Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies - Additional Information (Detail)

v3.21.1
Summary of Significant Accounting Policies - Additional Information (Detail)
 3 Months Ended
Mar. 31, 2021
USD ($)
Segment
Unit
Mar. 31, 2020
USD ($)
Unit
Jun. 26, 2013
Summary Of Significant Accounting Policies [Line Items]      
Number of operating segment | Segment 1    
Cash equivalents, maximum maturity period 90 days    
Equity method investments, unrealized intercompany profit (loss) not eliminated amount $ 0    
Number of reporting unit | Unit 1 1  
Impairment charges on goodwill $ 0 $ 0  
ASU 2016-13      
Summary Of Significant Accounting Policies [Line Items]      
Change in accounting principle, accounting standards update, adoption date Jan. 01, 2020    
Change in accounting principle, accounting standards update, Adopted true    
Change in accounting principle, accounting standards update, Immaterial Effect true    
ASU 2018-15      
Summary Of Significant Accounting Policies [Line Items]      
Change in accounting principle, accounting standards update, adoption date Jan. 01, 2020    
Change in accounting principle, accounting standards update, Adopted true    
Change in accounting principle, accounting standards update, Immaterial Effect true    
Equity or Balanced Portfolios      
Summary Of Significant Accounting Policies [Line Items]      
Percentage of asset management fee on threshold limit 1.00%    
Asset under management, threshold limit $ 10,000,000    
Percentage of asset management fee on balance 0.60%    
Fixed Income Portfolios      
Summary Of Significant Accounting Policies [Line Items]      
Percentage of asset management fee on threshold limit 0.40%    
Asset under management, threshold limit $ 10,000,000    
Percentage of asset management fee on balance 0.30%    
Cortina Equity Portfolios      
Summary Of Significant Accounting Policies [Line Items]      
Percentage of asset management fee on balance 0.80%    
Percentage of asset management fee on first threshold limit 1.00%    
Asset under management, first threshold limit $ 25,000,000    
Percentage of asset management fee on second threshold limit 0.90%    
Asset under management, second threshold limit $ 25,000,000    
Municipal Value Strategy      
Summary Of Significant Accounting Policies [Line Items]      
Percentage of income from asset management fee 0.65%    
Outsourced Chief Investment Officer Portfolios      
Summary Of Significant Accounting Policies [Line Items]      
Percentage of asset management fee on balance 0.24%    
Percentage of asset management fee on first threshold limit 0.40%    
Asset under management, first threshold limit $ 50,000,000    
Percentage of asset management fee on second threshold limit 0.32%    
Asset under management, second threshold limit $ 50,000,000    
Minimum      
Summary Of Significant Accounting Policies [Line Items]      
Identifiable finite-lived intangible assets, useful life 3 years    
Minimum | Private Funds      
Summary Of Significant Accounting Policies [Line Items]      
Prior written notice period to terminate investment management agreements 30 days    
Prior written notice period after receiving the affirmative vote, to terminate investment management agreements 60 days    
Percentage of income from asset management fee 0.25%    
Minimum | Non-discretionary Assets      
Summary Of Significant Accounting Policies [Line Items]      
Percentage of income from asset management fee 0.05%    
Maximum      
Summary Of Significant Accounting Policies [Line Items]      
Identifiable finite-lived intangible assets, useful life 20 years    
Maximum | Private Funds      
Summary Of Significant Accounting Policies [Line Items]      
Prior written notice period to terminate investment management agreements 90 days    
Prior written notice period after receiving the affirmative vote, to terminate investment management agreements 90 days    
Percentage of income from asset management fee 1.50%    
Maximum | Non-discretionary Assets      
Summary Of Significant Accounting Policies [Line Items]      
Percentage of income from asset management fee 0.01%    
Leasehold Improvements      
Summary Of Significant Accounting Policies [Line Items]      
Property, plant and equipment, useful life 10 years    
Other Fixed Assets | Minimum      
Summary Of Significant Accounting Policies [Line Items]      
Property, plant and equipment, useful life 3 years    
Other Fixed Assets | Maximum      
Summary Of Significant Accounting Policies [Line Items]      
Property, plant and equipment, useful life 7 years    
Equity Method Investments      
Summary Of Significant Accounting Policies [Line Items]      
Impairment charges related to equity method investments $ 0 $ 0  
Class A Common Stock      
Summary Of Significant Accounting Policies [Line Items]      
Common stock, voting rights one vote for each share    
Class B Common Stock      
Summary Of Significant Accounting Policies [Line Items]      
Common stock, voting rights one vote for each share    
Class of share exchangeable to another class one-for-one basis    
Silvercrest L.P | Class A Common Stock      
Summary Of Significant Accounting Policies [Line Items]      
Ownership percentage in a subsidiary 66.90%   66.90%
Common stock, voting rights one vote for each share