Summary of Significant Accounting Policies | Note 2. Summary of Significant Accounting Policies The accompanying consolidated financial statements reflect the application of certain significant accounting policies as described in this note and elsewhere in the footnotes. (a) Basis of Presentation The accompanying consolidated financial statements include the consolidated accounts of the Company and its wholly‑owned, controlled subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. Events occurring subsequent to December 31, 2018 have been evaluated for potential recognition or disclosure in the consolidated financial statements. (b) Use of Estimates The preparation of these consolidated financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the dates of the financial statements and the reported amounts of revenue and expenses during the reporting periods. On an ongoing basis, we evaluate our estimates and judgments, including those related to revenue recognition, the realizable value of inventories, valuing stock-based compensation instruments and reserves relating to tax assets and liabilities. Actual amounts could differ from these estimates. Changes in estimates are recorded in the period in which they become known. (c) Foreign Currency The functional currency for substantially all operations outside the United States is the local currency. Financial statements for these operations are translated into United States dollars at year‑end rates as to assets and liabilities and average exchange rates during the year as to revenue and expenses. The resulting translation adjustments are recorded in stockholders’ equity as an element of accumulated other comprehensive income (loss). Foreign currency transaction gains and losses are included in other income (expense) in the Consolidated Statements of Operations. For the year ended December 31, 2018 we had $1.3 million in foreign exchange loss. For the year ended December 31, 2017 we had $1.1 million in foreign exchange gains. For the year ended December 31, 2016 we had $0.6 million in foreign exchange losses. (d) Cash and Cash Equivalents Cash and cash equivalents consist of cash on hand and highly liquid investments with original maturities of ninety days or less. Cash equivalents consist primarily of money market funds, U.S Government and Agency Securities and deposit accounts. Cash equivalents are carried on the balance sheet at fair market value. (e) Inventories Inventories are carried at lower of cost or net realizable value, determined using the first‑in, first‑out (“FIFO”) method, or market. We periodically review our inventories and make provisions as necessary for estimated obsolescence or damaged goods to ensure values approximate lower of cost or net realizable value. The amount of such markdowns is equal to the difference between cost of inventory and the estimated market value based upon assumptions about future demands, selling prices, and market conditions. We record a provision for estimated excess inventory. The provision is determined using management’s assumptions of materials usage, based on estimates of demand and market conditions. If actual market conditions become less favorable than those projected by management, additional inventory write‑downs may be required. (f) Property, Plant and Equipment Property, plant and equipment are stated at cost, less accumulated depreciation and amortization. Depreciation and amortization are recorded using the straight‑line method over the estimated useful lives of the related assets as follows: Asset Classification Estimated Useful Life Land and buildings (under lease) Lesser of the lease term or estimated useful life of the asset Machinery and equipment 7 to 10 years On January 30, 2015, we sold our corporate headquarters facility. As part of this sale, we also entered into a 22-year lease agreement. We accounted for the sale leaseback transaction as a financing arrangement for financial reporting purposes. We retained the historical costs of the property and the related accumulated depreciation on our financial books within property, plant and equipment and will continue to depreciate the property for financial reporting purposes over the lesser of its remaining useful life or its initial lease term of 22 years. Repairs and maintenance costs are expensed as incurred. Expenditures for renewals and betterments are capitalized. (g) Impairment of Long‑Lived Assets We record impairment losses on long-lived assets when events and circumstances indicate that these assets might not be recoverable. Recoverability is measured by a comparison of the assets’ carrying amount to their expected future undiscounted net cash flows. If such assets are considered to be impaired, the impairment is measured based on the amount by which the carrying value exceeds its fair value. We did not have any indicators of impairment during the period ending December 31, 2018. We did not record an impairment charge in the years ended December 31, 2018, 2017, or 2016. Actual performance could be materially different from our current forecasts, which could impact estimates of undiscounted cash flows and may result in the impairment of the carrying amount of the long-lived assets in the future. This could be caused by strategic decisions made in response to economic and competitive conditions, the impact of the economic environment on our customer base, or a material adverse change in our relationships with significant customers. (h) Concentration of Risk and Off‑Balance Sheet Risk Financial instruments that potentially subject us to concentrations of credit risk are principally cash equivalents and accounts receivable. Our cash equivalents are principally maintained in investment grade money‑market funds, U.S. Government and Agency Securities and deposit accounts. We have no significant off‑balance‑sheet risk such as currency exchange contracts, option contracts or other hedging arrangements. Our exposure to market risk for changes in interest rates relates primarily to cash equivalents. The primary objective of our investment activities is to preserve principal without significantly increasing risk. This is accomplished by investing in marketable investment grade securities. We do not use derivative financial instruments to manage our investment portfolio and do not expect operating results or cash flows to be affected to any significant degree by any change in market interest rates. We perform ongoing credit evaluations of our customers’ financial condition and generally requires no collateral to secure accounts receivable. For selected overseas sales, we require customers to obtain letters of credit before product is shipped. We maintain an allowance for doubtful accounts based on our assessment of the collectability of accounts receivable. We review the allowance for doubtful accounts quarterly. We do not have any off‑balance sheet credit exposure related to our customers. Our customers consist of semiconductor chip manufacturers located throughout the world and net sales to our ten largest customers accounted for 76.9%, 73.3% and 70.2% of revenue in 2018, 2017 and 2016, respectively. For the year ended December 31, 2018, we had two customers representing 20.1% and 12.1% of total revenue, respectively. For the year ended December 31, 2017 we had two customers representing 24.9% and 13.1% of total revenue, respectively. For the year ended December 31, 2016, we had one customer representing 17.0% of total revenue. As of December 31, 2018, we had two customers account for 21.9% and 11.5% of consolidated accounts receivable, respectively. As of December 31, 2017, we had three customers account for 19.8%, 11.8% and 10.6% of consolidated accounts receivable, respectively. Some of the components and sub‑assemblies included in our products are obtained either from a sole source or a limited group of suppliers. Disruption to our supply source, resulting either from economic conditions or other factors, could affect our ability to deliver products to our customers. (i) Revenue Recognition Under Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 606, Revenue from Contracts with Customers or (“ASC 606”), revenue is recognized when a customer obtains control of promised goods or services in an amount that reflects the consideration we expect to receive in exchange for those goods or services. We measure revenue based on the consideration specified in the customer arrangement, and revenue is recognized when the performance obligations in the customer arrangement are satisfied. A performance obligation is a promise in a contract to transfer a distinct product or service to the customer. The transaction price of a contract is allocated to each distinct performance obligation based upon the relative standalone selling price for each performance obligation and recognized as revenue when or as, the customer receives the benefit of the performance obligation. To account for and measure revenue, we apply the following five steps: 1) Identify the contract with the customer A contract with a customer exists when (i) we enter into an enforceable contract with a customer that defines each party’s rights regarding the goods or services to be transferred and identifies the related payment terms, (ii) the contract has commercial substance, and (iii) we determine that collection of substantially all consideration for goods and services that are transferred is probable based on the customer’s intent and ability to pay the promised consideration. 2) Identify the performance obligations in the contract Performance obligations promised in a contract are identified based on the goods and services that will be transferred to the customer that are both capable of being distinct, whereby the customer can benefit from the good or service either on its own or together with other available resources, and are distinct in the context of the contract, whereby the transfer of the good or service is separately identifiable from other promises in the contract. To the extent a contract includes multiple promised goods and services, we must apply judgment to determine whether promised goods and services are capable of being distinct and distinct in the context of the contract. If these criteria are not met, the promised goods and services are accounted for as a combined performance obligation. Systems sales consist of multiple performance obligations, including the system itself and obligations that are not delivered simultaneously with the system. These undelivered obligations might include a combination of installation services, extended warranty and support and spare parts, all of which are generally covered by a single sales price. The aftermarket business includes both products and services type arrangements. Performance obligations in these contracts consist of used tools, spare parts, equipment upgrades, maintenance services and customer training. Customers who purchase new systems are provided an assurance-type warranty for one year after acceptance of the tool. For aftermarket transactions, we provide customers an assurance-type warranty for 90 days. Customers can choose to purchase extended warranty terms with enhanced support similar to a service-type warranty ranging from one to three years. In accordance with ASC 606, assurance-type warranties are not considered a performance obligation, whereas service-type warranties are. 3) Determine the transaction price The transaction price is determined based on the consideration to which we will be entitled in exchange for transferring goods and services to the customer. To the extent the transaction price includes variable consideration, we estimate the amount of variable consideration that should be included in the transaction price utilizing either the expected value method or the most likely amount method depending on the nature of the variable consideration. Variable consideration is included in the transaction price if, in our judgment, it is probable that a significant future reversal of cumulative revenue under the contract will not occur. Any estimates, including the effect of the constraint on variable consideration, are evaluated at each reporting period for any changes. In applying this guidance, Companies must also consider whether any significant financing components exist. The transaction price for all transactions is based on the price reflected in the individual customer’s purchase order. Variable consideration has not been identified as a significant component of the transaction price for any of our transactions. For those transactions where all performance obligations will be satisfied within one year or less, we apply the practical expedient outlined in ASC 606-10-32-18. This practical expedient allows us not to adjust promised consideration for the effects of a significant financing component if we expect at contract inception that the period between when we transfer the promised good or service to a customer and when the customer pays for that good or service will be one year or less. For those transactions that are expected to be completed after one year, we have assessed that there are no significant financing components because any difference between the promised consideration and the cash selling price of the good or service is for reasons other than the provision of financing. 4) Allocate the transaction price to performance obligations in the contract If the contract contains a single performance obligation, the entire transaction price is allocated to the single performance obligation. Contracts that contain multiple performance obligations require an allocation of the transaction price to each performance obligation on a relative standalone selling price basis unless the transaction price is variable and meets the criteria to be allocated entirely to a performance obligation or to a distinct service that forms part of a single performance obligation. Where required, we determine standalone selling price (SSP) for each obligation based on consideration of both market and Company specific factors, including the selling price and profit margin for similar products, the cost to produce, and the anticipated margin. For those contracts that contain multiple performance obligations (primarily systems sales, as well as some aftermarket contracts requiring both time and material inputs), we must determine the SSP. We use a cost plus margin approach in determining the SSP for any materials related performance obligations (such as upgrades, spare parts, systems). To determine the SSP for labor related performance obligations (such as the labor component of installation), we use directly observable inputs based on the standalone sale prices for these services. 5) Recognize revenue when or as we have satisfied a performance obligation We satisfy performance obligations either over time or at a point in time. Revenue is recognized over time if either 1) the customer simultaneously receives and consumes the benefits provided by the entity’s performance, 2) the entity’s performance creates or enhances an asset that the customer controls as the asset is created or enhanced, or 3) the entity’s performance does not create an asset with an alternative use to the entity and the entity has an enforceable right to payment for performance completed to date. If the entity does not satisfy a performance obligation over time, the related performance obligation is satisfied at a point in time by transferring the control of a promised good or service to a customer. Examples of control are using the asset to produce goods or services, enhance the value of other assets or settle liabilities, and holding or selling the asset. For over time recognition, ASC 606 requires us to select a single revenue recognition method for the performance obligation that faithfully depicts our performance in transferring control of the goods and services. The guidance allows entities to choose between two methods to measure progress toward complete satisfaction of a performance obligation: Output methods - recognize revenue on the basis of direct measurements of the value to the customer of the goods or services transferred to date relative to the remaining goods or services promised under the contract (e.g. surveys of performance completed to date, appraisals of results achieved, milestones reached, time elapsed, and units produced or units delivered); and Input methods - recognize revenue on the basis of the entity’s efforts or inputs to the satisfaction of a performance obligation (e.g., resources consumed, labor hours expended, costs incurred, or time elapsed) relative to the total expected inputs to the satisfaction of that performance obligation. We have the right to consideration from a customer in an amount that corresponds directly with the value to the customer of the entity’s performance completed to date (i.e. certain aftermarket contracts), as such we have elected a practical expedient to recognize revenue in the amount to which the entity has a right to invoice for such services. Product related revenues (whether for systems or aftermarket business) are recognized at a point in time, when they are shipped or delivered, depending on shipping terms. For installation services, revenue is recognized at a point in time, once the installation of the tool is complete. The nature of the installation services are such that the customer does not simultaneously receive and consume the benefits provided by the entity’s performance, nor does performance of installation services create or enhance an asset that the customer controls. Installation services do not create an asset with an alternative use to the entity, and the entity does not have an enforceable right to payment for performance completed to date. Contract liabilities are reflected as deferred revenue on the consolidated balance sheet. Contract liabilities relate to payments invoiced or received in advance of completion of performance obligations under a contract. Contract liabilities are recognized as revenue upon the fulfillment of performance obligations. Service-type warranties for any product are recognized over time, as these represent a stand ready obligation to service the product during the warranty period. Progress in the satisfaction of these performance obligations will be measured using an input method of time elapsed. Maintenance and service contracts are recognized over time. Progress in the satisfaction of these performance obligations will be measured using an input method of either time elapsed in the case of fixed period contracts, or labor hours expended, in the case of project based contracts. (j) Recognizing Assets related to Recoverable Customer Contract Costs We recognize an asset related to incremental costs incurred by us to obtain a contract with a customer if we expect to recover those costs. We will recognize an asset from costs incurred to fulfill a contract only if such costs relate directly to a contract with an entity that we can specifically identify, the costs incurred will generate or enhance resources that will be used in satisfying performance obligations in the future, and the costs are expected to be recovered. Any assets recognized related to costs to obtain or fulfill a contract are amortized on a systematic basis that is consistent with the transfer to the customer of the goods or services to which the asset relates. In substantially all of our business transactions, we incur incremental costs to obtain contracts with customers, in the form of sales commissions. We maintain a commission program which awards our employees for System sales, aftermarket activity and other individual goals. Under ASC 606, an asset is amortized on a systematic basis that is consistent with the transfer to the customer of the goods or services to which the asset relates. However, ASC 606 provides a practical expedient to allow for the recognition of commission expense when incurred if the amortization period of the asset that the entity otherwise would have recognized is one year or less. Based on the nature of our commission agreements, all commissions are expensed as incurred based upon the expectation that the amortization period would be one year or less. (k) Shipping and Handling Costs Shipping and handling costs are included in cost of revenue. (l) Stock‑Based Compensation We generally recognize compensation expense for all stock-based payments to employees and directors, including grants of stock options and restricted stock units, based on the grant‑date fair value of those stock‑based payments. For stock option awards, we use the Black‑Scholes option pricing model, adjusted for expected forfeitures. Other valuation models may be utilized in the limited circumstances where awards with market-based vesting considerations, such as the price of our common stock, or performance based awards, are granted. Stock‑based compensation expense is recognized ratably over the requisite service period. For each stock option or restricted stock unit grant with vesting based on a combination of time, market or performance conditions, where vesting will occur if either condition is met, the related compensation costs are recognized over the shorter of the explicit service period or the derived service period. See Note 13 for additional information relating to stock‑based compensation. (m) Income Taxes We record income taxes using the asset and liability method. Deferred income tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective income tax basis, and operating loss and tax credit carryforwards. Our consolidated financial statements contain certain deferred tax assets which have arisen primarily as a result of operating losses, as well as other temporary differences between financial and tax accounting. We establish a valuation allowance if the likelihood of realization of the deferred tax assets is reduced based on an evaluation of objective verifiable evidence. Significant management judgment is required in determining our provision for income taxes, our deferred tax assets and liabilities and any valuation allowance recorded against those net deferred tax assets. We evaluate the weight of all available evidence to determine whether it is more likely than not that some portion or all of the net deferred income tax assets will not be realized. Income taxes include the largest amount of tax benefit for an uncertain tax position that is more likely than not to be sustained upon audit based on the technical merits of the tax position. Settlements with tax authorities, the expiration of statutes of limitations for particular tax positions, or obtaining new information on particular tax positions may cause a change to the effective tax rate. We recognize accrued interest related to unrecognized tax benefits as interest expense and penalties within operating expense in the consolidated statements of operations. (n) Computation of Net Income per Share Basic earnings per share is computed by dividing income available to common stockholders (the numerator) by the weighted‑average number of common shares outstanding (the denominator) for the period. The computation of diluted earnings per share is similar to basic earnings per share, except that the denominator is increased to include the number of additional common shares that would have been outstanding if the potentially dilutive common shares had been issued, calculated using the treasury stock method. The components of net income per share are as follows: Year ended December 31, 2018 2017 2016 (in thousands, except per share data) Net income available to common stockholders $ 45,885 $ 126,959 $ 11,001 Weighted average common shares outstanding used in computing basic income per share 32,286 30,866 29,195 Incremental options and RSUs 1,716 2,570 1,752 Weighted average common shares used in computing diluted net income per share 34,002 33,436 30,947 Net income per share Basic $ 1.42 $ 4.11 $ 0.38 Diluted $ 1.35 $ 3.80 $ 0.36 Diluted weighted average common shares outstanding does not include options and restricted stock units outstanding to purchase 0.9 million common equivalent shares for the periods ended December 31, 2016, as their effect would have been anti-dilutive. (o) Accumulated Other Comprehensive Income The following table presents the changes in accumulated other comprehensive income, net of tax, by component for the year ended December 31, 2018: Foreign Defined benefit currency pension plan Total (in thousands) Balance at December 31, 2017 $ 2,756 $ (580) $ 2,176 Other comprehensive income and pension reclassification (1,794) 66 (1,728) Balance at December 31, 2018 $ 962 $ (514) $ 448 (p) Recent Accounting Guidance i. Accounting Standard Codification 606 on Revenue Recognition Adopted January 1, 2018 Effective January 1, 2018, we adopted FASB ASC Topic 606, Revenue from Contracts with Customers , or ASC 606. In accordance with ASC 606, we changed certain characteristics of our revenue recognition accounting policy as described below. On adoption, ASC 606 was applied only to open contracts using the modified retrospective method, where the cumulative effect of the initial application is recognized as an adjustment to opening retained earnings at January 1, 2018. Therefore, comparative prior periods have not been adjusted and continue to be reported under FASB ASC Topic 605, Revenue Recognition , or ASC 605. The impact of adoption on our consolidated statement of operations for the twelve months ended December 31, 2018 and consolidated balance sheet as of December 31, 2018 was as follows (in thousands): Twelve months ended December 31, 2018 Consolidated Statement of Operations As Reported ASC 606 Pro Forma Under ASC 605 Revenue: Product $ 415,922 $ (1,023) $ 414,899 Total revenue 442,575 (1,023) 441,552 Gross profit 179,636 (1,023) 178,613 Income from operations 59,959 (1,023) 58,936 Income before income taxes 54,705 (1,023) 53,682 Income tax provision 8,820 (165) 8,655 Net income $ 45,885 $ (858) $ 45,027 Net income per share: Basic $ 1.42 $ (0.03) $ 1.39 Diluted $ 1.35 $ (0.03) $ 1.32 December 31, 2018 Consolidated Balance Sheet As Reported ASC 606 Pro Forma Under ASC 605 Deferred income taxes $ 71,939 $ 165 $ 72,104 Total assets $ 548,441 $ 165 $ 548,606 Deferred revenue $ 22,584 $ 2,623 $ 25,207 Total current liabilities 84,997 2,623 87,620 Total liabilities 140,104 2,623 142,727 Accumulated deficit (157,260) (2,458) (159,718) Total stockholders' equity 408,337 (2,458) 405,879 Total liabilities and stockholders' equity $ 548,441 $ 165 $ 548,606 The impact of the adoption of ASC 606 on consolidated statements of comprehensive income and cash flows for the twelve months ended December 31, 2018 was not material. Upon adoption of ASC 606, we changed our accounting policy for the installation performance obligation included in all system sales. Previously under ASC 605, we deferred revenue for the greater of the fair value of the installation or the portion of contract consideration for which collection was contingent upon installation completion (the “retention”). The concept of contingent consideration is no longer relevant under ASC 606 and therefore we will only defer the portion of the transaction price allocated to the installation performance obligation. As a result of this change, we recorded a cumulative effect adjustment to increase retained earnings and decrease deferred revenue on January 1, 2018 by $1.6 million. Since the adoption, all new contracts are accounted for under ASC 606. Our revenue recognition policies addressing the nature, amount and timing of revenue and cash flows arising from contracts with customers are included in section (i) of Note 2, Summary of Significant Accounting Policies. ii. Accounting Standard Update 2016-15 on Cash Receipts Adopted January 1, 2018 In August 2016, the FASB issued ASU No. 2016-15 “Classification of Certain Cash Receipts and Cash Payments.” The ASU is intended to add or clarify guidance on the classification relating to specific cash flow receipts and payments in the statement of cash flows and to eliminate the diversity in practice related to such classifications. The guidance in ASU 2016-15 is required for annual reporting periods beginning after December 15, 2017, and is to be applied retrospectively for each period presented. Adoption of ASU 2016-15 had no material effect on our consolidated financial statements and disclosures. iii. Accounting Standard Update 2017-07 on Retirement Benefits Adopted January 1, 2018 In March 2017, the FASB issued ASU No. 2017-07 “Compensation – Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost.” The ASU is intended to improve the presentation of net periodic pension cost and net periodic postretirement benefit cost. The amendment applies to all entities offering a defined benefit pension plan, other postretirement benefit plans, or other types of benefits accounted for under Topic 715. The amendments in the ASU require an employer to report the service cost component in the same line item or items as other compensation costs arising from services rendered by the pertinent employees during the period. The other components of net benefit cost are required to be presented in the income statement separately from the service cost component and outside a subtotal of income from operations. The amendments in this ASU are effective for public business entities for annual periods beginning after December 15, 2017, including interim periods within the annual period. The amendments in this ASU should be applied retrospectively for the presentation of the service cost component and the other components of net periodic pension cost and net periodic postretirement benefit cost in the income statement and prospectively, on and after the effective date, for the capitalization of the service cost component of net periodic pension cost and net periodic postretirement benefit in assets. Adoption of ASU 2017-07 had no material effect on the consolidated financial statements and disclosures. iv. Accounting Standard Update 2016-02 on Leases to be Effective January 1, 2019 In February 2016, the FASB issued ASU No. 2016-02 “Leases.” The ASU requires lessees to recognize the rights and obligations created by most leases as assets and liabilities on their balance sheet and continue to recognize expenses on their income statement over the lease term. It will also require disclosures designed to give financial statement users information on the amount, timing, and uncertainty of cash flows arising from leases. The guidance is effective for annual reporting periods beginning after December 15, 2018, and interim periods within those years. Early adoption is permitted for all entities. In July 2018, the FASB issued ASU No. 2018-11 “Leases (Topic 842)” , that provides targeted improvements relating to the transition method options with which to adopt the new standard. Under this additional and optional transition method, an entity initially applies the new lease standard at the adoption date and recognizes a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption. An entity that elects this transition method must provide the required Topic 840 disclosures for all periods that continue to be in accordance with Topic 840. We will elect the package of practical expedients permitted under the transition guidance within the new standard, which among other things, allows us to carryforward the historical lease classification. We will make an accounting policy election to keep leases with an initial term of 12 months or less off of the balance sheet. We will use the transition method allowed under ASU 2018-11. We are currently finalizing our implementation of procedures regarding reporting and disclosure controls. We anticipate adopting the new standard on January 1, 2019 using the modified retrospective approach under the ASU 2018-11 transition method with the primary effect to be the recognition of additional right-of-use assets and corresponding li |