Acquisitions and Dispositions - Dispositions (Details) $ in Thousands		3 Months Ended			12 Months Ended
	Apr. 10, 2015 item	Sep. 30, 2017 USD ($)	Dec. 31, 2015 USD ($)	Jun. 30, 2015 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($) item
Summary of dispositions
Gain (loss) on sale or disposition of assets					$ (4,260)	$ 171	$ 3,650
RE/MAX Equity Group
Summary of dispositions
Number of brokerages having assets and liabilities sold | item							12
RE/MAX 100
Summary of dispositions
Number of brokerages having assets and liabilities sold | item	6
Gain Loss On Sale Or Disposition Of Assets Net | RE/MAX Equity Group
Summary of dispositions
Gain (loss) on sale or disposition of assets		$ (500)	$ 2,800
Gain Loss On Sale Or Disposition Of Assets Net | RE/MAX 100
Summary of dispositions
Gain (loss) on sale or disposition of assets				$ 600