Segment Information - Revenues (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	[1],[2]	$ 1,116	$ 1,054
Realogy Franchise Group
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	[1],[2]	168	179
Realogy Franchise Group | Royalties and Marketing Fees
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues		58	55
Realogy Franchise Group | Referral Fees
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues		2	3
Realogy Brokerage Group
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	[1],[2]	869	816
Realogy Title Group
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	[1],[2]	137	114
Corporate and Other
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	[1],[2],[3]	$ (58)	$ (55)

[1] Revenues for Realogy Franchise Group include intercompany referral commissions related to Realogy Advantage Broker Network paid by Realogy Brokerage Group of $2 million and $3 million for the three months ended March 31, 2020 and 2019, respectively. Such amounts are recorded as contra-revenues by Realogy Brokerage Group. There are no other material intersegment transactions.

[2] Transactions between segments are eliminated in consolidation. Revenues for the Realogy Franchise Group include intercompany royalties and marketing fees paid by Realogy Brokerage Group of $58 million and $55 million for the three months ended March 31, 2020 and 2019, respectively. Such amounts are eliminated through the Corporate and Other line.

[3] Includes the elimination of transactions between segments.