Significant Accounting Policies (Policies)	12 Months Ended
Significant Accounting Policies (Policies)	Dec. 31, 2016
Significant Accounting Policies
Basis of Presentation	(b) Basis of Presentation The accompanying audited Consolidated Financial Statements of the Company have been prepared in accordance with United States generally accepted accounting principles (“GAAP”). The Company reports interim quarters on a 13-week basis ending on the last Sunday of each period, which is determined at the start of each year. The Company’s fourth quarter always ends on the last day of the calendar year, December 31. During 2016 the interim quarters ended on April 3, July 3, and October 2, and during 2015 the interim quarters ended on March 29, June 28 and September 27. The Company reports these interim quarters as March 31, June 30, and September 30 in its interim consolidated financial statements.
Use of Estimates	(c) Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Although these estimates are based on management’s knowledge of current events and actions it may undertake in the future, these estimates may ultimately differ from actual results. Significant items subject to such estimates and assumptions include: (i) the best estimate of selling price for the Company’s products and services; (ii) allowances for doubtful accounts; (iii) inventory obsolescence; (iv) the useful lives and expected future cash flows of property, plant, and equipment and identifiable intangible assets; (v) the fair value of the Company’s reporting unit and related goodwill; (vi) the fair value, less cost to sell, of assets held for sale; (vii) investment valuations and the valuation of derivatives, deferred tax assets, and assets acquired in business combinations; (viii) the recoverability of long-lived assets; (ix) liabilities for product warranty and legal contingencies; (x) share-based compensation; and (xi) income tax uncertainties. Actual results could differ from those estimates.
Principles of Consolidation	(d) Principles of Consolidation The Consolidated Financial Statements include the accounts of the Company and its subsidiaries. Intercompany balances and transactions have been eliminated in consolidation. Companies acquired during each reporting period are reflected in the results of the Company effective from their respective dates of acquisition through the end of the reporting period.
Foreign Currencies	(e) Foreign Currencies Assets and liabilities of the Company’s foreign subsidiaries that operate using local functional currencies are translated using the exchange rates in effect at the balance sheet date. Results of operations are translated using monthly average exchange rates. Adjustments arising from the translation of the foreign currency financial statements of the Company’s subsidiaries into U.S. dollars, including intercompany transactions of a long-term nature, are reported as currency translation adjustments in “Accumulated other comprehensive income” in the Consolidated Balance Sheets. Foreign currency transaction gains or losses are included in “Other, net” in the Consolidated Statements of Operations.
Revenue Recognition	(f) Revenue Recognition The Company recognizes revenue when all of the following criteria have been met: persuasive evidence of an arrangement exists with a customer; delivery of the specified products has occurred or services have been rendered; prices are contractually fixed or determinable; and collectability is reasonably assured. Revenue is recorded including shipping and handling costs and excluding applicable taxes related to sales. Contracts with customers frequently contain multiple deliverables, such as systems, upgrades, components, spare parts, maintenance, and service plans. Judgment is required to properly identify the accounting units of the multiple-element arrangements and to determine how the revenue should be allocated among the accounting units. The Company also evaluates whether multiple transactions with the same customer or related parties should be considered part of a single, multiple-element arrangement based on an assessment of whether the contracts or agreements are negotiated or executed within a short time frame of each other or if there are indicators that the contracts are negotiated in contemplation of one another. Moreover, judgment is used in interpreting the commercial terms and determining when all criteria have been met in order to recognize revenue in the appropriate accounting period. When there are separate units of accounting, the Company allocates revenue to each element based on the following selling price hierarchy: vendor-specific objective evidence (“VSOE”) if available; third party evidence (“TPE”) if VSOE is not available; or the best estimate of selling price (“BESP”) if neither VSOE nor TPE is available. The Company uses BESP for the elements in its arrangements. The maximum revenue recognized on a delivered element is limited to the amount that is not contingent upon the delivery of additional items. The Company considers many facts when evaluating each of its sales arrangements to determine the timing of revenue recognition including its contractual obligations, the customer’s creditworthiness, and the nature of the customer’s post-delivery acceptance provisions. The Company’s system sales arrangements, including certain upgrades, generally include field acceptance provisions that may include functional or mechanical test procedures. For the majority of the arrangements, a customer source inspection of the system is performed in the Company’s facility or test data is sent to the customer documenting that the system is functioning to the agreed upon specifications prior to delivery. Historically, such source inspection or test data replicates the field acceptance provisions that are performed at the customer’s site prior to final acceptance of the system. When the Company objectively demonstrates that the criteria specified in the contractual acceptance provisions are achieved prior to delivery, revenue is recognized upon system delivery since there is no substantive contingency remaining related to the acceptance provisions at that date, subject to the retention amount constraint described below. For new products, new applications of existing products, or for products with substantive customer acceptance provisions where the Company cannot objectively demonstrate that the criteria specified in the contractual acceptance provisions have been achieved prior to delivery, revenue and the associated costs are deferred and fully recognized upon the receipt of final customer acceptance, assuming all other revenue recognition criteria have been met. The Company’s system sales arrangements, including certain upgrades, generally do not contain provisions for right of return, forfeiture, refund, or other purchase price concession. In the rare instances where such provisions are included, all revenue is deferred until such rights expire. The sales arrangements generally include installation. The installation process is not deemed essential to the functionality of the equipment since it is not complex; it does not require significant changes to the features or capabilities of the equipment or involve constructing elaborate interfaces or connections subsequent to factory acceptance. The Company has a demonstrated history of consistently completing installations in a timely manner and can reliably estimate the costs of such activities. Most customers engage the Company to perform the installation services, although there are other third-party providers with sufficient knowledge who could complete these services. Based on these factors, installation is deemed to be inconsequential or perfunctory relative to the system sale as a whole, and as a result, installation service is not considered a separate element of the arrangement. As such, the Company accrues the cost of the installation at the time of revenue recognition for the system. In many cases the Company’s products are sold with a billing retention, typically 10% of the sales price, which is payable by the customer when field acceptance provisions are completed. The amount of revenue recognized upon delivery of a system or upgrade, if any, is limited to the lower of i) the amount billed that is not contingent upon acceptance provisions or ii) the value of the arrangement consideration allocated to the delivered elements, if such sale is part of a multiple-element arrangement. The Company’s contractual terms with customers in Japan generally specify that title and risk and rewards of ownership transfer upon customer acceptance. As a result, for customers in Japan, revenue is recognized upon the receipt of written customer acceptance. A distributor is used for almost all sales to customers in Japan. Title passes to the distributor upon shipment; however, due to customary local business practices, the risks and rewards of ownership of the system transfer to the end-customers upon their acceptance. As such, the Company recognizes revenue upon receipt of written acceptance from the end customer. The Company recognizes revenue related to maintenance and service contracts ratably over the applicable contract term. The Company recognizes revenue from the sales of components, spare parts, and specified service engagements at the time of delivery in accordance with the terms of the applicable sales arrangement. Incremental direct costs incurred related to the acquisition of a customer contract, such as sales commissions, are expensed as incurred, even if the related revenue is deferred in accordance with the above policy.
Warranty Costs	(g) Warranty Costs The Company typically provides standard warranty coverage on its systems for one year from the date of final acceptance by providing labor and parts necessary to repair the systems during the warranty period. The Company accounts for the estimated warranty cost when revenue is recognized on the related system. Warranty cost is included in “Cost of sales” in the Consolidated Statements of Operations. The estimated warranty cost is based on the Company’s historical experience with its systems and regional labor costs. The Company calculates the average service hours by region and parts expense per system utilizing actual service records to determine the estimated warranty charge. The Company updates its warranty estimates on a semiannual basis when the actual product performance or field expense differs from original estimates.
Shipping and Handling Costs	(h) Shipping and Handling Costs Shipping and handling costs are expenses incurred to move, package, and prepare the Company’s products for shipment and to move the products to a customer’s designated location. These costs are generally comprised of payments to third-party shippers. Shipping and handling costs are included in “Cost of sales” in the Consolidated Statements of Operations.
Research and Development Costs	(i) Research and Development Costs Research and development costs are expensed as incurred and include charges for the development of new technology and the transition of existing technology into new products or services.
Advertising Expense	(j) Advertising Expense The cost of advertising is expensed as incurred and totaled $0.8 million, $0.9 million, and $0.6 million for the years ended December 31, 2016, 2015, and 2014, respectively.
Accounting for Share-Based Compensation	(k) Accounting for Share-Based Compensation Share-based awards exchanged for employee services are accounted for under the fair value method. Accordingly, share-based compensation cost is measured at the grant date based on the fair value of the award. The expense for awards is recognized over the employee’s requisite service period (generally the vesting period of the award). The Company has elected to treat awards with only service conditions and with graded vesting as one award. Consequently, the total compensation expense is recognized straight-line over the entire vesting period, so long as the compensation cost recognized at any date at least equals the portion of the grant date fair value of the award that is vested at that date. The Company uses the Black-Scholes option-pricing model to compute the estimated fair value of option awards, as well as purchase rights under the Employee Stock Purchase Plan. The Black-Scholes model includes assumptions regarding dividend yields, expected volatility, expected option term, and risk-free interest rates. See Note 15, “Stock Plans,” for additional information. In addition to stock options, restricted share awards (“RSAs”) and restricted stock units (“RSUs”) with time-based vesting, the Company issues performance share units and awards (“PSUs” and “PSAs”). Compensation cost for PSUs and PSAs is recognized over the requisite service period based on the timing and expected level of achievement of the performance targets. A change in the assessment of the probability of a performance condition being met is recognized in the period of the change in estimate. At the conclusion of the performance period, the number of shares granted may vary based on the level of achievement of the performance targets. See Note 1(u), “Recently Adopted Accounting Standards,” for additional information concerning the Company’s early adoption of Accounting Standards Update (“ASU”) 2016-09: Stock Compensation: Improvements to Employee Share-Based Payment Accounting.
Income Taxes	(l) Income Taxes Income taxes are accounted for under the asset and liability method. Deferred 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 tax bases and operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities from a change in tax rate is recognized in income in the period that includes the enactment date. See Note 1(u), “Recently Adopted Accounting Standards,” for additional information concerning the Company’s early adoption of ASU 2015-17: Balance Sheet Classification of Deferred Taxes.
Concentration of Credit Risk	(m) Concentration of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash and cash equivalents, investments, derivative financial instruments used in hedging activities, and accounts receivable. The Company invests in a variety of financial instruments and, by policy, limits the amount of credit exposure with any one financial institution or commercial issuer. The Company has not experienced any material credit losses on its investments. The Company maintains an allowance reserve for potentially uncollectible accounts for estimated losses resulting from the inability of its customers to make required payments. The Company evaluates its allowance for doubtful accounts based on a combination of factors. In circumstances where specific invoices are deemed to be uncollectible, the Company provides a specific allowance for bad debt against the amount due to reduce the net recognized receivable to the amount reasonably expected to be collected. The Company also provides allowances based on its write-off history. The allowance for doubtful accounts totaled $0.3 million and $0.2 million at December 31, 2016 and 2015, respectively. To further mitigate the Company’s exposure to uncollectable accounts, the Company may request certain customers provide a negotiable irrevocable letter of credit drawn on a reputable financial institution. These irrevocable letters of credit are typically issued to mature between zero and 90 days from the date the documentation requirements are met, typically when a system ships or upon receipt of final acceptance from the customer. The Company, at its discretion, may monetize these letters of credit on a non-recourse basis after they become negotiable, but before maturity. The fees associated with the monetization are included in “Selling, general, and administrative” in the Consolidated Statements of Operations and were insignificant for the years ended December 31, 2016, 2015, and 2014.
Fair Value of Financial Instruments	(n) Fair Value of Financial Instruments The carrying amounts of financial instruments, including cash and cash equivalents, accounts receivable, accounts payable, and accrued expenses reflected in the consolidated financial statements approximate fair value due to their short-term maturities. The fair value of debt for footnote disclosure purposes, including current maturities, is estimated using a discounted cash flow analysis based on the estimated current incremental borrowing rates for similar types of instruments.
Cash, Cash Equivalents, and Short-Term Investments	(o) Cash, Cash Equivalents, and Short-Term Investments All financial instruments purchased with an original maturity of three months or less at the time of purchase are considered cash equivalents. Such items may include liquid money market accounts, U.S. treasuries, government agency securities, and corporate debt. Investments that are classified as cash equivalents are carried at cost, which approximates fair value. The Company’s cash and cash equivalents includes $1.5 million and $18.0 million of cash equivalents at December 31, 2016 and 2015 respectively. A portion of the Company’s cash and cash equivalents is held by its subsidiaries throughout the world, frequently in each subsidiary’s respective functional currency, which is typically the U.S. dollar. Approximately 54% and 50% of cash and cash equivalents were maintained outside the United States at December 31, 2016 and 2015, respectively. Marketable securities are generally classified as available-for-sale for use in current operations, if required, and are reported at fair value, with unrealized gains and losses, net of tax, presented as a separate component of stockholders’ equity under the caption “Accumulated other comprehensive income.” These securities can include U.S. treasuries, government agency securities, corporate debt, and commercial paper, all with maturities of greater than three months when purchased. All realized gains and losses and unrealized losses resulting from declines in fair value that are other than temporary are included in “Other, net” in the Consolidated Statements of Operations. The specific identification method is used to determine the realized gains and losses on investments.
Inventories	(p) Inventories Inventories are stated at the lower of cost or net realizable value, with cost determined on a first-in, first-out basis. The Company reviews and sets standard costs on a periodic basis at current manufacturing costs in order to approximate actual costs. The Company assesses the valuation of all inventories, including manufacturing raw materials, work-in-process, finished goods, and spare parts, each quarter. Obsolete inventory or inventory in excess of management’s estimated usage requirement is written down to its estimated net realizable value if less than cost. Estimates of net realizable value include, but are not limited to, management’s forecasts related to the Company’s future manufacturing schedules, customer demand, technological and/or market obsolescence, general market conditions, possible alternative uses, and ultimate realization of excess inventory. If future customer demand or market conditions are less favorable than the Company’s projections, additional inventory write-downs may be required and would be reflected in cost of sales in the period the revision is made. Inventory acquired as part of a business combination is recorded at fair value on the date of acquisition. See Note 5, “Business Combinations,” for additional information.
Business Combinations	(q) Business Combinations The Company allocates the fair value of the purchase consideration of the Company’s acquisitions to the tangible assets, intangible assets, including in-process research and development (“IPR&D”), if any, and liabilities assumed, based on estimated fair values. The excess of the fair value of purchase consideration over the fair values of these identifiable assets and liabilities is recorded as goodwill. IPR&D is initially capitalized at fair value as an intangible asset with an indefinite life and assessed for impairment thereafter. When a project underlying reported IPR&D is completed, the corresponding amount of IPR&D is amortized over the asset’s estimated useful life. Acquisition-related expenses are recognized separately from the business combination and are expensed as incurred in “Selling, General, and Administrative” in the Consolidated Statements of Operations. See Note 5, “Business Combinations,” for additional information.
Goodwill and Indefinite-Lived Intangibles	(r) Goodwill and Indefinite-Lived Intangibles Goodwill is an asset representing the future economic benefits arising from assets acquired in a business combination that are not individually identified and separately recognized. Goodwill is measured as the excess of the consideration transferred over the net of the acquisition-date amounts of the identifiable assets acquired and liabilities assumed. Intangible assets with indefinite useful lives are measured at their respective fair values on the acquisition date. Intangible assets related to IPR&D projects are considered to be indefinite-lived until the completion or abandonment of the associated R&D efforts. If and when development is complete, the associated assets would be deemed long-lived and would then be amortized based on their respective estimated useful lives at that point in time. Goodwill and indefinite-lived intangibles are not amortized into results of operations but instead are evaluated for impairment. The Company performs the evaluation in the fourth quarter of each year or more frequently if impairment indicators arise. The Company may first perform a qualitative assessment of whether it is more likely than not that the reporting unit’s fair value is less than its carrying amount, and, if so, the Company then applies the two-step impairment test. The two-step impairment test first compares the fair value of the Company’s reporting unit to its carrying amount. If the fair value exceeds the carrying amount, goodwill is not impaired, and the Company is not required to perform further testing. If the carrying amount exceeds fair value, the Company determines the implied fair value of the goodwill and, if the carrying amount of the goodwill exceeds its implied fair value, then the Company records an impairment loss equal to the difference. The Company determines the fair value of its reporting unit based on a reconciliation of the fair value of the reporting unit to the Company’s adjusted market capitalization. The adjusted market capitalization is calculated by multiplying the average share price of the Company’s common stock for the last ten trading days prior to the measurement date by the number of outstanding common shares and adding a control premium.
Long-Lived Assets and Cost Method Investment	(s) Long-Lived Assets and Cost Method Investment Long-lived intangible assets consist of purchased technology, customer-related intangible assets, patents, trademarks, covenants not-to-compete, and software licenses and are initially recorded at fair value. Long-lived intangibles are amortized over their estimated useful lives in a method reflecting the pattern in which the economic benefits are consumed or straight-lined if such pattern cannot be reliably determined. Property, plant, and equipment are recorded at cost. Depreciation expense is calculated based on the estimated useful lives of the assets by using the straight-line method. Amortization of leasehold improvements is recognized using the straight-line method over the shorter of the remaining lease term or the estimated useful lives of the improvements. Long-lived assets and cost method investments are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. If circumstances require a long-lived asset or asset group be tested for possible impairment, a recoverability test is performed utilizing undiscounted cash flows expected to be generated by that asset or asset group compared to its carrying amount. If the carrying amount of the long-lived asset or asset group is not recoverable on an undiscounted cash flow basis, impairment is recognized to the extent the carrying amount exceeds its fair value. Fair value is determined through various valuation techniques including discounted cash flow models or, when available, quoted market values, and third-party appraisals.
Recent Accounting Pronouncements	(t) Recent Accounting Pronouncements The FASB issued ASU 2014-09, as amended: Revenue from Contracts with Customers, which has been codified as Accounting Standards Codification 606 (“ASC 606”). ASC 606 requires the Company’s revenue recognition to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the Company expects to be entitled in exchange for those goods or services. ASC 606 outlines a five-step model to make the revenue recognition determination and requires new financial statement disclosures. Publicly-traded companies are required to adopt ASC 606 for reporting periods beginning after December 15, 2017, but can adopt early for annual periods beginning after December 15, 2016. The Company is still finalizing its assessment of the impact of adopting the ASU on its consolidated financial statements and is still evaluating which method of adoption it will select. In January 2016, the FASB issued ASU 2016-01: Financial Instruments — Overall, which requires certain equity investments to be measured at fair value, with changes in fair value recognized in net income. Publicly-traded companies are required to adopt the ASU for reporting periods beginning after December 15, 2017; early adoption is permitted. The Company does not expect this ASU will have a material impact on its consolidated financial statements. In February 2016, the FASB issued ASU 2016-02: Leases, which generally requires the Company’s operating lessee rights and obligations to be recognized as assets and liabilities on the balance sheet. In addition, interest on lease liabilities is to be recognized separately from the amortization of right-of-use assets in the Statement of Operations. Further, payments of the principal portion of lease liabilities are to be classified as financing activities while payments of interest on lease liabilities and variable lease payments are to be classified as operating activities in the Statement of Cash Flows. The transition to the ASU will require leases at the beginning of the earliest period presented to be recognized and measured using a modified retrospective approach. The ASU is effective for fiscal years beginning after December 15, 2018, with early application permitted. The Company is evaluating the anticipated impact of adopting the ASU on its consolidated financial statements. In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows: Classification of Certain Cash Receipts and Cash Payments, which provides guidance on eight specific cash flow issues, including debt prepayments or debt extinguishment costs. Publicly-traded companies are required to adopt the update for reporting periods beginning after December 15, 2017. The Company does not expect this ASU will have a material impact on its consolidated financial statements. In October 2016, the FASB issued ASU 2016-16, Income Taxes: Intra-Entity Transfers of Assets Other Than Inventory, which requires that entities recognize the income tax consequences of an intra-entity transfer of an asset, other than inventory, when the transfer occurs. Publicly-traded companies are required to adopt the update for reporting periods beginning after December 15, 2017. The Company is evaluating the anticipated effect the ASU will have on its consolidated financial statements.
Recently Adopted Accounting Standards	(u) Recently Adopted Accounting Standards In March 2016, the FASB issued ASU 2016-09: Stock Compensation: Improvements to Employee Share-Based Payment Accounting, which simplifies several aspects of the accounting for share-based payments. The Company early adopted the ASU effective January 1, 2016. Beginning in 2016, excess tax benefits and deficiencies are recognized as income tax expense or benefit in the income statement in the reporting period incurred. The Company also made an accounting policy election to account for forfeitures when they occur. The ASU transition guidance requires that this election be applied on a modified retrospective basis through a cumulative-effect adjustment to retained earnings as of the beginning of the period in which the ASU is effective. Accordingly, the Company recorded a $1.3 million charge to the opening accumulated deficit balance with a corresponding adjustment to additional paid-in capital, resulting in no impact to the opening balance of total stockholders’ equity. In addition, the Company recorded additional deferred tax assets with an equally offsetting valuation allowance of $2.4 million. In November 2015, the FASB issued ASU 2015-17: Balance Sheet Classification of Deferred Taxes, which simplifies the presentation of deferred income taxes by requiring that deferred income tax liabilities and assets be classified as noncurrent in our consolidated balance sheet. Publicly-traded companies are required to adopt the update for reporting periods beginning after December 15, 2016, with early application permitted. The Company early adopted the ASU effective January 1, 2015. In accordance with the ASU’s transition requirements, the Company chose to apply the amendments in the update prospectively. As such, periods prior to 2015 have not been retrospectively adjusted. The adoption of this ASU did not have a material impact on the consolidated financial statements.