Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies - Additional Information (Detail)

v3.20.1
Summary of Significant Accounting Policies - Additional Information (Detail)
 3 Months Ended 12 Months Ended
Mar. 31, 2020
USD ($)
Segment
Unit
Mar. 31, 2019
USD ($)
Dec. 31, 2019
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    
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 65.40%     65.40%
Common stock, voting rights one vote for each share