| Document and Entity Information | Jan. 25, 2021 |
| Cover [Abstract] | |
| Security Exchange Name | NASDAQ |
| Amendment Flag | false |
| Entity Central Index Key | 0000880631 |
| Document Type | 8-K |
| Document Period End Date | Jan. 25, 2021 |
| Entity Registrant Name | WisdomTree Investments, Inc. |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-10932 |
| Entity Tax Identification Number | 13-3487784 |
| Entity Address, Address Line One | 245 Park Avenue |
| Entity Address, Address Line Two | 35th Floor |
| Entity Address, City or Town | New York |
| Entity Address, State or Province | NY |
| Entity Address, Postal Zip Code | 10167 |
| City Area Code | (212) |
| Local Phone Number | 801-2080 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common Stock, $0.01 par value |
| Trading Symbol | WETF |
| Entity Emerging Growth Company | false |
