Deferred Consideration - Schedule of Deferred Consideration (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Contractual gold payments	$ 4,250	$ 4,539	$ 12,834	$ 12,362
Contractual gold payments – gold ounces paid	2,375	2,375	7,125	7,125
Gain/(loss) on revaluation of deferred consideration - gold payments	$ 1,737	$ (8,870)	$ 5,066	$ (34,436)

Gain/loss from revaluation of deferred consideration.

No definition available.

Name:	wetf_GainLossFromChangeInDeferredConsideration
Namespace Prefix:	wetf_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration