Net Capital and Minimum Capital Requirements - Additional Information (Details) - USD ($)
$ in Thousands
Dec. 31, 2021
Dec. 31, 2020
AssetMark Trust Company    
Net Capital And Minimum Capital Requirements [Line Items]    
Liquid capital $ 12,375 $ 9,375
AssetMark Brokerage, LLC    
Net Capital And Minimum Capital Requirements [Line Items]    
Net capital $ 5 $ 5