ACQUISITIONS , SCHEDULE OF IDENTIFIED ASSETS AND LIABILITIES ASSUMED (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Feb. 21, 2018	Dec. 31, 2017	Dec. 31, 2016	Jun. 01, 2015
Business Acquisition [Line Items]
Goodwill	$ 1,548,976		$ 1,283,457	$ 1,254,866
ForRent, Division Of DE Holdings, Inc. [Member]
Business Acquisition [Line Items]
Cash and cash equivalents		$ 59
Accounts receivable		8,769
Indemnification asset		5,443
Goodwill		266,513			$ 267,000
Intangible assets		141,300
Deferred tax liabilities		(34,032)
Contingent sales tax liability		(6,260)
State uncertain income tax position liability		(2,047)
Other assets and liabilities		(3,453)
Fair value of identifiable net assets acquired		376,292
Previously Reported [Member] | ForRent, Division Of DE Holdings, Inc. [Member]
Business Acquisition [Line Items]
Cash and cash equivalents		59
Accounts receivable		8,769
Indemnification asset		5,443
Goodwill		266,720
Intangible assets		141,300
Deferred tax liabilities		(34,032)
Contingent sales tax liability		(6,260)
State uncertain income tax position liability		(2,047)
Other assets and liabilities		(3,453)
Fair value of identifiable net assets acquired		376,499
Restatement Adjustment [Member] | ForRent, Division Of DE Holdings, Inc. [Member]
Business Acquisition [Line Items]
Cash and cash equivalents		0
Accounts receivable		0
Indemnification asset		0
Goodwill		(207)
Intangible assets		0
Deferred tax liabilities		0
Contingent sales tax liability		0
State uncertain income tax position liability		0
Other assets and liabilities		0
Fair value of identifiable net assets acquired		$ (207)