of Revenue [Line Items]
Total revenues, less transaction-based expenses	489	465	970	927
Services transferred over time \| Exchanges Segment \| Data services revenues
Disaggregation of Revenue [Line Items]
Total revenues, less transaction-based expenses	240	231	475	463
Services transferred over time \| Exchanges Segment \| Services transferred over time related to risk management of open interest performance obligations
Disaggregation of Revenue [Line Items]
Total revenues, less transaction-based expenses	94	75	187	151
Services transferred over time \| Exchanges Segment \| Services transferred over time related to listings
Disaggregation of Revenue [Line Items]
Total revenues, less transaction-based expenses	122	126	244	252
Services transferred over time \| Exchanges Segment \| 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	33	64	61
Services transferred over time \| Fixed Income and Data Services Segment
Disaggregation of Revenue [Line Items]
Total revenues, less transaction-based expenses	464	440	921	880
Services transferred over time \| Fixed Income and Data Services Segment \| Data services revenues
Disaggregation of Revenue [Line Items]
Total revenues, less transaction-based expenses	457	434	906	864
Services transferred over time \| Fixed Income and Data Services Segment \| Services transferred over time related to risk management of open interest performance obligations
Disaggregation of Revenue [Line Items]
Total revenues, less transaction-based expenses	7	6	15	16
Services transferred over time \| Mortgage Technology Segment
Disaggregation of Revenue [Line Items]
Total revenues, less transaction-based expenses	392	168	785	337
Services transferred over time \| Mortgage Technology Segment \| Recurring revenues
Disaggregation of Revenue [Line Items]
Total revenues, less transaction-based expenses	387	164	777	329
Services transferred over time \| Mortgage Technology Segment \| Other
Disaggregation of Revenue [Line Items]
Total revenues, less transaction-based expenses	$ 5	$ 4	$ 8	$ 8