Organizational and Description of Business - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Operating losses	$ 61,279	$ 49,088	$ 63,450
WisdomTree Japan [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Operating losses	$ (4,520)	$ (4,553)	$ (4,382)
Acquisition of ETFS Business [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Business Acquisition, Effective Date of Acquisition	Apr. 11, 2018

Date when the acquirer obtains control of the acquiree, in CCYY-MM-DD format.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 25
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=84229725&loc=d3e848-128460

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 25
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=84229725&loc=d3e845-128460

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463

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