Restructuring Costs Facility and Operational Efficiencies Program (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Restructuring Reserve [Roll Forward]
Restructuring costs, net	[1],[2]	$ 9	$ 6	$ 21	$ 36
Restructuring and Related Cost, Expected Cost [Abstract]
Impairment loss		1		2
Real Estate Franchise Services
Restructuring Reserve [Roll Forward]
Restructuring costs, net				2
Company Owned Brokerage Services
Restructuring Reserve [Roll Forward]
Restructuring costs, net		6	4	10	21
Relocation Services
Restructuring Reserve [Roll Forward]
Restructuring costs, net		1	1	4	9
Title and Settlement Services
Restructuring Reserve [Roll Forward]
Restructuring costs, net		1	1	2	2
Corporate and Other
Restructuring Reserve [Roll Forward]
Restructuring costs, net		1		5	2
Personnel Related
Restructuring Reserve [Roll Forward]
Restructuring costs, net	[3]	5	3	16	17
Facility Related
Restructuring Reserve [Roll Forward]
Restructuring costs, net	[4]	4	$ 3	5	$ 12
Operational Efficiencies Program
Restructuring Reserve [Roll Forward]
Balance at December 31, 2018				0
Restructuring costs, net		9		18
Costs paid or otherwise settled				(12)
Balance at June 30, 2019		6		6
Restructuring and Related Cost, Expected Cost [Abstract]
Total amount expected to be incurred		54		54
Amount incurred to date		18		18
Total amount remaining to be incurred		36		36
Operational Efficiencies Program | Real Estate Franchise Services
Restructuring and Related Cost, Expected Cost [Abstract]
Total amount expected to be incurred		0		0
Amount incurred to date		0		0
Total amount remaining to be incurred		0		0
Operational Efficiencies Program | Company Owned Brokerage Services
Restructuring and Related Cost, Expected Cost [Abstract]
Total amount expected to be incurred		44		44
Amount incurred to date		10		10
Total amount remaining to be incurred		34		34
Operational Efficiencies Program | Relocation Services
Restructuring and Related Cost, Expected Cost [Abstract]
Total amount expected to be incurred		4		4
Amount incurred to date		4		4
Total amount remaining to be incurred		0		0
Operational Efficiencies Program | Title and Settlement Services
Restructuring and Related Cost, Expected Cost [Abstract]
Total amount expected to be incurred		1		1
Amount incurred to date		1		1
Total amount remaining to be incurred		0		0
Operational Efficiencies Program | Corporate and Other
Restructuring and Related Cost, Expected Cost [Abstract]
Total amount expected to be incurred		5		5
Amount incurred to date		3		3
Total amount remaining to be incurred		2		2
Operational Efficiencies Program | Personnel Related
Restructuring Reserve [Roll Forward]
Balance at December 31, 2018				0
Restructuring costs, net				13
Costs paid or otherwise settled				(8)
Balance at June 30, 2019		5		5
Restructuring and Related Cost, Expected Cost [Abstract]
Total amount expected to be incurred		13		13
Amount incurred to date		13		13
Total amount remaining to be incurred		0		0
Operational Efficiencies Program | Facility Related
Restructuring Reserve [Roll Forward]
Balance at December 31, 2018	[5]			0
Restructuring costs, net	[5]			5
Costs paid or otherwise settled	[5]			(4)
Balance at June 30, 2019	[5]	1		1
Restructuring and Related Cost, Expected Cost [Abstract]
Total amount expected to be incurred	[6]	41		41
Amount incurred to date	[6]	5		5
Total amount remaining to be incurred	[6]	$ 36		$ 36

[1] (c) The three months ended June 30, 2019 includes restructuring charges of $6 million in the Company Owned Real Estate Brokerage Services segment, $1 million in the Relocation Services segment, $1 million in the Title and Settlement Services segment and $1 million in Corporate and Other. The three months ended June 30, 2018 includes restructuring charges of $4 million in the Company Owned Real Estate Brokerage Services segment, $1 million in the Relocation Services segment and $1 million in the Title and Settlement Services segment. The six months ended June 30, 2019 includes restructuring charges of $10 million in the Company Owned Real Estate Brokerage Services segment, $4 million in the Relocation Services segment, $2 million in the Title and Settlement Services segment and $5 million in Corporate and Other. The six months ended June 30, 2018 includes restructuring charges of $2 million in the Real Estate Franchise Services segment, $21 million in the Company Owned Real Estate Brokerage Services segment, $9 million in the Relocation Services segment, $2 million in the Title and Settlement Services segment and $2 million in Corporate and Other.

[2] The three and six months ended June 30, 2019 include $9 million and $18 million, respectively, of expense related to the Facility and Operational Efficiencies Program and Leadership Realignment and zero and $3 million, respectively, of expense related to Other Restructuring Activities Program. Restructuring charges for three and six months ended June 30, 2018 relate to prior restructuring programs.

[3] Personnel-related costs consist of severance costs provided to employees who have been terminated and duplicate payroll costs during transition.

[4] Facility-related costs consist of costs associated with planned facility closures such as contract termination costs, amortization of lease assets that will continue to be incurred under the contract for its remaining term without economic benefit to the Company, accelerated depreciation on asset disposals and other facility and employee relocation related costs.

[5] In addition, the Company incurred an additional $2 million related to lease asset impairments in connection with the Facility and Operational Efficiencies Program during the six months ended June 30, 2019.

[6] Facility-related costs includes lease asset impairments expected to be incurred under the Facility and Operational Efficiencies Program.