Segment Reporting (Details) $ in Millions	3 Months Ended
	Mar. 31, 2020 USD ($) segment member	Mar. 31, 2019 USD ($) member
Segment Reporting Information [Line Items]
Number of reportable segments | segment	2
Revenues:
Total revenues	$ 2,115	$ 1,583
Transaction-based expenses	556	313
Total revenues, less transaction-based expenses	1,559	1,270
Operating expenses	677	605
Operating income	882	665
Trading and Clearing Segment
Revenues:
Total revenues	1,439	926
Transaction-based expenses	556	313
Total revenues, less transaction-based expenses	883	613
Operating expenses	310	228
Operating income	573	385
Data and Listings Segment
Revenues:
Total revenues	676	657
Transaction-based expenses	0	0
Total revenues, less transaction-based expenses	676	657
Operating expenses	367	377
Operating income	309	280
Sales Revenue, Net | Trading and Clearing Segment
Revenues:
Total revenues	$ 212	$ 95
Number of members | member	2	1
Concentration risk, percentage	24.00%	16.00%
Energy futures and options contracts
Revenues:
Total revenues	$ 353	$ 229
Energy futures and options contracts | Trading and Clearing Segment
Revenues:
Total revenues	353	229
Energy futures and options contracts | Data and Listings Segment
Revenues:
Total revenues	0	0
Agricultural and metals futures and options contracts
Revenues:
Total revenues	84	62
Agricultural and metals futures and options contracts | Trading and Clearing Segment
Revenues:
Total revenues	84	62
Agricultural and metals futures and options contracts | Data and Listings Segment
Revenues:
Total revenues	0	0
Financial futures and options contracts
Revenues:
Total revenues	123	83
Financial futures and options contracts | Trading and Clearing Segment
Revenues:
Total revenues	123	83
Financial futures and options contracts | Data and Listings Segment
Revenues:
Total revenues	0	0
Cash equities and equity options
Revenues:
Total revenues	669	390
Cash equities and equity options | Trading and Clearing Segment
Revenues:
Total revenues	669	390
Cash equities and equity options | Data and Listings Segment
Revenues:
Total revenues	0	0
Fixed income and credit
Revenues:
Total revenues	122	87
Fixed income and credit | Trading and Clearing Segment
Revenues:
Total revenues	122	87
Fixed income and credit | Data and Listings Segment
Revenues:
Total revenues	0	0
OTC and other transactions
Revenues:
Total revenues	13	11
OTC and other transactions | Trading and Clearing Segment
Revenues:
Total revenues	13	11
OTC and other transactions | Data and Listings Segment
Revenues:
Total revenues	0	0
Pricing and analytics
Revenues:
Total revenues	276	266
Pricing and analytics | Trading and Clearing Segment
Revenues:
Total revenues	0	0
Pricing and analytics | Data and Listings Segment
Revenues:
Total revenues	276	266
Exchange data and feeds
Revenues:
Total revenues	180	176
Exchange data and feeds | Trading and Clearing Segment
Revenues:
Total revenues	0	0
Exchange data and feeds | Data and Listings Segment
Revenues:
Total revenues	180	176
Desktops and connectivity
Revenues:
Total revenues	108	104
Desktops and connectivity | Trading and Clearing Segment
Revenues:
Total revenues	0	0
Desktops and connectivity | Data and Listings Segment
Revenues:
Total revenues	108	104
Listings
Revenues:
Total revenues	112	111
Listings | Trading and Clearing Segment
Revenues:
Total revenues	0	0
Listings | Data and Listings Segment
Revenues:
Total revenues	112	111
Other revenues
Revenues:
Total revenues	75	64
Other revenues | Trading and Clearing Segment
Revenues:
Total revenues	75	64
Other revenues | Data and Listings Segment
Revenues:
Total revenues	$ 0	$ 0