Organization and Summary of Significant Accounting Policies | 1. (a) AeroCentury Corp., a Delaware corporation incorporated in 1997, typically acquires used regional aircraft and engines for lease to foreign and domestic regional carriers. In August 2016, AeroCentury Corp. formed two wholly-owned subsidiaries, ACY 19002 Limited ("ACY 19002") and ACY 19003 Limited ("ACY 19003") for the purpose of acquiring aircraft using a combination of cash and financing separate from the parent's credit facility. Financial information for AeroCentury Corp., ACY 19002 and ACY 19003 (collectively, the "Company") is presented on a consolidated basis in accordance with accounting principles generally accepted in the United States of America ("GAAP") for interim financial information, the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. All intercompany balances and transactions have been eliminated in consolidation. For further information, refer to the financial statements and footnotes thereto included in the Company's annual report on Form 10-K for the year ended December 31, 2016. (b) The Company's condensed consolidated financial statements have been prepared in accordance with GAAP. The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. The Company bases its estimates on historical experience and on various other assumptions that are believed to be reasonable for making judgments that are not readily apparent from other sources. The most significant estimates with regard to these condensed consolidated financial statements are the residual values and useful lives of the Company's long lived assets, the amount and timing of future cash flows associated with each asset that are used to evaluate whether assets are impaired, accrued maintenance costs, accounting for income taxes, and the amounts recorded as allowances for doubtful accounts. (c) 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 fair value hierarchy under GAAP is based on three levels of inputs. 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. Assets and Liabilities Measured and Recorded at Fair Value on a Recurring Basis The carrying amount of the Company's money market funds included in cash and cash equivalents was $1,848,300 and $1,348,100 at March 31, 2017 and December 31, 2016, respectively. The fair value of the Company's money market funds is categorized as Level 1 under the GAAP fair value hierarchy. As of March 31, 2017 and December 31, 2016, there were no liabilities that were required to be measured and recorded at fair value on a recurring basis. Assets Measured and Recorded at Fair Value on a Nonrecurring Basis The Company determines fair value of long-lived assets held and used, such as aircraft and aircraft engines held for lease and assets held for sale, by reference to independent appraisals, quoted market prices (e.g., offers to purchase) and other factors. An impairment charge is recorded when the Company believes that the carrying value of an asset will not be recovered through future net cash flows and that the asset's carrying value exceeds its fair value. Assets held for sale The Company recorded no impairment charges on its aircraft held for sale during the three months ended March 31, 2017. Fair Value of Other Financial Instruments The Company's financial instruments, other than cash and cash equivalents, consist principally of finance leases receivable, amounts borrowed under its credit facility (the "Credit Facility") and notes payable under special purpose financing. The fair value of accounts receivable, finance leases receivable, accounts payable and the Company's maintenance reserves and accrued maintenance costs approximates the carrying value of these financial instruments. Borrowings under the Company's Credit Facility bear floating rates of interest that reset periodically to a market benchmark rate plus a credit margin. The Company believes the effective interest rate under the Credit Facility approximates current market rates for such indebtedness at the balance sheet date, and therefore that the outstanding principal and accrued interest of $114,393,800 and $110,183,600 at March 31, 2017 and December 31, 2016, respectively, approximate their fair values on such dates. The fair value of the Company's outstanding balance of its Credit Facility would be categorized as Level 3 under the GAAP fair value hierarchy. The amounts payable under the Company's special purpose financing are payable through the fourth quarter of 2020 and bear a fixed rate of interest, as described in Note 4(b) to the condensed consolidated financial statements. The outstanding principal and accrued interest of $16,639,000 and $17,654,200 approximates the fair value of such notes at March 31, 2017 and December 31, 2016. Such fair value would be categorized as Level 3 under the GAAP fair value hierarchy. (d) As of March 31, 2017, the Company had nine aircraft finance leases that contain lessee purchase options at prices substantially below the assets' estimated residual values at the exercise date for the options. Consequently, the Company considers the purchase options to be bargain purchase options and has classified the leases as finance leases for financial accounting purposes. The Company reports the discounted present value of (i) future minimum lease payments (including the bargain purchase option) and (ii) any residual value not subject to a bargain purchase option as a finance lease receivable on its balance sheet and accrues interest on the balance of the finance lease receivable based on the interest rate inherent in the applicable lease over the term of the lease. For sales-type finance leases, the Company recognizes as a gain or loss the amount equal to (i) the net investment in sales-type finance leases plus any initial direct costs and lease incentives less (ii) the net book value of the aircraft. The Company recognized interest earned on finance leases as "finance lease revenue" in the amount of $325,400 and $185,100 in the three months ended March 31, 2017 and 2016, respectively. (e) In May 2014, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update No. 2014-09 that created the new Topic 606 ("Topic 606") in the Accounting Standards Codification ("ASC"). Topic 606 also included numerous conforming additions and amendments to other Topics within the ASC. Topic 606 established new rules that affect the amount and timing of revenue recognition for contracts with customers, but does not affect lease accounting and reporting. As such, adoption of these provisions will not affect the Company's lease revenues but may affect the reporting of other of the Company's revenues. On August 12, 2015, the FASB deferred the effective date of the provisions included in Topic 606 to years commencing after December 15, 2017. Topic 606 can be adopted early for years commencing after December 15, 2016, and may be reflected using either a full retrospective method or a simplified method that does not recast prior periods but does disclose the effect of the adoption on the current period consolidated financial statements. The Company has not yet determined either the potential impact on its consolidated financial statements or the method it will elect to use in connection with the adoption of the changes included in Topic 606. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) The new standard requires a lessor to classify leases as sales-type, finance or operating. A lease will be treated as a sale if it transfers all of the risks and rewards, as well as control of the underlying asset, to the lessee. If risks and rewards are conveyed without the transfer of control, the lease is treated as a financing. If the lessor does not convey risks and rewards or control, an operating lease results. A modified retrospective transition approach is required for lessors for sales-type, direct financing, and operating leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements, with certain practical expedients available. The Company has reviewed those agreements under which it is the lessor, and believes that the accounting for its existing operating and finance leases will not be affected by adoption of ASU 2016-02, nor does it expect classification of its future leases to be significantly affected by adoption. The Company does expect that certain pre-lease costs that are currently capitalized and amortized over operating lease terms or offset against gain on sale in sales-type leases will instead be expensed when incurred under the new standards, but since such future amounts will be based on future facts and circumstances, the Company cannot determine the future effect of such requirement. The Company does not expect to adopt ASU 2016-02 early, and does expect to elect practical expedients in connection with its adoption, including not re-evaluating lease classification or capitalized initial direct costs on existing leases. The Company is not an obligor under any agreements that would be considered leases under ASU 2016-02, and so would be unaffected with respect to its adoption with respect to lessee accounting. In January 2017, the FASB issued ASU 2017-01, Business Combinations (Topic 805) In January 2017, the FASB issued ASU 2017-04, Intangibles -- Goodwill and Other (Topic 350) |