Summary of Significant Accounting Policies	12 Months Ended
Dec. 31, 2014
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies The accompanying consolidated financial statements reflect the application of the significant accounting policies described below. Nature of Operations Cognex Corporation is a leading provider of machine vision products that capture and analyze visual information in order to automate tasks, primarily in manufacturing processes, where vision is required. Use of Estimates in the Preparation of Financial Statements The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America (U.S. GAAP) requires management to make estimates and judgments that affect the reported amounts of assets and liabilities and the disclosure of contingent liabilities as of the balance sheet date, and the reported amounts of revenues and expenses during the year. Actual results could differ from those estimates. Significant estimates and judgments include those related to revenue recognition, investments, accounts receivable, inventories, long-lived assets, goodwill, warranty obligations, contingencies, stock-based compensation, income taxes, derivative instruments, and purchase accounting. Basis of Consolidation The consolidated financial statements include the accounts of Cognex Corporation and its subsidiaries, all of which are wholly-owned. All intercompany accounts and transactions have been eliminated. Foreign Currency Translation The financial statements of the Company’s foreign subsidiaries, where the local currency is the functional currency, are translated using exchange rates in effect at the end of the year for assets and liabilities and average exchange rates during the year for results of operations. The resulting foreign currency translation adjustment, net of tax, is recorded in shareholders’ equity as other comprehensive income (loss). Fair Value Measurements The Company applies a three-level valuation hierarchy for fair value measurements. The categorization of assets and liabilities within the valuation hierarchy is based upon the lowest level of input that is significant to the measurement of fair value. Level 1 inputs to the valuation methodology utilize unadjusted quoted market prices in active markets for identical assets and liabilities. Level 2 inputs to the valuation methodology are other observable inputs, including quoted market prices for similar assets and liabilities, quoted prices for identical and similar assets and liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data. Level 3 inputs to the valuation methodology are unobservable inputs based upon management’s best estimate of the inputs that market participants would use in pricing the asset or liability at the measurement date, including assumptions about risk. A change to the level of an asset or liability within the fair value hierarchy is determined at the end of a reporting period. Cash, Cash Equivalents, and Investments Money market instruments purchased with original maturities of three months or less are classified as cash equivalents and are stated at amortized cost. Debt securities with original maturities greater than three months and remaining maturities of one year or less are classified as short-term investments, as well as equity securities that the Company intends to sell within one year. Debt securities with remaining maturities greater than one year, as well as a limited partnership interest, are classified as long-term investments. It is the Company’s policy to invest in debt securities with effective maturities that do not exceed ten years. Debt securities with original maturities greater than three months are designated as available-for-sale and are reported at fair value, with unrealized gains and losses, net of tax, recorded in shareholders’ equity as other comprehensive income (loss). Equity securities that are held for short periods of time with the intention of selling them in the near term are designated as trading and are reported at fair value, with unrealized gains and losses recorded in current operations. Realized gains and losses are included in current operations, along with the amortization of the discount or premium on debt securities arising at acquisition, and are calculated using the specific identification method. The Company’s limited partnership interest is accounted for using the cost method because the Company’s investment is less than 5% of the partnership and the Company has no influence over the partnership’s operating and financial policies. Furthermore, the investment does not have a readily determinable market value, and therefore, does not qualify for fair value accounting. Management monitors the carrying value of its investments in debt securities and a limited partnership interest compared to their fair value to determine whether an other-than-temporary impairment has occurred. If the fair value of a debt security is less than its amortized cost, the Company assesses whether the impairment is other-than-temporary. In considering whether a decline in fair value is other-than-temporary, we consider many factors. In its evaluation of its debt securities, management considers the type of security, the credit rating of the security, the length of time the security has been in a loss position, the size of the loss position, our intent and ability to hold the security to expected recovery of value, and other meaningful information. An impairment is considered other-than-temporary if (i) the Company has the intent to sell the security, (ii) it is more likely than not that the Company will be required to sell the security before recovery of the entire amortized cost basis, or (iii) the Company does not expect to recover the entire amortized cost basis of the security. If impairment is considered other-than-temporary based upon condition (i) or (ii) described above, the entire difference between the amortized cost and the fair value of the security is recognized in current operations. If an impairment is considered other-than-temporary based upon condition (iii), the amount representing credit losses (defined as the difference between the present value of the cash flows expected to be collected and the amortized cost basis of the security) is recognized in current operations and the amount relating to all other factors is recognized in shareholders' equity as other comprehensive income (loss). In its evaluation of its limited partnership interest, management considers the duration and extent of the decline, the length of the Company’s commitment to the investment, general economic trends, and specific communications with the General Partner. Accounts Receivable The Company extends credit with various payment terms to customers based upon an evaluation of their financial condition. Accounts that are outstanding longer than the payment terms are considered to be past due. The Company establishes reserves against accounts receivable for potential credit losses and records bad debt expense in current operations when it determines receivables are at risk for collection based upon the length of time the receivable has been outstanding, the customer’s current ability to pay its obligations to the Company, general economic and industry conditions, as well as various other factors. Receivables are written off against these reserves in the period they are determined to be uncollectible and payments subsequently received on previously written-off receivables are recorded as a reversal of the bad debt expense. Inventories Inventories are stated at the lower of cost or market. Cost is determined using standard costs, which approximates actual costs under the first-in, first-out (FIFO) method. The Company’s inventory is subject to rapid technological change or obsolescence. The Company reviews inventory quantities on hand and estimates excess and obsolescence exposures based upon assumptions about future demand, product transitions, and market conditions, and records reserves to reduce the carrying value of inventories to their net realizable value. If actual future demand is less than estimated, additional inventory write-downs would be required. The Company generally disposes of obsolete inventory upon determination of obsolescence. The Company does not dispose of excess inventory immediately, due to the possibility that some of this inventory could be sold to customers as a result of differences between actual and forecasted demand. When inventory has been written down below cost, such reduced amount is considered the new cost basis for subsequent accounting purposes. As a result, the Company would recognize a higher than normal gross margin if the reserved inventory were subsequently sold. Property, Plant, and Equipment Property, plant, and equipment are stated at cost and depreciated using the straight-line method over the assets’ estimated useful lives. Buildings’ useful lives are 39 years, building improvements’ useful lives are ten years, and the useful lives of computer hardware and software, manufacturing test equipment, and furniture and fixtures range from two to five years. Leasehold improvements are depreciated over the shorter of the estimated useful lives or the remaining terms of the leases. Maintenance and repairs are expensed when incurred; additions and improvements are capitalized. Upon retirement or disposition, the cost and related accumulated depreciation of the disposed assets are removed from the accounts, with any resulting gain or loss included in current operations. Intangible Assets Intangible assets are stated at cost and amortized over the assets’ estimated useful lives. Intangible assets are either amortized in relation to the relative cash flows anticipated from the intangible asset or using the straight-line method, depending upon facts and circumstances. The useful lives of distribution networks range from eleven to twelve years, of customer contracts and relationships from eight to twelve years, and of completed technologies and other intangible assets from three to eight years. The Company evaluates the possible impairment of long-lived assets, including intangible assets, whenever events or circumstances indicate the carrying value of the assets may not be recoverable. At the occurrence of a certain event or change in circumstances, the Company evaluates the potential impairment of an asset by estimating the future undiscounted cash flows expected to result from the use and eventual disposition of the asset. If the sum of the estimated future cash flows is less than the carrying value, the Company determines the amount of such impairment by comparing the fair value of the asset to its carrying value. The fair value is based upon the present value of the estimated future cash flows using a discount rate commensurate with the risks involved. Goodwill Goodwill is stated at cost. The Company evaluates the possible impairment of goodwill annually each fourth quarter and whenever events or circumstances indicate the carrying value of the goodwill may not be recoverable. For the past four years, the Company has performed a qualitative assessment of goodwill (commonly known as “step zero”) to determine whether further impairment testing is necessary. Factors that management considers in this assessment include macroeconomic conditions, industry and market considerations, overall financial performance (both current and projected), changes in management or strategy, and changes in the composition or carrying amount of net assets. In addition, management takes into consideration the goodwill valuation under the last quantitative analysis that was performed. If this qualitative assessment indicates that it is more likely than not that the fair value of a reporting unit is less than its carrying amount, the entity would proceed to a two-step process. Step one compares the fair value of the reporting unit with its carrying value, including goodwill. If the carrying amount exceeds the fair value of the reporting unit, step two is required to measure the amount of impairment loss. Step two compares the implied fair value of the reporting unit goodwill to the carrying amount of the goodwill. Warranty Obligations The Company warrants its products to be free from defects in material and workmanship for periods primarily ranging from six months to three years from the time of sale based upon the product being purchased and the terms of the customer arrangement. Warranty obligations are evaluated and recorded at the time of sale since it is probable that customers will make claims under warranties related to products that have been sold and the amount of these claims can be reasonably estimated based upon historical costs to fulfill claims. Obligations may also be recorded subsequent to the time of sale whenever specific events or circumstances impacting product quality become known that would not have been taken into account using historical data. Contingencies Loss contingencies are accrued if the loss is probable and the amount of the loss can be reasonably estimated. Legal costs associated with potential loss contingencies, such as patent infringement matters, are expensed as incurred. Revenue Recognition The Company’s product revenue is derived from the sale of machine vision systems, which can take the form of hardware with embedded software or software-only, and related accessories. The Company also generates revenue by providing maintenance and support, training, consulting, and installation services to its customers. Certain of the Company’s arrangements include multiple deliverables that provide the customer with a combination of products or services. In order to recognize revenue, the Company requires that a signed customer contract or purchase order is received, the fee from the arrangement is fixed or determinable, and collection of the resulting receivable is probable. Assuming that these criteria have been met, product revenue is generally recognized upon delivery, revenue from maintenance and support programs is recognized ratably over the program period, revenue from training and consulting services is recognized over the period that the services are provided, and revenue from installation services is recognized when the customer has signed off that the installation is complete. When customer-specified acceptance criteria exists that are substantive, product revenue is deferred until these criteria have been met, along with the associated incremental direct costs. The majority of the Company’s product offerings consist of hardware with embedded software. Under the revenue recognition rules for tangible products, the fee from a multiple-deliverable arrangement is allocated to each of the deliverables based upon their relative selling prices as determined by a selling-price hierarchy. A deliverable in an arrangement qualifies as a separate unit of accounting if the delivered item has value to the customer on a stand-alone basis. A delivered item that does not qualify as a separate unit of accounting is combined with the other undelivered items in the arrangement and revenue is recognized for those combined deliverables as a single unit of accounting. The selling price used for each deliverable is based upon vendor-specific objective evidence (VSOE) if available, third-party evidence (TPE) if VSOE is not available, and management’s best estimate of selling price (BESP) if neither VSOE nor TPE are available. VSOE is the price charged for a deliverable when it is sold separately. TPE is the price of the Company’s or any competitor’s largely interchangeable products or services in stand-alone sales to similarly-situated customers. BESP is the price at which the Company would sell the deliverable if it were sold regularly on a stand-alone basis, considering market conditions and entity-specific factors. The selling prices used in the relative selling price allocation method for (1) certain of the Company’s services are based upon VSOE, (2) third-party accessories available from other vendors are based upon TPE, and (3) hardware products with embedded software, custom accessories, and services for which VSOE does not exist are based upon BESP. The Company does not believe TPE exists for these products and services because they are differentiated from competing products and services in terms of functionality and performance and there are no competing products or services that are largely interchangeable. For the Company’s Modular Vision Systems Division (MVSD), BESP has been established for each product line within each region, and for the Company’s Surface Inspection Systems Division (SISD), BESP has been established for each industry within each region. Management establishes BESP with consideration for market conditions, such as the impact of competition and geographic considerations, and entity-specific factors, such as the cost of the product and the division’s profit objectives. Management believes that BESP is reflective of reasonable pricing of that deliverable as if priced on a stand-alone basis. Under the revenue recognition rules for software-only products, the fee from a multiple-deliverable arrangement is allocated to each of the undelivered elements based upon VSOE, which is limited to the price charged when the same deliverable is sold separately, with the residual value from the arrangement allocated to the delivered element. The portion of the fee that is allocated to each deliverable is then recognized as revenue when the criteria for revenue recognition are met with respect to that deliverable. If VSOE does not exist for all of the undelivered elements, then all revenue from the arrangement is typically deferred until all elements have been delivered to the customer. The Company’s products are sold directly to end users, as well as to resellers including original equipment manufacturers (OEMs), distributors, and integrators. Revenue is recognized upon delivery of the product to the reseller, assuming all other revenue recognition criteria have been met. The Company establishes reserves against revenue for potential product returns, since the amount of future returns can be reasonably estimated based upon experience. These reserves have historically been immaterial. Amounts billed to customers related to shipping and handling, as well as reimbursements received from customers for out-of-pocket expenses, are classified as revenue, with the associated costs included in cost of revenue. Research and Development Research and development costs for internally-developed or acquired products are expensed when incurred until technological feasibility has been established for the product. Thereafter, all software costs are capitalized until the product is available for general release to customers. The Company determines technological feasibility at the time the product reaches beta in its stage of development. Historically, the time incurred between beta and general release to customers has been short, and therefore, the costs have been insignificant. As a result, the Company has not capitalized software costs associated with internally-developed products. Advertising Costs Advertising costs are expensed as incurred and totaled $1,289,000 in 2014, $1,656,000 in 2013, and $1,792,000 in 2012. Stock-Based Compensation The Company’s share-based payments that result in compensation expense consist of stock option grants and restricted stock awards. The Company has reserved a specific number of shares of its authorized but unissued shares for issuance upon the exercise of stock options or the granting of restricted stock. When a stock option is exercised or a restricted stock award is granted, the Company issues new shares from this pool. The fair values of stock options are estimated on the grant date using a binomial lattice model. Management is responsible for determining the appropriate valuation model and estimating these fair values, and in doing so, considers a number of factors, including information provided by an outside valuation advisor. The Company recognizes compensation expense related to stock options using the graded attribution method, in which expense is recognized on a straight-line basis over the service period for each separately vesting portion of the stock option as if the option was, in substance, multiple awards. The amount of compensation expense recognized at the end of the vesting period is based upon the number of stock options for which the requisite service has been completed. No compensation expense is recognized for options that are forfeited for which the employee does not render the requisite service. The term “forfeitures” is distinct from “expirations” and represents only the unvested portion of the surrendered option. The Company applies estimated forfeiture rates to its unvested options to arrive at the amount of compensation expense that is expected to be recognized over the requisite service period. At the end of each separately vesting portion of an option, the expense that was recognized by applying the estimated forfeiture rate is compared to the expense that should be recognized based upon the employee’s service, and a credit to expense is recorded related to those employees that have not rendered the requisite service. Taxes The Company recognizes a tax position in its financial statements when that tax position, based solely upon its technical merits, is more likely than not to be sustained upon examination by the relevant taxing authority. Those tax positions failing to qualify for initial recognition are recognized in the first interim period in which they meet the more likely than not standard, or are resolved through negotiation or litigation with the taxing authority, or upon expiration of the statutes of limitations. Derecognition of a tax position that was previously recognized occurs when an entity subsequently determines that a tax position no longer meets the more likely than not threshold of being sustained. Only the portion of the liability that is expected to be paid within one year is classified as a current liability. As a result, liabilities expected to be resolved without the payment of cash (e.g., resolution due to the expiration of the statutes of limitations) or are not expected to be paid within one year are not classified as current. It is the Company’s policy to record estimated interest and penalties as income tax expense and tax credits as a reduction in income tax expense. Deferred tax assets and liabilities are determined based upon the differences between the financial statement and tax bases of assets and liabilities as measured by the enacted tax rates that will be in effect when these differences reverse. Valuation allowances are provided if, based upon the weight of available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. Sales tax in the United States and similar taxes in other jurisdictions that are collected from customers and remitted to government authorities are presented on a gross basis (i.e., a receivable from the customer with a corresponding payable to the government). Amounts collected from customers and retained by the Company during tax holidays are recognized as nonoperating income when earned. Net Income Per Share Basic net income per share is computed by dividing net income available to common shareholders by the weighted-average number of common shares outstanding for the period. Diluted net income per share is computed by dividing net income available to common shareholders by the weighted-average number of common shares outstanding for the period plus potential dilutive common shares. Dilutive common equivalent shares consist of stock options and are calculated using the treasury stock method. Common equivalent shares do not qualify as participating securities. In periods where the Company records a net loss, potential common stock equivalents are not included in the calculation of diluted net loss per share. Comprehensive Income Comprehensive income is defined as the change in equity of a company during a period from transactions and other events and circumstances, excluding transactions resulting from investments by owners and distributions to owners. Accumulated other comprehensive loss, net of tax, as of December 31, 2014 and December 31, 2013, consists of foreign currency translation adjustments of $38,030,000 and $28,630,000, respectively; net unrealized losses on available-for-sale investments of $130,000 and $36,000, respectively; net unrealized gains on derivative instruments of $32,000 and $104,000, respectively; and losses on currency swaps, net of gains on long-term intercompany loans, of $1,271,000 and $1,271,000, respectively. Amounts reclassified from accumulated other comprehensive income to investment income on the Consolidated Statements of Operations were net realized gains of $673,000, $314,000, and $1,695,000 for 2014, 2013, and 2012, respectively. Concentrations of Risk Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash, cash equivalents, investments, and trade receivables. The Company has certain domestic and foreign cash balances that exceed the insured limits set by the Federal Deposit Insurance Corporation (FDIC) in the United States and equivalent regulatory agencies in foreign countries. The Company primarily invests in investment-grade debt securities and has established guidelines relative to credit ratings, diversification, and maturities of its debt securities that maintain safety and liquidity. The Company has not experienced any significant realized losses on its debt securities. The Company performs ongoing credit evaluations of its customers and maintains allowances for potential credit losses. The Company has not experienced any significant losses related to the collection of its accounts receivable. A significant portion of the Company’s MVSD product is manufactured by a third-party contractor located in Indonesia. This contractor has agreed to provide Cognex with termination notification periods and last-time-buy rights, if and when that may be applicable. We rely upon this contractor to provide quality product and meet delivery schedules. We engage in extensive product quality programs and processes, including actively monitoring the performance of our third-party manufacturers. Certain components are presently available only from a single source. Certain key electronic components that are purchased from strategic suppliers, such as processors or imagers, are fundamental to the design of Cognex products. A disruption in the supply of these key components, such as a last-time-buy announcement, natural disaster, financial bankruptcy, or other event, may require us to purchase a significant amount of inventory at unfavorable prices resulting in lower gross margins and higher risk of carrying excess or obsolete inventory. If we are unable to secure adequate supply from alternative sources, we may have to redesign our products, which may lead to a delay in manufacturing and a possible loss of sales. Derivative Instruments Derivative instruments are recorded on the Consolidated Balance Sheets at fair value. Changes in the fair value of derivatives are recorded each period in current operations or in shareholders' equity as other comprehensive income (loss), depending upon whether the derivative is designated as a hedge transaction and, if it is, the effectiveness of the hedge. At the inception of the contract, the Company designates foreign currency forward exchange contracts as either a cash flow hedge of certain forecasted foreign currency denominated sales and purchase transactions or as an economic hedge. Changes in the fair value of a derivative that is highly effective and that is designated and qualifies as a cash flow hedge are recorded in shareholders' equity as other comprehensive income (loss), and reclassified into current operations in the same period during which the hedged transaction affects current operations and in the same financial statement line item as that of the forecasted transaction. Cash flow hedges are evaluated for effectiveness quarterly. Any hedge ineffectiveness (which represents the amount by which the changes in the fair value of the derivative exceed the variability in the cash flows of the forecasted transaction) is recorded in current operations in the period in which ineffectiveness is determined. Changes in the fair value of the Company’s economic hedges (not designated as a cash flow hedge) are reported in current operations. The cash flows from derivative instruments are presented in the same category on the Consolidated Statements of Cash Flows as the category for the cash flows from the hedged item. Generally, this accounting policy election results in cash flows related to derivative instruments being classified as an operating activity on the Consolidated Statements of Cash Flows. The Company formally documents all relationships between hedging instruments and hedged items, as well as its risk-management objective and strategy for undertaking various hedge transactions. This process includes linking all derivatives that are designated as cash flow hedges to specific forecasted transactions. The Company also formally assesses (both at the hedge’s inception and on an ongoing basis) whether the derivatives that are used in hedging transactions have been highly effective in offsetting changes in the fair value or cash flows of hedged items and whether those derivatives may be expected to remain highly effective in future periods. When it is determined that a derivative is not (or has ceased to be) highly effective as a hedge, the Company discontinues hedge accounting prospectively, as discussed below. The Company discontinues hedge accounting prospectively when (1) it determines that the derivative is no longer effective in offsetting changes in the cash flows of a hedged item; (2) the derivative expires or is sold, terminated, or exercised; (3) it is no longer probable that the forecasted transaction will occur; or (4) management determines that designating the derivative as a hedging instrument is no longer appropriate or desired. When the Company discontinues hedge accounting because it is no longer probable that the forecasted transaction will occur in the originally expected period, the gain or loss on the derivative remains in accumulated other comprehensive income (loss) and is reclassified into current operations when the forecasted transaction affects current operations. However, if it is probable that a forecasted transaction will not occur by the end of the originally specified time period or within an additional two-month period of time thereafter, the gain or loss that was accumulated in other comprehensive income (loss) is recognized immediately in current operations. In all situations in which hedge accounting is discontinued and the derivative remains outstanding, the Company carries the derivative at fair value on the Consolidated Balance Sheets, recognizing changes in the fair value in current operations, unless it is designated in a new hedging relationship. The Company recognizes all derivative instruments as either current assets or current liabilities at fair value on the Consolidated Balance Sheets. When the Company is engaged in more than one outstanding derivative contract with the same counterparty and also has a legally enforceable master netting agreement with that counterparty, the “net” mark-to-market exposure represents the netting of the positive and negative exposures with that counterparty. Accordingly, cash flow hedges are presented net on the Consolidated Balance Sheets.

Summary of Significant Accounting Policies

The accompanying consolidated financial statements reflect the application of the significant accounting policies described below.

Nature of Operations

Cognex Corporation is a leading provider of machine vision products that capture and analyze visual information in order to automate tasks, primarily in manufacturing processes, where vision is required.

Use of Estimates in the Preparation of Financial Statements

The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America (U.S. GAAP) requires management to make estimates and judgments that affect the reported amounts of assets and liabilities and the disclosure of contingent liabilities as of the balance sheet date, and the reported amounts of revenues and expenses during the year. Actual results could differ from those estimates. Significant estimates and judgments include those related to revenue recognition, investments, accounts receivable, inventories, long-lived assets, goodwill, warranty obligations, contingencies, stock-based compensation, income taxes, derivative instruments, and purchase accounting.

Basis of Consolidation

The consolidated financial statements include the accounts of Cognex Corporation and its subsidiaries, all of which are wholly-owned. All intercompany accounts and transactions have been eliminated.

Foreign Currency Translation

The financial statements of the Company’s foreign subsidiaries, where the local currency is the functional currency, are translated using exchange rates in effect at the end of the year for assets and liabilities and average exchange rates during the year for results of operations. The resulting foreign currency translation adjustment, net of tax, is recorded in shareholders’ equity as other comprehensive income (loss).

Fair Value Measurements

The Company applies a three-level valuation hierarchy for fair value measurements. The categorization of assets and liabilities within the valuation hierarchy is based upon the lowest level of input that is significant to the measurement of fair value. Level 1 inputs to the valuation methodology utilize unadjusted quoted market prices in active markets for identical assets and liabilities. Level 2 inputs to the valuation methodology are other observable inputs, including quoted market prices for similar assets and liabilities, quoted prices for identical and similar assets and liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data. Level 3 inputs to the valuation methodology are unobservable inputs based upon management’s best estimate of the inputs that market participants would use in pricing the asset or liability at the measurement date, including assumptions about risk. A change to the level of an asset or liability within the fair value hierarchy is determined at the end of a reporting period.

Cash, Cash Equivalents, and Investments

Money market instruments purchased with original maturities of three months or less are classified as cash equivalents and are stated at amortized cost. Debt securities with original maturities greater than three months and remaining maturities of one year or less are classified as short-term investments, as well as equity securities that the Company intends to sell within one year. Debt securities with remaining maturities greater than one year, as well as a limited partnership interest, are classified as long-term investments. It is the Company’s policy to invest in debt securities with effective maturities that do not exceed ten years.

Debt securities with original maturities greater than three months are designated as available-for-sale and are reported at fair value, with unrealized gains and losses, net of tax, recorded in shareholders’ equity as other comprehensive income (loss). Equity securities that are held for short periods of time with the intention of selling them in the near term are designated as trading and are reported at fair value, with unrealized gains and losses recorded in current operations. Realized gains and losses are included in current operations, along with the amortization of the discount or premium on debt securities arising at acquisition, and are calculated using the specific identification method. The Company’s limited partnership interest is accounted for using the cost method because the Company’s investment is less than 5% of the partnership and the Company has no influence over the partnership’s operating and financial policies. Furthermore, the investment does not have a readily determinable market value, and therefore, does not qualify for fair value accounting.

Management monitors the carrying value of its investments in debt securities and a limited partnership interest compared to their fair value to determine whether an other-than-temporary impairment has occurred. If the fair value of a debt security is less than its amortized cost, the Company assesses whether the impairment is other-than-temporary. In considering whether a decline in fair value is other-than-temporary, we consider many factors. In its evaluation of its debt securities, management considers the type of security, the credit rating of the security, the length of time the security has been in a loss position, the size of the loss position, our intent and ability to hold the security to expected recovery of value, and other meaningful information. An impairment is considered other-than-temporary if (i) the Company has the intent to sell the security, (ii) it is more likely than not that the Company will be required to sell the security before recovery of the entire amortized cost basis, or (iii) the Company does not expect to recover the entire amortized cost basis of the security. If impairment is considered other-than-temporary based upon condition (i) or (ii) described above, the entire difference between the amortized cost and the fair value of the security is recognized in current operations. If an impairment is considered other-than-temporary based upon condition (iii), the amount representing credit losses (defined as the difference between the present value of the cash flows expected to be collected and the amortized cost basis of the security) is recognized in current operations and the amount relating to all other factors is recognized in shareholders' equity as other comprehensive income (loss). In its evaluation of its limited partnership interest, management considers the duration and extent of the decline, the length of the Company’s commitment to the investment, general economic trends, and specific communications with the General Partner.

Accounts Receivable

The Company extends credit with various payment terms to customers based upon an evaluation of their financial condition. Accounts that are outstanding longer than the payment terms are considered to be past due. The Company establishes reserves against accounts receivable for potential credit losses and records bad debt expense in current operations when it determines receivables are at risk for collection based upon the length of time the receivable has been outstanding, the customer’s current ability to pay its obligations to the Company, general economic and industry conditions, as well as various other factors. Receivables are written off against these reserves in the period they are determined to be uncollectible and payments subsequently received on previously written-off receivables are recorded as a reversal of the bad debt expense.

Inventories

Inventories are stated at the lower of cost or market. Cost is determined using standard costs, which approximates actual costs under the first-in, first-out (FIFO) method. The Company’s inventory is subject to rapid technological change or obsolescence. The Company reviews inventory quantities on hand and estimates excess and obsolescence exposures based upon assumptions about future demand, product transitions, and market conditions, and records reserves to reduce the carrying value of inventories to their net realizable value. If actual future demand is less than estimated, additional inventory write-downs would be required.

The Company generally disposes of obsolete inventory upon determination of obsolescence. The Company does not dispose of excess inventory immediately, due to the possibility that some of this inventory could be sold to customers as a result of differences between actual and forecasted demand. When inventory has been written down below cost, such reduced amount is considered the new cost basis for subsequent accounting purposes. As a result, the Company would recognize a higher than normal gross margin if the reserved inventory were subsequently sold.

Property, Plant, and Equipment

Property, plant, and equipment are stated at cost and depreciated using the straight-line method over the assets’ estimated useful lives. Buildings’ useful lives are 39 years, building improvements’ useful lives are ten years, and the useful lives of computer hardware and software, manufacturing test equipment, and furniture and fixtures range from two to five years. Leasehold improvements are depreciated over the shorter of the estimated useful lives or the remaining terms of the leases. Maintenance and repairs are expensed when incurred; additions and improvements are capitalized. Upon retirement or disposition, the cost and related accumulated depreciation of the disposed assets are removed from the accounts, with any resulting gain or loss included in current operations.

Intangible Assets

Intangible assets are stated at cost and amortized over the assets’ estimated useful lives. Intangible assets are either amortized in relation to the relative cash flows anticipated from the intangible asset or using the straight-line method, depending upon facts and circumstances. The useful lives of distribution networks range from eleven to twelve years, of customer contracts and relationships from eight to twelve years, and of completed technologies and other intangible assets from three to eight years. The Company evaluates the possible impairment of long-lived assets, including intangible assets, whenever events or circumstances indicate the carrying value of the assets may not be recoverable. At the occurrence of a certain event or change in circumstances, the Company evaluates the potential impairment of an asset by estimating the future undiscounted cash flows expected to result from the use and eventual disposition of the asset. If the sum of the estimated future cash flows is less than the carrying value, the Company determines the amount of such impairment by comparing the fair value of the asset to its carrying value. The fair value is based upon the present value of the estimated future cash flows using a discount rate commensurate with the risks involved.

Goodwill

Goodwill is stated at cost. The Company evaluates the possible impairment of goodwill annually each fourth quarter and whenever events or circumstances indicate the carrying value of the goodwill may not be recoverable. For the past four years, the Company has performed a qualitative assessment of goodwill (commonly known as “step zero”) to determine whether further impairment testing is necessary. Factors that management considers in this assessment include macroeconomic conditions, industry and market considerations, overall financial performance (both current and projected), changes in management or strategy, and changes in the composition or carrying amount of net assets. In addition, management takes into consideration the goodwill valuation under the last quantitative analysis that was performed. If this qualitative assessment indicates that it is more likely than not that the fair value of a reporting unit is less than its carrying amount, the entity would proceed to a two-step process. Step one compares the fair value of the reporting unit with its carrying value, including goodwill. If the carrying amount exceeds the fair value of the reporting unit, step two is required to measure the amount of impairment loss. Step two compares the implied fair value of the reporting unit goodwill to the carrying amount of the goodwill.

Warranty Obligations

The Company warrants its products to be free from defects in material and workmanship for periods primarily ranging from six months to three years from the time of sale based upon the product being purchased and the terms of the customer arrangement. Warranty obligations are evaluated and recorded at the time of sale since it is probable that customers will make claims under warranties related to products that have been sold and the amount of these claims can be reasonably estimated based upon historical costs to fulfill claims. Obligations may also be recorded subsequent to the time of sale whenever specific events or circumstances impacting product quality become known that would not have been taken into account using historical data.

Contingencies

Loss contingencies are accrued if the loss is probable and the amount of the loss can be reasonably estimated. Legal costs associated with potential loss contingencies, such as patent infringement matters, are expensed as incurred.

Revenue Recognition

The Company’s product revenue is derived from the sale of machine vision systems, which can take the form of hardware with embedded software or software-only, and related accessories. The Company also generates revenue by providing maintenance and support, training, consulting, and installation services to its customers. Certain of the Company’s arrangements include multiple deliverables that provide the customer with a combination of products or services. In order to recognize revenue, the Company requires that a signed customer contract or purchase order is received, the fee from the arrangement is fixed or determinable, and collection of the resulting receivable is probable. Assuming that these criteria have been met, product revenue is generally recognized upon delivery, revenue from maintenance and support programs is recognized ratably over the program period, revenue from training and consulting services is recognized over the period that the services are provided, and revenue from installation services is recognized when the customer has signed off that the installation is complete. When customer-specified acceptance criteria exists that are substantive, product revenue is deferred until these criteria have been met, along with the associated incremental direct costs.

The majority of the Company’s product offerings consist of hardware with embedded software. Under the revenue recognition rules for tangible products, the fee from a multiple-deliverable arrangement is allocated to each of the deliverables based upon their relative selling prices as determined by a selling-price hierarchy. A deliverable in an arrangement qualifies as a separate unit of accounting if the delivered item has value to the customer on a stand-alone basis. A delivered item that does not qualify as a separate unit of accounting is combined with the other undelivered items in the arrangement and revenue is recognized for those combined deliverables as a single unit of accounting. The selling price used for each deliverable is based upon vendor-specific objective evidence (VSOE) if available, third-party evidence (TPE) if VSOE is not available, and management’s best estimate of selling price (BESP) if neither VSOE nor TPE are available. VSOE is the price charged for a deliverable when it is sold separately. TPE is the price of the Company’s or any competitor’s largely interchangeable products or services in stand-alone sales to similarly-situated customers. BESP is the price at which the Company would sell the deliverable if it were sold regularly on a stand-alone basis, considering market conditions and entity-specific factors.

The selling prices used in the relative selling price allocation method for (1) certain of the Company’s services are based upon VSOE, (2) third-party accessories available from other vendors are based upon TPE, and (3) hardware products with embedded software, custom accessories, and services for which VSOE does not exist are based upon BESP. The Company does not believe TPE exists for these products and services because they are differentiated from competing products and services in terms of functionality and performance and there are no competing products or services that are largely interchangeable. For the Company’s Modular Vision Systems Division (MVSD), BESP has been established for each product line within each region, and for the Company’s Surface Inspection Systems Division (SISD), BESP has been established for each industry within each region. Management establishes BESP with consideration for market conditions, such as the impact of competition and geographic considerations, and entity-specific factors, such as the cost of the product and the division’s profit objectives. Management believes that BESP is reflective of reasonable pricing of that deliverable as if priced on a stand-alone basis.

Under the revenue recognition rules for software-only products, the fee from a multiple-deliverable arrangement is allocated to each of the undelivered elements based upon VSOE, which is limited to the price charged when the same deliverable is sold separately, with the residual value from the arrangement allocated to the delivered element. The portion of the fee that is allocated to each deliverable is then recognized as revenue when the criteria for revenue recognition are met with respect to that deliverable. If VSOE does not exist for all of the undelivered elements, then all revenue from the arrangement is typically deferred until all elements have been delivered to the customer.

The Company’s products are sold directly to end users, as well as to resellers including original equipment manufacturers (OEMs), distributors, and integrators. Revenue is recognized upon delivery of the product to the reseller, assuming all other revenue recognition criteria have been met. The Company establishes reserves against revenue for potential product returns, since the amount of future returns can be reasonably estimated based upon experience. These reserves have historically been immaterial.

Amounts billed to customers related to shipping and handling, as well as reimbursements received from customers for out-of-pocket expenses, are classified as revenue, with the associated costs included in cost of revenue.

Research and Development

Research and development costs for internally-developed or acquired products are expensed when incurred until technological feasibility has been established for the product. Thereafter, all software costs are capitalized until the product is available for general release to customers. The Company determines technological feasibility at the time the product reaches beta in its stage of development. Historically, the time incurred between beta and general release to customers has been short, and therefore, the costs have been insignificant. As a result, the Company has not capitalized software costs associated with internally-developed products.

Advertising Costs

Advertising costs are expensed as incurred and totaled $1,289,000 in 2014, $1,656,000 in 2013, and $1,792,000 in 2012.

Stock-Based Compensation

The Company’s share-based payments that result in compensation expense consist of stock option grants and restricted stock awards. The Company has reserved a specific number of shares of its authorized but unissued shares for issuance upon the exercise of stock options or the granting of restricted stock. When a stock option is exercised or a restricted stock award is granted, the Company issues new shares from this pool. The fair values of stock options are estimated on the grant date using a binomial lattice model. Management is responsible for determining the appropriate valuation model and estimating these fair values, and in doing so, considers a number of factors, including information provided by an outside valuation advisor.

The Company recognizes compensation expense related to stock options using the graded attribution method, in which expense is recognized on a straight-line basis over the service period for each separately vesting portion of the stock option as if the option was, in substance, multiple awards. The amount of compensation expense recognized at the end of the vesting period is based upon the number of stock options for which the requisite service has been completed. No compensation expense is recognized for options that are forfeited for which the employee does not render the requisite service. The term “forfeitures” is distinct from “expirations” and represents only the unvested portion of the surrendered option. The Company applies estimated forfeiture rates to its unvested options to arrive at the amount of compensation expense that is expected to be recognized over the requisite service period. At the end of each separately vesting portion of an option, the expense that was recognized by applying the estimated forfeiture rate is compared to the expense that should be recognized based upon the employee’s service, and a credit to expense is recorded related to those employees that have not rendered the requisite service.

Taxes

The Company recognizes a tax position in its financial statements when that tax position, based solely upon its technical merits, is more likely than not to be sustained upon examination by the relevant taxing authority. Those tax positions failing to qualify for initial recognition are recognized in the first interim period in which they meet the more likely than not standard, or are resolved through negotiation or litigation with the taxing authority, or upon expiration of the statutes of limitations. Derecognition of a tax position that was previously recognized occurs when an entity subsequently determines that a tax position no longer meets the more likely than not threshold of being sustained.

Only the portion of the liability that is expected to be paid within one year is classified as a current liability. As a result, liabilities expected to be resolved without the payment of cash (e.g., resolution due to the expiration of the statutes of limitations) or are not expected to be paid within one year are not classified as current. It is the Company’s policy to record estimated interest and penalties as income tax expense and tax credits as a reduction in income tax expense.

Deferred tax assets and liabilities are determined based upon the differences between the financial statement and tax bases of assets and liabilities as measured by the enacted tax rates that will be in effect when these differences reverse. Valuation allowances are provided if, based upon the weight of available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized.

Sales tax in the United States and similar taxes in other jurisdictions that are collected from customers and remitted to government authorities are presented on a gross basis (i.e., a receivable from the customer with a corresponding payable to the government). Amounts collected from customers and retained by the Company during tax holidays are recognized as nonoperating income when earned.

Net Income Per Share

Basic net income per share is computed by dividing net income available to common shareholders by the weighted-average number of common shares outstanding for the period. Diluted net income per share is computed by dividing net income available to common shareholders by the weighted-average number of common shares outstanding for the period plus potential dilutive common shares. Dilutive common equivalent shares consist of stock options and are calculated using the treasury stock method. Common equivalent shares do not qualify as participating securities. In periods where the Company records a net loss, potential common stock equivalents are not included in the calculation of diluted net loss per share.

Comprehensive Income

Comprehensive income is defined as the change in equity of a company during a period from transactions and other events and circumstances, excluding transactions resulting from investments by owners and distributions to owners. Accumulated other comprehensive loss, net of tax, as of December 31, 2014 and December 31, 2013, consists of foreign currency translation adjustments of $38,030,000 and $28,630,000, respectively; net unrealized losses on available-for-sale investments of $130,000 and $36,000, respectively; net unrealized gains on derivative instruments of $32,000 and $104,000, respectively; and losses on currency swaps, net of gains on long-term intercompany loans, of $1,271,000 and $1,271,000, respectively.

Amounts reclassified from accumulated other comprehensive income to investment income on the Consolidated Statements of Operations were net realized gains of $673,000, $314,000, and $1,695,000 for 2014, 2013, and 2012, respectively.

Concentrations of Risk

Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash, cash equivalents, investments, and trade receivables. The Company has certain domestic and foreign cash balances that exceed the insured limits set by the Federal Deposit Insurance Corporation (FDIC) in the United States and equivalent regulatory agencies in foreign countries. The Company primarily invests in investment-grade debt securities and has established guidelines relative to credit ratings, diversification, and maturities of its debt securities that maintain safety and liquidity. The Company has not experienced any significant realized losses on its debt securities.

The Company performs ongoing credit evaluations of its customers and maintains allowances for potential credit losses. The Company has not experienced any significant losses related to the collection of its accounts receivable.

A significant portion of the Company’s MVSD product is manufactured by a third-party contractor located in Indonesia. This contractor has agreed to provide Cognex with termination notification periods and last-time-buy rights, if and when that may be applicable. We rely upon this contractor to provide quality product and meet delivery schedules. We engage in extensive product quality programs and processes, including actively monitoring the performance of our third-party manufacturers. Certain components are presently available only from a single source. Certain key electronic components that are purchased from strategic suppliers, such as processors or imagers, are fundamental to the design of Cognex products. A disruption in the supply of these key components, such as a last-time-buy announcement, natural disaster, financial bankruptcy, or other event, may require us to purchase a significant amount of inventory at unfavorable prices resulting in lower gross margins and higher risk of carrying excess or obsolete inventory. If we are unable to secure adequate supply from alternative sources, we may have to redesign our products, which may lead to a delay in manufacturing and a possible loss of sales.

Derivative Instruments

Derivative instruments are recorded on the Consolidated Balance Sheets at fair value. Changes in the fair value of derivatives are recorded each period in current operations or in shareholders' equity as other comprehensive income (loss), depending upon whether the derivative is designated as a hedge transaction and, if it is, the effectiveness of the hedge. At the inception of the contract, the Company designates foreign currency forward exchange contracts as either a cash flow hedge of certain forecasted foreign currency denominated sales and purchase transactions or as an economic hedge. Changes in the fair value of a derivative that is highly effective and that is designated and qualifies as a cash flow hedge are recorded in shareholders' equity as other comprehensive income (loss), and reclassified into current operations in the same period during which the hedged transaction affects current operations and in the same financial statement line item as that of the forecasted transaction. Cash flow hedges are evaluated for effectiveness quarterly. Any hedge ineffectiveness (which represents the amount by which the changes in the fair value of the derivative exceed the variability in the cash flows of the forecasted transaction) is recorded in current operations in the period in which ineffectiveness is determined. Changes in the fair value of the Company’s economic hedges (not designated as a cash flow hedge) are reported in current operations. The cash flows from derivative instruments are presented in the same category on the Consolidated Statements of Cash Flows as the category for the cash flows from the hedged item. Generally, this accounting policy election results in cash flows related to derivative instruments being classified as an operating activity on the Consolidated Statements of Cash Flows.

The Company formally documents all relationships between hedging instruments and hedged items, as well as its risk-management objective and strategy for undertaking various hedge transactions. This process includes linking all derivatives that are designated as cash flow hedges to specific forecasted transactions. The Company also formally assesses (both at the hedge’s inception and on an ongoing basis) whether the derivatives that are used in hedging transactions have been highly effective in offsetting changes in the fair value or cash flows of hedged items and whether those derivatives may be expected to remain highly effective in future periods. When it is determined that a derivative is not (or has ceased to be) highly effective as a hedge, the Company discontinues hedge accounting prospectively, as discussed below.

The Company discontinues hedge accounting prospectively when (1) it determines that the derivative is no longer effective in offsetting changes in the cash flows of a hedged item; (2) the derivative expires or is sold, terminated, or exercised; (3) it is no longer probable that the forecasted transaction will occur; or (4) management determines that designating the derivative as a hedging instrument is no longer appropriate or desired. When the Company discontinues hedge accounting because it is no longer probable that the forecasted transaction will occur in the originally expected period, the gain or loss on the derivative remains in accumulated other comprehensive income (loss) and is reclassified into current operations when the forecasted transaction affects current operations. However, if it is probable that a forecasted transaction will not occur by the end of the originally specified time period or within an additional two-month period of time thereafter, the gain or loss that was accumulated in other comprehensive income (loss) is recognized immediately in current operations. In all situations in which hedge accounting is discontinued and the derivative remains outstanding, the Company carries the derivative at fair value on the Consolidated Balance Sheets, recognizing changes in the fair value in current operations, unless it is designated in a new hedging relationship.

The Company recognizes all derivative instruments as either current assets or current liabilities at fair value on the Consolidated Balance Sheets. When the Company is engaged in more than one outstanding derivative contract with the same counterparty and also has a legally enforceable master netting agreement with that counterparty, the “net” mark-to-market exposure represents the netting of the positive and negative exposures with that counterparty. Accordingly, cash flow hedges are presented net on the Consolidated Balance Sheets.