Acquisitions (Details) $ in Millions	3 Months Ended	12 Months Ended
Mar. 31, 2017 USD ($) real_estate_brokerage_operations	Dec. 31, 2016 USD ($) real_estate_brokerage_operations
Business Acquisition [Line Items]
Goodwill acquired	$ 1
Company Owned Brokerage Services
Business Acquisition [Line Items]
Goodwill acquired	1
Title and Settlement Services
Business Acquisition [Line Items]
Goodwill acquired	$ 0
NRT Business Combinations [Member] \| Company Owned Brokerage Services
Business Acquisition [Line Items]
Number of business acquired (in real estate brokerage related operations) \| real_estate_brokerage_operations	5	11
Cash consideration paid for acquisition	$ 1	$ 74
Goodwill acquired	$ 1	52
Liabilities established related to contingent consideration		9
Other assets acquired		5
Other liabilities acquired		3
NRT Business Combinations [Member] \| Customer relationships \| Company Owned Brokerage Services
Business Acquisition [Line Items]
Finite-lived intangible assets acquired		20
NRT Business Combinations [Member] \| Pendings and listings \| Company Owned Brokerage Services
Business Acquisition [Line Items]
Finite-lived intangible assets acquired		6
NRT Business Combinations [Member] \| Other intangible assets \| Company Owned Brokerage Services
Business Acquisition [Line Items]
Finite-lived intangible assets acquired		$ 3
TRG Business Combinations [Member] \| Title and Settlement Services
Business Acquisition [Line Items]
Number of business acquired (in real estate brokerage related operations) \| real_estate_brokerage_operations		1
Cash consideration paid for acquisition		$ 24
Goodwill acquired		20
Liabilities established related to contingent consideration		10
Other assets acquired		6
Other liabilities acquired		9
TRG Business Combinations [Member] \| Indefinite life—Trademarks (b) \| Title and Settlement Services
Business Acquisition [Line Items]
Indefinite-lived intangible assets acquired		3
TRG Business Combinations [Member] \| Indefinite life—Title plant shares (e) \| Title and Settlement Services
Business Acquisition [Line Items]
Indefinite-lived intangible assets acquired		7
TRG Business Combinations [Member] \| Pendings and listings \| Title and Settlement Services
Business Acquisition [Line Items]
Finite-lived intangible assets acquired		5
TRG Business Combinations [Member] \| Other intangible assets \| Title and Settlement Services
Business Acquisition [Line Items]
Finite-lived intangible assets acquired		$ 2

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Amount of increase in other liabilities (current and noncurrent), resulting from a business combination.

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Amount of liabilities incurred by the acquirer as part of consideration transferred in a business combination.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 25
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=6911189&loc=d3e6405-128476

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
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Amount of increase in assets, excluding financial assets, lacking physical substance with a definite life, from an acquisition.

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Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
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Amount of increase in assets, excluding financial assets and goodwill, lacking physical substance with an indefinite life, from an acquisition.

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The number of businesses acquired by the entity during the period.

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The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Investing Activities
-URI http://asc.fasb.org/extlink&oid=6516133

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
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-Section 45
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