Quarterly report pursuant to Section 13 or 15(d)

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

v3.21.2
Description of Business, Basis of Presentation and Recent Accounting Pronouncements - Additional Information (Detail)
3 Months Ended 6 Months Ended
Jun. 30, 2021
USD ($)
Office
Jun. 30, 2020
Office
Jun. 30, 2021
USD ($)
Office
Jun. 30, 2020
Office
Class of Stock [Line Items]        
Number of offices | Office     84  
Formation date     2013-06  
Percentage of common stock distributed     80.00%  
Commission's receivable settled period     10 days  
Line of credit | $ $ 0   $ 0  
Credit Agreement [Member]        
Class of Stock [Line Items]        
Line of credit | $ $ 0   $ 0  
Transaction Risk [Member]        
Class of Stock [Line Items]        
Concentration risk percentage 0.00% 0.00% 0.00% 0.00%
Customer Concentration Risk [Member] | Total revenues [Member]        
Class of Stock [Line Items]        
Concentration risk percentage 10.00% 10.00% 10.00% 10.00%
Customer Concentration Risk [Member] | Commissions receivable [Member]        
Class of Stock [Line Items]        
Concentration risk percentage 10.00% 10.00% 10.00% 10.00%
Geographic Concentration Risk [Member] | Total revenues [Member]        
Class of Stock [Line Items]        
Number of offices | Office 0 0 0 0
Concentration risk percentage 10.00% 10.00% 10.00% 10.00%
Geographic Concentration Risk [Member] | Total revenues [Member] | Maximum [Member] | CANADA [Member]        
Class of Stock [Line Items]        
Concentration risk percentage 2.00% 2.00% 2.00% 2.00%
IPO MMI [Member]        
Class of Stock [Line Items]        
IPO completion date     Nov. 05, 2013