| Cover | Jun. 06, 2022 |
| Cover [Abstract] | |
| Document Type | 8-K/A |
| Amendment Flag | true |
| Amendment Description | On June 7, 2022, AssetMark Financial Holdings, Inc. (the “Company”) filed a Current Report on Form 8-K (the “Original Report”) with the Securities and Exchange Commission to report the voting results of the Company’s 2022 annual meeting of stockholders. The sole purpose of this Amendment No. 1 on Form 8-K/A (this “Amendment”) is to correct a clerical error in the Original Report, namely the fiscal year referenced in the bullet point beginning “Proposal 2”. The bullet point beginning “Proposal 2” in the Original Report is hereby amended in its entirety to read as set forth below. Except for the foregoing, this Amendment does not modify or update any disclosure contained in the Original Report, and this Amendment should be read in conjunction with the Original Report. |
| Document Period End Date | Jun. 6, 2022 |
| Entity File Number | 001-38980 |
| Entity Registrant Name | AssetMark Financial Holdings, Inc. |
| Entity Central Index Key | 0001591587 |
| Entity Tax Identification Number | 30-0774039 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | 1655 Grant Street |
| Entity Address, Address Line Two | 10th Floor |
| Entity Address, City or Town | Concord |
| Entity Address, State or Province | CA |
| Entity Address, Postal Zip Code | 94520 |
| City Area Code | 925 |
| Local Phone Number | 521-2200 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common stock, $0.001 par value |
| Trading Symbol | AMK |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | false |
