Significant Accounting Policies [Text Block] | 2. Summary of Significant Accounting Policies The accompanying unaudited condensed consolidated financial statements reflect the application of significant accounting policies as described below and elsewhere in these notes to the condensed consolidated financial statements. Basis of presentation The accompanying unaudited condensed consolidated financial statements of the Company have been prepared in accordance with generally accepted accounting principles in the United States ("GAAP") for interim financial reporting and applicable quarterly reporting regulations of the Securities and Exchange Commission ("SEC"). In management's opinion, the accompanying interim unaudited condensed consolidated financial statements include all adjustments necessary for a fair statement of the financial position of the Company as of March 31, 2017 , the results of operations for the three months ended March 31, 2017 and 2016 , and cash flows for the three months ended March 31, 2017 and 2016 . Certain information and disclosures normally included in the notes to the annual financial statements prepared in accordance with GAAP have been omitted from these interim unaudited condensed consolidated financial statements pursuant to the rules and regulations of the SEC. Accordingly, these unaudited condensed consolidated financial statements should be read in conjunction with the consolidated financial statements in the Company's Annual Report on Form 10-K for the fiscal year ended December 31, 2016 ("Annual Report") filed with the SEC. The condensed consolidated balance sheet as of December 31, 2016 was derived from the Company's audited consolidated financial statements but does not include all disclosures required under GAAP. Basis of consolidation The unaudited condensed consolidated financial statements include the accounts of the Company, its wholly owned subsidiaries and a subsidiary where the Company exercises control. All intercompany transactions and balances have been eliminated in consolidation. The functional currency of PROS France SAS, formerly known as Cameleon Software SA ("PROS France") is the Euro. The financial statements of this subsidiary are translated into U.S. dollars using period-end rates of exchange for assets and liabilities, historical rates of exchange for equity, and average rates of exchange for the period for revenue and expenses. Translation gains (losses) are recorded in accumulated other comprehensive loss as a component of stockholders' equity. Dollar amounts The dollar amounts presented in the tabular data within these footnote disclosures are stated in thousands of dollars, except per share amounts, or as noted within the context of each footnote disclosure. Use of estimates The Company makes estimates and assumptions in the preparation of its unaudited condensed consolidated financial statements, and its estimates and assumptions may affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the unaudited condensed consolidated financial statements, and the reported amounts of revenue and expenses during the reporting periods. Actual results could differ from those estimates. The complexity and judgment required in the Company's estimation process, as well as issues related to the assumptions, risks and uncertainties inherent in the application of the percentage-of-completion method of accounting, affect the amounts of revenue, expenses, unbilled receivables and deferred revenue. Estimates are also used for, but not limited to, receivables, allowance for doubtful accounts, useful lives of assets, depreciation and amortization, income taxes and deferred tax asset valuation, valuation of stock options, other current liabilities and accrued liabilities. Numerous internal and external factors can affect estimates. The critical accounting policies related to the estimates and judgments are discussed in the Company's Annual Report under management's discussion and analysis of financial condition and results of operations. There have been no significant changes to the Company's critical accounting policies as described in the Company's Annual Report. Revenue recognition The Company derives its revenues primarily from subscription services fees, professional services, the perpetual licensing of its software products and the associated software maintenance and support services. The Company has historically derived the majority of its revenue from the licensing of its software products, the related implementation and associated software maintenance and support. More recently, it has emphasized its offers of subscription services that do not require customers to host its solutions in their data centers. The Company commences revenue recognition when all of the following criteria are met: • there is persuasive evidence of an arrangement; • the service has been or is being provided to the customer; • collection of the fee is reasonably assured; and • the amount of fees to be paid by the customer is fixed and determinable. Subscription services revenue Subscription services revenue is generally recognized ratably over the contractual term of the arrangement beginning on the date that the Company's service is made available to the customer, assuming all other revenue recognition criteria have been met. The Company's subscription contracts do not provide customers with the right to take possession of the software supporting the applications and, as a result, are accounted for as service contracts. Any revenue related to up-front activation or set-up fees are deferred and recognized ratably over the estimated period that the customer benefits from the related services. Direct and incremental costs related to up-front activation or set-up activities are capitalized until the date the Company's service is made available and then expensed ratably over the estimated period that the customer benefits from the related services. For the Company's subscription services that include professional services, the Company determines whether the professional services have standalone value. Professional services deemed to have standalone value are accounted for separately from subscription services and the subscription services revenue recognition commences on the date that the Company's service is made available to the customer. If determined that the professional services do not have standalone value, the transaction is treated as a single element and the subscription services and professional services revenue is deferred until the customer commences use of the subscription services, and the subscription services revenue is recognized over the remaining term of the arrangement. Maintenance and support revenue Maintenance and support revenue includes post-implementation customer support and the right to unspecified software updates and enhancements on a when-and-if-available basis. The Company recognizes revenue from maintenance arrangements ratably over the period in which the services are provided. License revenue The Company derives the majority of its license revenue from the sale of perpetual licenses. For software license arrangements that do not require significant modification or customization of the underlying software, the Company recognizes software licenses revenues upon software delivery, assuming all other revenue recognition criteria have been met. The Company evaluates the nature and scope of professional services for each arrangement, and if it determines that the professional services revenue should not be accounted for separately from license revenue, the license revenue is recognized together with the professional services revenue using the percentage-of-completion method or completed contract method. The completed contract method is also used for contracts where there is a risk over final acceptance by the customer or for contracts that are short-term in nature. The percentage-of-completion method is measured by the percentage of man-days incurred during the reporting period as compared to the estimated total man-days necessary for each contract for implementation of the software solutions. The Company believes that for each such project, man-days expended in proportion to total estimated man-days at completion represents the most reliable and meaningful measure for determining a project's progress toward completion. Under the Company's fixed-fee arrangements, should a loss be anticipated on a contract, the full amount of the loss is recorded when the loss is determinable. The Company also licenses software solutions under term license agreements that typically include maintenance during the license term. When maintenance is included for the entire term of the term license, there is no renewal rate and the Company has not established vendor specific objective evidence ("VSOE") of fair value for the maintenance on term licenses. For term license agreements, revenue and the associated costs are deferred until the delivery of the solution and recognized ratably over the remaining license term. Professional services revenue Professional services revenues are generally recognized as the services are rendered for time and material contracts, or on a proportional performance basis for fixed price contracts. The majority of the Company's professional services contracts are on a time and materials basis. Training revenues are recognized as the services are rendered. For the Company's subscription services that include professional services, the Company determines whether the professional services have standalone value. Professional services deemed to have standalone value are accounted for separately from subscription services and typically recognized as the services are performed. If determined that the professional services do not have standalone value, the transaction is treated as a single element, the professional services revenue is deferred until the customer commences use of the subscription services, and the professional services revenue is recognized over the remaining term of the arrangement. For software license arrangements that include professional services, the Company determines whether the professional services are considered essential to the functionality of the software using factors such as: the nature of its software products; whether they are ready for use by the customer upon receipt; the nature of professional services; the availability of services from other vendors; whether the timing of payments for license revenue coincides with performance of services; and whether milestones or acceptance criteria exist that affect the realizability of the software license fee. For professional services considered essential to the functionality of the software, the license revenue is recognized together with the professional services revenue using the percentage-of-completion method or completed contract method. The completed contract method is also used for contracts where there is a risk over final acceptance by the customer or for contracts that are short-term in nature. Multiple element arrangements For arrangements with multiple deliverables, the Company evaluates whether the individual deliverables qualify as separate units of accounting. In order to treat deliverables in a multiple deliverable arrangement as separate units of accounting, the deliverables must have standalone value upon delivery. If the deliverables have standalone value upon delivery, the Company accounts for each deliverable separately and revenue is recognized for the respective deliverables as they are delivered. When multiple deliverables included in an arrangement are separable into different units of accounting, the arrangement consideration is allocated to the identified separate units of accounting based on their relative selling price. Multiple deliverable arrangement accounting guidance provides a hierarchy when determining the relative selling price for each unit of accounting. VSOE of selling price, based on the price at which the item is regularly sold by the vendor on a standalone basis, should be used if it exists. If VSOE of selling price is not available, third-party evidence ("TPE") of selling price is used to establish the selling price if it exists. If neither VSOE nor TPE exist for a deliverable, arrangements with multiple deliverables can be separated into discrete units of accounting based on the Company's best estimate of selling price ("BESP"). The objective of BESP is to determine the price at which the Company would transact a sale if the product or service were sold on a standalone basis. The amount of arrangement fee allocated is limited by contingent revenues, if any. For transactions that only include software and software-related elements, the Company continues to account for such arrangements under the software revenue recognition standards which require it to establish VSOE of fair value to allocate arrangement consideration to multiple deliverables. For multiple-element arrangements that contain software and nonsoftware elements such as its subscription services, the Company allocates revenue between the software and software related elements as a group and any nonsoftware elements based on a relative fair value allocation. The Company determines fair value for each deliverable using the selling price hierarchy described above and utilizing VSOE of fair value if it exists. The Company applies the residual method to recognize revenue for the delivered elements in standalone software transactions. Under the residual method, the amount of revenue allocated to delivered elements equals the total arrangement consideration, less the aggregate fair value of any undelivered elements, typically maintenance, provided that VSOE of fair value exists for all undelivered elements. VSOE of fair value is based on the price charged when the element is sold separately or, in the case of maintenance, substantive renewal rates for maintenance. Revenue that has been recognized, but for which the Company has not invoiced the customer, is recorded as unbilled receivables. Invoices that have been issued before revenue has been recognized are recorded as deferred revenue in the accompanying consolidated balance sheets. Internal-use software Costs incurred to develop internal-use software during the development stage are capitalized, stated at cost, and depreciated using the straight-line method over the estimated useful lives of the assets. Development stage costs generally include salaries and personnel costs and third-party contractor expenses associated with internal-use software configuration, coding, installation and testing. For the three months ended March 31, 2017 and 2016 , the Company capitalized $0.6 million and zero , respectively, of internal-use software development costs related to cloud-based offerings. Capitalized internal-use software development costs related to cloud-based offerings are amortized using the straight-line method over the useful life of the asset. For the three months ended March 31, 2017 and 2016 , the Company amortized no capitalized internal-use software development costs. Capitalized software for internal use is included in property and equipment, net in the unaudited condensed consolidated balance sheets. Amortization of capitalized internal-use software development costs, if any, is included in cost of subscription revenues in the accompanying unaudited condensed consolidated statements of comprehensive income (loss). Impairment of long-lived assets Long-lived assets are reviewed for impairment whenever an event or change in circumstances indicates that the carrying amount of an asset or group of assets may not be recoverable. The impairment review includes comparison of future cash flows expected to be generated by the asset or group of assets with the associated assets' carrying value. If the carrying value of the asset or group of assets exceeds its expected future cash flows (undiscounted and without interest charges), an impairment loss is recognized to the extent that the carrying amount of the asset exceeds its fair value. The Company recorded no impairment charges during the three months ended March 31, 2017 and 2016 . Noncash share-based compensation The Company measures all share-based payments to its employees based on the grant date fair value of the awards and recognizes expenses in the Company's unaudited consolidated statement of comprehensive income (loss) on a straight-line basis over the periods during which the recipient is required to perform services (generally over the vesting period of the awards). To date, the Company has granted stock options, Restricted Stock Units ("RSUs"), stock settled Stock Appreciation Rights ("SARs"), and Market Stock Units ("MSUs"). RSUs include (i) time-based awards, and (ii) market-based awards in which the number of shares that vest are based upon attainment of target average per share closing price over a requisite trading period. MSUs are performance-based awards in which the number of shares that vest are based upon the Company's relative stockholder return. The following table presents the number of shares or units outstanding for each award type as of March 31, 2017 and December 31, 2016 , respectively, (in thousands): Award type March 31, 2017 December 31, 2016 Stock options 478 734 Restricted stock units (time-based) 2,347 2,237 Restricted stock units (market-based) 460 460 Stock appreciation rights 490 515 Market stock units 347 342 Stock options, time-based RSUs and SARs vest ratably between one and four years. Market-based RSUs vest if the average trailing closing price of the Company's Common Stock meets certain minimum performance hurdles for at least 105 calendar days prior to September 9, 2020, with 25% vesting at $27 , an additional 25% vesting at $33 , and the remaining 50% vesting at $41 . The actual number of MSUs that will be eligible to vest is based on the total stockholder return of the Company relative to the total stockholder return of the Russell 2000 Index ("Index") over their respective performance periods, as defined by each award's plan documents. The Company did not grant any stock options or SARs during the three months ended March 31, 2017 or 2016 . The fair value of the time-based RSUs is based on the closing price of the Company's stock on the date of grant. The Company estimates the fair value and the derived service period of the market-based RSUs on the date of grant using a Monte Carlo simulation model. The model requires the use of a number of assumptions including the expected volatility of the Company's stock, its risk-free interest rate and expected dividends. The Company's expected volatility at the date of grant was based on the historical volatility of the Company over the performance period. The fair value of the market-based RSUs is expensed over the derived service period for each separate vesting tranche. The derived service period for the vesting tranches of the market-based RSUs ranges between 1.01 and 1.98 years. The Company estimates the fair value of MSUs on the date of grant using a Monte Carlo simulation model. The determination of fair value of the MSUs is affected by the Company's stock price and a number of assumptions including the expected volatilities of the Company's stock and the Index, its risk-free interest rate and expected dividends. The Company's expected volatility at the date of grant was based on the historical volatilities of the Company and the Index over the performance period. The weighted average assumptions used to value the MSUs granted during the three months ended March 31, 2017 were as follows: March 31, 2017 Volatility 45.88% Risk-free interest rate 1.52% Expected option life in years 3.10 Dividend yield — Earnings per share The Company computes basic earnings (loss) per share by dividing net income (loss) attributable to common stockholders by the weighted average number of common shares outstanding. Diluted earnings (loss) per share is computed by dividing net income (loss) attributable to common stockholders by the weighted average number of common shares and dilutive potential common shares then outstanding. Diluted earnings per share reflect the assumed conversion of all dilutive securities, using the treasury stock method. Dilutive potential common shares consist of shares issuable upon the exercise of stock options, shares of unvested restricted stock units, and settlement of stock appreciation rights. When the Company incurs a net loss, the effect of the Company's outstanding stock options, stock appreciation rights and restricted stock units are not included in the calculation of diluted earnings (loss) per share as the effect would be anti-dilutive. Accordingly, basic and diluted net loss per share are identical. Short-term investments The Company's investments are available-for-sale commercial paper and certificate of deposit that are recorded at fair value in the consolidated balance sheets. The Company classifies all commercial paper regardless of original maturity at purchase date as investments. Unrealized gains and losses on available-for-sale securities are recorded, net of tax, as a component of accumulated other comprehensive income (loss), unless impairment is considered to be other-than-temporary. Other-than-temporary unrealized losses on available-for-sale securities are generally recorded in gain (loss) on investments, net, in the consolidated statements of comprehensive income (loss) unless certain criteria are met. The primary factors considered when determining if a charge must be recorded because a decline in the fair value of an investment is other-than-temporary include whether: (i) the fair value of the investment is significantly below the Company's cost basis; (ii) the financial condition of the issuer of the security has deteriorated; (iii) if a debt security, it is probable that the Company will be unable to collect all amounts due according to the contractual terms of the security; (iv) the decline in fair value has existed for an extended period of time; (v) if a debt security, such security has been downgraded by a rating agency; and (vi) the Company has the intent and ability to retain the investment for a period of time sufficient to allow for any anticipated recovery in fair value. Investments with remaining maturities of twelve months or less are classified as short-term investments since they are readily convertible to cash to fund short-term operations. Investments with remaining maturities of more than twelve months are classified as long-term investments. All of the Company's investments had contractual maturities of less than twelve months as of March 31, 2017 . Cost method investment Investments in equity securities of privately held companies without readily determinable fair value, where the Company does not exercise significant influence over the investee, are recorded using the cost method of accounting, carrying the investment at historical cost. If there are no identified events or changes in circumstances that might have an adverse effect on the cost method investments, the Company does not estimate the investments' fair value. For all investments, if a decline in the fair value of an investment below the carrying value is determined to be other-than-temporary, such investment is written down to its estimated fair value with a charge to current earnings. Fair value measurement The Company's financial assets that are included in cash and cash equivalents and that are measured at fair value on a recurring basis consisted of $96.8 million and $106.3 million invested in treasury money market funds at March 31, 2017 and December 31, 2016 , respectively. The fair value of the treasury money market funds is determined based on quoted market prices, which represents level 1 in the fair value hierarchy as defined by Accounting Standard Codification ("ASC") 820, " Fair Value Measurement and Disclosure ." The Company's short-term investments that are measured at fair value are comprised of zero and $10.0 million invested in available-for-sale commercial paper as of March 31, 2017 and December 31, 2016 , respectively, and $6.0 million invested in certificate of deposit at March 31, 2017 and December 31, 2016 . The fair value of these accounts is determined based on quoted market prices for similar assets in active markets, which represents level 2 in the fair value hierarchy. The Company recorded an immaterial amount of unrealized gain related to the short-term investments for the three months ended March 31, 2017 and 2016 . Reclassification adjustments for realized gain (loss) on available-for-sale securities in net income were immaterial for the three months ended March 31, 2017 and 2016 . At March 31, 2017 and December 31, 2016 , the Company held $2.0 million of equity securities in a privately held company. This investment is accounted for under the cost method and the Company measures it at fair value on a nonrecurring basis when it is deemed to be other-than-temporarily impaired. The Company estimates fair value of its cost method investment considering available information such as pricing in recent rounds of financing, current cash positions, earnings and cash flow forecasts, recent operational performance and any other readily available market data, which represents level 3 in the fair value hierarchy. As of March 31, 2017 , the Company determined there were no other-than-temporary impairments on its cost method investment. Deferred revenue and unbilled receivables Software license and implementation services that have been performed, but for which the Company has not invoiced the customer, are recorded as unbilled receivables, and invoices that have been issued before the software license and implementation, maintenance and subscription services have been performed are recorded as deferred revenue in the accompanying unaudited condensed consolidated balance sheets. Credit facility On January 27, 2017, the Company, through its wholly owned subsidiary PROS, Inc., entered into a Seventh Amendment (the "Seventh Amendment") to the $50 million secured Credit Agreement ("Revolver"). The Seventh Amendment provides for, among other things, an extension of the maturity date of the Revolver to July 2, 2022, and additional financial covenants with which the Company must comply if the Company's liquidity falls below an increased amount of $50 million or upon the occurrence of an event of default. The remaining material terms of the Revolver remain unchanged, and are summarized in the Company's Annual Report, Note 14. As of March 31, 2017 , the Company had no outstanding borrowings under the Revolver, and $0.2 million of unamortized debt issuance costs related to the Revolver is included in prepaid and other current assets and other long-term assets in the condensed consolidated balance sheets. For the three months ended March 31, 2017 and 2016 , the Company recorded an immaterial amount of amortization of debt issuance cost which is included in other expense, net in the unaudited condensed consolidated statements of comprehensive income (loss). Income taxes The Company recorded an income tax provision of $0.2 million for the three months ended March 31, 2017 and 2016 , primarily related to foreign income taxes and state taxes not based on income. The effective tax rate for both the three months ended March 31, 2017 and 2016 was (1)% . The income tax rates vary from the federal and state statutory rates primarily due to the valuation allowances on the Company’s deferred tax assets, the limitation on deductibility of certain officers’ compensation, and foreign and state taxes not based on income. The Company estimates its annual effective tax rate at the end of each quarterly period. Jurisdictions with a projected loss for the year where no tax benefit can be recognized due to the valuation allowances on the Company’s deferred tax assets are excluded from the estimated annual effective tax rate. The impact of such an exclusion could result in a higher or lower effective tax rate during a particular quarter depending on the mix and timing of actual earnings versus annual projections. Recently adopted accounting pronouncements In March 2016, the FASB issued ASU 2016-09, "Compensation – Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting" which is intended to simplify several aspects of the accounting for share-based payment transactions including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. This standard is effective for interim and annual reporting periods beginning after December 15, 2016. The Company adopted this standard on January 1, 2017. Upon adoption, the Company recognized the previously unrecognized excess tax benefits using the modified retrospective transition method, which resulted in a cumulative-effect adjustment of $4.2 million to accumulated deficit. The previously unrecognized excess tax effects were recorded as a deferred tax asset, which was fully offset by a valuation allowance and as such the cumulative adjustment had no net impact on the Company's financial statements. As required by ASU 2016-09, excess tax benefits recognized on stock-based compensation expense are reflected in the condensed consolidated statements of operations as a component of the provision for income taxes on a prospective basis. In addition, ASU 2016-09 allows companies to account for forfeitures as they occur or estimate expected forfeitures over the course of a vesting period; the Company has elected to continue to estimate forfeitures expected to occur to determine the amount of compensation cost to be recognized each period. Recent accounting pronouncements In May 2014, the FASB issued ASU 2014-09, "Revenue from Contracts with Customers (Topic 606)," which supersedes nearly all existing revenue recognition guidance under GAAP and permits the use of either the retrospective or cumulative effect transition method. In August 2015, the FASB issued ASU 2015-14, "Revenue from Contracts with Customers: Deferral of the Effective Date" which deferred the effective date of the new revenue standard for periods beginning after December 15, 2016 to December 15, 2017, with early adoption permitted but not earlier than the original effective date. In March 2016, the FASB issued ASU 2016-08, “Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations” which clarifies the implementation of guidance on principal versus agent considerations. In April 2016, the FASB issued ASU 2016-10, "Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligation and Licensing" which clarifies the implementation of guidance on identifying performance obligations and licensing. In May 2016, the FASB issued ASU 2016-12, "Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Practical Expedients", which clarifies the disclosure requirements for an entity that retrospectively applies the guidance in Topic 606. These standards are effective for the Company in the first quarter of fiscal 2018. The Company has not yet selected a transition method and is currently evaluating the effect that the updated standard will have on its consolidated financial statements and related disclosures. The Company continues to assess all potential impacts of the new standard, and currently believes the most significant impact relates to its accounting for arrangements that include term-based software licenses bundled with maintenance and support , the deferral of incremental costs of obtaining a contract with a customer, including the period of amortization of such costs and additional disclosures. Under current GAAP, the revenue attributable to these term-based software licenses is recognized ratably over the term of the arrangement because VSOE does not exist for the undelivered maintenance and support element as it is not sold separately. The requirement to have VSOE for undelivered elements to enable the separation of revenue for the delivered software licenses is eliminated under the new standard. Accordingly, under the new standard, the Company will be required to recognize as revenue a portion of the arrangement fee upon delivery of the software license. In addition, under current GAAP, the Company deferred only direct and incremental commission costs to obtain a contract and amortized those costs over the term |