Deferred Revenue - Schedule of Changes in Deferred Revenue (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Disaggregation Of Revenue [Roll Forward]
Deferred revenue, beginning balance	$ 259	$ 201
Additions	1,020	955
Amortization	(995)	(897)
Deferred revenue, ending balance	284	259
Annual Listing Revenue
Disaggregation Of Revenue [Roll Forward]
Deferred revenue, beginning balance	0	0
Additions	403	386
Amortization	(403)	(386)
Deferred revenue, ending balance	0	0
Original Listing Revenues
Disaggregation Of Revenue [Roll Forward]
Deferred revenue, beginning balance	13	19
Additions	39	12
Amortization	(33)	(18)
Deferred revenue, ending balance	19	13
Other Listing Revenues
Disaggregation Of Revenue [Roll Forward]
Deferred revenue, beginning balance	92	94
Additions	44	40
Amortization	(43)	(42)
Deferred revenue, ending balance	93	92
Data Services and Other Revenues
Disaggregation Of Revenue [Roll Forward]
Deferred revenue, beginning balance	95	86
Additions	451	444
Amortization	(453)	(435)
Deferred revenue, ending balance	93	95
Mortgage Technology
Disaggregation Of Revenue [Roll Forward]
Deferred revenue, beginning balance	59	2
Additions	83	73
Amortization	(63)	(16)
Deferred revenue, ending balance	$ 79	$ 59