Deferred Revenue - Schedule of Rollforward (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Disaggregation Of Revenue [Roll Forward]
Beginning balance	$ 284	$ 259
Additions	829	739
Amortization	(538)	(460)
Ending balance	575	538
Annual Listings Revenues
Disaggregation Of Revenue [Roll Forward]
Beginning balance	0	0
Additions	435	384
Amortization	(219)	(197)
Ending balance	216	187
Original Listings Revenues
Disaggregation Of Revenue [Roll Forward]
Beginning balance	19	13
Additions	31	19
Amortization	(19)	(14)
Ending balance	31	18
Other Listings Revenues
Disaggregation Of Revenue [Roll Forward]
Beginning balance	93	92
Additions	34	34
Amortization	(23)	(22)
Ending balance	104	104
Data Services and Other Revenues
Disaggregation Of Revenue [Roll Forward]
Beginning balance	93	95
Additions	283	265
Amortization	(222)	(206)
Ending balance	154	154
Mortgage technology
Disaggregation Of Revenue [Roll Forward]
Beginning balance	79	59
Additions	46	37
Amortization	(55)	(21)
Ending balance	$ 70	$ 75