Name:	us-gaap_CostMethodInvestments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The percentage rate used to calculate dividend payments on preferred stock.

No definition available.

Name:	us-gaap_PreferredStockDividendRatePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Amount of unrealized gain (loss) on investment.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585

Name:	us-gaap_UnrealizedGainLossOnInvestments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Cost method investment ownership percentage.

No definition available.

Name:	wetf_CostMethodInvestmentOwnershipPercentage
Namespace Prefix:	wetf_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Original fully diluted ownership interest percentage.

No definition available.

Name:	wetf_CostMethodInvestmentOwnershipPercentageDiluted
Namespace Prefix:	wetf_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Line items represent reporting concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

Name:	wetf_InvestmentsLineItems
Namespace Prefix:	wetf_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Number of Series A Preferred Shares purchased in AdvisorEngine.

No definition available.

Name:	wetf_NumberOfSharesPurchasedFromRelatedParties
Namespace Prefix:	wetf_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

Percentage of voting approval required to redeem all of the outstanding series A shares.

No definition available.

Name:	wetf_PercentageOfVotingApprovalRequiredToRedeemAllOfTheOutstandingSeriesAShares
Namespace Prefix:	wetf_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Percentage of voting approval required to redeem all of the outstanding series B shares.

No definition available.

Name:	wetf_PercentageOfVotingApprovalRequiredToRedeemAllOfTheOutstandingSeriesBSshares
Namespace Prefix:	wetf_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=wetf_SecurrencyIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=wetf_SecurrencySeriesAPreferredStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: