Annual report pursuant to Section 13 and 15(d)

Accounting Policies and Recent Accounting Pronouncements - Additional Information (Detail)

v3.22.0.1
Accounting Policies and Recent Accounting Pronouncements - Additional Information (Detail)
12 Months Ended
Dec. 31, 2021
USD ($)
Office
Segment
Dec. 31, 2020
USD ($)
Office
Dec. 31, 2019
USD ($)
Office
Accounting Policies [Line Items]      
Commission's receivable settled period 10 days    
Number of offices | Office 82    
Advertising Costs $ 830,000 $ 586,000 $ 889,000
Income tax benefit realized, percentage 50.00%    
Property and equipment, amortization method straight-line    
Number of reporting units | Segment 1    
Finite-lived intangible asset, amortization method straight-line    
Line of credit $ 0    
Credit Agreement [Member]      
Accounting Policies [Line Items]      
Line of credit $ 0    
Employee Stock Purchase Plan [Member]      
Accounting Policies [Line Items]      
Length of purchase intervals 6 months    
Expected dividend yield 0.00%    
Forfeiture rate 0.00%    
Payment of dividend $ 0    
Customer Concentration Risk [Member] | Total revenues [Member] | Customer [Member]      
Accounting Policies [Line Items]      
Concentration risk percentage 10.00% 10.00% 10.00%
Customer Concentration Risk [Member] | Commissions receivable [Member] | Customer [Member]      
Accounting Policies [Line Items]      
Concentration risk percentage 10.00% 10.00% 10.00%
Geographic Concentration Risk [Member] | Total revenues [Member]      
Accounting Policies [Line Items]      
Number of offices | Office 0 0 0
Geographic Concentration Risk [Member] | Total revenues [Member] | Customer [Member]      
Accounting Policies [Line Items]      
Concentration risk percentage 10.00% 10.00% 10.00%
Transaction Risk [Member] | Total revenues [Member] | Customer [Member]      
Accounting Policies [Line Items]      
Concentration risk percentage 0.00% 0.00% 0.00%
Minimum [Member]      
Accounting Policies [Line Items]      
Property and equipment, estimated useful lives 3 years    
Finite-lived intangible asset, useful life 1 year    
Deferred term for payment of additional commissions 1 year    
Minimum [Member] | Advances To Investment Sales And Financing Professionals [Member]      
Accounting Policies [Line Items]      
Advances to Investment Sales and Financing Professionals, Repayment Term 5 years    
Minimum [Member] | Loan To Investment Sales and Financing Professionals [Member]      
Accounting Policies [Line Items]      
Loans to Investment Sales and Financing Professionals, Repayment Term 1 year    
Maximum [Member]      
Accounting Policies [Line Items]      
Property and equipment, estimated useful lives 7 years    
Finite-lived intangible asset, useful life 7 years    
Deferred term for payment of additional commissions 3 years    
Maximum [Member] | Advances To Investment Sales And Financing Professionals [Member]      
Accounting Policies [Line Items]      
Advances to Investment Sales and Financing Professionals, Repayment Term 10 years    
Maximum [Member] | Loan To Investment Sales and Financing Professionals [Member]      
Accounting Policies [Line Items]      
Loans to Investment Sales and Financing Professionals, Repayment Term 7 years    
Maximum [Member] | Geographic Concentration Risk [Member] | Total revenues [Member] | CANADA [Member] | Customer [Member]      
Accounting Policies [Line Items]      
Concentration risk percentage 2.00% 2.00% 1.00%
Capitalization of Internal Labor [Member]      
Accounting Policies [Line Items]      
Property and equipment, estimated useful lives 5 years