Quarterly report pursuant to Section 13 or 15(d)

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

v3.4.0.3
Description of Business, Basis of Presentation and Recent Accounting Pronouncements - Additional Information (Detail)
$ in Millions
3 Months Ended
Mar. 31, 2016
USD ($)
Office
Mar. 31, 2015
Class of Stock [Line Items]    
Number of offices in the United States and Canada | Office 79  
Formation date 2013-06  
Contribution date Oct. 30, 2013  
Percentage of common stock distributed 80.00%  
Commission's receivable settled period 10 days  
Operating lease obligations | $ $ 84.8  
Customer Concentration Risk [Member] | Total revenues [Member]    
Class of Stock [Line Items]    
Concentration of credit risk percentage 10.00% 10.00%
Customer Concentration Risk [Member] | Commissions receivable [Member]    
Class of Stock [Line Items]    
Concentration of credit risk percentage 10.00% 10.00%