Acquisitions and Dispositions - Dispositions (Details) - HomeSmart $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2016 USD ($)	Sep. 30, 2016 USD ($)	May 13, 2016 Store
Disposal Group, Held-for-sale, Not Discontinued Operations
Business Acquisition [Line Items]
Disposal group, number of stores | Store			82
Disposal Group, Disposed of by Sale, Not Discontinued Operations
Business Acquisition [Line Items]
Loss on disposal		$ 4,200
Business exit costs	$ 40	1,400
Other operating expense (income), net | Disposal Group, Disposed of by Sale, Not Discontinued Operations
Business Acquisition [Line Items]
Loss on disposal		$ 4,200