Reconciliation of Assets from Segment to Consolidated (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 7,337	$ 7,421	$ 7,531
Real Estate Franchise Services
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	4,413	4,477
Company Owned Real Estate Brokerage Services
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	1,258	1,249
Relocation Services
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	1,029	1,081
Title and Settlement Services
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	486	416
Corporate and Other
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 151	$ 198