Segment Reporting - Schedule of Segment Reporting Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Segment Reporting Information [Line Items]
Total revenues	$ 2,277	$ 1,930	$ 6,840	$ 6,011
Transaction-based expenses	475	519	1,534	1,646
Total revenues, less transaction-based expenses	1,802	1,411	5,306	4,365
Operating expenses	924	784	2,737	2,112
Operating income	878	627	2,569	2,253
Exchanges Segment
Segment Reporting Information [Line Items]
Total revenues	1,434	1,337	4,376	4,406
Transaction-based expenses	475	519	1,534	1,646
Total revenues, less transaction-based expenses	959	818	2,842	2,760
Operating expenses	330	297	977	919
Operating income	629	521	1,865	1,841
Fixed Income and Data Services
Segment Reporting Information [Line Items]
Total revenues	477	450	1,403	1,360
Transaction-based expenses	0	0	0	0
Total revenues, less transaction-based expenses	477	450	1,403	1,360
Operating expenses	338	331	1,010	987
Operating income	139	119	393	373
Mortgage Technology Segment
Segment Reporting Information [Line Items]
Total revenues	366	143	1,061	245
Transaction-based expenses	0	0	0	0
Total revenues, less transaction-based expenses	366	143	1,061	245
Operating expenses	256	156	750	206
Operating income	110	(13)	311	39
Energy futures and options
Segment Reporting Information [Line Items]
Total revenues	316	229	900	858
Energy futures and options | Exchanges Segment
Segment Reporting Information [Line Items]
Total revenues	316	229	900	858
Energy futures and options | Fixed Income and Data Services
Segment Reporting Information [Line Items]
Total revenues	0	0	0	0
Energy futures and options | Mortgage Technology Segment
Segment Reporting Information [Line Items]
Total revenues	0	0	0	0
Agricultural and metals futures and options
Segment Reporting Information [Line Items]
Total revenues	56	54	177	197
Agricultural and metals futures and options | Exchanges Segment
Segment Reporting Information [Line Items]
Total revenues	56	54	177	197
Agricultural and metals futures and options | Fixed Income and Data Services
Segment Reporting Information [Line Items]
Total revenues	0	0	0	0
Agricultural and metals futures and options | Mortgage Technology Segment
Segment Reporting Information [Line Items]
Total revenues	0	0	0	0
Financial futures and options
Segment Reporting Information [Line Items]
Total revenues	93	76	281	275
Financial futures and options | Exchanges Segment
Segment Reporting Information [Line Items]
Total revenues	93	76	281	275
Financial futures and options | Fixed Income and Data Services
Segment Reporting Information [Line Items]
Total revenues	0	0	0	0
Financial futures and options | Mortgage Technology Segment
Segment Reporting Information [Line Items]
Total revenues	0	0	0
Cash equities and equity options
Segment Reporting Information [Line Items]
Total revenues	554	593	1,800	1,934
Cash equities and equity options | Exchanges Segment
Segment Reporting Information [Line Items]
Total revenues	554	593	1,800	1,934
Cash equities and equity options | Fixed Income and Data Services
Segment Reporting Information [Line Items]
Total revenues	0	0	0	0
Cash equities and equity options | Mortgage Technology Segment
Segment Reporting Information [Line Items]
Total revenues	0	0	0	0
OTC and other
Segment Reporting Information [Line Items]
Total revenues	84	73	239	219
OTC and other | Exchanges Segment
Segment Reporting Information [Line Items]
Total revenues	84	73	239	219
OTC and other | Fixed Income and Data Services
Segment Reporting Information [Line Items]
Total revenues	0	0	0	0
OTC and other | Mortgage Technology Segment
Segment Reporting Information [Line Items]
Total revenues	0	0	0	0
Data and connectivity services
Segment Reporting Information [Line Items]
Total revenues	208	201	623	589
Data and connectivity services | Exchanges Segment
Segment Reporting Information [Line Items]
Total revenues	208	201	623	589
Data and connectivity services | Fixed Income and Data Services
Segment Reporting Information [Line Items]
Total revenues	0	0	0	0
Data and connectivity services | Mortgage Technology Segment
Segment Reporting Information [Line Items]
Total revenues	0	0	0	0
Listings
Segment Reporting Information [Line Items]
Total revenues	123	111	356	334
Listings | Exchanges Segment
Segment Reporting Information [Line Items]
Total revenues	123	111	356	334
Listings | Fixed Income and Data Services
Segment Reporting Information [Line Items]
Total revenues	0	0	0	0
Listings | Mortgage Technology Segment
Segment Reporting Information [Line Items]
Total revenues	0	0	0	0
Fixed income execution
Segment Reporting Information [Line Items]
Total revenues	12	15	39	56
Fixed income execution | Exchanges Segment
Segment Reporting Information [Line Items]
Total revenues	0	0	0	0
Fixed income execution | Fixed Income and Data Services
Segment Reporting Information [Line Items]
Total revenues	12	15	39	56
Fixed income execution | Mortgage Technology Segment
Segment Reporting Information [Line Items]
Total revenues	0	0	0	0
CDS clearing
Segment Reporting Information [Line Items]
Total revenues	51	47	144	166
CDS clearing | Exchanges Segment
Segment Reporting Information [Line Items]
Total revenues	0	0	0	0
CDS clearing | Fixed Income and Data Services
Segment Reporting Information [Line Items]
Total revenues	51	47	144	166
CDS clearing | Mortgage Technology Segment
Segment Reporting Information [Line Items]
Total revenues	0	0	0	0
Fixed income data and analytics
Segment Reporting Information [Line Items]
Total revenues	272	259	804	756
Fixed income data and analytics | Exchanges Segment
Segment Reporting Information [Line Items]
Total revenues	0	0	0	0
Fixed income data and analytics | Fixed Income and Data Services
Segment Reporting Information [Line Items]
Total revenues	272	259	804	756
Fixed income data and analytics | Mortgage Technology Segment
Segment Reporting Information [Line Items]
Total revenues	0	0	0	0
Other data and network services
Segment Reporting Information [Line Items]
Total revenues	142	129	416	382
Other data and network services | Exchanges Segment
Segment Reporting Information [Line Items]
Total revenues	0	0	0	0
Other data and network services | Fixed Income and Data Services
Segment Reporting Information [Line Items]
Total revenues	142	129	416	382
Other data and network services | Mortgage Technology Segment
Segment Reporting Information [Line Items]
Total revenues	0	0	0	0
Origination technology
Segment Reporting Information [Line Items]
Total revenues	245	67	740	67
Origination technology | Exchanges Segment
Segment Reporting Information [Line Items]
Total revenues	0	0	0	0
Origination technology | Fixed Income and Data Services
Segment Reporting Information [Line Items]
Total revenues	0	0	0	0
Origination technology | Mortgage Technology Segment
Segment Reporting Information [Line Items]
Total revenues	245	67	740	67
Closing solutions
Segment Reporting Information [Line Items]
Total revenues	88	67	227	165
Closing solutions | Exchanges Segment
Segment Reporting Information [Line Items]
Total revenues	0	0	0	0
Closing solutions | Fixed Income and Data Services
Segment Reporting Information [Line Items]
Total revenues	0	0	0	0
Closing solutions | Mortgage Technology Segment
Segment Reporting Information [Line Items]
Total revenues	88	67	227	165
Data and analytics
Segment Reporting Information [Line Items]
Total revenues	19	5	55	5
Data and analytics | Exchanges Segment
Segment Reporting Information [Line Items]
Total revenues	0	0	0	0
Data and analytics | Fixed Income and Data Services
Segment Reporting Information [Line Items]
Total revenues	0	0	0	0
Data and analytics | Mortgage Technology Segment
Segment Reporting Information [Line Items]
Total revenues	19	5	55	5
Other
Segment Reporting Information [Line Items]
Total revenues	14	4	39	8
Other | Exchanges Segment
Segment Reporting Information [Line Items]
Total revenues	0	0	0	0
Other | Fixed Income and Data Services
Segment Reporting Information [Line Items]
Total revenues	0	0	0	0
Other | Mortgage Technology Segment
Segment Reporting Information [Line Items]
Total revenues	$ 14	$ 4	$ 39	$ 8