Deferred Consideration - Schedule of Deferred Consideration (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Contractual gold payments	$ 4,314	$ 4,063	$ 8,584	$ 7,823
Contractual gold payments – gold ounces paid	2,375	2,375	4,750	4,750
Gain/(loss) on revaluation of deferred consideration - gold payments	$ 497	$ (23,358)	$ 3,329	$ (25,566)

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