Acquisitions - Acquisitions (Details) - USD ($) $ in Thousands			3 Months Ended
	Feb. 26, 2018	Nov. 15, 2017	Mar. 31, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Goodwill			$ 154,196	$ 135,213
Accounting goodwill
Adjustments to acquisition accounting during the measurement period - goodwill			700
booj, LLC
Business Acquisition [Line Items]
Cash consideration	$ 26,300
Equity based compensation	10,000
Goodwill	$ 18,400
Re/Max Of Northern Illinois Inc.
Business Acquisition [Line Items]
Cash consideration		$ 35,700
Franchise agreements		22,800
Goodwill		12,920
Total purchase price		$ 35,720
Accounting goodwill
Adjustments to acquisition accounting during the measurement period - goodwill			700
Accounting franchise agreements
Adjustments to acquisition accounting during the measurement period - franchise agreements			$ (700)