Revenue Recognition - Narrative (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2019 USD ($) obligation	Jun. 30, 2018 USD ($)
Disaggregation of Revenue [Line Items]
Number of performance obligations | obligation			2
Number of performance obligations related to trade execution | obligation			1
Rebates	$ 220	$ 212	$ 435	$ 432
Period of recognition of performance obligations	2 years		2 years
Period of customer revenue list recognized for NYSE			9 years
Period of customer revenue list recognized for NYSE area and NYSE American			5 years
Period of customer revenue list recognized for NYSE, modifications			6 years
Period of customer revenue list recognized for NYSE area and NYSE American, modifications			3 years
Total revenues	$ 1,634	1,556	$ 3,217	3,136
Interest rates and other financial futures and options contracts
Disaggregation of Revenue [Line Items]
Total revenues	907	864	1,769	1,762
Trading and Clearing Segment
Disaggregation of Revenue [Line Items]
Total revenues	970	919	1,896	1,870
Trading and Clearing Segment | Interest rates and other financial futures and options contracts
Disaggregation of Revenue [Line Items]
Total revenues	$ 907	864	$ 1,769	1,762
Trading and Clearing Segment | Interest rates and other financial futures and options contracts | Transferred over Time
Disaggregation of Revenue [Line Items]
Period of recognition of performance obligations	1 month		1 month
Total revenues	$ 62	$ 65	$ 122	$ 128