Segment information - Reportable Segments Revenue and Adjusted EBITDA (Parenthetical) (Detail) (USD $)	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Segment Reporting Information [Line Items]
Total segment reporting revenues	$ 44,240,000	[1]	$ 40,312,000	[1]	$ 128,419,000	[1]	$ 118,628,000	[1]
Intersegment Eliminations
Segment Reporting Information [Line Items]
Total segment reporting revenues	$ (485,000)		$ (383,000)		$ (1,369,000)		$ (1,130,000)

[1] Transactions between the Real Estate Franchise Services and the Brokerages reportable segments are eliminated in consolidation. Revenues for the Real Estate Franchise Services reportable segment include intercompany amounts paid from the Company’s brokerage services business of $485,000 and $383,000 for the three months ended September 30, 2014 and 2013, respectively, and $1,369,000 and $1,130,000 for the nine months ended September 30, 2014 and 2013, respectively. Such amounts are eliminated in the Brokerages reportable segment