2.4.0.82010 - Disclosure - Summary of Significant Accounting Policies (Policies)truefalsefalse1false falsefalseD2013Q2YTDhttp://www.sec.gov/CIK0001018164duration2013-01-01T00:00:002013-06-30T00:00:001true 1us-gaap_AccountingPoliciesAbstractus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Summary of Significant Accounting Policies2false 2us-gaap_BasisOfAccountingPolicyPolicyTextBlockus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00<div style="font-size:10.0pt;font-family:Times New Roman;"> (a) Basis of Presentation: Our unaudited consolidated financial statements include the accounts of Willis Lease Finance Corporation and its subsidiaries (“we” or the “Company”) and have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission for reporting on Form 10-Q. Pursuant to such rules and regulations, certain information and note disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America have been condensed or omitted. The accompanying unaudited interim consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto, together with Management’s Discussion and Analysis of Financial Condition and Results of Operations, contained in our Annual Report on Form 10-K/A for the fiscal year ended December 31, 2012.   In the opinion of management, the accompanying unaudited consolidated financial statements contain all adjustments (consisting of only normal and recurring adjustments) necessary to present fairly our financial position as of June 30, 2013  and December 31, 2012, and the results of our operations for the three and six months ended June 30, 2013 and 2012, and our cash flows for the six months ended June 30, 2013 and 2012. The results of operations and cash flows for the period ended June 30, 2013 are not necessarily indicative of the results of operations or cash flows which may be reported for the remainder of 2013.   Management considers the continuing operations of our company to operate in one reportable segment. </div>falsefalsefalsenonnum:textBlockItemTypenaDisclosure of accounting policy for basis of accounting, or basis of presentation, used to prepare the financial statements (for example, US Generally Accepted Accounting Principles, Other Comprehensive Basis of Accounting, IFRS).No definition available.false0Basis of Presentation:3false 2us-gaap_FairValueMeasurementPolicyPolicyTextBlockus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00<div style="font-size:10.0pt;font-family:Times New Roman;"> (b) Fair Value Measurements:   Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs, to the extent possible. The standard describes a fair value hierarchy based on three levels of inputs, of which the first two are considered observable and the last unobservable, that may be used to measure fair value which are the following:   Level 1 - Quoted prices in active markets for identical assets or liabilities.   Level 2 - Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.   Level 3 - Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. </div>falsefalsefalsenonnum:textBlockItemTypenaDisclosure of accounting policy for fair value measurements, which may include, but is not limited to, how an entity that manages a group of financial assets and liabilities on the basis of its net exposure measures the fair value of those assets and liabilities.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6367646&loc=d3e18780-107790 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 35 -Paragraph 18G -URI http://asc.fasb.org/extlink&oid=15229074&loc=SL7494712-110257 false0Fair Value Measurements:falseSummary of Significant Accounting Policies (Policies)UnKnownUnKnownUnKnownUnKnowntruefalsefalseSheethttp://www.willislease.com/role/DisclosureSummaryOfSignificantAccountingPoliciesPolicies13