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Organization and Description of Business - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Operating losses	$ 16,131	$ 21,708	$ 38,725	$ 49,460
Recognition of foreign currency translation adjustment upon the liquidation of WisdomTree Japan Inc.	397		397
Other Nonoperating Gains and Losses [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Recognition of foreign currency translation adjustment upon the liquidation of WisdomTree Japan Inc.	397		397
WisdomTree Japan [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Operating losses	$ 85	$ 1,342	550	$ 3,698
Impairment - Japan office lease			$ 572
Acquisition of ETFS Business [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Business Acquisition, Effective Date of Acquisition			Apr. 11, 2018