ACQUISITIONS (Narrative) (Details) - USD ($) $ in Millions					3 Months Ended		9 Months Ended
	May 24, 2021	Apr. 14, 2021	Dec. 22, 2020	Jun. 24, 2020	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Business Acquisition [Line Items]
Effective income tax rate reconciliation, goodwill acquired deduction, amount							$ 17
Homes.com
Business Acquisition [Line Items]
Aggregate purchase price		$ 150
Purchase price, net of adjustments		$ 148
Acquisitions, including measurement period adjustments	$ 88
Transaction costs					$ 5		5
Accrual amount							7
Indemnification asset					7		7
Increase in revenue					8		12
Decrease in net income					7		10
Homesnap
Business Acquisition [Line Items]
Aggregate purchase price			$ 250
Acquisitions, including measurement period adjustments			$ 184
Ten-X
Business Acquisition [Line Items]
Aggregate purchase price				$ 188
Transaction costs					$ 3		$ 3
Increase in revenue						$ 12		$ 12
Decrease in net income						$ 5		$ 7
Ten-X | North America
Business Acquisition [Line Items]
Acquisitions, including measurement period adjustments				$ 134