Document and Entity Information (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Mar. 14, 2013	Jun. 30, 2012
Document and Entity Information
Entity Registrant Name	WILLIS LEASE FINANCE CORP
Entity Central Index Key	0001018164
Document Type	10-K
Document Period End Date	Dec. 31, 2012
Amendment Flag	true
Amendment Description	This Amendment No. 1 ("Amendment") to Form 10-K amends the Annual Report on Form 10-K for the fiscal year ended December 31, 2012, originally filed with the Securities and Exchange Commission on March 18, 2013 (the "Original 10-K"), of Willis Lease Finance Corporation (the "Registrant", the "Company", "we" and "our"). We are filing this Amendment with respect to Item 15 of the Original 10-K to include the separate condensed financial schedules for fiscal years ended December 31, 2012, 2011 and 2010, respectively, as Schedule I, which should be read in conjunction with the Company's consolidated financial statements and notes to the consolidated financial statements of the Original 10-K. Additionally, this Amendment corrects XBRL rendering that was incorrect at the time of the Original 10-K filing. In connection with the filing of this Amendment, the currently dated certifications from our Chief Executive Officer, our Chief Financial Officer and consent of the independent registered public accounting firm are attached as exhibits hereto. Except as described above, this Amendment does not amend, update or change the financial statements of the Company or any other items or disclosures contained in the Original 10-K and does not otherwise reflect events occurring subsequent to the original filing date of the Original 10-K on March 18, 2013.
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Public Float			$ 74.9
Entity Common Stock, Shares Outstanding		8,692,743
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	FY