Revenue Recognition - Schedule of Revenue Recognition (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Disaggregation of Revenue [Line Items]
Total revenues	$ 2,459	$ 2,429
Transaction-based expenses	560	632
Total revenues, less transaction-based expenses	1,899	1,797
Exchanges Segment
Disaggregation of Revenue [Line Items]
Total revenues	1,643	1,606
Transaction-based expenses	560	632
Total revenues, less transaction-based expenses	1,083	974
Fixed Income and Data Services Segment
Disaggregation of Revenue [Line Items]
Total revenues	509	468
Transaction-based expenses	0	0
Total revenues, less transaction-based expenses	509	468
Mortgage Technology Segment
Disaggregation of Revenue [Line Items]
Total revenues	307	355
Transaction-based expenses	0	0
Total revenues, less transaction-based expenses	307	355
Services transferred at a point in time
Disaggregation of Revenue [Line Items]
Total revenues, less transaction-based expenses	852	842
Services transferred at a point in time | Exchanges Segment
Disaggregation of Revenue [Line Items]
Total revenues, less transaction-based expenses	634	561
Services transferred at a point in time | Fixed Income and Data Services Segment
Disaggregation of Revenue [Line Items]
Total revenues, less transaction-based expenses	76	60
Services transferred at a point in time | Mortgage Technology Segment
Disaggregation of Revenue [Line Items]
Total revenues, less transaction-based expenses	142	221
Services transferred over time
Disaggregation of Revenue [Line Items]
Total revenues, less transaction-based expenses	1,047	955
Services transferred over time | Exchanges Segment
Disaggregation of Revenue [Line Items]
Total revenues, less transaction-based expenses	449	413
Services transferred over time | Fixed Income and Data Services Segment
Disaggregation of Revenue [Line Items]
Total revenues, less transaction-based expenses	433	408
Services transferred over time | Mortgage Technology Segment
Disaggregation of Revenue [Line Items]
Total revenues, less transaction-based expenses	$ 165	$ 134