Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies - Additional Information (Detail)

v3.19.2
Summary of Significant Accounting Policies - Additional Information (Detail)
 3 Months Ended 6 Months Ended 12 Months Ended
Jun. 30, 2019
USD ($)
Jun. 30, 2018
USD ($)
Jun. 30, 2019
USD ($)
Segment
Unit
Jun. 30, 2018
USD ($)
Dec. 31, 2018
Unit
Jan. 01, 2019
USD ($)
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 $ 0 $ 0      
Operating lease liabilities 41,768,000   41,768,000        
Operating lease, ROU assets 35,220,000   $ 35,220,000        
Accounting Standards Update 2016-02              
Summary Of Significant Accounting Policies [Line Items]              
Operating lease liabilities           $ 44,000,000  
Operating lease, ROU assets           $ 44,000,000  
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   $ 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   $ 10,000,000        
Percentage of asset management fee on balance     0.30%        
Municipal Value Strategy              
Summary Of Significant Accounting Policies [Line Items]              
Percentage of income from asset management fee     0.65%        
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 $ 0 $ 0      
Class A Common Stock              
Summary Of Significant Accounting Policies [Line Items]              
Common stock, voting rights     1 vote per share        
Class B Common Stock              
Summary Of Significant Accounting Policies [Line Items]              
Common stock, voting rights     1 vote per share        
Class of share exchangeable to another class     One share of Class A common stock        
Silvercrest L.P | Class A Common Stock              
Summary Of Significant Accounting Policies [Line Items]              
Ownership percentage in a subsidiary 63.80%   63.80%       63.80%
Common stock, voting rights     1 vote per share