Revenue Recognition - Disaggregation of Revenue (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Net revenues	[1]	$ 7,983	$ 6,221	$ 5,870
Realogy Franchise Group
Disaggregation of Revenue [Line Items]
Net revenues	[1]	1,249	1,059	1,158
Realogy Brokerage Group
Disaggregation of Revenue [Line Items]
Net revenues	[1]	6,189	4,742	4,409
Realogy Title Group
Disaggregation of Revenue [Line Items]
Net revenues	[1]	952	736	596
Corporate and Other
Disaggregation of Revenue [Line Items]
Net revenues	[1],[2]	(407)	(316)	(293)
Gross Commission Income
Disaggregation of Revenue [Line Items]
Net revenues	[3]	6,118	4,669	4,330
Gross Commission Income | Realogy Franchise Group
Disaggregation of Revenue [Line Items]
Net revenues	[3]	0	0	0
Gross Commission Income | Realogy Brokerage Group
Disaggregation of Revenue [Line Items]
Net revenues	[3]	6,118	4,669	4,330
Gross Commission Income | Realogy Title Group
Disaggregation of Revenue [Line Items]
Net revenues	[3]	0	0	0
Gross Commission Income | Corporate and Other
Disaggregation of Revenue [Line Items]
Net revenues	[3]	0	0	0
Service revenue
Disaggregation of Revenue [Line Items]
Net revenues	[4]	1,180	983	941
Service revenue | Realogy Franchise Group
Disaggregation of Revenue [Line Items]
Net revenues	[4]	227	243	351
Service revenue | Realogy Brokerage Group
Disaggregation of Revenue [Line Items]
Net revenues	[4]	29	26	11
Service revenue | Realogy Title Group
Disaggregation of Revenue [Line Items]
Net revenues	[4]	924	714	579
Service revenue | Corporate and Other
Disaggregation of Revenue [Line Items]
Net revenues	[4]	0	0	0
Franchise fees
Disaggregation of Revenue [Line Items]
Net revenues	[5]	521	419	386
Franchise fees | Realogy Franchise Group
Disaggregation of Revenue [Line Items]
Net revenues	[5]	914	725	668
Franchise fees | Realogy Brokerage Group
Disaggregation of Revenue [Line Items]
Net revenues	[5]	0	0	0
Franchise fees | Realogy Title Group
Disaggregation of Revenue [Line Items]
Net revenues	[5]	0	0	0
Franchise fees | Corporate and Other
Disaggregation of Revenue [Line Items]
Net revenues	[5]	(393)	(306)	(282)
Other
Disaggregation of Revenue [Line Items]
Net revenues	[6]	164	150	213
Other | Realogy Franchise Group
Disaggregation of Revenue [Line Items]
Net revenues	[6]	108	91	139
Other | Realogy Brokerage Group
Disaggregation of Revenue [Line Items]
Net revenues	[6]	42	47	68
Other | Realogy Title Group
Disaggregation of Revenue [Line Items]
Net revenues	[6]	28	22	17
Other | Corporate and Other
Disaggregation of Revenue [Line Items]
Net revenues	[6]	$ (14)	$ (10)	$ (11)

[1] Transactions between segments are eliminated in consolidation. Revenues for Realogy Franchise Group include intercompany royalties and marketing fees paid by Realogy Brokerage Group of $407 million, $316 million and $293 million for the years ended December 31, 2021, 2020 and 2019, respectively. Such amounts are eliminated through the Corporate and Other line.

[2] Includes the elimination of transactions between segments.

[3] Gross commission income at Realogy Brokerage Group is recognized at a point in time at the closing of a homesale transaction.

[4] Service revenue primarily consists of title and escrow fees at Realogy Title Group and are recognized at a point in time at the closing of a homesale transaction. Service revenue at Realogy Franchise Group includes relocation fees, which are recognized as revenue when or as the related performance obligation is satisfied dependent on the type of service performed, and fees related to leads and related services, which are recognized at a point in time at the closing of a homesale transaction or at the completion of the related service.

[5] Franchise fees at Realogy Franchise Group primarily include domestic royalties which are recognized at a point in time when the underlying franchisee revenue is earned (upon close of the homesale transaction).

[6] Other revenue is comprised of brand marketing funds received at Realogy Franchise Group from franchisees, third-party listing fees in 2019, and other miscellaneous revenues across all of the business segments.