Rudolph 10-Q 3 May 18 2018 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information Document - shares	3 Months Ended
	Mar. 31, 2018	Apr. 18, 2018
Document And Entity Information [Abstract]
Entity Registrant Name	RUDOLPH TECHNOLOGIES INC
Trading Symbol	RTEC
Entity Central Index Key	1,094,392
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Document Type	10-Q
Document Period End Date	Mar. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Common Stock, Shares Outstanding		31,806,084

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Current Assets:
Cash and cash equivalents	$ 68,055	$ 67,770
Marketable securities	112,266	109,589
Accounts receivable, less allowance of $523 and $460	74,672	65,283
Inventories, net	79,763	67,521
Income taxes receivable	4,971	7,220
Prepaid expenses and other current assets	6,045	4,699
Total current assets	345,772	322,082
Property, plant and equipment, net	17,498	17,342
Goodwill	22,495	22,495
Identifiable intangible assets, net	8,352	8,632
Other assets	15,385	15,371
Total assets	409,502	385,922
Current liabilities:
Accounts payable and accrued liabilities	31,966	26,800
Deferred revenue	7,897	6,223
Other current liabilities	9,016	9,284
Total current liabilities	48,879	42,307
Other non-current liabilities	10,894	10,461
Total liabilities	59,773	52,768
Commitments and contingencies
Stockholders’ equity:
Common stock	32	32
Additional paid-in capital	386,986	386,196
Accumulated other comprehensive loss	(550)	(1,205)
Accumulated deficit	(36,739)	(51,869)
Total stockholders’ equity	349,729	333,154
Total liabilities and stockholders’ equity	$ 409,502	$ 385,922

CONDENSED CONSOLIDATED BALANCE3

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Statement Of Financial Position [Abstract]
Allowance for Doubtful Accounts Receivable, Current	$ 523	$ 460

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Consolidated Statements Of Operations [Abstract]
Revenue	$ 73,096	$ 60,679
Cost of revenue	30,675	28,811
Gross profit	42,421	31,868
Operating expenses:
Research and development	11,783	12,010
Selling, general and administrative	12,793	9,668
Amortization	380	505
Total operating expenses	24,956	22,183
Operating income	17,465	9,685
Interest income, net	(391)	(191)
Other expense	182	269
Income before income taxes	17,674	9,607
Provision for income taxes	2,544	2,456
Net income	$ 15,130	$ 7,151
Earnings per share:
Basic	$ 0.48	$ 0.23
Diluted	$ 0.47	$ 0.22
Weighted average shares outstanding:
Basic	31,662	31,290
Diluted	32,317	32,058

CONDENSED CONSOLIDATED STATEME5

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Consolidated Statement Of Comprehensive Income [Abstract]
Net income	$ 15,130	$ 7,151
Other comprehensive income:
Change in net unrealized gains on marketable securities, net of tax	23	44
Change in currency translation adjustments	632	1,120
Total comprehensive income	$ 15,785	$ 8,315

CONDENSED CONSOLIDATED STATEME6

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities:
Net income	$ 15,130	$ 7,151
Adjustments to reconcile net income to net cash and cash equivalents provided by operating activities:
Amortization of intangibles	380	505
Depreciation	1,310	924
Foreign currency exchange loss	183	269
Change in fair value of contingent consideration	318	132
Share-based compensation	1,507	1,148
Provision for doubtful accounts and inventory valuation	705	951
Changes in operating assets and liabilities	(14,894)	3,144
Net cash and cash equivalents provided by operating activities	4,639	14,224
Cash flows from investing activities:
Purchases of marketable securities	(57,134)	(22,449)
Proceeds from sales of marketable securities	54,404	25,355
Purchases of property, plant and equipment	(1,442)	(1,724)
Net cash and cash equivalents (used in) provided by investing activities	(4,172)	1,182
Cash flows from financing activities:
Redemption of stock warrants	0	(1,025)
Tax payments related to shares withheld for share-based compensation plans	(839)	(803)
Issuance of shares through share-based compensation plans	122	107
Net cash and cash equivalents used in financing activities	(717)	(1,721)
Effect of exchange rate changes on cash and cash equivalents	535	701
Net increase in cash and cash equivalents	285	14,386
Cash and cash equivalents at beginning of period	67,770	37,859
Cash and cash equivalents at end of period	68,055	52,245
Supplemental disclosure of cash flow information:
Income taxes paid	$ 249	$ 208

Basis of Presentation

Basis of Presentation	3 Months Ended
	Mar. 31, 2018
Organization And Nature Of Operations [Abstract]
Basis of Presentation	NOTE 1. Basis of Presentation The accompanying interim unaudited condensed consolidated financial statements have been prepared by Rudolph Technologies, Inc. (the “Company” or “Rudolph”) and in the opinion of management reflect all adjustments, consisting of normal recurring accruals, necessary for their fair presentation in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”). Preparing financial statements requires management to make estimates and assumptions that affect amounts reported in the financial statements and accompanying notes. Actual amounts could differ materially from reported amounts. The interim results for the three month period ended March 31, 2018 are not necessarily indicative of results to be expected for the entire year or any future periods. This interim financial information should be read in conjunction with the financial statements and the notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 (“2017 10-K”) filed with the Securities and Exchange Commission (“SEC”). The accompanying condensed consolidated balance sheet at December 31, 2017 has been derived from the audited consolidated financial statements included in the 2017 10-K. Recent Accounting Pronouncements Recently Adopted Effective January 1, 2018, the Company adopted ASU No. 2016-16, “Income Tax (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory.” This ASU, which is part of the Board’s simplification initiative, is intended to reduce the complexity of U.S. GAAP and diversity in practice related to the tax consequences of certain types of intra-entity asset transfers, particularly those involving intellectual property. The adoption of ASU No. 2016-16 did not have any impact on the Company’s consolidated financial position, results of operations, and cash flows. Effective January 1, 2018, the Company adopted ASU No. 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments.” This ASU provides guidance on statement of cash flows presentation for eight specific cash flow issues where diversity in practice exists. The adoption of ASU No. 2016-15 did not have a material impact on the Company’s consolidated financial position, results of operations, and cash flows. Effective January 1, 2018, the Company adopted ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606),” which supersedes nearly all existing revenue recognition guidance. The core principle of Topic 606 is that revenue should be recognized to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. Recently Issued In February 2018, the FASB issued ASU 2018-02, “Income Statement – Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income.” The new guidance allows companies to reclassify stranded tax effects resulting from the Tax Cuts and Jobs Act (the “2017 Tax Act”) from accumulated other comprehensive income to retained earnings. The guidance also requires certain new disclosures regardless of a company’s election. The standard is effective for annual periods and interim periods within those annual periods beginning after December 15, 2018, with earlier adoption permitted. The adoption of ASU 2018-02 is not expected to have a material effect on the Company’s consolidated financial position, results of operations, and cash flows. In May 2017, the FASB issued ASU No. 2017-09, “Compensation - Stock Compensation (Topic718): Scope of Modification Accounting.” This ASU amends the scope of modification accounting for share-based payment arrangements and provides guidance on the types of changes to the terms or conditions of share-based payment awards to which an entity would be required to apply modification accounting under ASC 718. The ASU is effective for the fiscal years beginning after December 15, 2019 and for interim periods within those fiscal years. The Company is currently evaluating the effect the adoption of ASU No. 2017-09 will have on its consolidated financial position, results of operations, and cash flows. In January 2017, the FASB issued ASU No. 2017-04, “Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment.” This ASU eliminates Step 2 from the goodwill impairment test. Accordingly, if the carrying amount of a reporting unit exceeds its fair value, an impairment loss will be recognized in an amount equal to the excess, limited to the total amount of goodwill allocated to the reporting unit. The ASU is effective for the fiscal years beginning after December 15, 2019 and for interim periods within those fiscal years. The Company is currently evaluating the effect the adoption of ASU No. 2017-04 will have on its consolidated financial position, results of operations, and cash flows. In June 2016, the FASB issued ASU No. 2016-13, “Financial Instruments – Credit Losses (Topic 326),” which introduces new guidance for the accounting for credit losses on instruments within its scope. Given the breadth of that scope, the new ASU will impact both financial services and non-financial services entities. The standard is effective for fiscal years beginning after December 15, 2020. The Company is currently evaluating the effect the adoption of ASU No. 2016-13 will have on its consolidated financial position, results of operations, and cash flows. In February 2016, the FASB issued ASU No. 2016-02, “Leases (Topic 842).” The standard requires that lessees recognize assets and liabilities on the balance sheet for the rights and obligations created by all leases with terms of more than 12 months. ASU No. 2016-02 also requires disclosures designed to give financial statement users information on the amount, timing, and uncertainty of cash flows arising from leases. These disclosures include qualitative and quantitative information. The standard is effective for annual periods beginning after December 15, 2018 and for interim periods within those annual periods, with earlier adoption permitted. The adoption of this ASU will result in an increase in right-of-use assets and corresponding liabilities. The Company is evaluating the timing and other effects of its adoption of this ASU on its consolidated financial position, results of operations, and cash flows. Recently issued accounting guidance not discussed above is not applicable or did not have, or is not expected to have, a material impact to the Company.

Revenue

Revenue	3 Months Ended
	Mar. 31, 2018
Revenue From Contract With Customer [Abstract]
Revenue	NOTE 2. Revenue Adoption of Accounting Standards Codification (ASC) Topic 606, “Revenue from Contracts with Customers” On January 1, 2018, the Company adopted Topic 606 using the modified retrospective method applied to those contracts which were not completed as of January 1, 2018. Results for reporting periods beginning after January 1, 2018 are presented under Topic 606, while comparative information has not been restated and continues to be reported under the accounting standards in effect for those periods. The Company did not record a cumulative impact due to the adoption of Topic 606. Revenue Recognition Revenue is recognized when control of the promised goods or services are transferred to the Company’s customers in an amount that reflects the consideration the Company expects to be entitled to in exchange for those goods or services. The Company accounts for a contract when it has approval and commitment from both parties, the rights of the parties and payment terms are identified, the contract has commercial substance and collectability of consideration is probable. The Company has elected to account for shipping and handling activities as the fulfillment of a promise to transfer goods to the customer and therefore records these activities in Cost of revenue. Sales tax and any other taxes collected concurrent with revenue producing activities are excluded from revenue. Incidental items that are immaterial in the context of the contract are recognized as expense. These accounting policy elections are consistent with the manner in which the Company historically recorded these items. Contracts with customers may include multiple performance obligations. For such arrangements, the Company allocates revenue to each performance obligation based on its relative standalone selling price. The Company generally determines standalone selling prices based on the prices charged to customers or using expected cost plus margin. Disaggregated Revenue The following table presents the Company’s revenue disaggregated by revenue source (in thousands, unaudited): Three Months Ended March 31, 2018 2017 Systems $ 56,102 $ 43,893 Software licensing, support and maintenance 7,455 7,498 Parts 6,985 6,330 Services 2,554 2,958 Total revenue $ 73,096 $ 60,679 The following table represents a disaggregation of revenue by timing of revenue: Three Months Ended March 31, 2018 Point in time $ 69,396 Over time 3,700 Total revenue $ 73,096 See Note 14 for additional discussion of the Company’s disaggregated revenue detail. Systems Revenue Revenue from systems is recognized when the Company transfers control of the product to the customer. To indicate transfer of control, the Company must have a present right to payment, legal title must have passed to the customer and the customer must have the significant risks and rewards of ownership. The Company generally transfers control for system sales when the customer or the customer’s agent picks up the system at the Company’s facility. Payment for the majority of the Company’s systems have 80-90% of the invoice amount due within 30 days and the remaining amount due upon customer acceptance, which includes installation, recalibration and qualification by the customer. Customer acceptance is generally based on the Company’s products meeting published performance specifications, which have been demonstrated prior to shipment. The Company provides an assurance warranty on its systems for a period of twelve to fifteen months against defects in material and workmanship. The Company provides for the estimated cost of product warranties at the time revenue is recognized. Depending on the terms of the systems arrangement, the Company may also defer the recognition of a portion of the consideration expected to be received because the Company has to satisfy a future obligation (e.g., installation, training and extended warranties). The Company uses an observable price to determine the standalone selling price for separate performance obligations or a cost plus margin approach when one is not available. Software Licensing, Support and Maintenance Revenue Revenue from software licenses provides the customer with a right to use the software as it exists when made available to the customer. Revenue from software licenses are recognized upfront at the point in time when the software is made available to the customer. Licensing support and maintenance is recognized as the support and maintenance is provided, which is over the contract period. Payment for software licensing, support and maintenance is generally due in 30 days. Parts Revenue Revenue from parts is recognized when the Company transfers control of the product, which typically occurs when the Company ships the product from its facilities to the customer. Payment for parts is generally due in 30 days. Services Revenue Revenue from services primarily consists of service contracts, which provide additional maintenance coverage beyond the Company’s assurance warranty on its products, service labor, consulting and training. Revenue from service contracts is recognized ratably over the term of the service contract. Revenue from service labor, consulting and training is recognized as services are performed. Payment for services is generally due in 30 days. Contract Liabilities The Company records contract liabilities when the customer has been billed in advance of the Company completing its performance obligations. These amounts are recorded as deferred revenue in the Consolidated Balance Sheets. The opening balance in deferred revenue was $7,206 as of January 1, 2018. Changes in deferred revenue were as follows: Three Months Ended March 31, 2018 Beginning Balance, December 31, 2017 $ 7,206 Deferral of revenue 4,553 Recognition of deferred revenue (2,986 ) Ending Balance, March 31, 2018 $ 8,773 Practical Expedients The Company generally expenses sales commissions when incurred because the amortization period is one year or less. These costs are recorded within selling, general and administrative expenses. The Company does not adjust the amount of consideration for the effects of a significant financing component as the payment terms are generally one year or less. The Company does not disclose the value of remaining performance obligations for contracts with an original expected length of one year or less and contracts for which the Company recognizes revenue at the amount to which it has the right to invoice.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2018
Fair Value Measurements [Abstract]
Fair Value Measurements	NOTE 3. Fair Value Measurements The Company applies a three-level valuation hierarchy for fair value measurements. This hierarchy prioritizes the inputs into three broad levels. Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities. Level 2 inputs are quoted prices for similar assets and liabilities in active markets or inputs that are observable for the asset or liability, either directly or indirectly through market corroboration, for substantially the full term of the asset or liability. Level 3 inputs are unobservable inputs based on management’s assumptions used to measure assets and liabilities at fair value. A financial asset’s or liability’s fair value measurement classification within the hierarchy is determined based on the lowest level input that is significant to the fair value measurement. The following tables provide the assets and liabilities carried at fair value measured on a recurring basis at March 31, 2018 and December 31, 2017: Fair Value Measurements Using Carrying Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) March 31, 2018 Assets: Available-for-sale debt securities: Municipal notes and bonds $ 110,074 $ — $ 110,074 $ — Corporate bonds 2,192 — 2,192 — Total assets $ 112,266 $ — $ 112,266 $ — Liabilities: Contingent consideration - acquisitions $ 2,911 $ — $ — $ 2,911 Foreign currency forward exchange contracts 388 — 388 — Total liabilities $ 3,299 $ — $ 388 $ 2,911 December 31, 2017 Assets: Available-for-sale debt securities: Municipal notes and bonds $ 109,589 $ — $ 109,589 $ — Foreign currency forward exchange contracts 45 — 45 — Total assets $ 109,634 $ — $ 109,634 $ — Liabilities: Contingent consideration - acquisitions $ 2,593 $ — $ — $ 2,593 Total liabilities $ 2,593 $ — $ — $ 2,593 The Company’s available-for-sale debt securities classified as Level 1 are based on quoted market prices that are available in active markets. The Company’s available-for-sale debt securities classified as Level 2 are valued using observable inputs to quoted market prices, benchmark yields, reported trades, broker/dealer quotes or alternative pricing sources with reasonable levels of price transparency. The foreign currency forward exchange contracts are primarily measured based on the foreign currency spot and forward rates quoted by the banks or foreign currency dealers. Investment prices are obtained from third party pricing providers, which model prices utilizing the above observable inputs, for each asset class. Level 3 liabilities consisted of contingent consideration related to an acquisition for which the Company uses a discounted cash flow model to value these liabilities. The Level 3 assumptions used in the discounted cash flow model for the contingent consideration included projected revenue, timing of cash flows and estimates of discount rates of 9.4% and 8.6% for the three months ended March 31, 2018 and 2017, respectively. A significant decrease in the projected revenue or increase in discount rates could result in a significantly lower fair value measurement for the contingent consideration. This table presents a reconciliation of all liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) for the three months ended March 31, 2018: Fair Value Measurements Using Significant Unobservable Inputs (Level 3) Balance at December 31, 2017 $ 2,593 Additions — Total loss included in selling, general and administrative expense 318 Payments — Transfers into (out of) Level 3 — Balance at March 31, 2018 $ 2,911 See Note 4 for additional discussion regarding the fair value of the Company’s marketable securities. Fair Value of Other Financial Instruments The carrying value of cash and cash equivalents, accounts receivable, accounts payable and accrued liabilities approximates fair value because of the short-term maturity of these instruments. The estimated fair value of these obligations is based, primarily, on a market approach, comparing the Company’s interest rates to those rates the Company believes it would reasonably receive upon re-entry into the market. Judgment is required to estimate the fair value, using available market information and appropriate valuation methods.

Marketable Securities

Marketable Securities	3 Months Ended
	Mar. 31, 2018
Marketable Securities [Abstract]
Marketable Securities	NOTE 4. Marketable Securities The Company has evaluated its investment policies and has determined that all of its marketable securities, which is comprised of debt securities, are to be classified as available-for-sale. The Company’s available-for-sale debt securities are carried at fair value, with the unrealized gains and losses reported in Stockholders’ equity under the caption “Accumulated other comprehensive loss.” Realized gains and losses on available-for-sale debt securities are included in “Other expense” in the Condensed Consolidated Statements of Operations. The Company records other-than-temporary impairment charges for its available-for-sale debt securities when it intends to sell the securities, it is more-likely-than not that it will be required to sell the securities before a recovery, or when it does not expect to recover the entire amortized cost basis of the securities. The cost of securities sold is based on the specific identification method. The Company has determined that the gross unrealized losses on its marketable securities at March 31, 2018 and December 31, 2017 are temporary in nature. The Company reviews its investment portfolio to identify and evaluate marketable securities that have indications of possible impairment. Factors considered in determining whether a loss is other-than-temporary include the length of time and extent to which fair value has been less than the cost basis, credit quality and the Company’s ability and intent to hold the securities for a period of time sufficient to allow for any anticipated recovery in market value. At March 31, 2018 and December 31, 2017, marketable securities are categorized as follows: Amortized Cost Gross Unrealized Holding Gains Gross Unrealized Holding Losses Fair Value March 31, 2018 Municipal notes and bonds $ 110,211 $ 1 $ 138 $ 110,074 Corporate bond 2,192 — — 2,192 Total marketable securities $ 112,403 $ 1 $ 138 $ 112,266 December 31, 2017 Municipal notes and bonds $ 109,750 $ — $ 161 $ 109,589 Total marketable securities $ 109,750 $ — $ 161 $ 109,589 The amortized cost and estimated fair value of marketable securities classified by the maturity date listed on the security, regardless of the Condensed Consolidated Balance Sheet classification, is as follows at March 31, 2018 and December 31, 2017: March 31, 2018 December 31, 2017 Amortized Cost Fair Value Amortized Cost Fair Value Due within one year $ 99,714 $ 99,609 $ 104,742 $ 104,605 Due after one through five years 12,689 12,657 5,008 4,984 Due after five through ten years — — — — Due after ten years — — — — Total marketable securities $ 112,403 $ 112,266 $ 109,750 $ 109,589 The following table summarizes the estimated fair value and gross unrealized holding losses of marketable securities, aggregated by investment instrument and period of time in an unrealized loss position at March 31, 2018 and December 31, 2017: Unrealized Loss Position For Less Than 12 Months Unrealized Loss Position For Greater Than 12 Months Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses March 31, 2018 Municipal notes and bonds $ 98,376 $ 138 $ — $ — Total $ 98,376 $ 138 $ — $ — December 31, 2017 Municipal notes and bonds $ 98,805 $ 161 $ — $ — Total $ 98,805 $ 161 $ — $ — See Note 2 for additional discussion regarding the fair value of the Company’s marketable securities.

Derivative Instruments and Hedg

Derivative Instruments and Hedging Activities	3 Months Ended
	Mar. 31, 2018
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Derivative Instruments and Hedging Activities	NOTE 5. Derivative Instruments and Hedging Activities The Company, when it considers it to be appropriate, enters into forward exchange contracts to hedge the economic exposures arising from foreign currency denominated transactions. At March 31, 2018 and December 31, 2017, these contracts included the future sale of Japanese Yen to purchase U.S. dollars. Derivative instruments are recognized as either, “Prepaid expenses and other current assets” or “Other current liabilities” in the Condensed Consolidated Balance Sheets and are measured at fair value. The foreign currency forward exchange contracts were entered into by the Company’s Japanese subsidiary to economically hedge a portion of certain intercompany obligations. The forward exchange contracts are not designated as hedges for accounting purposes and decreases in the fair value of $433 and $250 for the three months ended March 31, 2018 and 2017, respectively, are recorded within the caption “Other expense (income)” in the Condensed Consolidated Statements of Operations. The dollar equivalent of the U.S. dollar forward exchange contracts and related fair values as of March 31, 2018 and December 31, 2017 were as follows: March 31, 2018 December 31, 2017 Notional amount $ 8,181 $ 8,417 Fair value of asset (liability) $ (388 ) $ 45

Purchased Intangible Assets

Purchased Intangible Assets	3 Months Ended
	Mar. 31, 2018
Purchased Intangible Assets [Abstract]
Purchased Intangible Assets	NOTE 6. Purchased Intangible Assets Purchased intangible assets as of March 31, 2018 and December 31, 2017 are as follows: Gross Carrying Amount Accumulated Amortization Net March 31, 2018 Finite-lived intangibles: Developed technology $ 65,927 $ 58,812 $ 7,115 Customer and distributor relationships 9,560 8,883 677 Trade names 4,361 3,801 560 Total identifiable intangible assets $ 79,848 $ 71,496 $ 8,352 December 31, 2017 Finite-lived intangibles: Developed technology $ 65,827 $ 58,522 $ 7,305 Customer and distributor relationships 9,560 8,818 742 Trade names 4,361 3,776 585 Total identifiable intangible assets $ 79,748 $ 71,116 $ 8,632 Intangible asset amortization expenses for the three months ended March 31, 2018 and 2017 were $380 and $505, respectively. Assuming no change in the gross carrying value of identifiable intangible assets and estimated lives, estimated amortization expense for the remainder of 2018 will be $1,146, and for each of the next five years estimated amortization expense amounts to $1,527 for 2019, $1,325 for 2020, $577 for 2021, $511 for 2022, and $494 for 2023.

Balance Sheet Details

Balance Sheet Details	3 Months Ended
	Mar. 31, 2018
Balance Sheet Detail [Abstract]
Balance Sheet Details	NOTE 7. Balance Sheet Details Inventories Inventories are comprised of the following: March 31, 2018 December 31, 2017 Materials $ 47,404 $ 39,765 Work-in-process 23,612 20,923 Finished goods 8,747 6,833 Total inventories $ 79,763 $ 67,521 The Company has established reserves of $13,161 and $13,035 as of March 31, 2018 and December 31, 2017, respectively, for slow moving and obsolete inventory, which are included in the amounts above. Property, Plant and Equipment Property, plant and equipment, net is comprised of the following: March 31, 2018 December 31, 2017 Land and building $ 2,584 $ 2,584 Machinery and equipment 29,789 29,870 Furniture and fixtures 3,143 3,201 Computer equipment and software 5,846 5,444 Leasehold improvements 9,346 9,472 50,708 50,571 Accumulated depreciation (33,210 ) (33,229 ) Total property, plant and equipment, net $ 17,498 $ 17,342 Other assets Other assets is comprised of the following: March 31, 2018 December 31, 2017 Deferred income taxes $ 14,879 $ 14,879 Other 506 492 Total other assets $ 15,385 $ 15,371 Other current liabilities Other current liabilities is comprised of the following: March 31, 2018 December 31, 2017 Intangible asset acquisition - Stella Alliance $ 200 $ 100 Contingent consideration - acquisitions 794 634 Customer deposits 2,347 5,561 Other 5,675 2,989 Total other current liabilities $ 9,016 $ 9,284 Other non-current liabilities Other non-current liabilities is comprised of the following: March 31, 2018 December 31, 2017 Unrecognized tax benefits (including interest) $ 4,694 $ 4,660 Contingent consideration - acquisitions 2,117 1,959 Deferred revenue 876 983 Other 3,207 2,859 Total other non-current liabilities $ 10,894 $ 10,461

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2018
Commitments And Contingencies [Abstract]
Commitments and Contingencies	NOTE 8. Commitments and Contingencies Intellectual Property Indemnification Obligations The Company has entered into agreements with customers that include limited intellectual property indemnification obligations that are customary in the industry. These guarantees generally require the Company to compensate the other party for certain damages and costs incurred as a result of third party intellectual property claims arising from these transactions. The nature of the intellectual property indemnification obligations prevents the Company from making a reasonable estimate of the maximum potential amount it could be required to pay to its customers. Historically, the Company has not made any indemnification payments under such agreements and no amount has been accrued in the accompanying consolidated financial statements with respect to these indemnification guarantees. Warranty Reserves The Company generally provides a warranty on its products for a period of 12 to 15 months against defects in material and workmanship. The Company estimates the costs that may be incurred during the warranty period and records a liability in the amount of such costs at the time revenue is recognized. The Company’s estimate is based primarily on historical experience. The Company periodically assesses the adequacy of its recorded warranty liabilities and adjusts the amounts as necessary. Settlements of warranty reserves are generally associated with sales that occurred during the 12 to 15 months prior to the quarter-end and warranty accruals are related to sales during the same year. Changes in the Company’s warranty reserves are as follows: Three Months Ended March 31, 2018 2017 Balance, beginning of the period $ 2,427 $ 1,788 Accruals 959 855 Usage (820 ) (648 ) Balance, end of the period $ 2,566 $ 1,995 Warranty reserves are reported in the Condensed Consolidated Balance Sheets within the caption “Accounts payable and accrued liabilities.” Legal Matters From time to time, the Company is subject to legal proceedings and claims in the ordinary course of business. There are no legal proceedings pending or threatened against the Company that management believes are likely to have a material adverse effect on the Company’s consolidated financial position or otherwise. Line of Credit The Company has a credit agreement with a bank that provides for a line of credit which is secured by the marketable securities the Company has with the bank. The Company is permitted to borrow up to 70% of the value of eligible securities held at the time the line of credit is accessed. The available line of credit as of March 31, 2018 was approximately $99 million with an available interest rate of 3.3%. The credit agreement is available to the Company until such time that either party terminates the arrangement at their discretion. The Company has not utilized the line of credit to date.

Share-Based Compensation

Share-Based Compensation	3 Months Ended
	Mar. 31, 2018
Share Based Compensation [Abstract]
Share-Based Compensation	NOTE 9. Share-Based Compensation Restricted Stock Unit Activity A summary of the activity with respect to the Company’s nonvested restricted stock units during the three months ended March 31, 2018 is as follows: Number of Shares Weighted Average Grant Date Fair Value Nonvested at December 31, 2017 1,014 $ 14.88 Granted 109 $ 27.36 Vested (159 ) $ 12.52 Forfeited (7 ) $ 13.37 Nonvested at March 31, 2018 957 $ 16.71 Included in the number of shares granted in the table directly above are 53 market performance-based restricted stock units (MPRSUs) granted to executives for 2018. Vesting of these MPRSUs is contingent upon the Company meeting certain total shareholder return (TSR) levels as compared to a select peer group over three years from the year granted. The 2018 MPRSUs cliff vest at the end of the three-year period and have a maximum potential to vest at 200% (105 shares) based on TSR performance. The related share-based compensation expense is determined based on the estimated fair value of the underlying shares on the date of grant and is recognized straight-line over the vesting term. The estimated fair value per share of the MPRSUs was $30.76. As of March 31, 2018 and December 31, 2017, there was $10,791 and $9,420 of total unrecognized compensation cost related to restricted stock units granted under the Company’s stock plans, respectively. That cost is expected to be recognized over a weighted average period of 2.2 years for each of the respective periods.

Other Expense

Other Expense	3 Months Ended
	Mar. 31, 2018
Other Income Expense [Abstract]
Other Expense	NOTE 10. Other Expense Other expense is comprised of the following: Three Months Ended March 31, 2018 2017 Foreign currency exchange losses (gains), net $ 183 $ 269 Rental income (1 ) — Total other expense $ 182 $ 269

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2018
Income Taxes [Abstract]
Income Taxes	NOTE 11. Income Taxes The following table provides details of income taxes: Three Months Ended March 31, 2018 2017 Income before income taxes $ 17,674 $ 9,607 Provision for income taxes $ 2,544 $ 2,456 Effective tax rate 14.4 % 25.6 % The income tax provision for the three months ended March 31, 2018 was computed based on the Company’s annual forecast of profit by jurisdiction and forecasted effective tax rate for the year. The changes in the Company’s effective tax rate for the three months ended March 31, 2018 as compared to the same period in 2017 are primarily due to enactment of U.S. tax reform, which provides for a change in the corporate tax rate from 35% to 21%, changes in the mix of forecasted earnings by jurisdictions and the Foreign Derived Intangible Income Deduction. The 2017 Tax Act was enacted on December 22, 2017. The 2017 Tax Act reduces the U.S. federal corporate income tax rate from 35% to 21%, requires companies to pay a one-time transition tax on earnings of certain foreign subsidiaries that were previously tax deferred and creates new taxes on certain foreign sourced earnings. The Company is applying the guidance in SAB 118 when accounting for the enactment-date effects of the 2017 Tax Act. At March 31, 2018, the Company has not completed its accounting for all of the tax effects of the 2017 Tax Act. In all cases, the Company will continue to make and refine its calculations as additional analysis is completed. The Company’s estimates may also be affected as it gains a more thorough understanding of the 2017 Tax Act. These changes could be material to income tax expense. Foreign-Derived Intangible Income: The 2017 Tax Act provides tax incentives to U.S. companies to earn income from the sale, lease or license of goods and services abroad in the form of a deduction for foreign-derived intangible income (“FDII”). FDII is taxed at an effective rate of 13.1% for taxable years beginning after December 31, 2017 and at an effective rate of 16.4% for taxable years beginning after December 31, 2025. The accounting for the deduction for FDII is similar to a special deduction and should be accounted for based on the guidance in ASC 740-10-25-37. The tax benefits for special deductions ordinarily are recognized no earlier than the year in which they are deductible on the tax return. As of March 31, 2018, the Company has made sufficient progress in its calculations to reasonably estimate the effect on its estimated annual effective tax rate. Due to the large portions of its sales being made to non-U.S. customers this adjustment decreased its effective tax rate by 4.8%. The Company will continue to refine its calculations, which may result in changes to this amount. The Company does not expect other provisions of the 2017 Tax Act, including global intangible low-taxed income (“GILTI”), the new interest expense limitations and base erosion anti-abuse tax (“BEAT”) to have a material impact on the Company’s effective tax rate. Deferred Tax Assets and Liabilities: The Company remeasured certain deferred tax assets and liabilities based on the rate to which they are expected to reverse to in the future, which is anticipated to be 21%. The Company recorded a provisional amount of $8.0 million as of December 31, 2017 related to the remeasurement of certain deferred tax balances. Due to the continued refinement of its transition tax calculation, discussed further below, and the effect it may have on the measurement of NOLs and other carryforwards, it will continue to analyze and refine its calculations related to the measurement of these balances. One-Time Transition Tax: The one-time transition tax is based on its total post-1986 earnings and profits (“E&P”), which it has deferred from U.S. income taxes under previous U.S. law. The Company originally recorded a provisional amount for its one-time transition tax liability for all of its foreign subsidiaries, resulting in a transition tax benefit (net of foreign tax credits) of $0.1 million being recorded at December 31, 2017. As it continues to refine its E&P analysis, the Company will refine its calculations of the one-time transition tax, which could affect the measurement of this liability. No additional income taxes have been provided for any remaining undistributed foreign earnings not subject to the transition tax, or any additional outside basis difference inherent in these entities, as these amounts continue to be indefinitely reinvested in foreign operations. The Company currently has a partial valuation allowance recorded against certain foreign and state net operating loss and credit carryforwards where the realizability of such deferred tax assets is substantially in doubt. Each quarter, the Company assesses the likelihood that it will be able to recover its deferred tax assets. The Company considers available evidence, both positive and negative, including forecasted earnings in assessing the need for a valuation allowance. As a result of the Company’s analysis, it concluded that it is more likely than not that a portion of its deferred tax assets will not be realized. Therefore, the Company continues to provide a valuation allowance against certain deferred tax assets. The Company continues to monitor available evidence and may reverse some or all of the remaining valuation allowance in future periods, if appropriate. The Company has a recorded valuation allowance against certain of its deferred tax assets of $2,447 as of March 31, 2018 and December 31, 2017.

Earnings Per Share

Earnings Per Share	3 Months Ended
	Mar. 31, 2018
Earnings Loss Per Share [Abstract]
Earnings Per Share	NOTE 12. Earnings Per Share Basic earnings per share is calculated using the weighted average number of shares of common stock outstanding during the period. Diluted earnings per share is computed in the same manner and also gives effect to all dilutive common equivalent shares outstanding during the period. Potential common shares that would have the effect of increasing diluted earnings per share are considered to be anti-dilutive. In accordance with U.S. GAAP, these shares were not included in calculating diluted earnings per share. The following table sets forth the weighted average number of stock options and restricted stock units that have been excluded from the calculation of diluted earnings per share as their effect would have been antidilutive: Three Months Ended March 31, 2018 2017 Stock options — — Restricted stock units 33 25 Total 33 25 The Company’s basic and diluted earnings per share amounts are as follows: Three Months Ended March 31, 2018 2017 Numerator: Net income $ 15,130 $ 7,151 Denominator: Basic earnings per share - weighted average shares outstanding 31,662 31,290 Effect of potential dilutive securities: Employee stock options and restricted stock units - dilutive shares 655 762 Warrant - dilutive shares — 6 Diluted earnings per share - weighted average shares outstanding 32,317 32,058 Earnings per share: Basic $ 0.48 $ 0.23 Diluted $ 0.47 $ 0.22

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss	3 Months Ended
	Mar. 31, 2018
Accumulated Other Comprehensive Loss [Abstract]
Accumulated Other Comprehensive Loss	NOTE 13. Accumulated Other Comprehensive Loss Comprehensive income includes net income, foreign currency translation adjustments, and net unrealized gains and losses on available-for-sale debt securities. See the Condensed Consolidated Statements of Comprehensive Income for the effect of the components of comprehensive income on the Company’s net income. The components of accumulated other comprehensive loss, net of tax, are as follows: Foreign currency translation adjustments Net unrealized (gains) losses on marketable securities Accumulated other comprehensive loss (income) Beginning Balance, December 31, 2017 $ 1,079 $ 126 $ 1,205 Net current period other comprehensive income (632 ) (23 ) (655 ) Reclassifications — — — Ending balance, March 31, 2018 $ 447 $ 103 $ 550

Segment Reporting and Geographi

Segment Reporting and Geographic Information	3 Months Ended
	Mar. 31, 2018
Segment Reporting And Geographic Information [Abstract]
Segment Reporting and Geographic Information	NOTE 14. Segment Reporting and Geographic Information The Company is engaged in the design, development, manufacture and support of high-performance control metrology, defect inspection, advanced packaging lithography and data analysis systems used by microelectronics device manufacturers. The Company and its subsidiaries currently operate in a single operating segment: the design, development, manufacture and support of high-performance process control defect inspection and metrology, advanced packaging lithography, and process control software systems used by microelectronics device manufacturers, and therefore the Company has one reportable segment. The Company’s chief operating decision maker is the Chief Executive Officer. The chief operating decision maker allocates resources and assesses performance of the business and other activities at the reporting segment level. The following table lists the different sources of revenue: Three Months Ended March 31, 2018 2017 Systems and Software: Process control $ 48,033 66 % $ 43,876 72 % Lithography 8,069 11 % 17 — % Software licensing, support and maintenance 7,455 10 % 7,498 13 % Parts 6,985 10 % 6,330 10 % Services 2,554 3 % 2,958 5 % Total revenue $ 73,096 100 % $ 60,679 100 % For geographical revenue reporting, revenue is attributed to the geographic location in which the product is shipped. Revenue by geographic region is as follows: Three Months Ended March 31 2018 2017 Revenue from third parties: United States $ 9,068 $ 9,009 Taiwan 14,467 13,833 Japan 4,130 3,208 China 17,971 14,101 South Korea 17,230 9,530 Singapore 4,282 3,266 Other Asia 1,917 114 Germany 1,324 3,080 Other Europe 2,707 4,538 Total revenue $ 73,096 $ 60,679 The following customer accounted for more than 10% of total revenue for the indicated periods. Three Months Ended March 31, 2018 2017 Customer A 14.2 % 17.2 % Customer B 11.2 % — %

Share Repurchase Authorization

Share Repurchase Authorization	3 Months Ended
	Mar. 31, 2018
Share Repurchase Program [Abstract]
Share Repurchase Authorization	NOTE 15. Share Repurchase Authorization In January 2015, the Board of Directors authorized the Company to repurchase up to 3,000 shares of the Company’s common stock with no established end date. The authorization allows for repurchases to be made in the open market or through negotiated transactions from time to time. During the three months ended March 31, 2018, the Company did not repurchase any shares of common stock pursuant to the share repurchase authorization. At March 31, 2018, there were 711 shares available for future stock repurchases under this share repurchase authorization. Shares of common stock purchased under the share repurchase authorization are retired.

Revenue (Tables)

Revenue (Tables)	3 Months Ended
	Mar. 31, 2018
Revenue Recognition [Abstract]
Schedule of Disaggregation of Revenue	The following table presents the Company’s revenue disaggregated by revenue source (in thousands, unaudited): Three Months Ended March 31, 2018 2017 Systems $ 56,102 $ 43,893 Software licensing, support and maintenance 7,455 7,498 Parts 6,985 6,330 Services 2,554 2,958 Total revenue $ 73,096 $ 60,679 The following table represents a disaggregation of revenue by timing of revenue: Three Months Ended March 31, 2018 Point in time $ 69,396 Over time 3,700 Total revenue $ 73,096
Schedule of Changes in Deferred Revenue	Changes in deferred revenue were as follows: Three Months Ended March 31, 2018 Beginning Balance, December 31, 2017 $ 7,206 Deferral of revenue 4,553 Recognition of deferred revenue (2,986 ) Ending Balance, March 31, 2018 $ 8,773

Fair Value Measurements - (Tabl

Fair Value Measurements - (Tables)	3 Months Ended
	Mar. 31, 2018
Fair Value Measurements [Abstract]
Fair Value Measurements, Recurring and Nonrecurring	The following tables provide the assets and liabilities carried at fair value measured on a recurring basis at March 31, 2018 and December 31, 2017: Fair Value Measurements Using Carrying Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) March 31, 2018 Assets: Available-for-sale debt securities: Municipal notes and bonds $ 110,074 $ — $ 110,074 $ — Corporate bonds 2,192 — 2,192 — Total assets $ 112,266 $ — $ 112,266 $ — Liabilities: Contingent consideration - acquisitions $ 2,911 $ — $ — $ 2,911 Foreign currency forward exchange contracts 388 — 388 — Total liabilities $ 3,299 $ — $ 388 $ 2,911 December 31, 2017 Assets: Available-for-sale debt securities: Municipal notes and bonds $ 109,589 $ — $ 109,589 $ — Foreign currency forward exchange contracts 45 — 45 — Total assets $ 109,634 $ — $ 109,634 $ — Liabilities: Contingent consideration - acquisitions $ 2,593 $ — $ — $ 2,593 Total liabilities $ 2,593 $ — $ — $ 2,593
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]	This table presents a reconciliation of all liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) for the three months ended March 31, 2018: Fair Value Measurements Using Significant Unobservable Inputs (Level 3) Balance at December 31, 2017 $ 2,593 Additions — Total loss included in selling, general and administrative expense 318 Payments — Transfers into (out of) Level 3 — Balance at March 31, 2018 $ 2,911

Marketable Securities - (Tables

Marketable Securities - (Tables)	3 Months Ended
	Mar. 31, 2018
Marketable Securities [Abstract]
Schedule of Marketable Securities by Category	At March 31, 2018 and December 31, 2017, marketable securities are categorized as follows: Amortized Cost Gross Unrealized Holding Gains Gross Unrealized Holding Losses Fair Value March 31, 2018 Municipal notes and bonds $ 110,211 $ 1 $ 138 $ 110,074 Corporate bond 2,192 — — 2,192 Total marketable securities $ 112,403 $ 1 $ 138 $ 112,266 December 31, 2017 Municipal notes and bonds $ 109,750 $ — $ 161 $ 109,589 Total marketable securities $ 109,750 $ — $ 161 $ 109,589
Schedule of Amortized Cost and Estimated Fair Value of Marketable Securities Classified by Maturity Date	The amortized cost and estimated fair value of marketable securities classified by the maturity date listed on the security, regardless of the Condensed Consolidated Balance Sheet classification, is as follows at March 31, 2018 and December 31, 2017: March 31, 2018 December 31, 2017 Amortized Cost Fair Value Amortized Cost Fair Value Due within one year $ 99,714 $ 99,609 $ 104,742 $ 104,605 Due after one through five years 12,689 12,657 5,008 4,984 Due after five through ten years — — — — Due after ten years — — — — Total marketable securities $ 112,403 $ 112,266 $ 109,750 $ 109,589
Summary of Estimated Fair Value and Gross Unrealized Holding Losses of Marketable Securities in Unrealized Loss Position	The following table summarizes the estimated fair value and gross unrealized holding losses of marketable securities, aggregated by investment instrument and period of time in an unrealized loss position at March 31, 2018 and December 31, 2017: Unrealized Loss Position For Less Than 12 Months Unrealized Loss Position For Greater Than 12 Months Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses March 31, 2018 Municipal notes and bonds $ 98,376 $ 138 $ — $ — Total $ 98,376 $ 138 $ — $ — December 31, 2017 Municipal notes and bonds $ 98,805 $ 161 $ — $ — Total $ 98,805 $ 161 $ — $ —

Derivative Instruments and He25

Derivative Instruments and Hedging Activities (Tables)	3 Months Ended
	Mar. 31, 2018
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Forward Contracts and Related Fair Values	The dollar equivalent of the U.S. dollar forward exchange contracts and related fair values as of March 31, 2018 and December 31, 2017 were as follows: March 31, 2018 December 31, 2017 Notional amount $ 8,181 $ 8,417 Fair value of asset (liability) $ (388 ) $ 45

Purchased Intangible Assets - (

Purchased Intangible Assets - (Tables)	3 Months Ended
	Mar. 31, 2018
Purchased Intangible Assets [Abstract]
Schedule of Purchased Intangible Assets	Purchased intangible assets as of March 31, 2018 and December 31, 2017 are as follows: Gross Carrying Amount Accumulated Amortization Net March 31, 2018 Finite-lived intangibles: Developed technology $ 65,927 $ 58,812 $ 7,115 Customer and distributor relationships 9,560 8,883 677 Trade names 4,361 3,801 560 Total identifiable intangible assets $ 79,848 $ 71,496 $ 8,352 December 31, 2017 Finite-lived intangibles: Developed technology $ 65,827 $ 58,522 $ 7,305 Customer and distributor relationships 9,560 8,818 742 Trade names 4,361 3,776 585 Total identifiable intangible assets $ 79,748 $ 71,116 $ 8,632

Balance Sheet Details (Tables)

Balance Sheet Details (Tables)	3 Months Ended
	Mar. 31, 2018
Balance Sheet Detail [Abstract]
Schedule of Inventories	Inventories are comprised of the following: March 31, 2018 December 31, 2017 Materials $ 47,404 $ 39,765 Work-in-process 23,612 20,923 Finished goods 8,747 6,833 Total inventories $ 79,763 $ 67,521
Schedule of Property, Plant and Equipment, Net	Property, plant and equipment, net is comprised of the following: March 31, 2018 December 31, 2017 Land and building $ 2,584 $ 2,584 Machinery and equipment 29,789 29,870 Furniture and fixtures 3,143 3,201 Computer equipment and software 5,846 5,444 Leasehold improvements 9,346 9,472 50,708 50,571 Accumulated depreciation (33,210 ) (33,229 ) Total property, plant and equipment, net $ 17,498 $ 17,342
Schedule of Other Assets	Other assets is comprised of the following: March 31, 2018 December 31, 2017 Deferred income taxes $ 14,879 $ 14,879 Other 506 492 Total other assets $ 15,385 $ 15,371
Schedule of Other Current Liabilities	Other current liabilities is comprised of the following: March 31, 2018 December 31, 2017 Intangible asset acquisition - Stella Alliance $ 200 $ 100 Contingent consideration - acquisitions 794 634 Customer deposits 2,347 5,561 Other 5,675 2,989 Total other current liabilities $ 9,016 $ 9,284
Schedule of Other Non-Current Liabilities	Other non-current liabilities is comprised of the following: March 31, 2018 December 31, 2017 Unrecognized tax benefits (including interest) $ 4,694 $ 4,660 Contingent consideration - acquisitions 2,117 1,959 Deferred revenue 876 983 Other 3,207 2,859 Total other non-current liabilities $ 10,894 $ 10,461

Commitments and Contingencies (

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2018
Commitments And Contingencies [Abstract]
Schedule of Changes in Warranty Reserves	Changes in the Company’s warranty reserves are as follows: Three Months Ended March 31, 2018 2017 Balance, beginning of the period $ 2,427 $ 1,788 Accruals 959 855 Usage (820 ) (648 ) Balance, end of the period $ 2,566 $ 1,995

Share-Based Compensation - (Tab

Share-Based Compensation - (Tables)	3 Months Ended
	Mar. 31, 2018
Share Based Compensation [Abstract]
Summary of Nonvested Restricted Stock Unit Activity	A summary of the activity with respect to the Company’s nonvested restricted stock units during the three months ended March 31, 2018 is as follows: Number of Shares Weighted Average Grant Date Fair Value Nonvested at December 31, 2017 1,014 $ 14.88 Granted 109 $ 27.36 Vested (159 ) $ 12.52 Forfeited (7 ) $ 13.37 Nonvested at March 31, 2018 957 $ 16.71

Other Expense (Tables)

Other Expense (Tables)	3 Months Ended
	Mar. 31, 2018
Other Income Expense [Abstract]
Schedule of Other Expense	Three Months Ended March 31, 2018 2017 Foreign currency exchange losses (gains), net $ 183 $ 269 Rental income (1 ) — Total other expense $ 182 $ 269

Income Taxes - (Tables)

Income Taxes - (Tables)	3 Months Ended
	Mar. 31, 2018
Income Taxes [Abstract]
Schedule of Effective Tax Rate	The following table provides details of income taxes: Three Months Ended March 31, 2018 2017 Income before income taxes $ 17,674 $ 9,607 Provision for income taxes $ 2,544 $ 2,456 Effective tax rate 14.4 % 25.6 %

Earnings Per Share - (Tables)

Earnings Per Share - (Tables)	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	The following table sets forth the weighted average number of stock options and restricted stock units that have been excluded from the calculation of diluted earnings per share as their effect would have been antidilutive: Three Months Ended March 31, 2018 2017 Stock options — — Restricted stock units 33 25 Total 33 25
Schedule of Earnings Per Share, Basic and Diluted	The Company’s basic and diluted earnings per share amounts are as follows: Three Months Ended March 31, 2018 2017 Numerator: Net income $ 15,130 $ 7,151 Denominator: Basic earnings per share - weighted average shares outstanding 31,662 31,290 Effect of potential dilutive securities: Employee stock options and restricted stock units - dilutive shares 655 762 Warrant - dilutive shares — 6 Diluted earnings per share - weighted average shares outstanding 32,317 32,058 Earnings per share: Basic $ 0.48 $ 0.23 Diluted $ 0.47 $ 0.22

Accumulated Other Comprehensi33

Accumulated Other Comprehensive Loss (Tables)	3 Months Ended
	Mar. 31, 2018
Accumulated Other Comprehensive Loss [Abstract]
Components of Accumulated Other Comprehensive Loss, Net of Tax	The components of accumulated other comprehensive loss, net of tax, are as follows: Foreign currency translation adjustments Net unrealized (gains) losses on marketable securities Accumulated other comprehensive loss (income) Beginning Balance, December 31, 2017 $ 1,079 $ 126 $ 1,205 Net current period other comprehensive income (632 ) (23 ) (655 ) Reclassifications — — — Ending balance, March 31, 2018 $ 447 $ 103 $ 550

Segment Reporting and Geograp34

Segment Reporting and Geographic Information - (Tables)	3 Months Ended
	Mar. 31, 2018
Segment Reporting And Geographic Information [Abstract]
Schedule of Revenue from External Customers by Products and Services	The following table lists the different sources of revenue: Three Months Ended March 31, 2018 2017 Systems and Software: Process control $ 48,033 66 % $ 43,876 72 % Lithography 8,069 11 % 17 — % Software licensing, support and maintenance 7,455 10 % 7,498 13 % Parts 6,985 10 % 6,330 10 % Services 2,554 3 % 2,958 5 % Total revenue $ 73,096 100 % $ 60,679 100 %
Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area	For geographical revenue reporting, revenue is attributed to the geographic location in which the product is shipped. Revenue by geographic region is as follows: Three Months Ended March 31 2018 2017 Revenue from third parties: United States $ 9,068 $ 9,009 Taiwan 14,467 13,833 Japan 4,130 3,208 China 17,971 14,101 South Korea 17,230 9,530 Singapore 4,282 3,266 Other Asia 1,917 114 Germany 1,324 3,080 Other Europe 2,707 4,538 Total revenue $ 73,096 $ 60,679
Schedule of Revenue by Major Customers by Reporting Segments	The following customer accounted for more than 10% of total revenue for the indicated periods. Three Months Ended March 31, 2018 2017 Customer A 14.2 % 17.2 % Customer B 11.2 % — %

Revenue - Schedule of Disaggreg

Revenue - Schedule of Disaggregation of Revenue by Revenue Source (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Disaggregation Of Revenue [Line Items]
Total revenue	$ 73,096	$ 60,679
Systems Revenue [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	56,102	43,893
Software Revenue
Disaggregation Of Revenue [Line Items]
Total revenue	7,455	7,498
Parts Revenue
Disaggregation Of Revenue [Line Items]
Total revenue	6,985	6,330
Service Revenue
Disaggregation Of Revenue [Line Items]
Total revenue	$ 2,554	$ 2,958

Revenue - Schedule of Disaggr36

Revenue - Schedule of Disaggregation of Revenue by Timing of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Disaggregation Of Revenue [Line Items]
Total revenue	$ 73,096	$ 60,679
Transferred at Point in Time
Disaggregation Of Revenue [Line Items]
Total revenue	69,396
Transferred over Time
Disaggregation Of Revenue [Line Items]
Total revenue	$ 3,700

Revenue - Additional Informatio

Revenue - Additional Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)
Disaggregation Of Revenue [Line Items]
Beginning Balance, December 31, 2017	$ 7,206
Systems Revenue [Member]
Disaggregation Of Revenue [Line Items]
Number of days for payment due from customer	30 days
Software Revenue
Disaggregation Of Revenue [Line Items]
Number of days for payment due from customer	30 days
Parts Revenue
Disaggregation Of Revenue [Line Items]
Number of days for payment due from customer	30 days
Service Revenue
Disaggregation Of Revenue [Line Items]
Number of days for payment due from customer	30 days
Minimum [Member] | Systems Revenue [Member]
Disaggregation Of Revenue [Line Items]
Percentage of invoice amount due	80.00%
Assurance warranty period against defects	12 months
Maximum [Member] | Systems Revenue [Member]
Disaggregation Of Revenue [Line Items]
Percentage of invoice amount due	90.00%
Assurance warranty period against defects	15 months

Revenue - Schedule of Changes i

Revenue - Schedule of Changes in Deferred Revenue (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)
Deferred Revenue Disclosure [Abstract]
Beginning Balance, December 31, 2017	$ 7,206
Deferral of revenue	4,553
Recognition of deferred revenue	(2,986)
Ending Balance, March 31, 2018	$ 8,773

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Assets and Liabilities Carried at Fair Value Measured on a Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Municipal notes and bonds	$ 110,074	$ 109,589
Corporate bonds	2,192
Foreign currency forward exchange contracts		45
Total assets	112,266	109,634
Contingent consideration - acquisitions	2,911	2,593
Foreign currency forward exchange contracts	388
Total liabilities	3,299	2,593
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Municipal notes and bonds	0	0
Corporate bonds	0
Foreign currency forward exchange contracts		0
Total assets	0	0
Contingent consideration - acquisitions	0	0
Foreign currency forward exchange contracts	0
Total liabilities	0	0
Significant Other Observable Inputs (Level 2) [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Municipal notes and bonds	110,074	109,589
Corporate bonds	2,192
Foreign currency forward exchange contracts		45
Total assets	112,266	109,634
Contingent consideration - acquisitions	0	0
Foreign currency forward exchange contracts	388
Total liabilities	388	0
Significant Unobservable Inputs (Level 3) [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Municipal notes and bonds	0	0
Corporate bonds	0
Foreign currency forward exchange contracts		0
Total assets	0	0
Contingent consideration - acquisitions	2,911	2,593
Foreign currency forward exchange contracts	0
Total liabilities	$ 2,911	$ 2,593

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Significant Unobservable Inputs (Level 3) [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Estimated discount rates	9.40%	8.60%

Fair Value Measurements - Recon

Fair Value Measurements - Reconciliation for All Liabilities Measured at Fair Value on Recurring Basis Using Significant Unobservable Inputs (level 3) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)
Fair Value Measurements [Abstract]
Balance at December 31, 2017	$ 2,593
Additions	0
Total loss included in selling, general and administrative expense	318
Payments	0
Transfers into (out of) Level 3	0
Balance at March 31, 2018	$ 2,911

Marketable Securities - Schedul

Marketable Securities - Schedule of Marketable Securities by Category (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 112,403	$ 109,750
Gross Unrealized Holding Gains	1	0
Gross Unrealized Holding Losses	138	161
Fair Value	112,266	109,589
Municipal Notes and Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	110,211	109,750
Gross Unrealized Holding Gains	1	0
Gross Unrealized Holding Losses	138	161
Fair Value	110,074	$ 109,589
Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	2,192
Gross Unrealized Holding Gains	0
Gross Unrealized Holding Losses	0
Fair Value	$ 2,192

Marketable Securities - Sched43

Marketable Securities - Schedule of Amortized Cost and Estimated Fair Value of Marketable Securities Classified by Maturity Date (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Available For Sale Securities Debt Maturities Fair Value [Abstract]
Amortized Cost, Due within one year	$ 99,714	$ 104,742
Amortized Cost, Due after one through five years	12,689	5,008
Amortized Cost, Due after five through ten years	0	0
Amortized Cost, Due after ten years	0	0
Amortized Cost, Total marketable securities	112,403	109,750
Fair Value, Due within one year	99,609	104,605
Fair Value, Due after one through five years	12,657	4,984
Fair Value, Due after five through ten years	0	0
Fair Value, Due after ten years	0	0
Fair Value, Total marketable securities	$ 112,266	$ 109,589

Marketable Securities - Summary

Marketable Securities - Summary of Estimated Fair Value and Gross Unrealized Holding Losses of Marketable Securities in Unrealized Loss Position (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Schedule of Available-for-sale Securities [Line Items]
Unrealized Loss Position For Less Than 12 Months, Fair Value	$ 98,376	$ 98,805
Unrealized Loss Position For Less Than 12 Months, Gross Unrealized Losses	(138)	(161)
Unrealized Loss Position For Greater Than 12 Months, Fair Value	0	0
Unrealized Loss Position For Greater Than 12 Months, Gross Unrealized Losses	0	0
Municipal Notes and Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized Loss Position For Less Than 12 Months, Fair Value	98,376	98,805
Unrealized Loss Position For Less Than 12 Months, Gross Unrealized Losses	(138)	(161)
Unrealized Loss Position For Greater Than 12 Months, Fair Value	0	0
Unrealized Loss Position For Greater Than 12 Months, Gross Unrealized Losses	$ 0	$ 0

Derivative Instruments and He45

Derivative Instruments and Hedging Activities - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Decrease in fair value of forward contracts	$ 433	$ 250

Derivative Instruments and He46

Derivative Instruments and Hedging Activities - Forward Contracts and Related Fair Values (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Notional amount	$ 8,181	$ 8,417
Fair value of asset (liability)	$ (388)	$ 45

Purchased Intangible Assets -47

Purchased Intangible Assets - (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Finite Lived Intangible Assets [Line Items]
Finite-lived intangibles, Gross Carrying Amount	$ 79,848	$ 79,748
Finite-lived intangibles, Accumulated Amortization	71,496	71,116
Finite-lived intangibles, Net	8,352	8,632
Developed Technology [Member]
Finite Lived Intangible Assets [Line Items]
Finite-lived intangibles, Gross Carrying Amount	65,927	65,827
Finite-lived intangibles, Accumulated Amortization	58,812	58,522
Finite-lived intangibles, Net	7,115	7,305
Customer and Distributor Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Finite-lived intangibles, Gross Carrying Amount	9,560	9,560
Finite-lived intangibles, Accumulated Amortization	8,883	8,818
Finite-lived intangibles, Net	677	742
Trade Names [Member]
Finite Lived Intangible Assets [Line Items]
Finite-lived intangibles, Gross Carrying Amount	4,361	4,361
Finite-lived intangibles, Accumulated Amortization	3,801	3,776
Finite-lived intangibles, Net	$ 560	$ 585

Purchased Intangible Assets - A

Purchased Intangible Assets - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Purchased Intangible Assets [Abstract]
Intangible asset amortization expense	$ 380	$ 505
Future amortization expense, Remainder of 2018	1,146
Future amortization expense, 2019	1,527
Future amortization expense, 2020	1,325
Future amortization expense, 2021	577
Future amortization expense, 2022	511
Future amortization expense, 2023	$ 494

Balance Sheet Details - Schedul

Balance Sheet Details - Schedule of Inventories (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Inventory Details [Abstract]
Materials	$ 47,404	$ 39,765
Work-in-process	23,612	20,923
Finished goods	8,747	6,833
Total inventories	$ 79,763	$ 67,521

Balance Sheet Details - Additio

Balance Sheet Details - Additional Information (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Balance Sheet Detail [Abstract]
Inventory valuation reserves	$ 13,161	$ 13,035

Balance Sheet Details - Sched51

Balance Sheet Details - Schedule of Property, Plant and Equipment, Net (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Property Plant And Equipment [Abstract]
Land and building	$ 2,584	$ 2,584
Machinery and equipment	29,789	29,870
Furniture and fixtures	3,143	3,201
Computer equipment and software	5,846	5,444
Leasehold improvements	9,346	9,472
Property, plant and equipment, gross	50,708	50,571
Accumulated depreciation	(33,210)	(33,229)
Total property, plant and equipment, net	$ 17,498	$ 17,342

Balance Sheet Details - Sched52

Balance Sheet Details - Schedule of Other Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Other Assets [Abstract]
Deferred income taxes	$ 14,879	$ 14,879
Other	506	492
Total other assets	$ 15,385	$ 15,371

Balance Sheet Details - Sched53

Balance Sheet Details - Schedule of Other Current Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Other Liabilities Current [Abstract]
Intangible asset acquisition - Stella Alliance	$ 200	$ 100
Contingent consideration - acquisitions	794	634
Customer deposits	2,347	5,561
Other	5,675	2,989
Total other current liabilities	$ 9,016	$ 9,284

Balance Sheet Details - Sched54

Balance Sheet Details - Schedule of Other Non-Current Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Other Liabilities Noncurrent [Abstract]
Unrecognized tax benefits (including interest)	$ 4,694	$ 4,660
Contingent consideration - acquisitions	2,117	1,959
Deferred revenue	876	983
Other	3,207	2,859
Total other non-current liabilities	$ 10,894	$ 10,461

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)
Commitments And Contingencies [Line Items]
Percentage of maximum borrowing capacity of value of eligible securities	70.00%
Available line of credit	$ 99
Available interest rate on line of credit	3.30%
Minimum [Member]
Commitments And Contingencies [Line Items]
Warranty period	12 months
Maximum [Member]
Commitments And Contingencies [Line Items]
Warranty period	15 months

Commitments and Contingencies56

Commitments and Contingencies - Schedule of Changes in Warranty Reserves (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Commitments And Contingencies [Abstract]
Balance, beginning of the period	$ 2,427	$ 1,788
Accruals	959	855
Usage	(820)	(648)
Balance, end of the period	$ 2,566	$ 1,995

Share-Based Compensation - Summ

Share-Based Compensation - Summary of Nonvested Restricted Stock Unit Activity (Details)	3 Months Ended
	Mar. 31, 2018$ / sharesshares
Restricted Stock Units Activity [Abstract]
Number of Shares, Nonvested beginning balance | shares	1,014
Number of Shares, Granted | shares	109
Number of Shares, Vested | shares	(159)
Number of Shares, Forfeited | shares	(7)
Number of Shares, Nonvested ending balance | shares	957
Weighted Average Grant Date Fair Value, Nonvested beginning balance | $ / shares	$ 14.88
Weighted Average Grant Date Fair Value, Granted | $ / shares	27.36
Weighted Average Grant Date Fair Value, Vested | $ / shares	12.52
Weighted Average Grant Date Fair Value, Forfeited | $ / shares	13.37
Weighted Average Grant Date Fair Value, Nonvested ending balance | $ / shares	$ 16.71

Share-Based Compensation - Addi

Share-Based Compensation - Additional Information (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Market performance-based restricted stock units granted	109
Maximum potential market performance-based restricted stock units to vest	105
Estimated fair value per share of the market performance-based restricted stock units	$ 30.76
Maximum potential market performance-based restricted stock units to vest percentage	200.00%
Market performance-based restricted stock units vesting period	3 years
Total unrecognized compensation cost related to restricted stock units granted	$ 10,791	$ 9,420
Unrecognized compensation cost related to restricted stock units, weighted average period	2 years 2 months 12 days	2 years 2 months 12 days
Market Performance Based Restricted Stock Units [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Market performance-based restricted stock units granted	53

Other Expense - Schedule of Oth

Other Expense - Schedule of Other Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Other Income Expense [Abstract]
Foreign currency exchange losses (gains), net	$ 183	$ 269
Rental income	(1)	0
Total other expense	$ 182	$ 269

Income Taxes - Schedule of Effe

Income Taxes - Schedule of Effective Tax Rate (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Taxes [Abstract]
Income before income taxes	$ 17,674	$ 9,607
Provision for income taxes	$ 2,544	$ 2,456
Effective tax rate	14.40%	25.60%

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2025
Income Taxes [Abstract]
Valuation allowance against deferred tax assets	$ 2,447	$ 2,447
Tax cuts and jobs act of 2017, incomplete accounting, change in tax rate, deferred tax assets, provisional income tax benefit		8,000
Transition tax expense		$ 100
Change in effective tax rate due to FDII	4.8
Effective income tax rate reconciliation, at federal statutory income tax rate, percent	21.00%	35.00%
Foreign derived intangible income (FDII) effective tax rate		13.1	16.4

Earnings Per Share - Schedule o

Earnings Per Share - Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share (Details) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Stock options	33	25
Employee Stock Option [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Stock options	0	0
Restricted Stock Units (RSUs) [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Stock options	33	25

Earnings Per Share - Schedule63

Earnings Per Share - Schedule of Earnings Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Earnings Per Share [Abstract]
Net income	$ 15,130	$ 7,151
Basic earnings per share - weighted average shares outstanding	31,662	31,290
Employee stock options and restricted stock units - dilutive shares	655	762
Warrant - dilutive shares	0	6
Diluted earnings per share - weighted average shares outstanding	32,317	32,058
Basic	$ 0.48	$ 0.23
Diluted	$ 0.47	$ 0.22

Accumulated Other Comprehensi64

Accumulated Other Comprehensive Loss - Components of Accumulated Other Comprehensive Loss, Net of Tax (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance, December 31, 2017	$ 333,154
Ending balance, March 31, 2018	349,729
Foreign Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance, December 31, 2017	1,079
Net current period other comprehensive income	(632)
Reclassifications	0
Ending balance, March 31, 2018	447
Net Unrealized (Gains) Losses on Marketable Securities [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance, December 31, 2017	126
Net current period other comprehensive income	(23)
Reclassifications	0
Ending balance, March 31, 2018	103
Accumulated Other Comprehensive Loss (Income) [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance, December 31, 2017	1,205
Net current period other comprehensive income	(655)
Reclassifications	0
Ending balance, March 31, 2018	$ 550

Segment Reporting and Geograp65

Segment Reporting and Geographic Information - Additional Information (Details)	3 Months Ended
	Mar. 31, 2018Segment
Segment Reporting [Abstract]
Number of reportable segments	1

Segment Reporting and Geograp66

Segment Reporting and Geographic Information - Schedule of Revenue from External Customers by Products and Services (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Segment Reporting Information [Line Items]
Revenues	$ 73,096	$ 60,679
Sales [Member] | Product [Member]
Segment Reporting Information [Line Items]
Concentration risk, percentage	100.00%	100.00%
Process Control [Member]
Segment Reporting Information [Line Items]
Revenues	$ 48,033	$ 43,876
Process Control [Member] | Sales [Member] | Product [Member]
Segment Reporting Information [Line Items]
Concentration risk, percentage	66.00%	72.00%
Lithography [Member]
Segment Reporting Information [Line Items]
Revenues	$ 8,069	$ 17
Lithography [Member] | Sales [Member] | Product [Member]
Segment Reporting Information [Line Items]
Concentration risk, percentage	11.00%
Software Revenue
Segment Reporting Information [Line Items]
Revenues	$ 7,455	$ 7,498
Software Revenue | Sales [Member] | Product [Member]
Segment Reporting Information [Line Items]
Concentration risk, percentage	10.00%	13.00%
Parts [Member]
Segment Reporting Information [Line Items]
Revenues	$ 6,985	$ 6,330
Parts [Member] | Sales [Member] | Product [Member]
Segment Reporting Information [Line Items]
Concentration risk, percentage	10.00%	10.00%
Services [Member]
Segment Reporting Information [Line Items]
Revenues	$ 2,554	$ 2,958
Services [Member] | Sales [Member] | Product [Member]
Segment Reporting Information [Line Items]
Concentration risk, percentage	3.00%	5.00%

Segment Reporting and Geograp67

Segment Reporting and Geographic Information - Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Segment Reporting Information [Line Items]
Revenues	$ 73,096	$ 60,679
United States [Member]
Segment Reporting Information [Line Items]
Revenues	9,068	9,009
Taiwan [Member]
Segment Reporting Information [Line Items]
Revenues	14,467	13,833
Japan [Member]
Segment Reporting Information [Line Items]
Revenues	4,130	3,208
China [Member]
Segment Reporting Information [Line Items]
Revenues	17,971	14,101
South Korea [Member]
Segment Reporting Information [Line Items]
Revenues	17,230	9,530
Singapore [Member]
Segment Reporting Information [Line Items]
Revenues	4,282	3,266
Other Asia [Member]
Segment Reporting Information [Line Items]
Revenues	1,917	114
Germany [Member]
Segment Reporting Information [Line Items]
Revenues	1,324	3,080
Other Europe [Member]
Segment Reporting Information [Line Items]
Revenues	$ 2,707	$ 4,538

Segment Reporting and Geograp68

Segment Reporting and Geographic Information - Schedule of Revenue by Major Customers by Reporting Segments (Details) - Sales [Member] - Customer [Member]	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Segment Reporting Information [Line Items]
Entity-wide revenue, major customer, percentage	11.20%
Customer A [Member]
Segment Reporting Information [Line Items]
Entity-wide revenue, major customer, percentage	14.20%	17.20%

Share Repurchase Authorization

Share Repurchase Authorization - Additional Information (Details)	Mar. 31, 2018shares
Share Repurchase Program [Abstract]
Stock Repurchase Program, Number of Shares Authorized to be Repurchased	3,000,000
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased	711,000