Commitments and Contingencies - Additional Information (Detail) (USD $)	1 Months Ended	9 Months Ended	12 Months Ended
	Mar. 31, 2011 sqft	Sep. 30, 2013 Lease	Dec. 31, 2010 sqft	Dec. 31, 2008 Property	Dec. 31, 2012
Loss Contingencies [Line Items]
Member distributions payable		$ 13,662,000
Self insurance program liability		278,000			360,000
RMCO
Loss Contingencies [Line Items]
Range of subleases in square feet	20,000
Number of retail tenants			2
Renewal options of subleases			Renewal options ranging from two 5-year renewal options to nine 5-year renewal options. Anticipated revenue from these subleases exceeds the expected costs that will be incurred by the Company.
Liability related to loss on sublease	1,932,000
Short-term portion of liability		375,000			351,000
Long-term portion of liability		689,000			972,000
Number of closed additional real estate brokerage offices				4
Closed office leases with remaining lease terms				In connection with these office closures, the Company abandoned office leases with remaining lease terms of eleven months to eight years.
Number of abandoned leases		2
Range of remaining lease terms		3 months
Total future cash payments		663,000			1,061,000
Member distributions payable		6,650,000
RMCO | Minimum
Loss Contingencies [Line Items]
Range of subleases in square feet			4,000
Range of subleases initial term			5 years
Percentage of discount rates charged to rent expense		2.75%
RMCO | Maximum
Loss Contingencies [Line Items]
Range of subleases in square feet			10,500
Range of subleases initial term			10 years
Percentage of discount rates charged to rent expense		18.03%
Weston Presiio
Loss Contingencies [Line Items]
Member distributions payable		1,000,000
R I H I
Loss Contingencies [Line Items]
Member distributions payable		$ 5,650,000