Goodwill and Other Intangible Assets - Additional Information (Details)
$ in Thousands
 12 Months Ended
Dec. 31, 2021
USD ($)
ReportingUnit
Dec. 31, 2020
USD ($)
ReportingUnit
Dec. 31, 2019
USD ($)
Goodwill And Intangible Assets [Line Items]      
Goodwill $ 436,821 $ 338,848  
Number of reporting units | ReportingUnit 1 1  
Amortization of Intangible Assets $ 7,243 $ 5,678 $ 4,755
Trade Names      
Goodwill And Intangible Assets [Line Items]      
Weighted average estimated remaining useful life 13 years    
AssetMark Trust Company Regulatory Status      
Goodwill And Intangible Assets [Line Items]      
Weighted average estimated remaining useful life 13 years    
Broker-Dealer License      
Goodwill And Intangible Assets [Line Items]      
Weighted average estimated remaining useful life 13 years    
Voyant Non-enterprise Distribution Channel Customer Relationships      
Goodwill And Intangible Assets [Line Items]      
Weighted average estimated remaining useful life 13 years    
GFPC Adviser Relationships      
Goodwill And Intangible Assets [Line Items]      
Weighted average estimated remaining useful life 13 years    
OBS Adviser and Trust Relationships      
Goodwill And Intangible Assets [Line Items]      
Weighted average estimated remaining useful life 13 years    
Voyant Trade Name      
Goodwill And Intangible Assets [Line Items]      
Weighted average estimated remaining useful life 13 years    
Voyant Technology      
Goodwill And Intangible Assets [Line Items]      
Weighted average estimated remaining useful life 13 years    
Voyant Non-compete Agreement      
Goodwill And Intangible Assets [Line Items]      
Weighted average estimated remaining useful life 13 years