Segment Reporting - Narrative (Details) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($) member	Jun. 30, 2022 USD ($) segment member	Jun. 30, 2021 USD ($) member
Segment Reporting Information [Line Items]
Number of reportable segments \| segment			3
Total revenues	$ 2,413	$ 2,134	$ 4,872	$ 4,563
Exchanges Segment
Segment Reporting Information [Line Items]
Total revenues	$ 1,604	$ 1,336	$ 3,247	$ 2,942
Revenue \| Exchanges Segment
Segment Reporting Information [Line Items]
Number of members \| member		1	1	1
Total revenues		$ 99	$ 213	$ 208
Revenue \| Exchanges Segment \| Customer Concentration Risk
Segment Reporting Information [Line Items]
Concentration risk, percentage		11.00%	10.00%	11.00%

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

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+ Details