Summary of Significant Accounting Policies - Services Provided to Marketing Funds by RE/MAX Franchising (Details) - Marketing funds - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cost charges	$ 17,789	$ 15,102
Technology - operating
Cost charges	12,245	6,244
Technology - capital
Cost charges	1,017	5,095
Marketing staff and administrative services
Cost charges	$ 4,527	$ 3,763	$ 3,800