Summary of Significant Accounting Policies	9 Months Ended
Sep. 30, 2012
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Organization and Basis of Presentation Aircastle Limited (“Aircastle,” the “Company,” “we,” “us” or “our”) is a Bermuda exempted company that was incorporated on October 29, 2004 under the provisions of Section 14 of the Companies Act of 1981 of Bermuda. Aircastle’s business is investing in aviation assets, including leasing, managing and selling commercial jet aircraft to airlines throughout the world and investing in aircraft related debt investments. Aircastle is a holding company that conducts its business through subsidiaries. Aircastle directly or indirectly owns all of the outstanding common shares of its subsidiaries. The consolidated financial statements presented are prepared in accordance with U.S. generally accepted accounting principles (“US GAAP”). We operate in a single segment. The accompanying consolidated financial statements are unaudited and have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”) for interim financial reporting and, in our opinion, reflect all adjustments, including normal recurring items, which are necessary to present fairly the results for interim periods. Operating results for the periods presented are not necessarily indicative of the results that may be expected for the entire year. Certain information and footnote disclosures normally included in consolidated financial statements prepared in accordance with US GAAP have been omitted in accordance with the rules and regulations of the SEC; however, we believe that the disclosures are adequate to make information presented not misleading. These financial statements should be read in conjunction with the consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2011. For the year ended December 31, 2011, we revised the presentation in our consolidated statements of cash flows to reflect the net change in restricted cash and cash equivalents from security deposits and maintenance payments as financing activities. For the nine months ended September 30, 2011, our consolidated statements of cash flows reflected the net change in restricted cash and cash equivalents from security deposits and maintenance payments as cash flows from operating activities. Therefore, the amounts included for the nine months ended September 30, 2011 have been reclassified to conform to the current period presentation. The Company’s management has reviewed and evaluated all events or transactions for potential recognition and/or disclosure since the balance sheet date of September 30, 2012 through the date on which the consolidated financial statements included in this Form 10-Q were issued. Principles of Consolidation The consolidated financial statements include the accounts of Aircastle and all of its subsidiaries. Aircastle consolidates eight Variable Interest Entities (“VIEs”) of which Aircastle is the primary beneficiary. All intercompany transactions and balances have been eliminated in consolidation. We consolidate VIEs in which we have determined that we are the primary beneficiary. We use judgment when deciding (a) whether an entity is subject to consolidation as a VIE, (b) who the variable interest holders are, (c) the potential expected losses and residual returns of the variable interest holders, and (d) which variable interest holder is the primary beneficiary. When determining which enterprise is the primary beneficiary, we consider (1) the entity’s purpose and design, (2) which variable interest holder has the power to direct the activities that most significantly impact the entity’s economic performance, and (3) the obligation to absorb losses of the entity or the right to receive benefits from the entity that could potentially be significant to the VIE. When certain events occur, we reconsider whether we are the primary beneficiary of VIEs. We do not reconsider whether we are a primary beneficiary solely because of operating losses incurred by an entity. Effective January 1, 2012, the Company adopted Financial Accounting Standards Board (the “FASB”) Accounting Standards Update (“ASU”) ASU 2011-04 (“ASU 2011-04”), Fair Value Measurement (Topic 820): Amendments to Achieve Common Fair Value Measurements and Disclosure Requirements in U.S. GAAP and IFRSs, to improve the comparability of fair value measurements presented and disclosed in financial statements prepared in accordance with US GAAP and IFRS. The amendments in this update change the wording used to describe the requirements in US GAAP for measuring fair value and for disclosing information about fair value measurements which include (1) those that clarify the FASB’s intent about the application of existing fair value measurement and disclosure requirements, and (2) those that change a particular principle or requirement for measuring fair value or for disclosing information about fair value measurement. ASU 2011-04 is effective for interim and annual reporting periods beginning after December 15, 2011. The adoption of ASU 2011-04 did not have a material impact on the Company’s consolidated financial statements. Also effective January 1, 2012, the Company adopted ASU 2011-12 (“ASU 2011-12”) Comprehensive Income (Topic 220): Deferral of the Effective Date for Amendments to the Presentation of Reclassifications of Items Out of Accumulated Other Comprehensive Income in Accounting Standards Update No. 2011-05. This ASU defers the ASU 2011-05 requirement that companies present reclassification adjustments for each component of accumulated other comprehensive income (“AOCI”) in both net income and other comprehensive income (“OCI”) on the face of the financial statements. During the deferral period, there is no requirement to separately present or disclose the reclassification adjustments into net income. The FASB expects to complete a project to reconsider the presentation requirement for reclassification adjustments in 2012. The deferral allows the FASB time to further research the matter. ASU 2011-12 is effective for interim and annual reporting periods beginning after December 15, 2011 and should be applied retrospectively. The adoption of ASU 2011-12 did not have a material impact on the Company’s consolidated financial statements. Risk and Uncertainties In the normal course of business, Aircastle encounters several significant types of economic risk including credit, market, aviation industry and capital market risks. Credit risk is the risk of a lessee’s inability or unwillingness to make contractually required payments and to fulfill its other contractual obligations. Market risk reflects the change in the value of derivatives and financings due to changes in interest rate spreads or other market factors, including the value of collateral underlying derivatives and financings. Aviation industry risk is the risk of a downturn in the commercial aviation industry which could adversely impact a lessee’s ability to make payments, increase the risk of unscheduled lease terminations and depress lease rates and the value of the Company’s aircraft. Capital market risk is the risk that the Company is unable to obtain capital at reasonable rates to fund the growth of our business or to refinance existing debt facilities. Use of Estimates The preparation of financial statements in conformity with US GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. While Aircastle believes that the estimates and related assumptions used in the preparation of the consolidated financial statements are appropriate, actual results could differ from those estimates. Investment in Finance Leases If a lease meets specific criteria at the inception of a new lease or at any lease modification date, we recognize the lease as a Net investment in finance lease on our Consolidated Balance Sheets. The net investment in finance leases consists of lease receivables, less the unearned income, plus the estimated unguaranteed residual value of the leased flight equipment at the lease end date. The unearned income is recognized as Other revenue in our Consolidated Statements of Income over the lease term in a manner that produces a constant rate of return on the Net investment in finance lease. Collectability of finance leases is evaluated periodically on an individual customer level. The evaluation of the collectability of the finance leases considers the credit of the lessee and the value of the underlying aircraft. Recent Unadopted Accounting Pronouncements In August 2010, the FASB issued an exposure draft, “Leases” (the “Lease ED”), which would replace the existing guidance in the Accounting Standards Codification (“ASC”) 840 (“ASC 840”), Leases. In June 2012, the FASB decided that leases would be classified as either leases of property or leases of assets other than property. Leases of property will continue to use operating lease accounting. Leases of other than property would use the receivable residual approach. Under the receivable residual approach, a lease receivable would be recognized for the lessor’s right to receive lease payments, a portion of the carrying amount of the underlying asset would be allocated between the right of use granted to the lessee and the lessor’s residual value and profit or loss would only be recognized at commencement if it is reasonably assured. The FASB completed all of its deliberations and decided to re-expose the Lease ED in the first quarter of 2013. We anticipate that the final standard may have an effective date no earlier than 2016. When and if the proposed guidance becomes effective, it may have a significant impact on the Company’s consolidated financial statements. Although we believe the presentation of our financial statements, and those of our lessees could change, we do not believe the accounting pronouncement will change the fundamental economic reasons for which the airlines lease aircraft. Therefore, we do not believe it will have a material impact on our business.

Summary of Significant Accounting Policies

Organization and Basis of Presentation

Aircastle Limited (“Aircastle,” the “Company,” “we,” “us” or “our”) is a Bermuda exempted company that was incorporated on October 29, 2004 under the provisions of Section 14 of the Companies Act of 1981 of Bermuda. Aircastle’s business is investing in aviation assets, including leasing, managing and selling commercial jet aircraft to airlines throughout the world and investing in aircraft related debt investments.

Aircastle is a holding company that conducts its business through subsidiaries. Aircastle directly or indirectly owns all of the outstanding common shares of its subsidiaries. The consolidated financial statements presented are prepared in accordance with U.S. generally accepted accounting principles (“US GAAP”). We operate in a single segment.

The accompanying consolidated financial statements are unaudited and have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”) for interim financial reporting and, in our opinion, reflect all adjustments, including normal recurring items, which are necessary to present fairly the results for interim periods. Operating results for the periods presented are not necessarily indicative of the results that may be expected for the entire year. Certain information and footnote disclosures normally included in consolidated financial statements prepared in accordance with US GAAP have been omitted in accordance with the rules and regulations of the SEC; however, we believe that the disclosures are adequate to make information presented not misleading. These financial statements should be read in conjunction with the consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2011.

For the year ended December 31, 2011, we revised the presentation in our consolidated statements of cash flows to reflect the net change in restricted cash and cash equivalents from security deposits and maintenance payments as financing activities. For the nine months ended September 30, 2011, our consolidated statements of cash flows reflected the net change in restricted cash and cash equivalents from security deposits and maintenance payments as cash flows from operating activities. Therefore, the amounts included for the nine months ended September 30, 2011 have been reclassified to conform to the current period presentation.

The Company’s management has reviewed and evaluated all events or transactions for potential recognition and/or disclosure since the balance sheet date of September 30, 2012 through the date on which the consolidated financial statements included in this Form 10-Q were issued.

Principles of Consolidation

The consolidated financial statements include the accounts of Aircastle and all of its subsidiaries. Aircastle consolidates eight Variable Interest Entities (“VIEs”) of which Aircastle is the primary beneficiary. All intercompany transactions and balances have been eliminated in consolidation.

We consolidate VIEs in which we have determined that we are the primary beneficiary. We use judgment when deciding (a) whether an entity is subject to consolidation as a VIE, (b) who the variable interest holders are, (c) the potential expected losses and residual returns of the variable interest holders, and (d) which variable interest holder is the primary beneficiary. When determining which enterprise is the primary beneficiary, we consider (1) the entity’s purpose and design, (2) which variable interest holder has the power to direct the activities that most significantly impact the entity’s economic performance, and (3) the obligation to absorb losses of the entity or the right to receive benefits from the entity that could potentially be significant to the VIE. When certain events occur, we reconsider whether we are the primary beneficiary of VIEs. We do not reconsider whether we are a primary beneficiary solely because of operating losses incurred by an entity.

Effective January 1, 2012, the Company adopted Financial Accounting Standards Board (the “FASB”) Accounting Standards Update (“ASU”) ASU 2011-04 (“ASU 2011-04”), Fair Value Measurement (Topic 820): Amendments to Achieve Common Fair Value Measurements and Disclosure Requirements in U.S. GAAP and IFRSs, to improve the comparability of fair value measurements presented and disclosed in financial statements prepared in accordance with US GAAP and IFRS. The amendments in this update change the wording used to describe the requirements in US GAAP for measuring fair value and for disclosing information about fair value measurements which include (1) those that clarify the FASB’s intent about the application of existing fair value measurement and disclosure requirements, and (2) those that change a particular principle or requirement for measuring fair value or for disclosing information about fair value measurement. ASU 2011-04 is effective for interim and annual reporting periods beginning after December 15, 2011. The adoption of ASU 2011-04 did not have a material impact on the Company’s consolidated financial statements.

Also effective January 1, 2012, the Company adopted ASU 2011-12 (“ASU 2011-12”) Comprehensive Income (Topic 220): Deferral of the Effective Date for Amendments to the Presentation of Reclassifications of Items Out of Accumulated Other Comprehensive Income in Accounting Standards Update No. 2011-05. This ASU defers the ASU 2011-05 requirement that companies present reclassification adjustments for each component of accumulated other comprehensive income (“AOCI”) in both net income and other comprehensive income (“OCI”) on the face of the financial statements. During the deferral period, there is no requirement to separately present or disclose the reclassification adjustments into net income. The FASB expects to complete a project to reconsider the presentation requirement for reclassification adjustments in 2012. The deferral allows the FASB time to further research the matter. ASU 2011-12 is effective for interim and annual reporting periods beginning after December 15, 2011 and should be applied retrospectively. The adoption of ASU 2011-12 did not have a material impact on the Company’s consolidated financial statements.

Risk and Uncertainties

In the normal course of business, Aircastle encounters several significant types of economic risk including credit, market, aviation industry and capital market risks. Credit risk is the risk of a lessee’s inability or unwillingness to make contractually required payments and to fulfill its other contractual obligations. Market risk reflects the change in the value of derivatives and financings due to changes in interest rate spreads or other market factors, including the value of collateral underlying derivatives and financings. Aviation industry risk is the risk of a downturn in the commercial aviation industry which could adversely impact a lessee’s ability to make payments, increase the risk of unscheduled lease terminations and depress lease rates and the value of the Company’s aircraft. Capital market risk is the risk that the Company is unable to obtain capital at reasonable rates to fund the growth of our business or to refinance existing debt facilities.

Use of Estimates

The preparation of financial statements in conformity with US GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. While Aircastle believes that the estimates and related assumptions used in the preparation of the consolidated financial statements are appropriate, actual results could differ from those estimates.

Investment in Finance Leases

If a lease meets specific criteria at the inception of a new lease or at any lease modification date, we recognize the lease as a Net investment in finance lease on our Consolidated Balance Sheets. The net investment in finance leases consists of lease receivables, less the unearned income, plus the estimated unguaranteed residual value of the leased flight equipment at the lease end date. The unearned income is recognized as Other revenue in our Consolidated Statements of Income over the lease term in a manner that produces a constant rate of return on the Net investment in finance lease.

Collectability of finance leases is evaluated periodically on an individual customer level. The evaluation of the collectability of the finance leases considers the credit of the lessee and the value of the underlying aircraft.

Recent Unadopted Accounting Pronouncements

In August 2010, the FASB issued an exposure draft, “Leases” (the “Lease ED”), which would replace the existing guidance in the Accounting Standards Codification (“ASC”) 840 (“ASC 840”), Leases. In June 2012, the FASB decided that leases would be classified as either leases of property or leases of assets other than property. Leases of property will continue to use operating lease accounting. Leases of other than property would use the receivable residual approach. Under the receivable residual approach, a lease receivable would be recognized for the lessor’s right to receive lease payments, a portion of the carrying amount of the underlying asset would be allocated between the right of use granted to the lessee and the lessor’s residual value and profit or loss would only be recognized at commencement if it is reasonably assured. The FASB completed all of its deliberations and decided to re-expose the Lease ED in the first quarter of 2013. We anticipate that the final standard may have an effective date no earlier than 2016. When and if the proposed guidance becomes effective, it may have a significant impact on the Company’s consolidated financial statements. Although we believe the presentation of our financial statements, and those of our lessees could change, we do not believe the accounting pronouncement will change the fundamental economic reasons for which the airlines lease aircraft. Therefore, we do not believe it will have a material impact on our business.