Document and Entity Information - shares
6 Months Ended
Jun. 30, 2019
Jul. 25, 2019
Document and Entity Information [Abstract]    
Document Type 10-Q  
Amendment Flag false  
Document Fiscal Year Focus 2019  
Document Period End Date Jun. 30, 2019  
Trading Symbol WETF  
Document Fiscal Period Focus Q2  
Entity Registrant Name WisdomTree Investments, Inc.  
Entity Central Index Key 0000880631  
Current Fiscal Year End Date --12-31  
Entity Filer Category Large Accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   155,099,477
Document Transition Report false  
Document Quarterly 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