XML 84 R62.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Related Party Transactions (Details) |  | 12 Months Ended |  |
--- | --- | --- | --- | ---
Dec. 08, 2016 USD ($) $ / shares | Dec. 31, 2017 USD ($) engine | Dec. 31, 2016 USD ($) | Dec. 31, 2015 USD ($) | Apr. 01, 2016 USD ($) | Mar. 31, 2016 $ / shares
Related Party and Similar Transactions |  |  |  |  |  |
Repurchased price | $ / shares | $ 24.95 |  |  |  |  | $ 21.59
Number of shares repurchased | $ 40,000 |  |  |  |  |
Percentage of difference in repurchase and closing price | 2.00% |  |  |  |  |
Closing price | $ / shares | $ 25.46 |  |  |  |  |
WMES |  |  |  |  |  |
Related Party and Similar Transactions |  |  |  |  |  |
Number of engines sold to third party | engine |  | 2 |  |  |  |
Proceeds from sale of engine |  | $ 14,800,000 |  |  |  |
WMES | Other Revenue |  |  |  |  |  |
Related Party and Similar Transactions |  |  |  |  |  |
Asset Management Fees |  | $ 2,400,000 | $ 2,100,000 | $ 1,700,000 |  |
CASC Willis |  |  |  |  |  |
Related Party and Similar Transactions |  |  |  |  |  |
Number of engines sold to third party | engine |  | 1 |  |  |  |
Proceeds from sale of engine |  | $ 11,200,000 |  |  |  |
Chief Executive Officer [Member] |  |  |  |  |  |
Related Party and Similar Transactions |  |  |  |  |  |
Number of shares repurchased |  |  |  |  | $ 60,000 |
Mikchalk Lake LLC |  |  |  |  |  |
Related Party and Similar Transactions |  |  |  |  |  |
Expenses payable |  | $ 80,000 |  |  |  |

X
- Definition Amount of fixed fee revenue for the management of an investment fund portfolio. Excludes investment advisory, distribution and servicing, and performance fees. + References No definition available. + Details
Name: | us-gaap_AssetManagementFees1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Carrying amount as of the balance sheet date of obligations due all related parties. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 850 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(k)(1)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.15(3),(4)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.17) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 + Details
Name: | us-gaap_DueToRelatedPartiesCurrentAndNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
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: | us-gaap_RelatedPartyTransactionLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the number of engines sold by the entity. + References No definition available. + Details
Name: | wlfc_NumberOfEnginesSold
Namespace Prefix: | wlfc_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount Number of shares repurchased + References No definition available. + Details
Name: | wlfc_NumberOfSharesRepurchased
Namespace Prefix: | wlfc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Represents the amount of cash inflow from sale of engines. + References No definition available. + Details
Name: | wlfc_RelatedPartyTransactionProceedsFromSaleOfEngines
Namespace Prefix: | wlfc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The price of the stock at the close of the period. + References No definition available. + Details
Name: | wlfc_StockRepurchasedDuringPeriodClosingPricePerShare
Namespace Prefix: | wlfc_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition The differential percentage between stock repurchase and closing price. + References No definition available. + Details
Name: | wlfc_StockRepurchasedDuringPeriodDifferentialPercentBetweenPurchaseAndClosingPrice
Namespace Prefix: | wlfc_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition The price at which the shares are bought back by the entity. + References No definition available. + Details
Name: | wlfc_StockRepurchasedDuringPeriodPurchasePricePerShare
Namespace Prefix: | wlfc_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=wlfc_WillisMitsuiAndCompanyEngineSupportLimitedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=us-gaap_OtherIncomeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=wlfc_CSCWillisEngineLeaseCompanyLimitedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=us-gaap_ChiefExecutiveOfficerMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=wlfc_MikchalkLakeLlcMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |