XML 78 R62.htm IDEA: XBRL DOCUMENT
v3.7.0.1

Goodwill and Intangible Assets - Summary of Indefinite-lived Intangible Asset (Detail) $ in Thousands | 3 Months Ended
--- | ---
Mar. 31, 2017 USD ($)
Indefinite-lived Intangible Assets [Line Items] |
Beginning balance | $ 9,953
Ending balance | 9,953
GreenHaven Commodity Services, LLC [Member] |
Indefinite-lived Intangible Assets [Line Items] |
Beginning balance | 9,953
Increases/(decreases) | 0
Ending balance | $ 9,953

X
- Definition Line items represent financial 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. + References No definition available. + Details
Name: | us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275 + Details
Name: | us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of increase in assets, excluding financial assets and goodwill, lacking physical substance with an indefinite life, from an acquisition. + References No definition available. + Details
Name: | us-gaap_IndefinitelivedIntangibleAssetsAcquired
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=wetf_GreenHavenCommodityServicesLlcMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |