Quarterly report pursuant to Section 13 or 15(d)

Description of Business, Basis of Presentation, Recent Accounting Pronouncements and Accounting Policies - Additional Information (Detail)

v2.4.0.8
Description of Business, Basis of Presentation, Recent Accounting Pronouncements and Accounting Policies - Additional Information (Detail) (USD $)
 3 Months Ended 12 Months Ended 3 Months Ended 0 Months Ended
Mar. 31, 2014
Subsidiary
Office
Mar. 31, 2014
Maximum [Member]
Commissions receivable [Member]
Credit concentration risk [Member]
Dec. 31, 2013
Maximum [Member]
Commissions receivable [Member]
Credit concentration risk [Member]
Mar. 31, 2014
Maximum [Member]
Total revenues [Member]
Customer Concentration Risk [Member]
Mar. 31, 2013
Maximum [Member]
Total revenues [Member]
Customer Concentration Risk [Member]
Mar. 31, 2014
MMI [Member]
Nov. 05, 2013
IPO [Member]
Class of Stock [Line Items]              
Number of offices in the United States and Canada 76            
Number of wholly owned subsidiaries 2            
Formation date           2013-06  
Percentage of common stock distributed 80.00%            
Common stock sold             6,900,000
Common stock sold and issued under IPO, price per share             $ 12.00
Description of IPO             On November 5, 2013, MMI completed its Initial Public Offering ("IPO") of 6,900,000 shares of common stock at a price to the public of $12.00 per share.
Customer risk percentage   10.00% 10.00% 10.00% 10.00%