XML 97 R80.htm IDEA: XBRL DOCUMENT
v3.19.2

Investment - Summary of Ranges and Weighted Averages of Significant Unobservable Inputs Used to Quantitative Assessments (Detail) - Advisor Engine [Member] - Preferred Stock [Member] - Level 3 [Member] | 6 Months Ended
--- | ---
Jun. 30, 2019
Minimum [Member] | Market Approach Valuation Technique [Member] |
Fair Value Inputs Assets Quantitative Informations [Line Items] |
Revenue multiple | 4.7
Maximum [Member] | Market Approach Valuation Technique [Member] |
Fair Value Inputs Assets Quantitative Informations [Line Items] |
Revenue multiple | 5.4
Weighted Average [Member] | Market Approach Valuation Technique [Member] |
Fair Value Inputs Assets Quantitative Informations [Line Items] |
Revenue multiple | 5.0
Weighted Average [Member] | Income Approach Valuation Technique [Member] |
Fair Value Inputs Assets Quantitative Informations [Line Items] |
Weighted average cost of capital ("WACC") | 26.00%

X
- Definition Value of input used to measure investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (bbb)(2) -URI http://asc.fasb.org/extlink&oid=99377789&loc=d3e19207-110258 + Details
Name: | us-gaap_EquitySecuritiesFvNiMeasurementInput
Namespace Prefix: | us-gaap_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | instant

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: | wetf_FairValueInputsAssetsQuantitativeInformationsLineItems
Namespace Prefix: | wetf_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Weighted average cost of capital. + References No definition available. + Details
Name: | wetf_WeightedAverageCostOfCapital
Namespace Prefix: | wetf_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=wetf_AdvisorEngineMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=us-gaap_PreferredStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ValuationTechniqueAxis=us-gaap_MarketApproachValuationTechniqueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_WeightedAverageMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ValuationTechniqueAxis=us-gaap_IncomeApproachValuationTechniqueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |