Cover Page - USD ($)	12 Months Ended
	Dec. 31, 2020	Feb. 08, 2021	Jun. 30, 2020
Cover [Abstract]
Document Type	10-K/A
Amendment Flag	true
Document Fiscal Year Focus	2020
Document Period End Date	Dec. 31, 2020
Trading Symbol	WETF
Document Fiscal Period Focus	FY
Entity Registrant Name	WisdomTree Investments, Inc.
Entity Central Index Key	0000880631
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 478,656,235
Entity Common Stock, Shares Outstanding		149,815,815
Document Transition Report	false
Document Annual Report	true
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common Stock
Security Exchange Name	NASDAQ
Entity File Number	001-10932
Entity Address, Address Line One	245 Park Avenue, 35th Floor
Entity Address, City or Town	New York
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10167
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	13-3487784
City Area Code	212
Local Phone Number	801-2080
ICFR Auditor Attestation Flag	true
Amendment Description	Explanatory Note This Form 10-K/A Amendment No. 1 to the Annual Report on Form 10-K for the year ended December 31, 2020, as originally filed on February 19, 2021 (the “Original Filing”), of WisdomTree Investments, Inc. is being filed for the sole purpose of filing exhibits thereto as required by certain rules under Regulation S-K as follows:   ITEM 15. EXHIBITS; FINANCIAL STATEMENT SCHEDULES (b). Exhibits   10.21 Employment Agreement between the Registrant and Alexis Marinof, dated June 8, 2017   10.22 Amendment to Employment Agreement between the Registrant and Alexis Marinof, dated July 20, 2017   10.23 Form of Performance-Based Restricted Stock Unit Award Agreement for U.S. Executive Officers after January 1, 2021   10.24 Form of Performance-Based Restricted Stock Unit Award Agreement for U.K. Executive Officers after January 1, 2021   31.1 Rule 13a-14(a) / 15d- 14(a) Certification   31.2 Rule 13a-14(a) / 15d- 14(a) Certification   31.3 Rule 13a-14(a) / 15d- 14(a) Certification   32.1 Certification pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 Except as expressly noted herein, this Form 10-K/A Amendment No. 1 does not modify or update in any way disclosures made in the Original Filing. The Original Filing continues to speak as of the date of the Original Filing, and we have not updated the disclosures contained therein to reflect any events that occurred at a date subsequent to the filing of the Original Filing other than expressly indicated in this Form 10-K/A and this amendment does not reflect events occurring after the filing of the Original Filing. Accordingly, this Form 10-K/A Amendment No. 1 should be read in conjunction with the Original Filing and our other filings made with the SEC on or subsequent to February 19, 2021. Unless otherwise indicated, references to “the Company,” “we,” “us,” “our” and “WisdomTree” mean WisdomTree Investments, Inc. and its subsidiaries. WisdomTree® and Modern Alpha® are registered trademarks of WisdomTree Investments, Inc. in the United States and in other countries. All other trademarks are the property of their respective owners.