Related Party Transactions - Summary of Revenues from Advisory Services Provided to Related Parties (Detail) - Advisory Services [Member] - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Related Party Transaction [Line Items]
Revenues from advisory services	$ 71,616	$ 62,950
WisdomTree Trust [Member]
Related Party Transaction [Line Items]
Revenues from advisory services	40,536	39,601
Manjer Issuers [Member]
Related Party Transaction [Line Items]
Revenues from advisory services	27,045	20,258
WisdomTree Multi Asset Issuer PLC And WisdomTree Issuer PLC [Member]
Related Party Transaction [Line Items]
Revenues from advisory services	$ 4,035	2,528
WisdomTree Commodity Services LLC [Member]
Related Party Transaction [Line Items]
Revenues from advisory services		198
WisdomTree Asset Management Canada, Inc [Member]
Related Party Transaction [Line Items]
Revenues from advisory services		$ 365