Short And Long-Term Debt Securitization Obligations (Details) £ in Millions, $ in Millions		3 Months Ended			9 Months Ended
		Sep. 30, 2019 USD ($)		Sep. 30, 2018 USD ($)	Sep. 30, 2019 USD ($)		Sep. 30, 2018 USD ($)	Sep. 30, 2019 GBP (£)	Dec. 31, 2018 USD ($)
Debt Instrument [Line Items]
Securitization obligations		$ 228			$ 228				$ 231
Securitization obligations
Debt Instrument [Line Items]
Securitization obligations		228			228				231
Relocation receivables and other related relocation assets that collateralize securitization obligations		271			271				238
Interest expense, debt		$ 2		$ 2	$ 6		$ 6
Weighted average interest rate, securitization obligations		4.30%		3.70%	4.30%		3.70%	4.30%
Securitization obligations | Apple Ridge Funding LLC
Debt Instrument [Line Items]
Total capacity, securitization obligations	[1],[2]	$ 250			$ 250
Securitization obligations		216	[1],[3]		216	[1],[3]			218
Securitization obligations | Cartus Financing Limited
Debt Instrument [Line Items]
Total capacity, securitization obligations	[1],[2]	18			18
Securitization obligations		$ 12	[1],[4]		$ 12	[1],[4]			$ 13
Securitization obligations | Cartus Financing Limited | Revolving Credit Facility
Debt Instrument [Line Items]
Total capacity, securitization obligations | £								£ 10
Securitization obligations | Cartus Financing Limited | Working Capital Facility
Debt Instrument [Line Items]
Total capacity, securitization obligations | £								£ 5

[1] Available capacity is subject to maintaining sufficient relocation related assets to collateralize these securitization obligations.

[2] The Term Loan A provides for quarterly amortization payments, which commenced on June 30, 2018, totaling per annum 2.5%, 2.5%, 5.0%, 7.5% and 10.0% of the original principal amount of the Term Loan A, with the balance of the Term Loan A due at maturity on February 8, 2023. The interest rates with respect to the Term Loan A are based on, at the Company's option, (a) adjusted LIBOR plus an additional margin or (b) ABR plus an additional margin, in each case subject to adjustment based on the then current senior secured leverage ratio. Based on the previous quarter's senior secured leverage ratio, the LIBOR margin was 2.25% and the ABR margin was 1.25% for the three months ended September 30, 2019.

[3] As of September 30, 2019, the Company had $250 million of borrowing capacity under the Apple Ridge Funding LLC securitization program leaving $34 million of available capacity.

[4] Consists of a £10 million revolving loan facility and a £5 million working capital facility. As of September 30, 2019, the Company had $18 million of borrowing capacity under the Cartus Financing Limited securitization program leaving $6 million of available capacity. In August 2019, Realogy Group extended the existing Cartus Financing Limited securitization program to August 2020.