XML 80 R66.htm IDEA: XBRL DOCUMENT
v3.19.3

Fair Value Measurements - Summary of Reconciliation of Recurring Fair Value Measurements (Detail) - Deferred Consideration Obligation [Member] - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2019 | Sep. 30, 2018 | Sep. 30, 2019 | Sep. 30, 2018
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |  |  |
Beginning balance | $ 161,273 | $ 162,848 | $ 161,540 | $ 172,746
Net realized losses | 3,502 | 2,880 | 9,710 | 5,595
Net unrealized losses/(gains) | 6,306 | (7,732) | 5,939 | (17,630)
Settlements | (3,441) | (1,941) | (9,549) | (4,656)
Ending balance | $ 167,640 | $ 156,055 | $ 167,640 | $ 156,055

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_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of settlements of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258 + Details
Name: | us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Fair value of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258 + Details
Name: | us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Fair value measurement with unobservable inputs reconciliation recurring basis liability net unrealized gain loss included in earnings and other comprehensive income. + References No definition available. + Details
Name: | wetf_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityNetUnrealizedGainLossIncludedInEarningsAndOtherComprehensiveIncome
Namespace Prefix: | wetf_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Liability Realized Gain Loss Included In Earnings + References No definition available. + Details
Name: | wetf_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityRealizedGainLossIncludedInEarnings
Namespace Prefix: | wetf_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_FairValueByLiabilityClassAxis=wetf_DeferredConsiderationObligationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |