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

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

Current fully diluted ownership percentage.

No definition available.

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

Impairment on Thesys preferred stock.

No definition available.

Name:	wetf_ImpairmentOnThesysPreferredStock
Namespace Prefix:	wetf_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

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.

No definition available.

Name:	wetf_PercentageOfVotingApprovalRequired
Namespace Prefix:	wetf_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Number of shares awarded in Thesys Series Y Preferred Shares.

No definition available.

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

Name:	us-gaap_StatementClassOfStockAxis=wetf_SeriesYPreferredStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

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

Name:	us-gaap_InvestmentTypeAxis=us-gaap_ConvertiblePreferredStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: