XML 58 R42.htm IDEA: XBRL DOCUMENT
v3.3.1.900

Organization and Summary of Significant Accounting Policies (Equipment Held of Operating Lease) (Details) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2015 USD ($) engine aircraft | Dec. 31, 2014 USD ($) | Dec. 31, 2013 USD ($)
Equipment Held for Operating Lease |  |  |
Impairment charge | $ 9,181 | $ 5,602 | $ 6,461
Minimum |  |  |
Equipment Held for Operating Lease |  |  |
Estimated useful life | 3 years |  |
Maximum |  |  |
Equipment Held for Operating Lease |  |  |
Estimated useful life | 15 years |  |
Engines and related equipment |  |  |
Equipment Held for Operating Lease |  |  |
Number of engines | engine | 52 |  |
Engines and related equipment | Maximum |  |  |
Equipment Held for Operating Lease |  |  |
Estimated useful life | 15 years |  |
Aircraft |  |  |
Equipment Held for Operating Lease |  |  |
Number of aircraft | aircraft | 5 |  |
Aircraft | Minimum |  |  |
Equipment Held for Operating Lease |  |  |
Estimated useful life | 13 years |  |
Residual value (as a percent) | 15.00% |  |
Aircraft | Maximum |  |  |
Equipment Held for Operating Lease |  |  |
Estimated useful life | 20 years |  |
Residual value (as a percent) | 17.00% |  |
Engines and aircraft |  |  |
Equipment Held for Operating Lease |  |  |
Equipment net book value | $ 129,600 |  |
Impairment charge | $ 600 | $ 2,400 | $ 0
Engines and aircraft | Minimum |  |  |
Equipment Held for Operating Lease |  |  |
Estimated useful life | 3 years |  |
Engines and aircraft | Maximum |  |  |
Equipment Held for Operating Lease |  |  |
Estimated useful life | 78 years |  |
New engine [Member] | Maximum |  |  |
Equipment Held for Operating Lease |  |  |
Estimated useful life | 25 years |  |
Equipment held for lease Member | Engines and related equipment |  |  |
Equipment Held for Operating Lease |  |  |
Estimated useful life | 15 years |  |
Residual value (as a percent) | 55.00% |  |
Equipment held for lease Member | Spare part packages |  |  |
Equipment Held for Operating Lease |  |  |
Residual value (as a percent) | 25.00% |  |
Equipment held for lease Member | Spare part packages | Minimum |  |  |
Equipment Held for Operating Lease |  |  |
Estimated useful life | 14 years |  |
Equipment held for lease Member | Spare part packages | Maximum |  |  |
Equipment Held for Operating Lease |  |  |
Estimated useful life | 15 years |  |

X
- Definition Nonrecurring impairment charges related to the write-off of production-related equipment and inventory. This tag is used when an Entity charges this cost to cost of goods sold. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.2(a)) -URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688 + Details
Name: | us-gaap_ProductionRelatedImpairmentsOrCharges
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.13) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_PropertyPlantAndEquipmentGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Stated as a percentage, the estimated or actual value of the asset at the end of its useful life or when it is no longer serviceable (cannot be used for its original purpose) divided by its [historical] capitalized cost. + References No definition available. + Details
Name: | us-gaap_PropertyPlantAndEquipmentSalvageValuePercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment. + References No definition available. + Details
Name: | us-gaap_PropertyPlantAndEquipmentUsefulLife
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

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

X
- Definition Number of Aircraft + References No definition available. + Details
Name: | wlfc_NumberOfAircraft
Namespace Prefix: | wlfc_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of Engines + References No definition available. + Details
Name: | wlfc_NumberOfEngines
Namespace Prefix: | wlfc_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorPropertyClassAxis=wlfc_EnginesAndRelatedEquipmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorPropertyClassAxis=wlfc_AircraftMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorPropertyClassAxis=wlfc_EnginesAndAircraftMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorPropertyClassAxis=wlfc_NewEngineMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis=us-gaap_PropertyAvailableForOperatingLeaseMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorPropertyClassAxis=wlfc_SparePartPackagesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |