Basis of Presentation (Policies)	9 Months Ended
Basis of Presentation (Policies)	Sep. 30, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
The Company and Nature of Operations	The Company and Nature of Operations FalconStor Software, Inc., a Delaware Corporation (the "Company"), is a leading software-defined storage company offering a converged data services software platform that is hardware agnostic. As a global company, our vision is to deliver enterprise class, software-defined, intelligent data services combined with predictive analytics across any primary or secondary storage hardware, in the cloud or on premise. The Company mission is to help IT organizations realize more economic value out of existing environments and any future storage investments while reducing complexity, maximizing flexibility and improving operational efficiency. Our award-winning solutions are available and supported worldwide by OEMs as well as leading service providers, system integrators, resellers and the Company.
Principles of Consolidation	Principles of Consolidation The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All significant intercompany balances and transactions have been eliminated in consolidation.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America ("GAAP") requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. The Company’s significant estimates include those related to revenue recognition, accounts receivable allowances, share-based payment compensation, valuation of derivatives, capitalizable software development costs, valuation of goodwill and other intangible assets and income taxes. Actual results could differ from those estimates. The financial market volatility in many countries where the Company operates has impacted and may continue to impact the Company’s business. Such conditions could have a material impact on the Company’s significant accounting estimates discussed above.
Unaudited Interim Financial Information	Unaudited Interim Financial Information The accompanying unaudited interim condensed consolidated financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). Certain information and note disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations relating to interim financial statements. In the opinion of management, the accompanying unaudited interim condensed consolidated financial statements reflect all adjustments, consisting only of normal recurring adjustments, necessary to present fairly the financial position of the Company at September 30, 2016, and the results of its operations for the three and nine months ended September 30, 2016 and 2015. The results of operations of any interim period are not necessarily indicative of the results of operations to be expected for the full fiscal year. These condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes set forth in the Company's Annual Report on Form 10-K for the year ended December 31, 2015 ("2015 Form 10-K").
Recently Adopted and Issued Accounting Pronouncements	Recently Adopted Accounting Pronouncements In November 2014, the Financial Accounting Standards Board (the "FASB") issued new guidance which requires an entity to determine whether the host contract in a hybrid financial instrument issued in the form of a share is more akin to debt or to equity by considering the economic characteristics and risks of the entire hybrid financial instrument, including the embedded derivative feature that is being evaluated for separate accounting from the host contract. The effects of initially adopting the amendments in this update should be applied on a modified retrospective basis to existing hybrid financial instruments issued in the form of a share as of the beginning of the fiscal year for which the amendments are effective. The amendments in this update are effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2015, which for the Company was the first quarter of 2016. The adoption of this new accounting guidance by Company has not had any impact on the Company's consolidated financial position, results of operations or cash flows. In August 2014, the FASB issued new guidance which requires an entity to evaluate whether there are conditions or events, in the aggregate, that raise substantial doubt about the entity's ability to continue as a going concern within one year after the date that the financial statements are issued (or within one year after the financial statements are available to be issued when applicable), and to provide related footnote disclosures in certain circumstances. The amendments in this update are effective for the annual period ending after December 15, 2016, and for annual and interim periods thereafter, which for the Company is the annual period ending December 31, 2016. The adoption of this new accounting guidance by Company has not had any impact on the Company's consolidated financial position, results of operations or cash flows. (f) Recently Issued Accounting Pronouncements In August 2016, the FASB issued new guidance on presentation and classification of eight specific items within the statement of cash flows, including (i) debt prepayment or debt extinguishment costs, (ii) settlement of zero-coupon debt instruments or other debt instruments with coupon rates that are insignificant in relation to the effective interest rate of the borrowing, (iii) contingent consideration payments made after a business combination, (iv) proceeds from the settlement of insurance claims, (v) proceeds from the settlement of corporate-owned life insurance policies, including bank-owned life insurance policies, (vi) distributions received from equity method investees, (vii) beneficial interests in securitization transactions, and (viii) separately identifiable cash flows and application of the predominance principle. This update is effective for annual reporting periods, and interim periods therein, beginning after December 15, 2017, which for the Company will be the annual period ending December 31, 2018. Early adoption, including adoption in an interim period, is permitted. The Company does not expect the adoption of this guidance to have a material impact on its consolidated financial statements and related disclosures. In March 2016, the FASB issued new guidance on accounting for employee share-based payment awards to simplify the accounting related to several aspects of accounting for share-based payment transactions, including income tax consequences of share-based payment transactions, classification of awards as either equity or liabilities, forfeitures, and classification on the statement of cash flows. The new standard is effective for the annual period beginning after December 15, 2016, including interim reporting periods within that period, which for the Company will be the annual period ending December 31, 2017. Early adoption, including adoption in an interim period, is permitted. The standard requires the use of several transition methods including a modified retrospective transition method, retrospective method and prospective method. The Company is evaluating the effect that this new guidance will have on its consolidated financial statements and related disclosures. In February 2016, the FASB issued new guidance on leases to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. This new guidance will replace existing guidance on leases in accounting principles generally accepted in the United States when it becomes effective. The new standard is effective for the annual period beginning after December 15, 2018, including interim reporting periods within that period, which for the Company will be the annual period ending December 31, 2019. Early application is permitted. The standard requires the use of a modified retrospective transition method; however, certain optional practical expedients may be applied. The Company is evaluating the effect that this new guidance will have on its consolidated financial statements and related disclosures. In January 2016, the FASB issued new guidance on the recognition, measurement, presentation and disclosure of financial assets and financial liabilities. The standard (i) requires an entity to measure equity investments, except those accounted for under the equity method of accounting or those that result in consolidation of the investee, at fair value with changes in fair value recognized in net income, (ii) simplifies the impairment assessment of equity investments without readily determinable fair values by requiring an entity to perform a qualitative assessment to identify impairment, (iii) changes certain presentation and disclosure requirements related to financial assets and financial liabilities, and (iv) clarifies that an entity should evaluate the need for a valuation allowance on a deferred tax asset related to available-for-sale securities in combination with the entity's other deferred tax assets. The amendments in this update are effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2017, which for the Company will be the annual period ending December 31, 2018. Early adoption, including adoption in an interim period, is not permitted except for certain amendments in this update. The Company has not yet adopted this guidance and currently does not expect the adoption of the new guidance by the Company to have a significant impact on the Company's financial results. In November 2015, the FASB issued new guidance which requires an entity to classify deferred tax liabilities and assets, along with any related valuation allowance, as non-current in its consolidated balance sheet. The amendments in this update may be applied either prospectively to all deferred tax liabilities and assets or retrospectively to all periods presented. The amendments in this update are effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2016, which for the Company will be the annual period ending December 31, 2017. Early adoption, including adoption in an interim period, is permitted. The Company has not yet adopted this guidance and currently does not expect the adoption of the new guidance by the Company to have a significant impact on the Company's financial results. In May 2014, the FASB issued new guidance which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. This new guidance will replace most existing revenue recognition guidance in Generally Accepted Accounting Principles in the United States when it becomes effective. The new standard is effective for the annual period beginning after December 15, 2017, including interim reporting periods within that period, which for the Company will be the annual period ending December 31, 2018. Early application as of January 1, 2017 is permitted. The standard permits the use of either the retrospective or cumulative effect transition method. The Company is evaluating the effect that this new guidance will have on its consolidated financial statements and related disclosures. The Company has not yet selected a transition method nor has it determined the effect of the standard on its financial reporting.
Revenue Recognition	Revenue Recognition The Company derives its revenue from sales of its products, support and services. Product revenue consists of the Company’s software integrated with industry standard hardware and sold as complete turn-key integrated solutions, as stand-alone software applications or sold on a subscription or consumption basis. Depending on the nature of the arrangement revenue related to turn-key solutions and stand-alone software applications are generally recognized upon shipment and delivery of license keys. For certain arrangements revenue is recognized based on usage or ratably over the term of the arrangement. Support and services revenue consists of both maintenance revenues and professional services revenues. Revenue is recorded net of applicable sales taxes. In accordance with the authoritative guidance issued by the FASB on revenue recognition, the Company recognizes revenue when persuasive evidence of an arrangement exists, the fee is fixed or determinable, delivery has occurred, and collection of the resulting receivable is deemed probable. Products delivered to a customer on a trial basis are not recognized as revenue until the trial period has ended and acceptance has occurred by the customer. Reseller and distributor customers typically send the Company a purchase order when they have an end user identified. For bundled arrangements that include either maintenance or both maintenance and professional services, the Company uses the residual method to determine the amount of product revenue to be recognized. Under the residual method, consideration is allocated to the undelivered elements based upon vendor-specific objective evidence (“VSOE”) of the fair value of those elements, with the residual of the arrangement fee allocated to and recognized as product revenue. If VSOE does not exist for all undelivered elements of an arrangement, the Company recognizes total revenue from the arrangement ratably over the term of the maintenance agreement. The Company's long-term portion of deferred revenue consists of (i) payments received for maintenance contracts with terms in excess of one year as of the balance sheet date, and (ii) payments received for product sales bundled with multiple years of maintenance but for which VSOE did not exist for all undelivered elements of the arrangement. The Company provides an allowance for product returns as a reduction of revenue, based upon historical experience and known or expected trends. When more than one element, such as hardware, software and services are contained in a single arrangement, the Company will first allocate revenue based upon the relative selling price into two categories: (1) non-software components, such as hardware and any hardware-related items, as required system software that functions with the hardware to deliver the essential functionality of the hardware and related post-contract customer support, and software as service subscriptions and (2) software components and applications, such as post-contract customer support and other services. The Company will then allocate revenue within the non-software category to each element based upon their relative selling price using a hierarchy of VSOE, third-party evidence of selling price (“TPE”) or estimated selling prices (“ESP”), if VSOE or TPE does not exist. The Company will allocate revenue within the software category to the undelivered elements based upon their fair value using VSOE with the residual revenue allocated to the delivered elements. If the Company cannot objectively determine the VSOE of the fair value of any undelivered software element, the Company will defer revenue for all software components until all elements are delivered and services have been performed, until fair value can objectively be determined for any remaining undelivered elements, or until software maintenance is the only undelivered element which the Company does not have VSOE for, in which case revenue is recognized over the maintenance term for all software elements. Revenues associated with maintenance services are deferred and recognized as revenue ratably over the term of the contract. Revenues associated with software implementation and software engineering services are recognized when the services are performed. Costs of providing these services are included in cost of support and services. The Company has entered into various distribution, licensing and joint promotion agreements with OEMs, whereby the Company has provided the OEM a non-exclusive software license to install the Company’s software on certain hardware or to resell the Company’s software in exchange for payments based on the products distributed by these OEMs. Such payments from the OEM or distributor are recognized as revenue in the period reported by the OEM. From time to time the Company will enter into funded software development arrangements. Under such arrangements, revenue recognition will not commence until final delivery and/or acceptance of the product. For arrangements where the Company has VSOE for the undelivered elements, the Company will follow the residual method and recognize product revenue upon final delivery and/or acceptance of the product. For arrangements where the Company does not have VSOE for the undelivered elements, the Company will recognize the entire arrangement fee ratably commencing at the time of final delivery and/or acceptance through the end of the service period in the arrangement. Certain arrangements, for which VSOE of fair value for the undelivered maintenance elements cannot be established, are accounted for as a single unit of account. The revenue recognized from single units of accounting are typically allocated and classified on the consolidated statements of operations as product revenue and support and services revenue. Since VSOE cannot be established, VSOE of similar maintenance offerings provides the basis for the support and services revenue classification, and the remaining residual consideration provides the basis for the product revenue classification.