XML 42 R32.htm IDEA: XBRL DOCUMENT
v3.21.2

Summary of Significant Accounting Policies (Details) - Contingencies related to COVID-19 - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended | 12 Months Ended
--- | --- | --- | ---
Sep. 30, 2021 | Sep. 30, 2020 | Sep. 30, 2021 | Sep. 30, 2020 | Dec. 31, 2020
Property, Plant and Equipment [Line Items] |  |  |  |  |
Percentage of workforce furloughed or subject to reduced compensation, COVID-19 |  |  |  |  | 9.00%
Reduction to revenue, rent concessions | $ 0.3 | $ 2.1 | $ 0.5 | $ 5.2 |

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

X
- Definition Percentage Of Workforce Furloughed Or Subject To Reduced Compensation + References No definition available. + Details
Name: | wlfc_PercentageOfWorkforceFurloughedOrSubjectToReducedCompensation
Namespace Prefix: | wlfc_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Reduction To Revenue, Rent Concessions + References No definition available. + Details
Name: | wlfc_ReductionToRevenueRentConcessions
Namespace Prefix: | wlfc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_UnusualOrInfrequentItemAxis=wlfc_ContingenciesrelatedtoCOVID19Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |