Percentage of voting equity interests acquired at the acquisition date in the business combination.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=56956515&loc=d3e1392-128463

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- Definition

Percentage of equity in the acquiree held by the acquirer immediately before the acquisition date in a business combination.

+ References

No definition available.

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- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=51801978&loc=d3e6351-108592

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=49121117&loc=d3e13531-108611

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=51801978&loc=d3e6404-108592

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=49121117&loc=d3e13537-108611

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- References

No definition available.

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- Definition

Percentage of subsidiary's or equity method investee's stock owned by parent immediately after all stock transactions.

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the minimum number of days for which lease rent and maintenance reserve payments are past due.

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Represents the amount of maintenance reserve payments receivable that are more than 30 days past due.

+ References

No definition available.

+ Details

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Namespace Prefix:	wlfc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Represents the amount of lease rents receivable due to delinquency in rental payments by lessees.

+ References

No definition available.

+ Details

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Namespace Prefix:	wlfc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Represents the amount of lease rent receivables that are more than 30 days past due.

+ References

No definition available.

+ Details

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Namespace Prefix:	wlfc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Organization [Line Items]

+ References

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Data Type:	xbrli:stringItemType
Balance Type:	na
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- Details

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Data Type:	na
Balance Type:
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- Details

Name:	us-gaap_BusinessAcquisitionAxis=wlfc_WOLFA340LLCMember
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Data Type:	na
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Organization and Summary of Significant Accounting Policies (Organization and Revenue Recognition) (Details) - USD ($)		12 Months Ended
	Sep. 18, 2013	Dec. 31, 2015	Sep. 16, 2013
Revenue Recognition
Lease rent to be received, more than 30 days past due		$ 5,300,000
Maintenance reserve payments to be received, more than 30 days past due		$ 2,900,000
Minimum number of days for which lease rent and maintenance reserve payments are past due		30 days
Revenue \| Customer concentration risk \| One largest customer
Organizations [Line Items]
Percentage of concentration risk		8.40%
Lease rents due		$ 0
WOLF
Organizations [Line Items]
Previously held interest (as a percent)			50.00%
Acquisition of the remaining outstanding shares (as a percent)	50.00%
Controlling interest assumed (as a percent)	100.00%
WOLF
Organizations [Line Items]
Previously held interest (as a percent)			50.00%