Onto Innovation (ONTO) 10-K 3 Mar 17 2016 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Feb. 24, 2017	Jun. 24, 2016
Document And Entity Information [Abstract]
Entity Registrant Name	NANOMETRICS INC
Entity Central Index Key	704,532
Document Type	10-K
Document Period End Date	Dec. 31, 2016
Amendment Flag	false
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	FY
Trading Symbol	NANO
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		25,160,223
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 498.8

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 26, 2015
Current assets:
Cash and cash equivalents	$ 47,062	$ 38,154
Marketable securities	82,899	44,931
Accounts receivable, net of allowances of $73 and $150, respectively	39,457	37,832
Inventories	38,837	47,749
Inventories-delivered systems	2,457	2,856
Prepaid expenses and other	5,667	6,592
Total current assets	216,379	178,114
Property, plant and equipment, net	44,226	44,493
Goodwill	8,940	9,415
Intangible assets, net	412	1,867
Deferred income tax assets	17,399	1,118
Other assets	474	533
Total assets	287,830	235,540
Current liabilities:
Accounts payable	11,342	11,675
Accrued payroll and related expenses	12,656	10,097
Deferred revenue	9,168	12,790
Other current liabilities	8,047	8,878
Income taxes payable	813	1,771
Total current liabilities	42,026	45,211
Deferred revenue	816	827
Income taxes payable	841	775
Deferred tax liability	20	521
Other long-term liabilities	353	878
Total liabilities	44,056	48,212
Commitments and contingencies (Note 11)
Stockholders’ equity:
Preferred stock, $0.001 par value; 3,000,000 shares authorized; no shares issued or outstanding	0	0
Common stock, $0.001 par value, 47,000,000 shares authorized: 25,070,889 and 24,224,286, respectively, issued and outstanding	25	24
Additional paid-in capital	271,969	258,715
Accumulated deficit	(22,174)	(66,209)
Accumulated other comprehensive income	(6,046)	(5,202)
Total stockholders’ equity	243,774	187,328
Total liabilities and stockholders’ equity	$ 287,830	$ 235,540

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 26, 2015
Statement Of Financial Position [Abstract]
Allowances for doubtful accounts	$ 73	$ 150
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized	3,000,000	3,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	47,000,000	47,000,000
Common stock, shares issued	25,070,889	24,224,286
Common stock, shares outstanding	25,070,889	24,224,286

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Net revenues:
Products	$ 185,066	$ 146,945	$ 133,589
Service	36,063	40,422	32,854
Total net revenues	221,129	187,367	166,443
Costs of net revenues:
Cost of products	85,391	76,224	68,812
Cost of service	20,160	19,450	19,086
Amortization of intangible assets	1,454	2,026	2,723
Total costs of net revenues	107,005	97,700	90,621
Gross profit	114,124	89,667	75,822
Operating expenses:
Research and development	31,443	32,701	33,776
Selling	30,181	28,055	27,033
General and administrative	23,381	22,444	23,980
Amortization of intangible assets	24	114	420
Restructuring charge	0	1,380	2,266
Total operating expenses	85,029	84,694	87,475
Income (loss) from operations	29,095	4,973	(11,653)
Other (income) expense:
Interest income	35	71	47
Interest expense	(285)	(289)	(389)
Other income (expense), net	290	813	374
Total other income (expense), net	40	595	32
Income (loss) before income taxes	29,135	5,568	(11,621)
Provision for (benefit from) income taxes	(14,900)	2,663	19,497
Net income (loss)	$ 44,035	$ 2,905	$ (31,118)
Net income (loss) per share:
Basic (in dollars per share)	$ 1.79	$ 0.12	$ (1.30)
Diluted (in dollars per share)	$ 1.75	$ 0.12	$ (1.30)
Weighted average shares used in per share calculation:
Basic (in shares)	24,655	24,059	23,958
Diluted (in shares)	25,153	24,375	23,958

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Statement Of Income And Comprehensive Income [Abstract]
Net income (loss)	$ 44,035	$ 2,905	$ (31,118)
Other comprehensive income (loss):
Change in foreign currency translation adjustment	(869)	(2,344)	(3,239)
Employee benefit plan adjustment	(17)	(76)	(106)
Net change on unrealized gains (losses) on available-for-sale investments	42	(13)	(36)
Other comprehensive loss	(844)	(2,433)	(3,381)
Comprehensive income (loss)	$ 43,191	$ 472	$ (34,499)

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive Income
Beginning Balance Value at Dec. 28, 2013	$ 207,373	$ 24	$ 244,733	$ (37,996)	$ 612
Beginning Balance Shares at Dec. 28, 2013		23,537,275
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(31,118)			(31,118)
Employee benefit plan adjustment	(106)				(106)
Foreign currency translation adjustments	(3,239)				(3,239)
Unrealized gain on investments, net of tax	(36)				(36)
Issuance of common stock under stock-based compensation plans	5,255		5,255
Issuance of common stock under stock-based compensation plans, Shares		639,087
Stock-based compensation expense	6,752		6,752
Repurchases and retirement of common stock under share repurchase plans	$ (5,344)		(5,344)
Repurchases and retirement of common stock under share repurchase plans, Shares	(362,633)	(362,633)
Ending Balance Value at Dec. 27, 2014	$ 179,537	$ 24	251,396	(69,114)	(2,769)
Ending Balance Shares at Dec. 27, 2014		23,813,729
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	2,905			2,905
Employee benefit plan adjustment	(76)				(76)
Foreign currency translation adjustments	(2,344)				(2,344)
Unrealized gain on investments, net of tax	(13)				(13)
Issuance of common stock under stock-based compensation plans	2,792		2,792
Issuance of common stock under stock-based compensation plans, Shares		521,607
Stock-based compensation expense	6,248		6,248
Repurchases and retirement of common stock under share repurchase plans	$ (1,721)		(1,721)
Repurchases and retirement of common stock under share repurchase plans, Shares	(111,050)	(111,050)
Ending Balance Value at Dec. 26, 2015	$ 187,328	$ 24	258,715	(66,209)	(5,202)
Ending Balance Shares at Dec. 26, 2015	24,224,286	24,224,286
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ 44,035			44,035
Employee benefit plan adjustment	(17)				(17)
Foreign currency translation adjustments	(869)				(869)
Unrealized gain on investments, net of tax	42				42
Issuance of common stock under stock-based compensation plans	6,625	$ 1	6,624
Issuance of common stock under stock-based compensation plans, Shares		846,603
Stock-based compensation expense	7,666		7,666
Excess tax benefit related to stock options	$ (1,036)		(1,036)
Repurchases and retirement of common stock under share repurchase plans, Shares	0
Ending Balance Value at Dec. 31, 2016	$ 243,774	$ 25	$ 271,969	$ (22,174)	$ (6,046)
Ending Balance Shares at Dec. 31, 2016	25,070,889	25,070,889

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Cash flows from operating activities:
Net income (loss)	$ 44,035	$ 2,905	$ (31,118)
Reconciliation of net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization	8,295	9,075	9,767
Stock-based compensation	7,666	6,248	6,752
Excess tax benefit from equity awards	1,036
Disposal of fixed assets	478	1,121	249
Inventory write-down	2,110	2,645	2,897
Deferred income taxes	(16,783)	345	17,915
Changes in fair value of contingent payments to Zygo Corporation	(1,175)	(56)	201
Changes in assets and liabilities:
Accounts receivable	(2,707)	(12,610)	3,861
Inventories	4,526	(16,431)	(7,173)
Inventories-delivered systems	399	(943)	4,988
Prepaid expenses and other	905	3,271	2,303
Accounts payable, accrued and other liabilities	2,462	4,167	1,790
Deferred revenue	(3,634)	1,006	(12,855)
Income taxes payable	(1,928)	828	(212)
Net cash provided by (used in) operating activities	45,685	1,571	(635)
Cash flows from investing activities:
Sales of marketable securities	5,955	3,383
Maturities of marketable securities	38,775	41,863	38,839
Purchases of marketable securities	(82,864)	(41,449)	(41,100)
Purchases of property, plant and equipment	(3,999)	(1,846)	(5,792)
Net cash provided by (used in) investing activities	(42,133)	1,951	(8,053)
Cash flows from financing activities:
Payments to Zygo Corporation related to acquisition	(315)	(851)	(587)
Proceeds from sale of shares under employee stock option plans and purchase plan	8,447	3,974	5,958
Excess tax benefit from equity awards	(1,036)
Taxes paid on net issuance of stock awards	(1,822)	(1,182)	(702)
Net cash provided by (used in) financing activities	5,274	220	(675)
Effect of exchange rate changes on cash and cash equivalents	82	(264)	(726)
Net increase (decrease) in cash and cash equivalents	8,908	3,478	(10,089)
Cash and cash equivalents, beginning of period	38,154	34,676	44,765
Cash and cash equivalents, end of period	47,062	38,154	34,676
Supplemental disclosure of cash flow information:
Cash paid (refund) for income taxes, net	3,767	(826)	861
Supplemental disclosure of non-cash investing activities:
Transfer of inventory to property, plant and equipment, net	$ 2,345	1,469	3,275
Share Repurchase Plans [Member]
Cash flows from financing activities:
Repurchases of common stock		$ (1,721)	$ (5,344)

Nature of Business, Basis of Pr

Nature of Business, Basis of Presentation and Significant Accounting Policies	12 Months Ended
	Dec. 31, 2016
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Nature of Business, Basis of Presentation and Significant Accounting Policies	Note 1. Nature of Business, Basis of Presentation and Significant Accounting Policies Description of Business – Nanometrics Incorporated (“Nanometrics” or the “Company”) and its wholly-owned subsidiaries design, manufacture, market, sell and support optical critical dimension ("OCD"), thin film and overlay dimension metrology and inspection systems used primarily in the manufacturing of semiconductors, solar photovoltaics (“solar PV”) and high-brightness LEDs (“HB-LED”), as well as by customers in the silicon wafer and data storage industries. Nanometrics' metrology systems precisely measure a wide range of film types deposited on substrates during manufacturing to control manufacturing processes and increase production yields in the fabrication of integrated circuits. The Company’s OCD technology is a patented critical dimension measurement technology that is used to precisely determine the dimensions on the semiconductor wafer that directly control the resulting performance of the integrated circuit devices. The thin film metrology systems use a broad spectrum of wavelengths, high-sensitivity optics, proprietary software, and patented technology to measure the thickness and uniformity of films deposited on silicon and other substrates as well as their chemical composition. The overlay metrology systems are used to measure the overlay accuracy of successive layers of semiconductor patterns on wafers in the photolithography process. Nanometrics' inspection systems are used to find defects on patterned and unpatterned wafers at nearly every stage of the semiconductor production flow. The corporate headquarters of Nanometrics is located in Milpitas, California. Basis of Presentation – The consolidated financial statements include Nanometrics Incorporated and its wholly-owned subsidiaries. All significant intercompany accounts and transactions have been eliminated in consolidation. Fiscal Year – On October 17, 2014, the Board of Directors of the Company approved a change in the Company's fiscal year from a fiscal year ending on the Saturday closest to December 31 to a 52/53 week fiscal year ending on the last Saturday of the calendar year. For fiscal year ended December 31, 2016, the period presented consisted of a 53-week year. For fiscal years ended December 26, 2015 and December 27, 2014 the periods presented consisted of a 52-week year. Upgrade Revenue and Related Cost - Beginning the first quarter of 2016, revenues associated with upgrade sales are now included under Products Revenues, and the related costs in Cost of Products Revenue. This change was due to the types of upgrades currently being sold, which are primarily system software and hardware performance upgrades to extend the features and functionality of a product. Previously upgrades consisted of a group of parts and/or software that change the existing configuration of a product. For the twelve months ended December 31, 2016, $11.0 million related to upgrade sales and $2.4 million of costs, are included in Products Revenues and Cost of Products Revenues. For the year ended December 26, 2015, $7.9 million related to upgrade sales, and $3.0 million of costs, are included in Service Revenues and Costs of Service Revenues, respectively, in the accompanying Condensed Consolidated Statement of Operations. Use of Estimates – The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America ("U.S. GAAP") requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reported period. Actual results could differ materially from those estimates. Estimates are used for, but not limited to, revenue recognition, the provision for doubtful accounts, the provision for excess, obsolete, or slow moving inventories, valuation of intangible and long-lived assets, warranty accruals, income taxes, valuation of stock-based compensation, and contingencies. Foreign Currency Translation – The assets and liabilities of foreign subsidiaries are translated from their respective local functional currencies at exchange rates in effect at the balance sheet date and income and expense accounts are translated at average exchange rates during the reporting period. Resulting translation adjustments are reflected in “Accumulated other comprehensive income,” a component of stockholders’ equity. Foreign currency transaction gains and losses, as well as remeasurement of assets and liabilities denominated in a currency other than the functional currency are reflected in “Other income (expense)” in the consolidated statements of operations in the period incurred, and consists of a $0.4 million loss, a $0.5 million gain and a $0.1 million gain for the years ended December 31, 2016, December 26, 2015, and December 27, 2014, respectively. Revenue Recognition – The Company derives revenue from the sale of process control metrology and inspection systems and related upgrades (“product revenue”) as well as spare part sales, billable service and service contracts (together “service revenue”). Upgrades are system software and hardware performance upgrades that extend the features and functionality of a product. As discussed above, commencing in the first quarter of 2016, upgrades are included in product revenue, which consists of sales of complete, advanced process control metrology and inspection systems (the “system(s)”). Nanometrics’ systems consist of hardware and software components that function together to deliver the essential functionality of the system. Arrangements for sales of systems and upgrades often include defined customer-specified acceptance criteria. In summary, the Company recognizes revenue when persuasive evidence of an arrangement exists, delivery has occurred or services have been rendered, the seller's price is fixed or determinable, and collectability is reasonably assured. For repeat product sales to existing customers, revenue recognition occurs at the time title and risk of loss transfer to the customer, which usually occurs upon shipment from the Company's manufacturing location, if it can be reliably demonstrated that the product has successfully met the defined customer specified acceptance criteria and all other recognition criteria have been met. For initial sales where the product has not previously met the defined customer specified acceptance criteria, product revenues are recognized upon the earlier of receipt of written customer acceptance or expiration of the contractual acceptance period. In Japan, where contractual terms with the customer specify risk of loss and title transfers upon customer acceptance, revenue is recognized upon receipt of written customer acceptance, provided that all other recognition criteria have been met. The Company warrants its products against defects in manufacturing. Upon recognition of product revenue, a liability is recorded for anticipated warranty costs. On occasion, customers request a warranty period longer than the Company's standard warranty. In those instances, where extended warranty services are separately quoted to the customer, the associated revenue is deferred and recognized as service revenue ratably over the term of the extended warranty period. The portion of service contracts and extended warranty services agreements that are uncompleted at the end of any reporting period are included in deferred revenue. As part of its customer services, the Company sells software that is considered to be an upgrade to a customer's existing systems. These standalone software sales are not essential to the tangible product's functionality and are accounted for under software revenue recognition rules which require vendor specific objective evidence (“VSOE”) of fair value to allocate revenue in a multiple element arrangement. Revenue from software sales is recognized when the software is delivered to the customer, provided that all other recognition criteria have been met. The majority of other upgrades are sold based on published specifications. For simple upgrades that do not require major configuration, revenue is recognized at the time title and risk of loss transfer to the customer, which is usually upon shipment. For complex and extensive upgrades, specific acceptance or prior acceptance for a similar upgrade is required in order to recognize revenue. Revenue related to spare parts is recognized upon shipment. Revenue related to billable services is recognized as the services are performed. Service contracts may be purchased by the customer during or after the warranty period and revenue is recognized ratably over the service contract period. Frequently, the Company delivers products and various services in a single transaction. The Company's deliverables consist of tools, installation, upgrades, billable services, spare parts, and service contracts. The Company's typical multi-element arrangements include a sale of one or multiple tools that include installation and standard warranty. Other arrangements consist of a sale of tools bundled with service elements or delivery of different types of services. The Company's tools, upgrades, and spare parts are generally delivered to customers within a period of up to six months from order date. Installation is usually performed soon after delivery of the tool. The portion of revenue associated with installation is deferred based on relative selling price and that revenue is recognized upon completion of the installation and receipt of final acceptance. Billable services are billed on a time and materials basis and performed as requested by customers. Under service contract arrangements, services are provided as needed over the fixed arrangement term, which terms can be up to twelve months. The Company does not grant its customers a general right of return or any refund terms and imposes a penalty on orders cancelled prior to the scheduled shipment date. The Company regularly evaluates its revenue arrangements to identify deliverables and to determine whether these deliverables are separable into multiple units of accounting. The Company allocates the arrangement consideration among the deliverables based on relative selling prices. The Company has established VSOE for some of its products and services when a substantial majority of selling prices falls within a narrow range when sold separately. For deliverables with no established VSOE, the Company uses best estimate of selling price to determine standalone selling price for such deliverable. The Company does not use third party evidence to determine standalone selling price since this information is not widely available in the market as the Company's products contain a significant element of proprietary technology and the solutions offered differ substantially from competitors. The Company has established a process for developing estimated selling prices, which incorporates historical selling prices, the effect of market conditions, gross margin objectives, pricing practices, as well as entity-specific factors. The Company monitors and evaluates estimated selling price on a regular basis to ensure that changes in circumstances are accounted for in a timely manner. When certain elements in multiple-element arrangements are not delivered or accepted at the end of a reporting period, the relative selling prices of undelivered elements are deferred until these elements are delivered and/or accepted. If deliverables cannot be accounted for as separate units of accounting, the entire arrangement is accounted for as a single unit of accounting and revenue is deferred until all elements are delivered and all revenue recognition requirements are met. Business Combinations - The Company allocates the purchase price of acquired companies to the tangible and intangible assets acquired and liabilities assumed based upon their estimated fair values at the acquisition date. The purchase price allocation process requires management to make significant estimates and assumptions, especially at the acquisition date with respect to intangible assets and inventory acquired. While best estimates and assumptions as a part of the purchase price allocation process are used to accurately value assets acquired and liabilities assumed at the acquisition date, estimates are inherently uncertain and subject to refinement. As a result, during the measurement period, which may be up to one year from the acquisition date, the Company may record adjustments to the assets acquired and liabilities assumed, with the corresponding offset to goodwill. Upon the conclusion of the measurement period or final determination of the values of assets acquired or liabilities assumed, whichever comes first, any subsequent adjustments are recorded in the consolidated statements of operations. The Company estimates the fair value of inventory acquired by utilizing the net realizable value method which is based on the estimated sales price of the product less appropriate costs to complete and selling costs. Examples of critical estimates in valuing certain intangible assets that were acquired or may be acquired in the future include but are not limited to: • future expected cash flows from sales of products, services and acquired developed technologies and patents; • expected costs to develop the in-process research and development into commercially viable products and estimated cash flows from the projects when completed; • the acquired company's customer relationships, as well as assumptions about the estimated useful lives of the relationships; and • discount rates. Unanticipated events and circumstances may occur that may affect the accuracy or validity of assumptions, estimates or actual results associated with business combinations. Cash, Cash Equivalents and Marketable Securities – The Company considers all highly liquid investments with original maturities of three months or less, when purchased, to be cash equivalents. Marketable securities are classified as “available-for-sale” and are reported at fair value with unrealized gains and losses reported in stockholders' equity as a component of other comprehensive income. The cost of securities sold is based on the specific identification method. The Company classifies its investments as current based on the nature of the investment and their availability for use in current operations. The Company reviews its investment portfolio quarterly to determine if any securities may be other-than-temporarily impaired due to increased credit risk, changes in industry or sector of a certain instrument or ratings downgrades. Fair Value of Financial Instruments – Financial instruments include cash and cash equivalents, accounts receivable and accounts payable. Cash equivalents are stated at fair market value based on quoted market prices. The carrying values of accounts receivable and accounts payable approximate their fair values because of the short-term maturity of these financial instruments. Derivatives – The Company enters into foreign currency forward exchange contracts to protect against currency exchange risks associated with existing assets and liabilities. A foreign currency forward exchange contract acts as a hedge by increasing in value when underlying assets decrease in value or underlying liabilities increase in value due to changes in foreign exchange rates. Conversely, a foreign currency forward exchange contract decreases in value when underlying assets increase in value or underlying liabilities decrease in value due to changes in foreign exchange rates. These forward contracts are not designated as accounting hedges, so the unrealized gains and losses are recognized in other income, net, in advance of the actual foreign currency cash flows with the fair value of these forward contracts being recorded as accrued liabilities or other current assets. The Company does not use forward contracts for trading purposes. Allowance for Doubtful Accounts – The Company maintains allowances for estimated losses resulting from the inability of its customers to make required payments. Credit limits are established through a process of reviewing the financial history and stability of its customers. Where appropriate and available, the Company obtains credit rating reports and financial statements of customers when determining or modifying their credit limits. The Company regularly evaluates the collectability of its trade receivable balances based on a combination of factors such as the length of time the receivables are past due, customary payment practices in the respective geographies and historical collection experience with customers. The Company believes that its allowance for doubtful accounts adequately reflects the risk associated with its receivables. If the financial conditions of a customer were to deteriorate, resulting in their inability to make payments, the Company may need to record additional allowances, which would result in additional general and administrative expenses being recorded for the period in which such determination was made. Inventories – Inventories are stated at the lower of cost, which approximates actual cost on a first-in, first-out basis, or market. The Company is exposed to a number of economic and industry factors that could result in portions of inventory becoming either obsolete or in excess of anticipated usage, or saleable only for amounts that are less than their carrying amounts. These factors include, but are not limited to, technological changes in the market, the Company’s ability to meet changing customer requirements, competitive pressures in products and prices, and the availability of key components from suppliers. The Company has established inventory reserves when conditions exist that suggest that inventory may be in excess of anticipated demand or is obsolete based upon assumptions about future demand for the Company’s products and market conditions. Once a reserve has been established, it is maintained until the part to which it relates is sold or is otherwise disposed of. The Company regularly evaluates its ability to realize the value of inventory based on a combination of factors including the following: historical usage rates, forecasted sales of usage, product end-of-life dates, estimated current and future market values and new product introductions. For demonstration inventory, the Company also considers the age of the inventory and potential cost to refurbish the inventory prior to sale. Demonstration inventory is amortized over its useful life and the amortization expense is included in total inventory write down on the statements of cash flows. When recorded, reserves are intended to reduce the carrying value of the Company’s inventory to its net realizable value. If actual demand for the Company’s products deteriorates, or market conditions are less favorable than those that the Company projects, additional reserves may be required. Inventories – delivered systems – The Company reflects the cost of systems that were invoiced upon shipment but deferred for revenue recognition purposes separate from its inventory held for sale as “Inventories – delivered systems.” Property, Plant and Equipment – Property, plant and equipment are stated at cost. Depreciation and amortization is computed using the straight–line method over the following estimated useful lives of the assets: Building and Improvements 5-40 years Machinery and equipment 3-10 years Furniture and fixtures 3-10 years Software 3-7 years Goodwill and Intangible Assets – Goodwill is initially recorded when the purchase price paid for an acquisition exceeds the estimated fair value of the net identified tangible and intangible assets acquired. Intangible assets with finite lives are amortized over their respective useful lives on a straight-line basis and are also evaluated annually for impairment or whenever events or circumstances occur which indicate that those assets might be impaired. Goodwill and indefinite lived assets are not amortized but tested annually for impairment. The Company’s impairment review process is completed during the fourth quarter of each year or whenever events, or circumstances occur which indicate that an impairment may have occurred. The Company assesses qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying value. If, after assessing the qualitative factors, the Company determines that it is not likely that the fair value of a reporting unit is less than its carrying value, then performing the two-step impairment test is unnecessary. However, if the Company concludes otherwise, then it is required to perform the first step of the two-step goodwill impairment test. The first step requires a comparison of the fair value of Nanometrics’ reporting unit to its net book value. If the fair value of the reporting unit is greater than its carrying value, then no impairment is deemed to have occurred. If the fair value is less, then the second step must be performed to determine the amount, if any, of actual impairment. Amortization of intangible assets with finite lives is computed using the straight-line method over the following estimated useful lives of the assets: Developed technology 5-10 years Customer relationships 2-10 years Brand name 5-10 years Patented technology 7-10 years Trademark 5 years Long-Lived Assets – The Company evaluates its long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. When the sum of the undiscounted future net cash flows expected to result from the use of the asset and its eventual disposition is less than its carrying amount, impairment may exist. To determine the amount of impairment, the Company compares the fair value of the asset to its carrying value. If the carrying value of the asset exceeds its fair value, an impairment loss equal to the difference is recognized. See Note 7, "Goodwill and Intangible Assets" for further details. Income Tax Assets and Liabilities – The Company accounts for income taxes such that deferred tax assets and liabilities must be recognized using enacted tax rates for the effect of temporary differences between the book and tax accounting for assets and liabilities. Also, deferred tax assets are reduced by a valuation allowance to the extent that management cannot conclude that it is more likely than not that a portion of the deferred tax asset will be realized in the future. The Company evaluates the deferred tax assets on a continuous basis throughout the year to determine whether or not a valuation allowance is appropriate. Factors used in this determination include future expected income and the underlying asset or liability which generated the temporary tax difference. The income tax provision is primarily impacted by federal statutory rates, state and foreign income taxes and changes in the valuation allowance. Product Warranties – The Company sells the majority of its products with a twelve-month repair or replacement warranty from the date of acceptance, which generally represents the date of shipment. The Company provides an accrual for estimated future warranty costs based upon the historical relationship of warranty costs to the cost of products sold. The estimated future warranty obligations related to product sales are reported in the period in which the related revenue is recognized. The estimated future warranty obligations are affected by the warranty periods, sales volumes, product failure rates, material usage and labor and replacement costs incurred in correcting a product failure. If actual product failure rates, material usage, labor or replacement costs differ from the Company’s estimates, revisions to the estimated warranty obligations would be required. For new product introductions where limited or no historical information exists, the Company may use warranty information from other previous product introductions to guide it in estimating the warranty accrual. The warranty accrual represents the best estimate of the amount necessary to settle future and existing claims on products sold as of the balance sheet date. The Company periodically assesses the adequacy of its recorded warranty reserve and adjusts the amounts in accordance with changes in these factors. Shipping and Handling Costs – Shipping and handling costs are included as a component of cost of net revenues. Advertising Costs – The Company expenses advertising costs as incurred. Advertising costs were $0.2 million in 2016, $0.3 million in 2015, and $0.2 million in 2014. Defined Employee Benefit Plans – The Company maintains a defined benefit pension plan in Taiwan for which current service costs are charged to operations as they accrue based on services rendered by employees during the year. Pension benefit obligations are determined by using management’s actuarial assumptions, including discount rates, assumed asset rates of return, compensation increases and employee turnover rates. Net Income (Loss) Per Share - Basic net income (loss) per share excludes dilution and is computed by dividing net income (loss) by the number of weighted average common shares outstanding for the period. Diluted net income per share reflects the potential dilution from outstanding dilutive stock options (using the treasury stock method) restricted stock units subject to vesting and shares issuable under the employee stock purchase plan. In applying the treasury stock method 0.5 million and 0.3 million stock option shares for fiscal year 2016 and 2015, respectively, were included in the calculation of diluted shares. During fiscal 2014, the Company incurred a net loss, therefore, diluted net loss per share excludes 0.4 million shares that were anti-dilutive. Certain Significant Risks and Uncertainties – Financial instruments that potentially subject us to a concentration of credit risk consist of cash, cash equivalents, marketable securities, and accounts receivable. The Company's cash and cash equivalents are primarily invested in deposit accounts and money market accounts with large financial institutions. At times, these deposits and securities may exceed federally insured limits; however, the Company has not experienced any losses on such accounts. The Company invests its cash not required for use in operations in high credit quality securities based on the Company's investment policy. The Company's investment policy provides guidelines and limits regarding credit quality, investment concentration, investment type, and maturity that the Company believes will provide liquidity while reducing risk of loss of capital. Investments are of a short-term nature and include investments in commercial paper, corporate debt securities, U.S. Treasury, U.S. Government, and U.S. Agency debt. The Company sells its products primarily to end users in the United States, Asia and Europe and, generally, does not require its customers to provide collateral or other security to support accounts receivable. Management performs ongoing credit evaluations of its customers’ financial condition and maintains an allowance for estimated potential bad debt losses. The Company’s customer base is highly concentrated and historically, a relatively small number of customers have accounted for a significant portion of its revenues. Aggregate revenue from the Company's top five largest customers in 2016, 2015 and 2014 consisted of 73%, 69% and 72%, respectively, of its total net revenues. The Company participates in a dynamic high technology industry and believes that changes in any of the following areas could have a material adverse effect on its future financial position, results of operations or cash flows: advances and trends in new technologies and industry standards; competitive pressures in the form of new products or price reductions on current products; changes in product mix; changes in the overall demand for products offered; changes in third-party manufacturers; changes in key suppliers; changes in certain strategic relationships or customer relationships; litigation or claims against the Company based on intellectual property, patent, product, regulatory or other factors; fluctuations in foreign currency exchange rates; risk associated with changes in domestic and international economic and/or political regulations; availability of necessary components or sub-assemblies; disruption of manufacturing facilities; and its ability to attract and retain employees necessary to support its growth. Certain components and sub-assemblies used in the Company’s products are purchased from a sole supplier or a limited group of suppliers. In particular, the Company currently purchases its spectroscopic ellipsometer and robotics used in its advanced measurement systems from a sole supplier or a limited group of suppliers located in the United States. Any shortage or interruption in the supply of any of the components or sub-assemblies used in its products or its inability to procure these components or sub-assemblies from alternate sources on acceptable terms could have a material adverse effect on its business, financial condition and results of operations.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	12 Months Ended
	Dec. 31, 2016
Accounting Changes And Error Corrections [Abstract]
Recent Accounting Pronouncements	Note 2. Recent Accounting Pronouncements Recently Issued Accounting Pronouncements In January 2017, the Financial Accounting Standards Board (the "FASB") issued an accounting standard update which simplifies the subsequent measurement of goodwill and removes step 2 from the goodwill impairment test. Instead, an entity should record an impairment charge based on excess of a reporting unit’s carrying amount over its fair value. The standard is effective for public companies for fiscal years beginning after December 15, 2019. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The Company is currently evaluating the effect of this update on its consolidated financial condition and results of operations. In October 2016, the FASB issued an accounting standard update which requires the recognition of the income tax consequences of an intra-entity transfer of an asset, other than inventory, when the transfer occurs. This standard will be effective for annual reporting periods beginning after December 15, 2017, including interim reporting period within those annual periods. Early adoption is permitted. This standard update is required to be adopted using the modified retrospective approach, with a cumulative catch-up adjustment to retained earnings in the period of adoption. The Company is currently evaluating the impact of adopting this standard on its consolidated financial condition and results of operations. In August 2016, the FASB issued an accounting standard which addresses eight specific cash flow classification issues. This update is effective for public companies for fiscal years beginning after December 15, 2017 and interim periods within those fiscal years. Early adoption is permitted, including in an interim period. If early adopted in an interim period, any adjustments should be reflected as of the beginning of the fiscal year that includes that interim period, and all the amendments must be adopted in the same period. The standard is to be applied through a retrospective transition method to each period presented. If it is impracticable to apply retrospectively for some of the issues, the amendments for those issues would be applied prospectively as of the earliest date practicable. The Company is currently evaluating the impact of adopting this update on its consolidated statements of cash flows. In June 2016, the FASB issued an accounting standard which requires measurement and timely recognition of expected credit losses for financial assets. The update is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Early adoption is permitted as of the fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. The standard is to be applied through a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is effective. The Company is currently evaluating the effect of this update on its consolidated financial condition and results of operations. In March 2016, the FASB issued an accounting standards update that simplifies several aspects of the accounting for share-based payment award transactions, including income tax consequences, classification of awards as equity or liability, and classification on the statement of cash flows. The standard is effective for public companies for annual reporting periods beginning after December 16, 2016, and interim periods within those annual periods. Early adoption is permitted. Upon adoption, the Company will continue to estimate forfeitures expected to occur to determine the amount of compensation cost to be recognized in each period. The standard requires excess tax benefits and tax deficiencies to be recorded in the income statement when the awards vest or are settled rather than paid-in capital increasing volatility in results of operations. The Company will apply the presentation requirements for the cash flows related to excess tax benefits. The cash flows related to employee taxes paid for withheld shares will be presented as a financing activity as required under the new guidance. Finally, the standard eliminates the requirement to delay the recognition of excess tax benefits until it reduces current taxes payable. The Company is unable to estimate the impact of adoption as it is dependent upon future stock option exercises which cannot be predicted. However, the Company is expecting the adoption of the standard to have an impact on net income, basic and diluted earnings per share, deferred tax assets, net cash from operations, and the effective tax rate. In February 2016, the FASB issued an accounting standards update which requires lessees to record a right-of-use asset and a corresponding lease liability on the balance sheet (with the exception of short-term leases). For lessees, leases will continue to be classified as either operating or financing in the income statement. The standard is effective for public companies for annual reporting periods beginning after December 15, 2018, including interim periods within those fiscal years. Early adoption is permitted. This standard is required to be applied with a modified retrospective transition approach. The Company generally does not finance purchases of equipment or other capital, but does lease some equipment and facilities. The Company is currently evaluating the impact of this standard on its consolidated financial statements and related disclosures but anticipates the majority of its existing operating lease commitments will be recognized as operating lease liabilities and right-of-use assets. In November 2015, the Financial Accounting Standards Board (“FASB”) issued an accounting standards update that amends existing guidance to require that deferred income tax liabilities and assets be classified as noncurrent in a classified balance sheet, and eliminates the prior guidance which required an entity to separate deferred tax liabilities and assets into a current amount and a noncurrent amount in a classified balance sheet. As permitted, the Company early-adopted this standard in fiscal year 2015 on a prospective basis. No prior periods were retrospectively adjusted. In July 2015, the FASB issued an accounting standards update which simplifies the measurement of inventory by requiring inventory to be measured at the lower of cost and net realizable value. The new standard applies only to inventories for which cost is determined by methods other than last-in-first-out and the retail inventory method. It is effective for public companies for annual reporting periods beginning after December 15, 2016, and interim periods within those fiscal years. The Company does not expect the application of this standard to have a material impact on our consolidated financial statements. In May 2014, the FASB issued an accounting standards update which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. The updated standard will replace most existing revenue recognition guidance in U.S. GAAP when it becomes effective and permits the use of either the retrospective or cumulative effect transition method. In August 2015, the FASB deferred for one year the effective date of the new revenue standard, with early adoption permitted but not earlier than the original effective date. Consequently, the new standard will be effective for the Company on December 31, 2017 and the Company does not plan to adopt early. The Company has not yet selected a transition method and is currently evaluating the effect that the updated standard will have on its consolidated financial statements and related disclosures. While the Company continues to assess the impact of the new standard, the Company believes the most likely impact will be to the accounting for arrangements that include incentives or services bundled with volume purchases. Under current U.S. GAAP, the revenue attributable to these incentives is recognized when the incentives performance conditions are met. While the Company currently expects revenue related to these arrangements to remain unchanged, the nature of the performance obligations may change the timing of the revenue recognition. The Company is currently evaluating the impact of the new standard on these arrangements and will continue to monitor industry activities and other guidance provided by the accounting profession and regulators and adjust our approach and implementation plans as required.

Fair Value Measurements and Dis

Fair Value Measurements and Disclosures	12 Months Ended
	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Fair Value Measurements and Disclosures	Note 3. Fair Value Measurements and Disclosures The Company determines the fair values of its financial instruments based on the fair value hierarchy established in FASB Accounting Standards Codification ("ASC") 820, Fair Value Measurement Level 1 — Quoted prices in active markets for identical assets or liabilities. Level 2 — Inputs other than Level 1 that are observable, either directly or indirectly, such as 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 financial instrument. Level 3 — Unobservable inputs that are supported by little or no market activity and are significant to the fair value of the assets or liabilities. Such unobservable inputs include an estimated discount rate used in the Company's discounted present value analysis of future cash flows, which reflects the Company's estimate of debt with similar terms in the current credit markets. As there is currently minimal activity in such markets, the actual rate could be materially different. Fair value is defined as the price that would be received upon the sale of an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The standard assumes that the transaction to sell the asset or transfer the liability occurs in the principal or most advantageous market for the asset or liability and establishes that the fair value of an asset or liability shall be determined based on the assumptions that market participants would use in pricing the asset or liability. The following tables present the Company’s assets and liabilities measured at estimated fair value on a recurring basis, excluding accrued interest components, categorized in accordance with the fair value hierarchy (in thousands), as of the following dates: December 31, 2016 December 26, 2015 Fair Value Measurements Using Input Types Fair Value Measurements Using Input Types Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Assets: Cash equivalents: Money market funds $ 959 $ — $ — $ 959 $ 590 $ — $ — $ 590 Commercial paper and corporate debt securities — 2,499 — 2,499 — 4,568 — 4,568 Total cash equivalents $ 959 $ 2,499 $ — $ 3,458 $ 590 $ 4,568 $ — $ 5,158 Marketable securities: U.S. Treasury, U.S. Government and U.S. Government agency debt securities — 17,072 — 17,072 4,401 20,164 — 24,565 Certificate of deposits — 23,019 — 23,019 — — — — Commercial paper — 22,402 — 22,402 — 1,884 — 1,884 Municipal securities and corporate debt securities — 14,943 — 14,943 — 18,482 — 18,482 Asset backed securities — 5,463 — 5,463 — — — — Total marketable securities $ — $ 82,899 $ — $ 82,899 $ 4,401 $ 40,530 $ — $ 44,931 Total (1) $ 959 $ 85,398 $ — $ 86,357 $ 4,991 $ 45,098 $ — $ 50,089 Liabilities: Contingent consideration payable $ — $ — $ — $ — $ — $ — $ 1,490 $ 1,490 (1) Excludes $43.6 million and $33.0 million held in operating accounts as of December 31, 2016 and December 26, 2015, respectively. The fair values of the marketable securities that are classified as Level 1 in the table above were derived from quoted market prices for identical assets or liabilities in active markets that the Company has the ability to access. The fair value of marketable securities that are classified as Level 2 in the table above were derived from non-binding market consensus prices that were corroborated by observable market data, quoted market prices for similar instruments, or pricing models, such as discounted cash flow techniques with all significant inputs derived from or corroborated by observable market data. There were no transfers of instruments between Level 1, Level 2 and Level 3 during the financial periods presented. Changes in Level 3 liabilities (in thousands) Fair value at December 27, 2014 $ 2,397 Payments made to Zygo Corporation (851 ) Change in fair value included in earnings (56 ) Fair value at December 26, 2015 1,490 Payments made to Zygo Corporation (315 ) Change in fair value included in earnings (1,175 ) Fair value at December 31, 2016 $ — As of December 31, 2016, the Company settled its liabilities of $1.2 million from Zygo Corporation, a wholly-owned subsidiary of AMETEK, Inc. (“Zygo”). Under the settlement agreement with Zygo, the company is released from any existing and future contingent liability related to the supply agreement. As of December 26, 2015, the Company had liabilities of $1.5 million resulting from the acquisition of certain assets from Zygo which are measured at fair value on a recurring basis. Of the $1.5 million of Zygo liability at December 26, 2015, $0.9 million was a current liability and $0.6 million was a long-term liability. The fair values of these liabilities were determined using Level 3 inputs using a discounted cash flow model incorporating assumptions that market participants would use in their estimates of fair value. Some of these assumptions included estimates for discount rate, and timing and the amount of cash flows. Derivatives The Company uses foreign currency forward contracts to mitigate variability in gains and losses generated from the re-measurement of certain monetary assets and liabilities denominated in foreign currencies. These derivatives are carried at fair value with changes recorded in other income (expense), net in the consolidated statements of operations. Changes in the fair value of these derivatives are largely offset by re-measurement of the underlying assets and liabilities. The derivatives have maturities of approximately 30 days. The loss on settlement of forward foreign currency contracts included in the fiscal year ended December 31, 2016 and December 26, 2015, were $1.7 million and $0.3 million, respectively, and these balances are included in other income (expense), net, in the consolidated statements of operations. The following table summarizes the Company’s outstanding derivative instruments on a gross basis: As of December 31, 2016 As of December 26, 2015 Notional Principal Notional Principal (in millions) (in millions) Undesignated Hedges: Forward Foreign Currency Contracts $ 13.9 $ 30.5

Cash and Investments

Cash and Investments	12 Months Ended
	Dec. 31, 2016
Investments Debt And Equity Securities [Abstract]
Cash and Investments	Note 4. Cash and Investments The following table presents cash, cash equivalents, and available-for-sale investments as of the following dates (in thousands): December 31, 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Market Value Cash $ 43,604 $ — $ — $ 43,604 Cash equivalents: Money market funds 959 — — 959 Commercial paper and corporate debt securities 2,499 — — 2,499 Marketable securities: U.S. Treasury securities 5,667 — — 5,667 U.S. Government agency securities 11,412 — (7 ) 11,405 Certificates of deposits 23,000 19 — 23,019 Commercial paper 22,402 — — 22,402 Corporate debt securities 14,194 — (6 ) 14,188 Municipal securities 756 — (1 ) 755 Asset-backed securities 5,466 — (3 ) 5,463 Total cash, cash equivalents, and marketable securities $ 129,959 $ 19 $ (17 ) $ 129,961 December 26, 2015 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Market Value Cash $ 32,996 $ — $ — $ 32,996 Cash equivalents: Money market funds 590 — — 590 Commercial paper and corporate debt securities 4,568 — — 4,568 Marketable securities: U.S. Treasury securities 4,411 — (10 ) 4,401 U.S. Government agency securities 20,193 1 (29 ) 20,165 Commercial paper 1,884 — — 1,884 Corporate debt securities 14,759 — (23 ) 14,736 Municipal securities 3,747 1 (3 ) 3,745 Total cash, cash equivalents, and marketable securities $ 83,148 $ 2 $ (65 ) $ 83,085 Available-for-sale marketable securities, readily convertible to cash, with maturity dates of 90 days or less are classified as cash equivalents, while those with maturity dates greater than 90 days are classified as marketable securities within short-term assets. All marketable securities as of December 31, 2016 and December 26, 2015, were available-for-sale and reported at fair value based on the estimated or quoted market prices as of the balance sheet date. Gross realized gain and losses on sale of securities are recorded in other income, net, in our statement of operations. Net realized gains and losses for fiscal 2016, 2015, and 2014 was $0.5 million, $0.2 million and $0.2 million, respectively. Unrealized gains or losses, net of tax effect, are recorded in accumulated other comprehensive income (loss) within stockholders' equity. Both the gross unrealized gains and gross unrealized losses for the fiscal years ended December 31, 2016, and December 26, 2015 were insignificant and no marketable securities had other than temporary impairment. All marketable securities as of December 31, 2016 and December 26, 2015, had maturity dates of less than two years.

Accounts Receivable

Accounts Receivable	12 Months Ended
	Dec. 31, 2016
Receivables [Abstract]
Accounts Receivable	Note 5. Accounts Receivable The Company maintains arrangements under which eligible accounts receivable in Japan are sold without recourse to unrelated third-party financial institutions. These receivables were not included in the consolidated balance sheets as the criteria for sale treatment had been met. After a transfer of financial assets, an entity stops recognizing the financial assets when control has been surrendered. The agreement met the criteria of a true sale of these assets since the acquiring party retained the title to these receivables and had assumed the risk that the receivables will be collectible. The Company pays administrative fees as well as interest ranging from 0.77% to 1.68% based on the anticipated length of time between the date the sale is consummated and the expected collection date of the receivables sold. The Company sold $31.5 million and $15.7 million of receivables during fiscal years ended December 31, 2016 and December 26, 2015, respectively. There were no material gains or losses on the sale of such receivables. There were no amounts due from such third party financial institutions at December 31, 2016 and December 26, 2015.

Financial Statement Components

Financial Statement Components	12 Months Ended
	Dec. 31, 2016
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Financial Statement Components	Note 6. Financial Statement Components The following tables provide details of selected financial statement components as of the following dates (in thousands): At December 31, 2016 December 26, 2015 Inventories: Raw materials and sub-assemblies $ 23,506 $ 26,784 Work in process 10,347 12,862 Finished goods 4,984 8,103 Inventories 38,837 47,749 Inventories-delivered systems 2,457 2,856 Total inventories $ 41,294 $ 50,605 Property, plant and equipment, net: (1) Land $ 15,568 $ 15,569 Building and improvements 20,532 20,158 Machinery and equipment 35,659 32,995 Furniture and fixtures 2,282 2,266 Software 9,756 8,245 Capital in progress 2,748 1,328 Total property, plant and equipment, gross 86,545 80,561 Accumulated depreciation and amortization (42,319 ) (36,068 ) Total property, plant and equipment, net $ 44,226 $ 44,493 (1) Total depreciation and amortization expense for the years ended December 31, 2016, December 26, 2015 and December 27, 2014 was $6.8 million, $6.9 million, and $6.6 million, respectively. Other Current Liabilities: Accrued warranty $ 3,838 $ 4,504 Accrued taxes 290 646 Customer deposits 581 290 Retrofit liability 432 — Fair value of current portion of contingent payments to Zygo Corporation related to acquisition — 945 Accrued professional services 424 481 Accrued royalties 1,233 437 Other 1,249 1,575 Total other current liabilities $ 8,047 $ 8,878 Components of Accumulated Other Comprehensive Income (Loss) Years Ended Foreign Currency Translations Defined Benefit Pension Plans Unrealized Income (Loss) on Investment Accumulated Other Comprehensive Income Balance as of December 27, 2014 $ (2,604 ) $ (134 ) $ (31 ) $ (2,769 ) Current period change (2,344 ) (76 ) (13 ) (2,433 ) Balance as of December 26, 2015 (4,948 ) (210 ) (44 ) (5,202 ) Current period change (869 ) (17 ) 42 (844 ) Balance as of December 31, 2016 $ (5,817 ) $ (227 ) $ (2 ) $ (6,046 ) The items above, except for unrealized income (loss) on investment, did not impact the Company’s income tax provision. The amounts reclassified from each component of accumulated other comprehensive income into income statement line items were insignificant.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	12 Months Ended
	Dec. 31, 2016
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	Note 7. Goodwill and Intangible Assets The following table summarizes the activity in the Company’s goodwill during the years ended December 31, 2016 and December 26, 2015, respectively (in thousands): Amounts Balance as of December 28, 2014 $ 10,494 Foreign currency movements (1,079 ) Balance as of December 26, 2015 9,415 Foreign currency movements (475 ) Balance as of December 31, 2016 $ 8,940 There were no business acquisitions made by the Company during fiscal years 2016, 2015 and 2014. Goodwill Impairment and Long-lived Asset Impairment The Company’s impairment review process is completed during the fourth quarter of each year, or whenever events or circumstances occur that indicate that an impairment may have occurred. The goodwill impairment assessment involves three tests, Step 0, Step 1 and Step 2. The Company performs a Step 0 test, which involves an initial qualitative assessment to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying value. If, after assessing the qualitative factors, the Company determines that it is more likely than not that the fair value of a reporting unit is less than its carrying value, then performing the two-step impairment test is necessary. Otherwise, no further testing is necessary. The Company completed its annual goodwill impairment assessment during the fourth quarter of 2016 by first performing a Step 0 qualitative assessment. As part of this assessment, the Company considered the trading value of the Company's stock, the industry trends, and the Company's sales forecast and products plans. The Company concluded that it was more likely than not that the fair value was more than the carrying values of the Company's reporting unit and therefore did not proceed to the Step 1 goodwill impairment test. The process of evaluating the potential impairment of long-lived assets is highly subjective and requires significant judgment. In estimating the fair value of these assets, the Company made estimates and judgments about future revenues and cash flows. The Company’s forecasts were based on assumptions that are consistent with the plans and estimates the Company is using to manage its business. Changes in these estimates could change the Company’s conclusion regarding impairment of the long-lived assets and potentially result in future impairment charges for all or a portion of their balance at December 31, 2016. The Company did not record any impairment charges related to goodwill in fiscal year 2016. The Company assesses if there have been triggers that may require it to evaluate the reasonableness of the remaining estimated useful lives of its intangible assets. No such triggers were identified during fiscal year 2016. Finite-lived intangible assets are recorded at cost, less accumulated amortization. Finite-lived intangible assets as of December 31, 2016 and December 26, 2015 consisted of the following (in thousands): December 31, 2016 Adjusted cost Accumulated amortization Net carrying amount Developed technology $ 15,726 $ (15,380 ) $ 346 Customer relationships 9,322 (9,322 ) — Brand names 1,927 (1,927 ) — Patented technology 2,252 (2,186 ) 66 Trademark 80 (80 ) — Total $ 29,307 $ (28,895 ) $ 412 December 26, 2015 Adjusted cost Accumulated amortization Net carrying amount Developed technology $ 16,098 $ (14,387 ) $ 1,711 Customer relationships 9,364 (9,364 ) — Brand names 1,927 (1,903 ) 24 Patented technology 2,252 (2,120 ) 132 Trademark 80 (80 ) — Total $ 29,721 $ (27,854 ) $ 1,867 The amortization of finite-lived intangibles is computed using the straight-line method. Estimated lives of finite-lived intangibles range from two to ten years. Total amortization expense for the fiscal years ended December 31, 2016, December 26, 2015 and December 27, 2014, was $1.5 million, $2.1 million and $3.1 million, respectively. There were no impairment charges related to intangible assets recorded during the year ended December 31, 2016. The estimated future amortization expense of finite intangible assets as of December 31, 2016, is as follows (in thousands): Fiscal Years Amounts 2017 206 2018 140 2019 66 Thereafter — Total future amortization expense $ 412

Warranties

Warranties	12 Months Ended
	Dec. 31, 2016
Product Warranties Disclosures [Abstract]
Warranties	Note 8. Warranties Product Warranty – The Company sells the majority of its products with a 12 months repair or replacement warranty from the date of acceptance or shipment date. The Company provides an accrual for estimated future warranty costs based upon the historical relationship of warranty costs to the cost of products sold. The estimated future warranty obligations related to product sales are recorded in the period in which the related revenue is recognized. The estimated future warranty obligations are affected by the warranty periods, sales volumes, product failure rates, material usage, and labor and replacement costs incurred in correcting a product failure. If actual product failure rates, material usage, labor or replacement costs were to differ from the Company’s estimates, revisions to the estimated warranty obligations would be required. For new product introductions where limited or no historical information exists, the Company may use warranty information from other previous product introductions to guide it in estimating its warranty accrual. The warranty accrual represents the best estimate of the amount necessary to settle future and existing claims on products sold as of the balance sheet date. The Company periodically assesses the adequacy of its reported warranty reserve and adjusts such amounts in accordance with changes in these factors. Components of the warranty accrual, which were included in the accompanying consolidated balance sheets with other current liabilities, were as follows (in thousands): Years Ended December 31, 2016 December 26, 2015 Balance as of beginning of period $ 4,504 $ 2,953 Accruals for warranties issued during period 4,509 8,332 Settlements during the period (5,175 ) (6,781 ) Balance as of end of period $ 3,838 $ 4,504

Restructuring

Restructuring	12 Months Ended
	Dec. 31, 2016
Restructuring And Related Activities [Abstract]
Restructuring	Note. 9. Restructuring The Company recorded a restructuring charge of approximately $2.3 million in 2014 as a result of its decision to consolidate and reorganize certain aspects of its operations, primarily in the U.K. This amount included charges primarily related to employee severance, other expenses (primarily vendor contract termination costs) and early termination costs of a facility lease. The Company recorded a restructuring charge of approximately $1.4 million in 2015 as a result of its decision to maximize operating effectiveness. This amount includes charges primarily related to employee severance and related costs. As of December 31, 2016, the Company had completed and settled in full all cash payments related to these charges. The table below summarizes the components of the Company’s restructuring reserves for the years ended December 31, 2016 and December 26, 2015, and December 27, 2014 (in thousands): Employee severance and benefits Facility termination costs Other Total Balance as of December 28, 2013 $ — $ — $ — $ — Charges 1,163 784 319 2,266 Cash Payments (780 ) (201 ) (288 ) (1,269 ) Balance as of December 27, 2014 $ 383 $ 583 $ 31 $ 997 Charges 1,369 — 11 1,380 Cash Payments (1,752 ) (334 ) (35 ) (2,121 ) Balance as of December 26, 2015 $ — $ 249 $ 7 $ 256 Charges — — — — Cash Payments — (249 ) (7 ) (256 ) Balance as of December 31, 2016 $ — $ — $ — $ —

Line of Credit and Debt Obligat

Line of Credit and Debt Obligations	12 Months Ended
	Dec. 31, 2016
Debt Disclosure [Abstract]
Line of Credit and Debt Obligations	Note 10. Line of Credit and Debt Obligations Line of Credit – The Company’s revolving line of credit facility of up to $12.0 million expired on May 30, 2016 and was not renewed.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2016
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 11. Commitments and Contingencies Intellectual Property Indemnification Obligations – The Company will, from time to time, in the normal course of business, agree to indemnify certain customers, vendors or others against third party claims that Nanometrics’ products, when used for their intended purpose(s), or the Company’s intellectual property, infringe the intellectual property rights of such third parties or other claims made against parties with whom it enters into contractual relationships. It is not possible to determine the maximum potential amount of liability under these indemnification obligations due to the limited history of prior indemnification claims and the unique facts and circumstances that are likely to be involved in each particular claim. Historically, the Company has not made payments under these obligations and believes that the estimated fair value of these agreements is immaterial. Accordingly, no liabilities have been recorded for these obligations in the accompanying consolidated balance sheets as of December 31, 2016 and December 26, 2015. The Company maintains certain open inventory purchase agreements with its suppliers to ensure a smooth and continuous supply availability for key components. The Company’s liability under these purchase commitments is generally restricted to a forecasted time-horizon as mutually agreed upon between the parties. This forecasted time-horizon can vary among different suppliers. The Company estimates its open inventory purchase commitment as of December 31, 2016 was approximately $30.6 million. Actual expenditures will vary based upon the volume of the transactions and length of contractual service provided. In addition, the amounts paid under these arrangements may be less in the event that the arrangements are renegotiated or cancelled. The Company leases facilities and certain equipment under non-cancelable operating leases. Rent expense, which is recorded on a straight-line basis over the term of the respective lease, for 2016, 2015 and 2014 was approximately $1.8 million, $1.7 million and $2.0 million, respectively. Future minimum lease payments under its operating leases are as follows (in thousands): Operating Leases 2017 $ 1,562 2018 1,189 2019 755 2020 301 2021 79 Thereafter — Total $ 3,886 On June 17, 2009, the Company announced a strategic business partnership with Zygo Corporation (“Zygo”) whereby it has purchased inventory and certain other assets from Zygo, and the two companies entered into a supply agreement. The Company made payments to Zygo over a period of time as acquired inventory was sold and other aspects of the supply agreement were executed. The Company made royalty and sustaining engineering payments of $0.3 million and $0.9 million to Zygo in fiscal years 2016 and 2015, respectively. On December 8, 2016, the Company amended its agreement with Zygo, of which, the Company is released from any existing and future contingent liabilities to Zygo.

Net Income (Loss) Per Share

Net Income (Loss) Per Share	12 Months Ended
	Dec. 31, 2016
Earnings Per Share [Abstract]
Net Income (Loss) Per Share	Note 12. Net Income (Loss) Per Share The Company presents both basic and diluted net income (loss) per share on the face of its consolidated statements of operations. Basic net income (loss) per share excludes the effect of potentially dilutive shares and is computed by dividing net income (loss) by the weighted-average number of shares of common stock outstanding for the period. Diluted net income per share is computed using the weighted-average number of shares of common stock outstanding for the period plus the effect to all potentially dilutive common shares outstanding during the period, including contingently issuable shares and certain stock options, calculated using the treasury stock method. A reconciliation of the share denominator of the basic and diluted net income (loss) per share computations is as follows (in thousands): Years Ended December 31, 2016 December 26, 2015 December 27, 2014 Weighted average common shares outstanding used in basic net income (loss) per share calculation 24,655 24,059 23,958 Potential dilutive common stock equivalents, using treasury stock method 498 316 — Weighted average shares used in diluted net income (loss) per share calculation 25,153 24,375 23,958 For the year ended December 31, 2016, December 26, 2015, and December 27, 2014, the Company had securities outstanding which could potentially dilute basic earnings per share in the future. For the years ended December 31, 2016 and December 26, 2015, weighted average common share equivalents consisting of stock options and restricted stock units included in the calculation of diluted net income per share were 0.5 million and 0.3 million shares, respectively. For the year ended December 27, 2014 potential dilutive common stock equivalents of 0.4 million shares were anti-dilutive and therefore were excluded from the calculation due to the net loss position.

Stockholders' Equity and Stock-

Stockholders' Equity and Stock-Based Compensation	12 Months Ended
	Dec. 31, 2016
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stockholders' Equity and Stock-Based Compensation	Note 13. Stockholders' Equity and Stock-Based Compensation Stockholders' Equity Preferred and Common Stock The authorized capital stock of Nanometrics consists of 47,000,000 shares of common stock, par value $0.001 per share, and 3,000,000 shares of preferred stock, par value $0.001 per share. Stock Repurchase On May 29, 2012, the Company's Board of Directors approved a program to repurchase up to $20.0 million of its common stock, referred to as the 2012 program. Stock repurchases under this program may be made through open market and privately negotiated transactions, at times and in such amounts as management deems appropriate. The timing and actual number of shares repurchased is dependent on a variety of factors including price, corporate and regulatory requirements and other market conditions. There were no shares repurchased and retired during fiscal year 2016. Shares repurchased and retired for fiscal year 2015 and 2014 of the applicable repurchase programs, with the associated cost of repurchase and amount available for repurchase at the end of the respective periods are as follows (in thousands, except number of shares and weighted average price per share): Fiscal Year 2015 Fiscal Year 2014 Number of shares of common stock repurchased 111,050 362,633 Weighted average price per share $ 15.49 $ 14.74 Total cost of repurchase $ 1,721 $ 5,344 Amount available for repurchase at end of period $ 4,397 $ 6,118 $4.4 million remained available for the future repurchase of our common stock under the 2012 program. Stock Option Plans The Nanometrics option plans are as follows: Plan Name Participants Shares Authorized 2005 Equity Incentive Plan Employees, consultants and directors 7,292,594 2002 Non-statutory Stock Option Plan Employees and consultants 1,200,000 2000 Employee Stock Option Plan Employees and consultants 2,450,000 2000 Director Stock Option Plan Non-employee directors 250,000 Accent Optical Technologies, Inc. Stock Incentive Plan Employees and consultants 205,003 Employee Stock Purchase Plan Under the 2003 Employee Stock Purchase Plan (“ESPP”), eligible employees are allowed to have salary withholdings of up to 10% of their base compensation to purchase shares of common stock at a price equal to 85% of the lower of the market value of the stock at the beginning or end of each six-month offering period, subject to an annual statutory limitation. At the end of the fiscal year ended December 31, 2016, the Company had 0.1 million shares remaining for issuance under the ESPP. Shares purchased under the ESPP were 212,619 shares, 125,504 shares and 122,112 shares in 2016, 2015 and 2014 at a weighted average price of $14.29, $13.98 and $13.76, respectively. Stock-based Compensation The Company measures and recognizes compensation expense for all share-based payment awards made to employees and directors including employee stock options, restricted stock units and employee stock purchases related to the Employee Stock Purchase Plan (collectively “Employee Stock Purchases”) based on estimated fair values. The fair value of share-based payment awards is estimated on the date of grant using an option-pricing model. The value of the portion of the award that is ultimately expected to vest is recognized as expense over the requisite service periods in the Company's consolidated statement of operations. Valuation and Expense Information The fair value of stock-based awards to employees is calculated using the Black-Scholes option pricing model, which requires subjective assumptions, including future stock price volatility and expected time to exercise. The expected life of options granted were calculated using the simplified method allowed by the SAB 107. The risk-free rates were based on the U.S Treasury rates in effect during the corresponding period of grant. The expected volatility was based on the historical volatility of the Company's stock price. These factors could change in the future, which would affect the stock-based compensation expense in future periods. The weighted-average fair value of stock-based compensation to employees is based on the single option valuation approach. Forfeitures are estimated and it is assumed no dividends will be declared. The estimated fair value of stock-based compensation awards to employees is amortized over the vesting period of the options. The weighted-average fair value calculations are based on the following average assumptions: Fiscal Year 2016 Fiscal Year 2015 Fiscal Year 2014 Stock Options: Expected life — — 4.6 years Volatility — — 54.9 % Risk free interest rate — — 1.54 % Dividends — — — Employee Stock Purchase Plan: Expected life 0.5 years 0.5 years 0.5 years Volatility 38.7 % 36.9 % 31.2 % Risk free interest rate 0.44 % 0.12 % 0.54 % Dividends — — — Stock Options and Restricted Stock Units (“RSUs”) On May 24, 2013, the Company approved further amendments to the 2005 Equity Incentive Plan including: increasing the number of shares of common stock authorized by 2.6 million shares, changing the multiplier ratio from 2:1 to 1.7:1 against the plan for each award, other than a stock option or stock appreciation right, and providing the maximum term of stock options to be seven years. All other terms remained the same. Stock Options The weighted average fair value per share of the stock options awarded in fiscal year 2014 was $8.13. No stock options were granted in fiscal years 2015 and 2016. A summary of activity of stock options is as follows: Number of Shares Outstanding (Options) Weighted Average Exercise Price Weighted Average Remaining Contractual Term (Years) Aggregate Intrinsic Value (in Thousands) Options Outstanding at December 27, 2014 1,382,993 $ 13.92 3.41 $ 4,108 Exercised (229,510 ) 9.65 Cancelled/Forfeited (94,012 ) 16.67 Outstanding at December 26, 2015 1,059,471 14.61 2.47 $ 1,920 Exercised (442,339 ) 13.66 Cancelled/Forfeited (176,587 ) 15.83 Outstanding at December 31, 2016 440,545 15.06 2.12 $ 4,405 Exercisable at December 31, 2016 407,920 $ 14.94 2.00 $ 4,129 The aggregate intrinsic value in the above table represents the total pretax intrinsic value, based on the Company’s closing stock price of $25.06 as of December 31, 2016, which would have been received by the option holders had all option holders exercised their options as of that date. The total intrinsic value of options exercised during 2016, 2015 and 2014 was $2.7 million, $1.6 million and $3.0 million, respectively. The fair value of options vested during 2016, 2015 and 2014 was $0.7 million, $1.5 million and $3.2 million, respectively. The following table summarizes ranges of outstanding and exercisable options as of December 31, 2016. Options Outstanding Options Exercisable Exercise Prices Number Outstanding Weighted Average Remaining Contractual Life (Years) Weighted Average Exercise Price Number Exercisable Weighted Average Exercise Price $9.5-$10.46 17,400 0.32 $ 10.05 17,400 $ 10.05 $11.37-$11.37 114,166 0.88 11.37 114,166 11.37 $12.98-$15.33 45,691 3.01 14.36 38,954 14.34 $15.35-$15.74 44,437 2.58 15.65 40,586 15.65 $15.85-$15.85 60,000 3.19 15.85 56,250 15.85 $15.97-$17.33 57,166 2.30 16.89 48,527 16.85 $17.7-$18.27 36,935 2.34 18.12 33,267 18.15 $18.51-$18.51 13,750 4.13 18.51 8,333 18.51 $18.79-$18.79 1,000 4.23 18.79 437 18.79 $19.03-$19.03 50,000 2.13 $ 19.03 50,000 $ 19.03 $9.5-$19.03 440,545 407,920 As of December 31, 2016, the total unrecognized compensation costs related to unvested stock options was $0.2 million and is expected to be recognized as an expense over a weighted average remaining amortization period of 0.65 years. Restricted Stock Units (“RSUs”) Each RSU counts against the Company’s “2005 Equity Incentive Plan” at a ratio of one and seven tenths shares for each unit granted but represents an amount equal to the fair value of one share of the Company’s common stock. The Company granted 476,667 and 506,459 RSUs during the years ended December 31, 2016 and December 26, 2015, respectively, to key employees with vesting periods up to three years. A summary of activity for RSUs is as follows: Summary of activity for RSUs Number of RSUs Weighted Average Fair Value Outstanding RSUs as of December 27, 2014 563,337 $ 17.90 Granted 506,459 15.62 Released (237,520 ) 16.59 Cancelled (119,033 ) 16.59 Outstanding RSUs as of December 26, 2015 713,243 15.99 Granted 476,667 17.45 Released (315,872 ) 16.05 Cancelled (54,253 ) 16.29 Outstanding RSUs as of December 31, 2016 819,785 $ 16.79 As of December 31, 2016, the total unrecognized compensation costs related to RSU's was $8.0 million and is expected to be recognized as an expense over a weighted average remaining amortization period of 1.77 years. Market-Based Performance Stock Units (“PSUs”) In addition to granting RSUs that vest on the passage of time only, the Company granted PSUs to an executive. The PSUs will vest in three equal tranches over one, two, three years based on the relative performance of the Company’s stock during those periods, compared to a peer group over the same period. If target stock price performance is achieved, 66.7% of the shares of the Company’s stock subject to the PSUs will vest, and up to a maximum of 100% of the shares subject to the PSUs will vest if the maximum stock price performance is achieved for each tranche. A summary of activity for PSUs is as follows: Summary of activity for PSUs Number of PSUs Weighted Average Fair Value Outstanding PSUs as of December 27, 2014 — — Granted 60,000 $ 12.23 Outstanding PSUs as of December 26, 2015 60,000 12.23 Granted 67,500 8.52 Released (13,333 ) 12.03 Cancelled (6,667 ) 12.03 Outstanding PSUs as of December 31, 2016 107,500 $ 9.94 Valuation of PSUs On the date of grant, the Company estimated the fair value of PSUs using a Monte Carlo simulation model. The assumptions for the valuation of PSUs are summarized as follows: 2016 Award 2015 Award Grant Date Fair Value Per Share $ 8.52 $ 12.23 Weighted-average assumptions/inputs: Expected Dividend — — Range of risk-free interest rates 0.92% 0.25%-1.1% Range of expected volatilities for peer group 22%-93% 23%-65% The number of RSUs granted during fiscal year 2016 was 476,667, which counted as 810,334 shares, and PSUs granted during fiscal year 2016 was 67,500, which counted as 114,750 against the 2005 Equity Incentive Plan. The number of RSUs cancelled during fiscal year 2016 was 54,253, which counted as 92,230 shares and PSUs cancelled during fiscal year 2016 was 6,667, which counted as 11,334, against the 2005 Equity Incentive Plan. Each RSU represents an amount equal to the fair value of one share of the Company's common stock. A summary of activity under the Company’s stock option plans including options, RSUs and PSUs during fiscal year 2016, 2015 and 2014 and shares available for grant as of the respective period end dates, is as follows: Fiscal Year 2016 Fiscal Year 2015 Fiscal Year 2014 Shares available for grant at beginning of fiscal year 1,916,589 2,464,082 2,937,001 Options - granted — — (74,300 ) Options - cancelled 176,587 94,012 191,061 Options - expired plan shares (116,192 ) (1,800 ) (17,491 ) RSUs - granted (810,334 ) (860,980 ) (805,120 ) RSUs - cancelled 92,230 202,356 167,404 RSUs - shares issued to satisfy tax withholding obligations 179,117 120,919 65,527 PSUs - granted (114,750 ) (102,000 ) PSUs - cancelled 11,334 — — Shares available for grant at end of fiscal year 1,334,581 1,916,589 2,464,082 Stock-based Compensation Expense Stock-based compensation expense recognized during the period is based on the value of the portion of share-based payment awards that is ultimately expected to vest during the period. As stock-based compensation expense recognized in the consolidated statement of operations for the years ended December 31, 2016, December 26, 2015 and December 27, 2014 is based on awards expected to vest, it has been reduced for estimated forfeitures. ASC 740 requires forfeitures to be estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates. The Company's estimated forfeiture rates are based on historical forfeiture experience, which the Company believes is the best available information to estimate the future forfeiture rate. Tax benefits resulting from tax deductions in excess of the compensation cost recognized for those options are required to be separately classified in the consolidated statements of cash flows. The Company recognized $1.0 million of excess tax benefit in fiscal year 2016, and none in both fiscal years 2015 and 2014, respectively. Stock-based compensation expense for all share-based payment awards made to the Company’s employees and directors pursuant to the employee stock option and employee stock purchase plans by function were as follows (in thousands): Fiscal Year 2016 Fiscal Year 2015 Fiscal Year 2014 Cost of products $ 403 $ 274 $ 268 Cost of service 509 309 287 Research and development 1,408 1,036 1,245 Selling 2,046 1,881 1,642 General and administrative 3,300 2,748 3,243 Restructuring — — 67 Total stock-based compensation expense related to employee stock options and employee stock purchases $ 7,666 $ 6,248 $ 6,752

Defined Benefit Pension Plan

Defined Benefit Pension Plan	12 Months Ended
	Dec. 31, 2016
Compensation And Retirement Disclosure [Abstract]
Defined Benefit Pension Plan	Note 14. Defined Benefit Pension Plan Nanometrics sponsors a statutory government mandated defined benefit pension plan (the “Benefit Plan”) in Taiwan for its local employees. The fair value of plan assets was $0.2 million for each of the fiscal years ended 2016, 2015 and 2014, respectively; and the net funding deficiency of the Benefit Plan was $0.4 million, $0.3 million, and $0.3 million for the fiscal years ended December 31, 2016, December 26, 2015, and December 27, 2014, respectively. Based on the nature and limited extent of the pension plan, we determined this pension plan was not material for separate disclosure.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Income Taxes	Note 15. Income Taxes Income Tax Assets and Liabilities - The Company accounts for income taxes whereby deferred tax assets and liabilities are recognized using enacted tax rates for the effect of temporary differences between the book and tax accounting for assets and liabilities. Also, deferred tax assets are reduced by a valuation allowance to the extent that management cannot conclude that it is more likely than not that a portion of the deferred tax asset will be realized in the future. The Company evaluates the deferred tax assets on a continuous basis throughout the year to determine whether or not a valuation allowance is appropriate. Factors used in this determination include future expected income and the underlying asset or liability which generated the temporary tax difference. The income tax provision is primarily impacted by federal statutory rates, state and foreign income taxes, and changes in the valuation allowance. Income (loss) before provision for income taxes consists of the following (in thousands): Years Ended December 31, 2016 December 26, 2015 December 27, 2014 Domestic $ 25,372 $ 178 $ (15,691 ) Foreign 3,763 5,390 4,070 Income (loss) before income taxes $ 29,135 $ 5,568 $ (11,621 ) The provision (benefit) for income taxes consists of the following (in thousands): Years Ended December 31, 2016 December 26, 2015 December 27, 2014 Current: Federal $ 697 $ 148 $ 358 State 85 3 (151 ) Foreign 2,111 2,266 1,327 2,893 2,417 1,534 Deferred: Federal (16,641 ) 190 17,368 State (320 ) 3 550 Foreign (832 ) 53 45 (17,793 ) 246 17,963 Provision (benefit) for income taxes $ (14,900 ) $ 2,663 $ 19,497 Significant components of the Company's deferred tax assets and liabilities are as follows (in thousands): At December 31, 2016 December 26, 2015 Deferred tax assets: Reserves and accruals $ 11,043 $ 13,712 Deferred revenue 349 1,154 Shared based compensation 2,590 3,856 Tax credit carry-forwards 10,112 8,658 Net operating losses 8,434 13,218 Depreciation & amortization (2,898 ) 366 Other (1,252 ) 94 Total deferred tax assets 28,378 41,058 Less: Valuation allowance (10,980 ) (36,786 ) Total deferred tax assets net of valuation allowance 17,398 4,272 Deferred tax liabilities: Depreciation & amortization (6 ) (2,537 ) Other (14 ) (1,137 ) Total deferred tax liabilities (20 ) (3,674 ) Net deferred tax assets $ 17,378 $ 598 As of December 31, 2016, the Company had net operating loss carryforwards of $26.7 million in California and $31.8 million in foreign countries, which begin to expire in 2018. A total of $3.1 million of the California net operating loss carryforward and $1.3 million of the foreign net operating loss carryforward are related to excess tax benefits as a result of stock option exercises, and therefore will be recorded in additional paid-in capital in the period that they become realized. During the year ended December 31, 2016, the Company realized $0.2 million of excess tax benefits as a result of stock option exercises, therefore, $0.1 million was recorded to additional paid-in capital. As of December 31, 2016, the Company had available carryforward Federal and California R&D tax credits of $8.6 million and $7.8 million, respectively. Federal R&D tax credit carryforwards begin to expire in 2026. State R&D tax credits carryforward indefinitely. A total of $0.2 million of the state R&D tax credits are related to excess tax benefits as a result of stock option exercises, and therefore will be recorded to additional paid-in-capital in the period that they become realized. During the years ended December 31, 2016 and December 26, 2015, the change in valuation allowances was $(25.8) million and $1.6 million, respectively. The valuation allowance decrease in 2016 was primarily related to the release of a valuation allowance against a significant portion of the Company’s U.S. deferred tax assets, as well as valuation allowance release against a portion of our foreign deferred tax assets. The realization of deferred tax assets is primarily dependent on the Company generating sufficient U.S. and foreign taxable income in future fiscal years. The Company regularly assesses the need for a valuation allowance against its deferred tax assets. In making that assessment, the Company considers both positive and negative evidence related to the likelihood of realization of the deferred tax assets to determine, based on the weight of available evidence, whether it is more-likely-than-not that some or all of the deferred tax assets will not be realized. For the year ended December 31, 2016, the Company possessed enough positive evidence to determine that is was more-likely-than-not that the Company would utilize a significant portion of its deferred tax assets. Therefore, the Company released $27.4 million of valuation allowance. The Company continues to maintain valuation allowances against its California and certain foreign deferred tax assets as a result of uncertainties regarding the realization of the asset due to cumulative losses and uncertainty of future taxable income. The Company will continue to assess the realizability of the deferred tax assets in each of the applicable jurisdictions and maintain the valuation allowances until sufficient positive evidence exists to support a reversal. In the event the Company determines that the deferred tax assets are realizable, an adjustment to the valuation allowances will be reflected in the tax provision for the period such determination is made. Changes in tax laws and tax rates could affect the Company's recorded deferred tax assets and liabilities in the future. The Company's tax liabilities involve dealing with uncertainties in the application of complex tax laws and regulations in a multitude of jurisdictions across its global operations. Management will account for any such changes or factors in the period in which such law changes are enacted. Differences between income taxes computed by applying the statutory federal income tax rate to income (loss) before income taxes and the provision (benefit) for income taxes consist of the following (in thousands): Years Ended December 31, 2016 December 26, 2015 December 27, 2014 Income taxes computed at U.S. statutory rate $ 10,197 $ 1,949 $ (4,067 ) State income taxes 223 28 (109 ) Foreign tax rate differential 3,502 342 777 Change in valuation allowance (25,738 ) 1,648 23,894 Non-deductible Equity Compensation 380 311 242 Tax credits (3,191 ) (1,834 ) (2,187 ) Domestic production activities deduction (354 ) — — Liabilities for uncertain tax positions 67 74 118 Other, net 14 145 829 Provision (benefit) for income taxes $ (14,900 ) $ 2,663 $ 19,497 Certain amounts of the income tax rate reconciliation for the years ended December 27, 2014, were reclassified to other components within the reconciliation to be consistent with classification used for the year ended December 26, 2015 and the year ended December 31, 2016. There was no impact to the total provision (benefit) for income taxes based on these reclassifications. As of December 31, 2016, approximately $3.7 million of undistributed earnings from non-U.S. operations held by the Company's foreign subsidiaries are designated as indefinitely reinvested outside the U.S. Accordingly, no additional U.S. income taxes or additional foreign withholding taxes have been provided thereon. The amount of unrecognized deferred tax liability related to these earnings would be immaterial. The Company recognizes tax liabilities for uncertain tax positions and adjusts these liabilities when its judgment changes as a result of the evaluation of new information not previously available. Due to the complexity of some of these uncertainties, the ultimate resolution may result in a payment that is materially different from the Company's current estimate of the tax liabilities. These differences will be reflected as increases or decreases to income tax expense in the period in which they are determined. The accounting for uncertainty in income taxes recognized in an enterprise's financial statements prescribes a recognition threshold and measurement attribute for the financial statement recognition and measurement of a tax position taken or expected to be taken on a tax return, and the derecognition of tax benefits, classification on the balance sheet, interest and penalties, accounting in interim periods, disclosure, and transition. A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows (in thousands): Rollforward Table (at Gross): As of December 31, 2016 December 26, 2015 December 27, 2014 Unrecognized tax benefits - beginning of the period $ 6,961 $ 6,442 $ 4,436 Gross increases-tax positions in prior period 23 127 655 Gross decreases-tax positions in prior period (1,193 ) (306 ) (123 ) Gross increases-current-period tax positions 686 698 1,541 Lapse of statute of limitations — — (67 ) Unrecognized tax benefits - end of the period $ 6,477 $ 6,961 $ 6,442 The unrecognized tax benefit at December 31, 2016 was $6.5 million, of which $3.7 million would impact the effective tax rate if recognized. The Company accrues interest and penalties related to unrecognized tax benefits in its provision for income taxes. The total amount of penalties and interest were not material as of December 31, 2016, December 26, 2015 and December 27, 2014. The Company does not expect a material change in its unrecognized tax benefits within the next 12 months. The Company is subject to taxation in the U.S. and various states including California, and foreign jurisdictions including Korea, Japan, Taiwan, and China. Due to tax attribute carry-forwards, the Company is subject to examination for tax years 2003 forward for U.S. tax purposes. The Company was also subject to examination in various states for tax years 2002 forward. The Company is subject to examination for tax years 2007 forward for various foreign jurisdictions.

Segment, Geographic, Product an

Segment, Geographic, Product and Significant Customer Information	12 Months Ended
	Dec. 31, 2016
Segment Reporting [Abstract]
Segment, Geographic, Product and Significant Customer Information	Note 16. Segment, Geographic, Product and Significant Customer Information The Company has one operating segment, which is the sale, design, manufacture, marketing and support of thin film and optical critical dimension systems. The Chief Executive Officer has been identified as the Chief Operating Decision Maker (“CODM”) because he has the final authority over resource allocation decisions and performance assessment. The CODM does not receive discrete financial information about individual components of the Company's business. For the years ended December 31, 2016, December 26, 2015, and December 27, 2014, the Company recorded revenue from customers primarily in the United States, Asia and Europe. The following tables summarize total net revenues and long-lived assets (excluding intangible assets) attributed to significant countries (in thousands): Years Ended December 31, 2016 December 26, 2015 December 27, 2014 Total net revenues (1): South Korea $ 44,735 $ 30,572 $ 41,381 China 43,460 17,373 28,702 Singapore 37,096 17,395 7,905 United States 29,887 36,720 36,123 Taiwan 27,189 46,715 19,790 Japan 26,604 31,140 15,185 Other 12,158 7,452 17,357 Total net revenues $ 221,129 $ 187,367 $ 166,443 (1) December 31, 2016 December 26, 2015 Long-lived tangible assets: United States $ 42,688 $ 42,581 Taiwan 818 1,056 South Korea 554 697 Japan 57 59 All Other 109 100 Total long-lived tangible assets $ 44,226 $ 44,493 The Company’s product lines differ primarily based on the environment in which the systems will be used. Automated systems are used primarily in high-volume production environments. Materials characterization products are primarily used to measure the composition, band gap, structure, and other physical and electrical properties of semiconducting materials for discrete electronic industry, high brightness LED and solar/photovoltaic structures in both development and high volume environments. Integrated systems are installed inside wafer processing equipment to provide near real-time measurements for improving process control and increasing throughput. Revenues by product type were as follows (in thousands): Years Ended December 31, 2016 December 26, 2015 December 27, 2014 Automated Systems $ 127,378 $ 102,386 $ 108,768 Integrated Systems 43,846 31,579 15,334 Materials Characterization Systems 13,842 12,980 9,487 Total product revenues $ 185,066 $ 146,945 $ 133,589 The following customers accounted for 10% or more of total accounts receivable, net: Years Ended December 31, 2016 December 26, 2015 December 27, 2014 Taiwan Semiconductor Manufacturing Company Limited 20.1 % 25.6 % 20.2 % Samsung Electronics Co. Ltd. 14.3 % *** 10.0 % Micron Technology, Inc. 11.8 % *** 23.7 % Intel Corporation 11.1 % *** *** Toshiba Corporation 10.2 % 27.1 % *** GLOBALFOUNDRIES *** *** 10.2 % *** The customer accounted for less than 10% of total accounts receivable, net, as of that period end. The following customers accounted for 10% or more of total net revenue: Years Ended December 31, 2016 December 26, 2015 December 27, 2014 Micron Technology, Inc. 20.3 % 15.8 % 10.4 % Intel Corporation 18.0 % *** 12.6 % SK Hynix 15.3 % 10.7 % 12.2 % Taiwan Semiconductor Manufacturing Company Limited 10.0 % 19.4 % *** Samsung Electronics Co. Ltd. *** 13.2 % 26.9 % Toshiba Corporation *** 10.2 % *** *** The customer accounted for less than 10% of total net revenue during the period.

Schedule II - VALUATION AND QUA

Schedule II - VALUATION AND QUALIFYING ACCOUNTS	12 Months Ended
	Dec. 31, 2016
Valuation And Qualifying Accounts [Abstract]
Schedule II - VALUATION AND QUALIFYING ACCOUNTS	NANOMETRICS INCORPORATED VALUATION AND QUALIFYING ACCOUNTS Our allowance for doubtful accounts receivable consists of the following (in thousands): Year Ended Balance at beginning of period Additions to Allowance Charges Utilized/Write-offs Balance at end of period December 31, 2016 $ 150 $ — $ (77 ) $ 73 December 26, 2015 $ 253 $ 10 $ (113 ) $ 150 December 27, 2014 $ 293 $ — $ (40 ) $ 253 Our valuation allowance for deferred tax assets consists of the following (in thousands): Year Ended Balance at beginning of period Additions to Allowance Charges Utilized/Write-offs Balance at end of period December 31, 2016 $ 36,786 $ 1,643 $ (27,449 ) $ 10,980 December 26, 2015 $ 35,835 $ 951 $ — $ 36,786 December 27, 2014 $ 11,665 $ 24,170 $ — $ 35,835

Nature of Business, Basis of 25

Nature of Business, Basis of Presentation and Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2016
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Description of Business	Description of Business – Nanometrics Incorporated (“Nanometrics” or the “Company”) and its wholly-owned subsidiaries design, manufacture, market, sell and support optical critical dimension ("OCD"), thin film and overlay dimension metrology and inspection systems used primarily in the manufacturing of semiconductors, solar photovoltaics (“solar PV”) and high-brightness LEDs (“HB-LED”), as well as by customers in the silicon wafer and data storage industries. Nanometrics' metrology systems precisely measure a wide range of film types deposited on substrates during manufacturing to control manufacturing processes and increase production yields in the fabrication of integrated circuits. The Company’s OCD technology is a patented critical dimension measurement technology that is used to precisely determine the dimensions on the semiconductor wafer that directly control the resulting performance of the integrated circuit devices. The thin film metrology systems use a broad spectrum of wavelengths, high-sensitivity optics, proprietary software, and patented technology to measure the thickness and uniformity of films deposited on silicon and other substrates as well as their chemical composition. The overlay metrology systems are used to measure the overlay accuracy of successive layers of semiconductor patterns on wafers in the photolithography process. Nanometrics' inspection systems are used to find defects on patterned and unpatterned wafers at nearly every stage of the semiconductor production flow. The corporate headquarters of Nanometrics is located in Milpitas, California.
Basis of Presentation	Basis of Presentation – The consolidated financial statements include Nanometrics Incorporated and its wholly-owned subsidiaries. All significant intercompany accounts and transactions have been eliminated in consolidation.
Fiscal Year	Fiscal Year – On October 17, 2014, the Board of Directors of the Company approved a change in the Company's fiscal year from a fiscal year ending on the Saturday closest to December 31 to a 52/53 week fiscal year ending on the last Saturday of the calendar year. For fiscal year ended December 31, 2016, the period presented consisted of a 53-week year. For fiscal years ended December 26, 2015 and December 27, 2014 the periods presented consisted of a 52-week year.
Upgrade Revenue and Related Cost	Upgrade Revenue and Related Cost - Beginning the first quarter of 2016, revenues associated with upgrade sales are now included under Products Revenues, and the related costs in Cost of Products Revenue. This change was due to the types of upgrades currently being sold, which are primarily system software and hardware performance upgrades to extend the features and functionality of a product. Previously upgrades consisted of a group of parts and/or software that change the existing configuration of a product. For the twelve months ended December 31, 2016, $11.0 million related to upgrade sales and $2.4 million of costs, are included in Products Revenues and Cost of Products Revenues. For the year ended December 26, 2015, $7.9 million related to upgrade sales, and $3.0 million of costs, are included in Service Revenues and Costs of Service Revenues, respectively, in the accompanying Condensed Consolidated Statement of Operations.
Use of Estimates	Use of Estimates – The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America ("U.S. GAAP") requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reported period. Actual results could differ materially from those estimates. Estimates are used for, but not limited to, revenue recognition, the provision for doubtful accounts, the provision for excess, obsolete, or slow moving inventories, valuation of intangible and long-lived assets, warranty accruals, income taxes, valuation of stock-based compensation, and contingencies.
Foreign Currency Translation	Foreign Currency Translation – The assets and liabilities of foreign subsidiaries are translated from their respective local functional currencies at exchange rates in effect at the balance sheet date and income and expense accounts are translated at average exchange rates during the reporting period. Resulting translation adjustments are reflected in “Accumulated other comprehensive income,” a component of stockholders’ equity. Foreign currency transaction gains and losses, as well as remeasurement of assets and liabilities denominated in a currency other than the functional currency are reflected in “Other income (expense)” in the consolidated statements of operations in the period incurred, and consists of a $ 0.4 million loss, a $0.5 million gain and a $0.1 million gain for the years ended December 31, 2016, December 26, 2015, and December 27, 2014, respectively.
Revenue Recognition	Revenue Recognition – The Company derives revenue from the sale of process control metrology and inspection systems and related upgrades (“product revenue”) as well as spare part sales, billable service and service contracts (together “service revenue”). Upgrades are system software and hardware performance upgrades that extend the features and functionality of a product. As discussed above, commencing in the first quarter of 2016, upgrades are included in product revenue, which consists of sales of complete, advanced process control metrology and inspection systems (the “system(s)”). Nanometrics’ systems consist of hardware and software components that function together to deliver the essential functionality of the system. Arrangements for sales of systems and upgrades often include defined customer-specified acceptance criteria. In summary, the Company recognizes revenue when persuasive evidence of an arrangement exists, delivery has occurred or services have been rendered, the seller's price is fixed or determinable, and collectability is reasonably assured. For repeat product sales to existing customers, revenue recognition occurs at the time title and risk of loss transfer to the customer, which usually occurs upon shipment from the Company's manufacturing location, if it can be reliably demonstrated that the product has successfully met the defined customer specified acceptance criteria and all other recognition criteria have been met. For initial sales where the product has not previously met the defined customer specified acceptance criteria, product revenues are recognized upon the earlier of receipt of written customer acceptance or expiration of the contractual acceptance period. In Japan, where contractual terms with the customer specify risk of loss and title transfers upon customer acceptance, revenue is recognized upon receipt of written customer acceptance, provided that all other recognition criteria have been met. The Company warrants its products against defects in manufacturing. Upon recognition of product revenue, a liability is recorded for anticipated warranty costs. On occasion, customers request a warranty period longer than the Company's standard warranty. In those instances, where extended warranty services are separately quoted to the customer, the associated revenue is deferred and recognized as service revenue ratably over the term of the extended warranty period. The portion of service contracts and extended warranty services agreements that are uncompleted at the end of any reporting period are included in deferred revenue. As part of its customer services, the Company sells software that is considered to be an upgrade to a customer's existing systems. These standalone software sales are not essential to the tangible product's functionality and are accounted for under software revenue recognition rules which require vendor specific objective evidence (“VSOE”) of fair value to allocate revenue in a multiple element arrangement. Revenue from software sales is recognized when the software is delivered to the customer, provided that all other recognition criteria have been met. The majority of other upgrades are sold based on published specifications. For simple upgrades that do not require major configuration, revenue is recognized at the time title and risk of loss transfer to the customer, which is usually upon shipment. For complex and extensive upgrades, specific acceptance or prior acceptance for a similar upgrade is required in order to recognize revenue. Revenue related to spare parts is recognized upon shipment. Revenue related to billable services is recognized as the services are performed. Service contracts may be purchased by the customer during or after the warranty period and revenue is recognized ratably over the service contract period. Frequently, the Company delivers products and various services in a single transaction. The Company's deliverables consist of tools, installation, upgrades, billable services, spare parts, and service contracts. The Company's typical multi-element arrangements include a sale of one or multiple tools that include installation and standard warranty. Other arrangements consist of a sale of tools bundled with service elements or delivery of different types of services. The Company's tools, upgrades, and spare parts are generally delivered to customers within a period of up to six months from order date. Installation is usually performed soon after delivery of the tool. The portion of revenue associated with installation is deferred based on relative selling price and that revenue is recognized upon completion of the installation and receipt of final acceptance. Billable services are billed on a time and materials basis and performed as requested by customers. Under service contract arrangements, services are provided as needed over the fixed arrangement term, which terms can be up to twelve months. The Company does not grant its customers a general right of return or any refund terms and imposes a penalty on orders cancelled prior to the scheduled shipment date. The Company regularly evaluates its revenue arrangements to identify deliverables and to determine whether these deliverables are separable into multiple units of accounting. The Company allocates the arrangement consideration among the deliverables based on relative selling prices. The Company has established VSOE for some of its products and services when a substantial majority of selling prices falls within a narrow range when sold separately. For deliverables with no established VSOE, the Company uses best estimate of selling price to determine standalone selling price for such deliverable. The Company does not use third party evidence to determine standalone selling price since this information is not widely available in the market as the Company's products contain a significant element of proprietary technology and the solutions offered differ substantially from competitors. The Company has established a process for developing estimated selling prices, which incorporates historical selling prices, the effect of market conditions, gross margin objectives, pricing practices, as well as entity-specific factors. The Company monitors and evaluates estimated selling price on a regular basis to ensure that changes in circumstances are accounted for in a timely manner. When certain elements in multiple-element arrangements are not delivered or accepted at the end of a reporting period, the relative selling prices of undelivered elements are deferred until these elements are delivered and/or accepted. If deliverables cannot be accounted for as separate units of accounting, the entire arrangement is accounted for as a single unit of accounting and revenue is deferred until all elements are delivered and all revenue recognition requirements are met.
Business Combinations	Business Combinations - The Company allocates the purchase price of acquired companies to the tangible and intangible assets acquired and liabilities assumed based upon their estimated fair values at the acquisition date. The purchase price allocation process requires management to make significant estimates and assumptions, especially at the acquisition date with respect to intangible assets and inventory acquired. While best estimates and assumptions as a part of the purchase price allocation process are used to accurately value assets acquired and liabilities assumed at the acquisition date, estimates are inherently uncertain and subject to refinement. As a result, during the measurement period, which may be up to one year from the acquisition date, the Company may record adjustments to the assets acquired and liabilities assumed, with the corresponding offset to goodwill. Upon the conclusion of the measurement period or final determination of the values of assets acquired or liabilities assumed, whichever comes first, any subsequent adjustments are recorded in the consolidated statements of operations. The Company estimates the fair value of inventory acquired by utilizing the net realizable value method which is based on the estimated sales price of the product less appropriate costs to complete and selling costs. Examples of critical estimates in valuing certain intangible assets that were acquired or may be acquired in the future include but are not limited to: • future expected cash flows from sales of products, services and acquired developed technologies and patents; • expected costs to develop the in-process research and development into commercially viable products and estimated cash flows from the projects when completed; • the acquired company's customer relationships, as well as assumptions about the estimated useful lives of the relationships; and • discount rates. Unanticipated events and circumstances may occur that may affect the accuracy or validity of assumptions, estimates or actual results associated with business combinations.
Cash and Cash Equivalents	Cash, Cash Equivalents and Marketable Securities – The Company considers all highly liquid investments with original maturities of three months or less, when purchased, to be cash equivalents.
Marketable Securities	Marketable securities are classified as “available-for-sale” and are reported at fair value with unrealized gains and losses reported in stockholders' equity as a component of other comprehensive income. The cost of securities sold is based on the specific identification method. The Company classifies its investments as current based on the nature of the investment and their availability for use in current operations. The Company reviews its investment portfolio quarterly to determine if any securities may be other-than-temporarily impaired due to increased credit risk, changes in industry or sector of a certain instrument or ratings downgrades.
Fair Value of Financial Instruments	Fair Value of Financial Instruments – Financial instruments include cash and cash equivalents, accounts receivable and accounts payable. Cash equivalents are stated at fair market value based on quoted market prices. The carrying values of accounts receivable and accounts payable approximate their fair values because of the short-term maturity of these financial instruments.
Derivatives	Derivatives – The Company enters into foreign currency forward exchange contracts to protect against currency exchange risks associated with existing assets and liabilities. A foreign currency forward exchange contract acts as a hedge by increasing in value when underlying assets decrease in value or underlying liabilities increase in value due to changes in foreign exchange rates. Conversely, a foreign currency forward exchange contract decreases in value when underlying assets increase in value or underlying liabilities decrease in value due to changes in foreign exchange rates. These forward contracts are not designated as accounting hedges, so the unrealized gains and losses are recognized in other income, net, in advance of the actual foreign currency cash flows with the fair value of these forward contracts being recorded as accrued liabilities or other current assets. The Company does not use forward contracts for trading purposes.
Allowance for Doubtful Accounts	Allowance for Doubtful Accounts – The Company maintains allowances for estimated losses resulting from the inability of its customers to make required payments. Credit limits are established through a process of reviewing the financial history and stability of its customers. Where appropriate and available, the Company obtains credit rating reports and financial statements of customers when determining or modifying their credit limits. The Company regularly evaluates the collectability of its trade receivable balances based on a combination of factors such as the length of time the receivables are past due, customary payment practices in the respective geographies and historical collection experience with customers. The Company believes that its allowance for doubtful accounts adequately reflects the risk associated with its receivables. If the financial conditions of a customer were to deteriorate, resulting in their inability to make payments, the Company may need to record additional allowances, which would result in additional general and administrative expenses being recorded for the period in which such determination was made.
Inventories	Inventories – Inventories are stated at the lower of cost, which approximates actual cost on a first-in, first-out basis, or market. The Company is exposed to a number of economic and industry factors that could result in portions of inventory becoming either obsolete or in excess of anticipated usage, or saleable only for amounts that are less than their carrying amounts. These factors include, but are not limited to, technological changes in the market, the Company’s ability to meet changing customer requirements, competitive pressures in products and prices, and the availability of key components from suppliers. The Company has established inventory reserves when conditions exist that suggest that inventory may be in excess of anticipated demand or is obsolete based upon assumptions about future demand for the Company’s products and market conditions. Once a reserve has been established, it is maintained until the part to which it relates is sold or is otherwise disposed of. The Company regularly evaluates its ability to realize the value of inventory based on a combination of factors including the following: historical usage rates, forecasted sales of usage, product end-of-life dates, estimated current and future market values and new product introductions. For demonstration inventory, the Company also considers the age of the inventory and potential cost to refurbish the inventory prior to sale. Demonstration inventory is amortized over its useful life and the amortization expense is included in total inventory write down on the statements of cash flows. When recorded, reserves are intended to reduce the carrying value of the Company’s inventory to its net realizable value. If actual demand for the Company’s products deteriorates, or market conditions are less favorable than those that the Company projects, additional reserves may be required. Inventories – delivered systems – The Company reflects the cost of systems that were invoiced upon shipment but deferred for revenue recognition purposes separate from its inventory held for sale as “Inventories – delivered systems.”
Property, Plant and Equipment	Property, Plant and Equipment – Property, plant and equipment are stated at cost. Depreciation and amortization is computed using the straight–line method over the following estimated useful lives of the assets: Building and Improvements 5-40 years Machinery and equipment 3-10 years Furniture and fixtures 3-10 years Software 3-7 years
Goodwill and Intangible Assets	Goodwill and Intangible Assets – Goodwill is initially recorded when the purchase price paid for an acquisition exceeds the estimated fair value of the net identified tangible and intangible assets acquired. Intangible assets with finite lives are amortized over their respective useful lives on a straight-line basis and are also evaluated annually for impairment or whenever events or circumstances occur which indicate that those assets might be impaired. Goodwill and indefinite lived assets are not amortized but tested annually for impairment. The Company’s impairment review process is completed during the fourth quarter of each year or whenever events, or circumstances occur which indicate that an impairment may have occurred. The Company assesses qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying value. If, after assessing the qualitative factors, the Company determines that it is not likely that the fair value of a reporting unit is less than its carrying value, then performing the two-step impairment test is unnecessary. However, if the Company concludes otherwise, then it is required to perform the first step of the two-step goodwill impairment test. The first step requires a comparison of the fair value of Nanometrics’ reporting unit to its net book value. If the fair value of the reporting unit is greater than its carrying value, then no impairment is deemed to have occurred. If the fair value is less, then the second step must be performed to determine the amount, if any, of actual impairment. Amortization of intangible assets with finite lives is computed using the straight-line method over the following estimated useful lives of the assets: Developed technology 5-10 years Customer relationships 2-10 years Brand name 5-10 years Patented technology 7-10 years Trademark 5 years
Long-Lived Assets	Long-Lived Assets – The Company evaluates its long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. When the sum of the undiscounted future net cash flows expected to result from the use of the asset and its eventual disposition is less than its carrying amount, impairment may exist. To determine the amount of impairment, the Company compares the fair value of the asset to its carrying value. If the carrying value of the asset exceeds its fair value, an impairment loss equal to the difference is recognized. See Note 7, "Goodwill and Intangible Assets" for further details.
Income Tax Assets and Liabilities	Income Tax Assets and Liabilities – The Company accounts for income taxes such that deferred tax assets and liabilities must be recognized using enacted tax rates for the effect of temporary differences between the book and tax accounting for assets and liabilities. Also, deferred tax assets are reduced by a valuation allowance to the extent that management cannot conclude that it is more likely than not that a portion of the deferred tax asset will be realized in the future. The Company evaluates the deferred tax assets on a continuous basis throughout the year to determine whether or not a valuation allowance is appropriate. Factors used in this determination include future expected income and the underlying asset or liability which generated the temporary tax difference. The income tax provision is primarily impacted by federal statutory rates, state and foreign income taxes and changes in the valuation allowance.
Product Warranties	Product Warranties – The Company sells the majority of its products with a twelve-month repair or replacement warranty from the date of acceptance, which generally represents the date of shipment. The Company provides an accrual for estimated future warranty costs based upon the historical relationship of warranty costs to the cost of products sold. The estimated future warranty obligations related to product sales are reported in the period in which the related revenue is recognized. The estimated future warranty obligations are affected by the warranty periods, sales volumes, product failure rates, material usage and labor and replacement costs incurred in correcting a product failure. If actual product failure rates, material usage, labor or replacement costs differ from the Company’s estimates, revisions to the estimated warranty obligations would be required. For new product introductions where limited or no historical information exists, the Company may use warranty information from other previous product introductions to guide it in estimating the warranty accrual. The warranty accrual represents the best estimate of the amount necessary to settle future and existing claims on products sold as of the balance sheet date. The Company periodically assesses the adequacy of its recorded warranty reserve and adjusts the amounts in accordance with changes in these factors.
Shipping and Handling Costs	Shipping and Handling Costs – Shipping and handling costs are included as a component of cost of net revenues.
Advertising Costs	Advertising Costs – The Company expenses advertising costs as incurred. Advertising costs were $ 0.2 million in 2016, $0.3 million in 2015, and $0.2 million in 2014.
Defined Employee Benefit Plans	Defined Employee Benefit Plans – The Company maintains a defined benefit pension plan in Taiwan for which current service costs are charged to operations as they accrue based on services rendered by employees during the year. Pension benefit obligations are determined by using management’s actuarial assumptions, including discount rates, assumed asset rates of return, compensation increases and employee turnover rates.
Net Income (Loss) Per Share	Net Income (Loss) Per Share - Basic net income (loss) per share excludes dilution and is computed by dividing net income (loss) by the number of weighted average common shares outstanding for the period. Diluted net income per share reflects the potential dilution from outstanding dilutive stock options (using the treasury stock method) restricted stock units subject to vesting and shares issuable under the employee stock purchase plan. In applying the treasury stock method 0.5 million and 0.3 million stock option shares for fiscal year 2016 and 2015, respectively, were included in the calculation of diluted shares. During fiscal 2014, the Company incurred a net loss, therefore, diluted net loss per share excludes 0.4 million shares that were anti-dilutive.
Certain Significant Risks and Uncertainties	Certain Significant Risks and Uncertainties – Financial instruments that potentially subject us to a concentration of credit risk consist of cash, cash equivalents, marketable securities, and accounts receivable. The Company's cash and cash equivalents are primarily invested in deposit accounts and money market accounts with large financial institutions. At times, these deposits and securities may exceed federally insured limits; however, the Company has not experienced any losses on such accounts. The Company invests its cash not required for use in operations in high credit quality securities based on the Company's investment policy. The Company's investment policy provides guidelines and limits regarding credit quality, investment concentration, investment type, and maturity that the Company believes will provide liquidity while reducing risk of loss of capital. Investments are of a short-term nature and include investments in commercial paper, corporate debt securities, U.S. Treasury, U.S. Government, and U.S. Agency debt. The Company sells its products primarily to end users in the United States, Asia and Europe and, generally, does not require its customers to provide collateral or other security to support accounts receivable. Management performs ongoing credit evaluations of its customers’ financial condition and maintains an allowance for estimated potential bad debt losses. The Company’s customer base is highly concentrated and historically, a relatively small number of customers have accounted for a significant portion of its revenues. Aggregate revenue from the Company's top five largest customers in 2016, 2015 and 2014 consisted of 73%, 69% and 72%, respectively, of its total net revenues. The Company participates in a dynamic high technology industry and believes that changes in any of the following areas could have a material adverse effect on its future financial position, results of operations or cash flows: advances and trends in new technologies and industry standards; competitive pressures in the form of new products or price reductions on current products; changes in product mix; changes in the overall demand for products offered; changes in third-party manufacturers; changes in key suppliers; changes in certain strategic relationships or customer relationships; litigation or claims against the Company based on intellectual property, patent, product, regulatory or other factors; fluctuations in foreign currency exchange rates; risk associated with changes in domestic and international economic and/or political regulations; availability of necessary components or sub-assemblies; disruption of manufacturing facilities; and its ability to attract and retain employees necessary to support its growth. Certain components and sub-assemblies used in the Company’s products are purchased from a sole supplier or a limited group of suppliers. In particular, the Company currently purchases its spectroscopic ellipsometer and robotics used in its advanced measurement systems from a sole supplier or a limited group of suppliers located in the United States. Any shortage or interruption in the supply of any of the components or sub-assemblies used in its products or its inability to procure these components or sub-assemblies from alternate sources on acceptable terms could have a material adverse effect on its business, financial condition and results of operations.

Nature of Business, Basis of 26

Nature of Business, Basis of Presentation and Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2016
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Estimated useful lives of property, plant and equipment	Depreciation and amortization is computed using the straight–line method over the following estimated useful lives of the assets: Building and Improvements 5-40 years Machinery and equipment 3-10 years Furniture and fixtures 3-10 years Software 3-7 years
Estimated Useful Lives of Intangible Assets	Amortization of intangible assets with finite lives is computed using the straight-line method over the following estimated useful lives of the assets: Developed technology 5-10 years Customer relationships 2-10 years Brand name 5-10 years Patented technology 7-10 years Trademark 5 years

Fair Value Measurements and D27

Fair Value Measurements and Disclosures (Tables)	12 Months Ended
	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Assets and liabilities measurements at estimated fair value on recurring basis excluding accrued interest components	The following tables present the Company’s assets and liabilities measured at estimated fair value on a recurring basis, excluding accrued interest components, categorized in accordance with the fair value hierarchy (in thousands), as of the following dates: December 31, 2016 December 26, 2015 Fair Value Measurements Using Input Types Fair Value Measurements Using Input Types Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Assets: Cash equivalents: Money market funds $ 959 $ — $ — $ 959 $ 590 $ — $ — $ 590 Commercial paper and corporate debt securities — 2,499 — 2,499 — 4,568 — 4,568 Total cash equivalents $ 959 $ 2,499 $ — $ 3,458 $ 590 $ 4,568 $ — $ 5,158 Marketable securities: U.S. Treasury, U.S. Government and U.S. Government agency debt securities — 17,072 — 17,072 4,401 20,164 — 24,565 Certificate of deposits — 23,019 — 23,019 — — — — Commercial paper — 22,402 — 22,402 — 1,884 — 1,884 Municipal securities and corporate debt securities — 14,943 — 14,943 — 18,482 — 18,482 Asset backed securities — 5,463 — 5,463 — — — — Total marketable securities $ — $ 82,899 $ — $ 82,899 $ 4,401 $ 40,530 $ — $ 44,931 Total (1) $ 959 $ 85,398 $ — $ 86,357 $ 4,991 $ 45,098 $ — $ 50,089 Liabilities: Contingent consideration payable $ — $ — $ — $ — $ — $ — $ 1,490 $ 1,490 (1) Excludes $43.6 million and $33.0 million held in operating accounts as of December 31, 2016 and December 26, 2015, respectively.
Fair value measurement on recurring basis, unobservable input reconciliation	Changes in Level 3 liabilities (in thousands) Fair value at December 27, 2014 $ 2,397 Payments made to Zygo Corporation (851 ) Change in fair value included in earnings (56 ) Fair value at December 26, 2015 1,490 Payments made to Zygo Corporation (315 ) Change in fair value included in earnings (1,175 ) Fair value at December 31, 2016 $ —
Outstanding derivative instruments	The following table summarizes the Company’s outstanding derivative instruments on a gross basis: As of December 31, 2016 As of December 26, 2015 Notional Principal Notional Principal (in millions) (in millions) Undesignated Hedges: Forward Foreign Currency Contracts $ 13.9 $ 30.5

Cash and Investments (Tables)

Cash and Investments (Tables)	12 Months Ended
	Dec. 31, 2016
Investments Debt And Equity Securities [Abstract]
Cash, Cash Equivalents and Available-for-Sale Investments	The following table presents cash, cash equivalents, and available-for-sale investments as of the following dates (in thousands): December 31, 2016 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Market Value Cash $ 43,604 $ — $ — $ 43,604 Cash equivalents: Money market funds 959 — — 959 Commercial paper and corporate debt securities 2,499 — — 2,499 Marketable securities: U.S. Treasury securities 5,667 — — 5,667 U.S. Government agency securities 11,412 — (7 ) 11,405 Certificates of deposits 23,000 19 — 23,019 Commercial paper 22,402 — — 22,402 Corporate debt securities 14,194 — (6 ) 14,188 Municipal securities 756 — (1 ) 755 Asset-backed securities 5,466 — (3 ) 5,463 Total cash, cash equivalents, and marketable securities $ 129,959 $ 19 $ (17 ) $ 129,961 December 26, 2015 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Market Value Cash $ 32,996 $ — $ — $ 32,996 Cash equivalents: Money market funds 590 — — 590 Commercial paper and corporate debt securities 4,568 — — 4,568 Marketable securities: U.S. Treasury securities 4,411 — (10 ) 4,401 U.S. Government agency securities 20,193 1 (29 ) 20,165 Commercial paper 1,884 — — 1,884 Corporate debt securities 14,759 — (23 ) 14,736 Municipal securities 3,747 1 (3 ) 3,745 Total cash, cash equivalents, and marketable securities $ 83,148 $ 2 $ (65 ) $ 83,085

Financial Statement Components

Financial Statement Components (Tables)	12 Months Ended
	Dec. 31, 2016
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Selected financial statement components	The following tables provide details of selected financial statement components as of the following dates (in thousands): At December 31, 2016 December 26, 2015 Inventories: Raw materials and sub-assemblies $ 23,506 $ 26,784 Work in process 10,347 12,862 Finished goods 4,984 8,103 Inventories 38,837 47,749 Inventories-delivered systems 2,457 2,856 Total inventories $ 41,294 $ 50,605 Property, plant and equipment, net: (1) Land $ 15,568 $ 15,569 Building and improvements 20,532 20,158 Machinery and equipment 35,659 32,995 Furniture and fixtures 2,282 2,266 Software 9,756 8,245 Capital in progress 2,748 1,328 Total property, plant and equipment, gross 86,545 80,561 Accumulated depreciation and amortization (42,319 ) (36,068 ) Total property, plant and equipment, net $ 44,226 $ 44,493 (1) Total depreciation and amortization expense for the years ended December 31, 2016, December 26, 2015 and December 27, 2014 was $6.8 million, $6.9 million, and $6.6 million, respectively. Other Current Liabilities: Accrued warranty $ 3,838 $ 4,504 Accrued taxes 290 646 Customer deposits 581 290 Retrofit liability 432 — Fair value of current portion of contingent payments to Zygo Corporation related to acquisition — 945 Accrued professional services 424 481 Accrued royalties 1,233 437 Other 1,249 1,575 Total other current liabilities $ 8,047 $ 8,878
Components of accumulated other comprehensive income (loss)	Components of Accumulated Other Comprehensive Income (Loss) Years Ended Foreign Currency Translations Defined Benefit Pension Plans Unrealized Income (Loss) on Investment Accumulated Other Comprehensive Income Balance as of December 27, 2014 $ (2,604 ) $ (134 ) $ (31 ) $ (2,769 ) Current period change (2,344 ) (76 ) (13 ) (2,433 ) Balance as of December 26, 2015 (4,948 ) (210 ) (44 ) (5,202 ) Current period change (869 ) (17 ) 42 (844 ) Balance as of December 31, 2016 $ (5,817 ) $ (227 ) $ (2 ) $ (6,046 )

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2016
Goodwill And Intangible Assets Disclosure [Abstract]
Schedule of goodwill	The following table summarizes the activity in the Company’s goodwill during the years ended December 31, 2016 and December 26, 2015, respectively (in thousands): Amounts Balance as of December 28, 2014 $ 10,494 Foreign currency movements (1,079 ) Balance as of December 26, 2015 9,415 Foreign currency movements (475 ) Balance as of December 31, 2016 $ 8,940
Summary of finite-lived intangible assets	Finite-lived intangible assets are recorded at cost, less accumulated amortization. Finite-lived intangible assets as of December 31, 2016 and December 26, 2015 consisted of the following (in thousands): December 31, 2016 Adjusted cost Accumulated amortization Net carrying amount Developed technology $ 15,726 $ (15,380 ) $ 346 Customer relationships 9,322 (9,322 ) — Brand names 1,927 (1,927 ) — Patented technology 2,252 (2,186 ) 66 Trademark 80 (80 ) — Total $ 29,307 $ (28,895 ) $ 412 December 26, 2015 Adjusted cost Accumulated amortization Net carrying amount Developed technology $ 16,098 $ (14,387 ) $ 1,711 Customer relationships 9,364 (9,364 ) — Brand names 1,927 (1,903 ) 24 Patented technology 2,252 (2,120 ) 132 Trademark 80 (80 ) — Total $ 29,721 $ (27,854 ) $ 1,867
Estimated future amortization expense	The estimated future amortization expense of finite intangible assets as of December 31, 2016, is as follows (in thousands): Fiscal Years Amounts 2017 206 2018 140 2019 66 Thereafter — Total future amortization expense $ 412

Warranties (Tables)

Warranties (Tables)	12 Months Ended
	Dec. 31, 2016
Product Warranties Disclosures [Abstract]
Components of the warranty accrual	Components of the warranty accrual, which were included in the accompanying consolidated balance sheets with other current liabilities, were as follows (in thousands): Years Ended December 31, 2016 December 26, 2015 Balance as of beginning of period $ 4,504 $ 2,953 Accruals for warranties issued during period 4,509 8,332 Settlements during the period (5,175 ) (6,781 ) Balance as of end of period $ 3,838 $ 4,504

Restructuring (Tables)

Restructuring (Tables)	12 Months Ended
	Dec. 31, 2016
Restructuring And Related Activities [Abstract]
Components of the restructuring reserve	The table below summarizes the components of the Company’s restructuring reserves for the years ended December 31, 2016 and December 26, 2015, and December 27, 2014 (in thousands): Employee severance and benefits Facility termination costs Other Total Balance as of December 28, 2013 $ — $ — $ — $ — Charges 1,163 784 319 2,266 Cash Payments (780 ) (201 ) (288 ) (1,269 ) Balance as of December 27, 2014 $ 383 $ 583 $ 31 $ 997 Charges 1,369 — 11 1,380 Cash Payments (1,752 ) (334 ) (35 ) (2,121 ) Balance as of December 26, 2015 $ — $ 249 $ 7 $ 256 Charges — — — — Cash Payments — (249 ) (7 ) (256 ) Balance as of December 31, 2016 $ — $ — $ — $ —

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2016
Commitments And Contingencies Disclosure [Abstract]
Future minimum lease payments under operating leases	Future minimum lease payments under its operating leases are as follows (in thousands): Operating Leases 2017 $ 1,562 2018 1,189 2019 755 2020 301 2021 79 Thereafter — Total $ 3,886

Net Income (Loss) Per Share (Ta

Net Income (Loss) Per Share (Tables)	12 Months Ended
	Dec. 31, 2016
Earnings Per Share [Abstract]
Reconciliation of the basic and diluted net income (loss) per share computations	A reconciliation of the share denominator of the basic and diluted net income (loss) per share computations is as follows (in thousands): Years Ended December 31, 2016 December 26, 2015 December 27, 2014 Weighted average common shares outstanding used in basic net income (loss) per share calculation 24,655 24,059 23,958 Potential dilutive common stock equivalents, using treasury stock method 498 316 — Weighted average shares used in diluted net income (loss) per share calculation 25,153 24,375 23,958

Stockholders' Equity and Stoc35

Stockholders' Equity and Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share repurchases	Shares repurchased and retired for fiscal year 2015 and 2014 of the applicable repurchase programs, with the associated cost of repurchase and amount available for repurchase at the end of the respective periods are as follows (in thousands, except number of shares and weighted average price per share): Fiscal Year 2015 Fiscal Year 2014 Number of shares of common stock repurchased 111,050 362,633 Weighted average price per share $ 15.49 $ 14.74 Total cost of repurchase $ 1,721 $ 5,344 Amount available for repurchase at end of period $ 4,397 $ 6,118
Option plans	The Nanometrics option plans are as follows: Plan Name Participants Shares Authorized 2005 Equity Incentive Plan Employees, consultants and directors 7,292,594 2002 Non-statutory Stock Option Plan Employees and consultants 1,200,000 2000 Employee Stock Option Plan Employees and consultants 2,450,000 2000 Director Stock Option Plan Non-employee directors 250,000 Accent Optical Technologies, Inc. Stock Incentive Plan Employees and consultants 205,003
Stock options and employee stock purchase plan assumptions	The weighted-average fair value calculations are based on the following average assumptions: Fiscal Year 2016 Fiscal Year 2015 Fiscal Year 2014 Stock Options: Expected life — — 4.6 years Volatility — — 54.9 % Risk free interest rate — — 1.54 % Dividends — — — Employee Stock Purchase Plan: Expected life 0.5 years 0.5 years 0.5 years Volatility 38.7 % 36.9 % 31.2 % Risk free interest rate 0.44 % 0.12 % 0.54 % Dividends — — —
Stock option plans activity	A summary of activity of stock options is as follows: Number of Shares Outstanding (Options) Weighted Average Exercise Price Weighted Average Remaining Contractual Term (Years) Aggregate Intrinsic Value (in Thousands) Options Outstanding at December 27, 2014 1,382,993 $ 13.92 3.41 $ 4,108 Exercised (229,510 ) 9.65 Cancelled/Forfeited (94,012 ) 16.67 Outstanding at December 26, 2015 1,059,471 14.61 2.47 $ 1,920 Exercised (442,339 ) 13.66 Cancelled/Forfeited (176,587 ) 15.83 Outstanding at December 31, 2016 440,545 15.06 2.12 $ 4,405 Exercisable at December 31, 2016 407,920 $ 14.94 2.00 $ 4,129
Ranges of outstanding and exercisable options	The following table summarizes ranges of outstanding and exercisable options as of December 31, 2016. Options Outstanding Options Exercisable Exercise Prices Number Outstanding Weighted Average Remaining Contractual Life (Years) Weighted Average Exercise Price Number Exercisable Weighted Average Exercise Price $9.5-$10.46 17,400 0.32 $ 10.05 17,400 $ 10.05 $11.37-$11.37 114,166 0.88 11.37 114,166 11.37 $12.98-$15.33 45,691 3.01 14.36 38,954 14.34 $15.35-$15.74 44,437 2.58 15.65 40,586 15.65 $15.85-$15.85 60,000 3.19 15.85 56,250 15.85 $15.97-$17.33 57,166 2.30 16.89 48,527 16.85 $17.7-$18.27 36,935 2.34 18.12 33,267 18.15 $18.51-$18.51 13,750 4.13 18.51 8,333 18.51 $18.79-$18.79 1,000 4.23 18.79 437 18.79 $19.03-$19.03 50,000 2.13 $ 19.03 50,000 $ 19.03 $9.5-$19.03 440,545 407,920
Summary of activity for RSUs	A summary of activity for RSUs is as follows: Summary of activity for RSUs Number of RSUs Weighted Average Fair Value Outstanding RSUs as of December 27, 2014 563,337 $ 17.90 Granted 506,459 15.62 Released (237,520 ) 16.59 Cancelled (119,033 ) 16.59 Outstanding RSUs as of December 26, 2015 713,243 15.99 Granted 476,667 17.45 Released (315,872 ) 16.05 Cancelled (54,253 ) 16.29 Outstanding RSUs as of December 31, 2016 819,785 $ 16.79
Summary of activity for PSUs	A summary of activity for PSUs is as follows: Summary of activity for PSUs Number of PSUs Weighted Average Fair Value Outstanding PSUs as of December 27, 2014 — — Granted 60,000 $ 12.23 Outstanding PSUs as of December 26, 2015 60,000 12.23 Granted 67,500 8.52 Released (13,333 ) 12.03 Cancelled (6,667 ) 12.03 Outstanding PSUs as of December 31, 2016 107,500 $ 9.94
PSUs valuation assumptions	The assumptions for the valuation of PSUs are summarized as follows: 2016 Award 2015 Award Grant Date Fair Value Per Share $ 8.52 $ 12.23 Weighted-average assumptions/inputs: Expected Dividend — — Range of risk-free interest rates 0.92% 0.25%-1.1% Range of expected volatilities for peer group 22%-93% 23%-65%
Stock-based compensation expense for all share-based payment awards	Stock-based compensation expense for all share-based payment awards made to the Company’s employees and directors pursuant to the employee stock option and employee stock purchase plans by function were as follows (in thousands): Fiscal Year 2016 Fiscal Year 2015 Fiscal Year 2014 Cost of products $ 403 $ 274 $ 268 Cost of service 509 309 287 Research and development 1,408 1,036 1,245 Selling 2,046 1,881 1,642 General and administrative 3,300 2,748 3,243 Restructuring — — 67 Total stock-based compensation expense related to employee stock options and employee stock purchases $ 7,666 $ 6,248 $ 6,752
Stock Options, RSUs and PSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option plans activity including options, RSUs and PSUs	A summary of activity under the Company’s stock option plans including options, RSUs and PSUs during fiscal year 2016, 2015 and 2014 and shares available for grant as of the respective period end dates, is as follows: Fiscal Year 2016 Fiscal Year 2015 Fiscal Year 2014 Shares available for grant at beginning of fiscal year 1,916,589 2,464,082 2,937,001 Options - granted — — (74,300 ) Options - cancelled 176,587 94,012 191,061 Options - expired plan shares (116,192 ) (1,800 ) (17,491 ) RSUs - granted (810,334 ) (860,980 ) (805,120 ) RSUs - cancelled 92,230 202,356 167,404 RSUs - shares issued to satisfy tax withholding obligations 179,117 120,919 65,527 PSUs - granted (114,750 ) (102,000 ) PSUs - cancelled 11,334 — — Shares available for grant at end of fiscal year 1,334,581 1,916,589 2,464,082

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Income (loss) before provision for income taxes	Income (loss) before provision for income taxes consists of the following (in thousands): Years Ended December 31, 2016 December 26, 2015 December 27, 2014 Domestic $ 25,372 $ 178 $ (15,691 ) Foreign 3,763 5,390 4,070 Income (loss) before income taxes $ 29,135 $ 5,568 $ (11,621 )
Provision (benefit) for income taxes	The provision (benefit) for income taxes consists of the following (in thousands): Years Ended December 31, 2016 December 26, 2015 December 27, 2014 Current: Federal $ 697 $ 148 $ 358 State 85 3 (151 ) Foreign 2,111 2,266 1,327 2,893 2,417 1,534 Deferred: Federal (16,641 ) 190 17,368 State (320 ) 3 550 Foreign (832 ) 53 45 (17,793 ) 246 17,963 Provision (benefit) for income taxes $ (14,900 ) $ 2,663 $ 19,497
Components of deferred tax assets and liabilities	Significant components of the Company's deferred tax assets and liabilities are as follows (in thousands): At December 31, 2016 December 26, 2015 Deferred tax assets: Reserves and accruals $ 11,043 $ 13,712 Deferred revenue 349 1,154 Shared based compensation 2,590 3,856 Tax credit carry-forwards 10,112 8,658 Net operating losses 8,434 13,218 Depreciation & amortization (2,898 ) 366 Other (1,252 ) 94 Total deferred tax assets 28,378 41,058 Less: Valuation allowance (10,980 ) (36,786 ) Total deferred tax assets net of valuation allowance 17,398 4,272 Deferred tax liabilities: Depreciation & amortization (6 ) (2,537 ) Other (14 ) (1,137 ) Total deferred tax liabilities (20 ) (3,674 ) Net deferred tax assets $ 17,378 $ 598
Income Tax Rate Reconciliation	Differences between income taxes computed by applying the statutory federal income tax rate to income (loss) before income taxes and the provision (benefit) for income taxes consist of the following (in thousands): Years Ended December 31, 2016 December 26, 2015 December 27, 2014 Income taxes computed at U.S. statutory rate $ 10,197 $ 1,949 $ (4,067 ) State income taxes 223 28 (109 ) Foreign tax rate differential 3,502 342 777 Change in valuation allowance (25,738 ) 1,648 23,894 Non-deductible Equity Compensation 380 311 242 Tax credits (3,191 ) (1,834 ) (2,187 ) Domestic production activities deduction (354 ) — — Liabilities for uncertain tax positions 67 74 118 Other, net 14 145 829 Provision (benefit) for income taxes $ (14,900 ) $ 2,663 $ 19,497
Reconciliation of unrecognized tax benefits	A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows (in thousands): Rollforward Table (at Gross): As of December 31, 2016 December 26, 2015 December 27, 2014 Unrecognized tax benefits - beginning of the period $ 6,961 $ 6,442 $ 4,436 Gross increases-tax positions in prior period 23 127 655 Gross decreases-tax positions in prior period (1,193 ) (306 ) (123 ) Gross increases-current-period tax positions 686 698 1,541 Lapse of statute of limitations — — (67 ) Unrecognized tax benefits - end of the period $ 6,477 $ 6,961 $ 6,442

Segment, Geographic, Product 37

Segment, Geographic, Product and Significant Customer Information (Tables)	12 Months Ended
	Dec. 31, 2016
Segment Reporting [Abstract]
Total net revenue	The following tables summarize total net revenues and long-lived assets (excluding intangible assets) attributed to significant countries (in thousands): Years Ended December 31, 2016 December 26, 2015 December 27, 2014 Total net revenues (1): South Korea $ 44,735 $ 30,572 $ 41,381 China 43,460 17,373 28,702 Singapore 37,096 17,395 7,905 United States 29,887 36,720 36,123 Taiwan 27,189 46,715 19,790 Japan 26,604 31,140 15,185 Other 12,158 7,452 17,357 Total net revenues $ 221,129 $ 187,367 $ 166,443 (1)
Long-lived tangible assets	December 31, 2016 December 26, 2015 Long-lived tangible assets: United States $ 42,688 $ 42,581 Taiwan 818 1,056 South Korea 554 697 Japan 57 59 All Other 109 100 Total long-lived tangible assets $ 44,226 $ 44,493
Revenues by product type	The Company’s product lines differ primarily based on the environment in which the systems will be used. Automated systems are used primarily in high-volume production environments. Materials characterization products are primarily used to measure the composition, band gap, structure, and other physical and electrical properties of semiconducting materials for discrete electronic industry, high brightness LED and solar/photovoltaic structures in both development and high volume environments. Integrated systems are installed inside wafer processing equipment to provide near real-time measurements for improving process control and increasing throughput. Revenues by product type were as follows (in thousands): Years Ended December 31, 2016 December 26, 2015 December 27, 2014 Automated Systems $ 127,378 $ 102,386 $ 108,768 Integrated Systems 43,846 31,579 15,334 Materials Characterization Systems 13,842 12,980 9,487 Total product revenues $ 185,066 $ 146,945 $ 133,589
Customers accounted for 10% or more of total accounts receivable	The following customers accounted for 10% or more of total accounts receivable, net: Years Ended December 31, 2016 December 26, 2015 December 27, 2014 Taiwan Semiconductor Manufacturing Company Limited 20.1 % 25.6 % 20.2 % Samsung Electronics Co. Ltd. 14.3 % *** 10.0 % Micron Technology, Inc. 11.8 % *** 23.7 % Intel Corporation 11.1 % *** *** Toshiba Corporation 10.2 % 27.1 % *** GLOBALFOUNDRIES *** *** 10.2 % *** The customer accounted for less than 10% of total accounts receivable, net, as of that period end.
Customers accounted for 10% or more of total revenue	The following customers accounted for 10% or more of total net revenue: Years Ended December 31, 2016 December 26, 2015 December 27, 2014 Micron Technology, Inc. 20.3 % 15.8 % 10.4 % Intel Corporation 18.0 % *** 12.6 % SK Hynix 15.3 % 10.7 % 12.2 % Taiwan Semiconductor Manufacturing Company Limited 10.0 % 19.4 % *** Samsung Electronics Co. Ltd. *** 13.2 % 26.9 % Toshiba Corporation *** 10.2 % *** *** The customer accounted for less than 10% of total net revenue during the period.

Nature of Business, Basis of 38

Nature of Business, Basis of Presentation and Significant Accounting Policies - Textual (Details) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)Customershares	Dec. 26, 2015USD ($)Customershares	Dec. 27, 2014USD ($)Customershares
Accounting Policies [Line Items]
Fiscal year duration	371 days	364 days	364 days
Products revenues	$ 185,066	$ 146,945	$ 133,589
Cost of products revenues	85,391	76,224	68,812
Service revenues	36,063	40,422	32,854
Cost of service revenues	20,160	19,450	19,086
Foreign currency transaction gain (loss)	$ (400)	500	100
Maximum period of delivery to customers	6 months
Maximum period services are provided over the fixed arrangement term	12 months
Maximum measurement period	1 year
Product warranty period	12 months
Advertising costs	$ 200	$ 300	$ 200
Potential dilutive common stock equivalents, using treasury stock method | shares	498	316	0
Anti-dilutive common stock equivalents excluded from calculation | shares			400
Number of Major Customer | Customer	5	5	5
Sales Revenue, Goods, Net [Member] | Customer Concentration Risk [Member]
Accounting Policies [Line Items]
Concentration of risk percentage	73.00%	69.00%	72.00%
Stock Options [Member]
Accounting Policies [Line Items]
Potential dilutive common stock equivalents, using treasury stock method | shares	500	300
Reclassification [Member]
Accounting Policies [Line Items]
Products revenues	$ 11,000
Cost of products revenues	$ 2,400
Service revenues		$ 7,900
Cost of service revenues		$ 3,000
Minimum [Member]
Accounting Policies [Line Items]
Fiscal year duration	364 days
Maximum [Member]
Accounting Policies [Line Items]
Fiscal year duration	371 days

Nature of Business, Basis of 39

Nature of Business, Basis of Presentation and Significant Accounting Policies - Estimated Useful Lives of Property, Plant and Equipment (Details)	12 Months Ended
	Dec. 31, 2016
Building and Improvements [Member] | Minimum [Member]
Accounting Policies [Line Items]
Estimated useful lives of depreciable assets	5 years
Building and Improvements [Member] | Maximum [Member]
Accounting Policies [Line Items]
Estimated useful lives of depreciable assets	40 years
Machinery and equipment [Member] | Minimum [Member]
Accounting Policies [Line Items]
Estimated useful lives of depreciable assets	3 years
Machinery and equipment [Member] | Maximum [Member]
Accounting Policies [Line Items]
Estimated useful lives of depreciable assets	10 years
Furniture and fixtures [Member] | Minimum [Member]
Accounting Policies [Line Items]
Estimated useful lives of depreciable assets	3 years
Furniture and fixtures [Member] | Maximum [Member]
Accounting Policies [Line Items]
Estimated useful lives of depreciable assets	10 years
Software [Member] | Minimum [Member]
Accounting Policies [Line Items]
Estimated useful lives of depreciable assets	3 years
Software [Member] | Maximum [Member]
Accounting Policies [Line Items]
Estimated useful lives of depreciable assets	7 years

Nature of Business, Basis of 40

Nature of Business, Basis of Presentation and Significant Accounting Policies - Estimated Useful Lives of Intangible Assets (Details)	12 Months Ended
	Dec. 31, 2016
Minimum [Member]
Accounting Policies [Line Items]
Finite-lived intangibles estimated lives	2 years
Maximum [Member]
Accounting Policies [Line Items]
Finite-lived intangibles estimated lives	10 years
Developed technology [Member] | Minimum [Member]
Accounting Policies [Line Items]
Finite-lived intangibles estimated lives	5 years
Developed technology [Member] | Maximum [Member]
Accounting Policies [Line Items]
Finite-lived intangibles estimated lives	10 years
Customer relationships [Member] | Minimum [Member]
Accounting Policies [Line Items]
Finite-lived intangibles estimated lives	2 years
Customer relationships [Member] | Maximum [Member]
Accounting Policies [Line Items]
Finite-lived intangibles estimated lives	10 years
Brand name [Member] | Minimum [Member]
Accounting Policies [Line Items]
Finite-lived intangibles estimated lives	5 years
Brand name [Member] | Maximum [Member]
Accounting Policies [Line Items]
Finite-lived intangibles estimated lives	10 years
Patented technology [Member] | Minimum [Member]
Accounting Policies [Line Items]
Finite-lived intangibles estimated lives	7 years
Patented technology [Member] | Maximum [Member]
Accounting Policies [Line Items]
Finite-lived intangibles estimated lives	10 years
Trademark [Member]
Accounting Policies [Line Items]
Finite-lived intangibles estimated lives	5 years

Fair Value Measurements and D41

Fair Value Measurements and Disclosures - Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 26, 2015
Assets:
Total marketable securities	$ 82,899	$ 44,931
Fair Value, Measurements, Recurring [Member]
Assets:
Total cash equivalents	3,458	5,158
Total marketable securities	82,899	44,931
Total	86,357	50,089
Liabilities:
Contingent consideration payable	0	1,490
Money market funds [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Total cash equivalents	959	590
Commercial paper and corporate debt securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Total cash equivalents	2,499	4,568
U.S. Treasury, U.S. Government and U.S. Government agency debt securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Total marketable securities	17,072	24,565
Certificates of deposits [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Total marketable securities	23,019	0
Commercial paper [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Total marketable securities	22,402	1,884
Municipal securities and corporate debt securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Total marketable securities	14,943	18,482
Asset-backed Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Total marketable securities	5,463	0
Cash [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Total cash equivalents	43,600	33,000
Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Total cash equivalents	959	590
Total marketable securities	0	4,401
Total	959	4,991
Liabilities:
Contingent consideration payable	0	0
Level 1 [Member] | Money market funds [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Total cash equivalents	959	590
Level 1 [Member] | Commercial paper and corporate debt securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Total cash equivalents	0	0
Level 1 [Member] | U.S. Treasury, U.S. Government and U.S. Government agency debt securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Total marketable securities	0	4,401
Level 1 [Member] | Certificates of deposits [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Total marketable securities	0	0
Level 1 [Member] | Commercial paper [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Total marketable securities	0	0
Level 1 [Member] | Municipal securities and corporate debt securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Total marketable securities	0	0
Level 1 [Member] | Asset-backed Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Total marketable securities	0	0
Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Total cash equivalents	2,499	4,568
Total marketable securities	82,899	40,530
Total	85,398	45,098
Liabilities:
Contingent consideration payable	0	0
Level 2 [Member] | Money market funds [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Total cash equivalents	0	0
Level 2 [Member] | Commercial paper and corporate debt securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Total cash equivalents	2,499	4,568
Level 2 [Member] | U.S. Treasury, U.S. Government and U.S. Government agency debt securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Total marketable securities	17,072	20,164
Level 2 [Member] | Certificates of deposits [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Total marketable securities	23,019	0
Level 2 [Member] | Commercial paper [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Total marketable securities	22,402	1,884
Level 2 [Member] | Municipal securities and corporate debt securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Total marketable securities	14,943	18,482
Level 2 [Member] | Asset-backed Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Total marketable securities	5,463	0
Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Total cash equivalents	0	0
Total marketable securities	0	0
Total	0	0
Liabilities:
Contingent consideration payable	0	1,490
Level 3 [Member] | Money market funds [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Total cash equivalents	0	0
Level 3 [Member] | Commercial paper and corporate debt securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Total cash equivalents	0	0
Level 3 [Member] | U.S. Treasury, U.S. Government and U.S. Government agency debt securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Total marketable securities	0	0
Level 3 [Member] | Certificates of deposits [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Total marketable securities	0	0
Level 3 [Member] | Commercial paper [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Total marketable securities	0	0
Level 3 [Member] | Municipal securities and corporate debt securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Total marketable securities	0	0
Level 3 [Member] | Asset-backed Securities [Member] | Fair Value, Measurements, Recurring [Member]
Assets:
Total marketable securities	$ 0	$ 0

Fair Value Measurements and D42

Fair Value Measurements and Disclosures - Unobservable Input Reconciliation (Details) - Level 3 [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015
Fair value measurement on recurring basis, unobservable input reconciliation [Roll Forward]
Fair value, beginning balance	$ 1,490	$ 2,397
Change in fair value included in earnings	(1,175)	(56)
Fair Value, ending balance		1,490
Zygo Corporation [Member]
Fair value measurement on recurring basis, unobservable input reconciliation [Roll Forward]
Payments made to Zygo Corporation	$ (315)	$ (851)

Fair Value Measurements and D43

Fair Value Measurements and Disclosures - Textual (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015
Forward Foreign Currency Contracts [Member]
Fair Value Measurements and Disclosures (Textual) [Abstract]
Derivative term	30 days
Forward Foreign Currency Contracts [Member] | Other Income (Expense), Net [Member]
Fair Value Measurements and Disclosures (Textual) [Abstract]
Gain (loss) on settlement of derivatives	$ (1.7)	$ (0.3)
Zygo Corporation [Member]
Fair Value Measurements and Disclosures (Textual) [Abstract]
Liabilities settled from acquisition	$ 1.2
Fair Value, Measurements, Recurring [Member] | Zygo Corporation [Member]
Fair Value Measurements and Disclosures (Textual) [Abstract]
Liabilities resulting from the acquisition of certain assets from acquisitions, measured at fair value		1.5
Current liability at fair value		0.9
Long-term liability at fair value		$ 0.6

Fair Value Measurements and D44

Fair Value Measurements and Disclosures - Outstanding Derivative Instruments (Details) - USD ($)	Dec. 31, 2016	Dec. 26, 2015
Not Designated as Hedging Instrument [Member] | Forward Foreign Currency Contracts [Member]
Derivatives Fair Value [Line Items]
Notional Principal	$ 13,900,000	$ 30,500,000

Cash and Investments (Details)

Cash and Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 26, 2015
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	$ 129,959	$ 83,148
Gross Unrealized Gains	19	2
Gross Unrealized Losses	(17)	(65)
Estimated Fair Market Value	129,961	83,085
Commercial paper [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	22,402	1,884
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Market Value	22,402	1,884
U.S. Government agency securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	11,412	20,193
Gross Unrealized Gains	0	1
Gross Unrealized Losses	(7)	(29)
Estimated Fair Market Value	11,405	20,165
Corporate debt securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	14,194	14,759
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(6)	(23)
Estimated Fair Market Value	14,188	14,736
Asset-backed Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	5,466
Gross Unrealized Gains	0
Gross Unrealized Losses	(3)
Estimated Fair Market Value	5,463
Cash [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	43,604	32,996
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Market Value	43,604	32,996
Money market funds [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	959	590
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Market Value	959	590
U.S. Treasury securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	5,667	4,411
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	(10)
Estimated Fair Market Value	5,667	4,401
Certificates of deposits [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	23,000
Gross Unrealized Gains	19
Gross Unrealized Losses	0
Estimated Fair Market Value	23,019
Commercial paper and corporate debt securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	2,499	4,568
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Market Value	2,499	4,568
Municipal securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	756	3,747
Gross Unrealized Gains	0	1
Gross Unrealized Losses	(1)	(3)
Estimated Fair Market Value	$ 755	$ 3,745

Cash and Investments - Addition

Cash and Investments - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Investments Debt And Equity Securities [Abstract]
Net realized gains and losses	$ 0.5	$ 0.2	$ 0.2
Investment maturity period, less than	2 years	2 years

Accounts Receivable - Textual (

Accounts Receivable - Textual (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015
Accounts Receivable (Additional Textual) [Abstract]
Sold receivables amount	$ 31,500,000	$ 15,700,000
Gains or losses on sale of accounts receivables	0	0
Due from unrelated third parties	$ 0	$ 0
Minimum [Member]
Accounts Receivable (Textual) [Abstract]
Administrative fees as well as interest percent	0.77%
Maximum [Member]
Accounts Receivable (Textual) [Abstract]
Administrative fees as well as interest percent	1.68%

Financial Statement Component48

Financial Statement Components - Selected Financial Statement Components (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Inventories:
Raw materials and sub-assemblies	$ 23,506	$ 26,784
Work in process	10,347	12,862
Finished goods	4,984	8,103
Inventories	38,837	47,749
Inventories-delivered systems	2,457	2,856
Total inventories	41,294	50,605
Property, plant and equipment, net:
Total property, plant and equipment, gross	86,545	80,561
Accumulated depreciation and amortization	(42,319)	(36,068)
Total property, plant and equipment, net	44,226	44,493
Depreciation and amortization expense	6,800	6,900	$ 6,600
Accrued warranty	3,838	4,504	$ 2,953
Accrued taxes	290	646
Customer deposits	581	290
Retrofit liability	432
Fair value of current portion of contingent payments to Zygo Corporation related to acquisition		945
Accrued professional services	424	481
Accrued royalties	1,233	437
Other	1,249	1,575
Total other current liabilities	8,047	8,878
Land [Member]
Property, plant and equipment, net:
Total property, plant and equipment, gross	15,568	15,569
Building and improvements [Member]
Property, plant and equipment, net:
Total property, plant and equipment, gross	20,532	20,158
Machinery and equipment [Member]
Property, plant and equipment, net:
Total property, plant and equipment, gross	35,659	32,995
Furniture and fixtures [Member]
Property, plant and equipment, net:
Total property, plant and equipment, gross	2,282	2,266
Software [Member]
Property, plant and equipment, net:
Total property, plant and equipment, gross	9,756	8,245
Capital in progress [Member]
Property, plant and equipment, net:
Total property, plant and equipment, gross	$ 2,748	$ 1,328

Financial Statement Component49

Financial Statement Components - Components of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning of period	$ (5,202)	$ (2,769)
Current period change	(844)	(2,433)	$ (3,381)
End of period	(6,046)	(5,202)	(2,769)
Foreign Currency Translations [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning of period	(4,948)	(2,604)
Current period change	(869)	(2,344)
End of period	(5,817)	(4,948)	(2,604)
Defined Benefit Pension Plans [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning of period	(210)	(134)
Current period change	(17)	(76)
End of period	(227)	(210)	(134)
Unrealized Income (Loss) on Investment [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning of period	(44)	(31)
Current period change	42	(13)
End of period	$ (2)	$ (44)	$ (31)

Goodwill and Intangible Asset50

Goodwill and Intangible Assets - Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015
Goodwill [Roll Forward]
Beginning balance	$ 9,415	$ 10,494
Foreign currency movements	(475)	(1,079)
Ending balance	$ 8,940	$ 9,415

Goodwill and Intangible Asset51

Goodwill and Intangible Assets - Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 26, 2015
Summary of Finite-lived intangible assets
Adjusted cost	$ 29,307	$ 29,721
Accumulated amortization	(28,895)	(27,854)
Finite lived intangible assets, Net carrying amount	412	1,867
Developed technology [Member]
Summary of Finite-lived intangible assets
Adjusted cost	15,726	16,098
Accumulated amortization	(15,380)	(14,387)
Finite lived intangible assets, Net carrying amount	346	1,711
Customer relationships [Member]
Summary of Finite-lived intangible assets
Adjusted cost	9,322	9,364
Accumulated amortization	(9,322)	(9,364)
Finite lived intangible assets, Net carrying amount	0	0
Brand names [Member]
Summary of Finite-lived intangible assets
Adjusted cost	1,927	1,927
Accumulated amortization	(1,927)	(1,903)
Finite lived intangible assets, Net carrying amount		24
Patented technology [Member]
Summary of Finite-lived intangible assets
Adjusted cost	2,252	2,252
Accumulated amortization	(2,186)	(2,120)
Finite lived intangible assets, Net carrying amount	66	132
Trademark [Member]
Summary of Finite-lived intangible assets
Adjusted cost	80	80
Accumulated amortization	(80)	(80)
Finite lived intangible assets, Net carrying amount	$ 0	$ 0

Goodwill and Intangible Asset52

Goodwill and Intangible Assets - Textual (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Finite-Lived Intangible Assets [Line Items]
Total amortization expense	$ 1,500,000	$ 2,100,000	$ 3,100,000
Impairment charges	$ 0
Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangibles estimated lives	2 years
Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangibles estimated lives	10 years

Goodwill and Intangible Asset53

Goodwill and Intangible Assets - Future Amortization (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 26, 2015
Estimated future amortization expense
2,017	$ 206
2,018	140
2,019	66
Thereafter	0
Finite lived intangible assets, Net carrying amount	$ 412	$ 1,867

Warranties - Textual (Details)

Warranties - Textual (Details)	12 Months Ended
	Dec. 31, 2016
Product Warranties Disclosures [Abstract]
Product warranty period	12 months

Warranties (Details)

Warranties (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015
Components of the warranty accrual [Roll Forward]
Balance as of beginning of period	$ 4,504	$ 2,953
Accruals for warranties issued during period	4,509	8,332
Settlements during the period	(5,175)	(6,781)
Balance as of end of period	$ 3,838	$ 4,504

Restructuring - Textual (Detail

Restructuring - Textual (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Restructuring Cost And Reserve [Line Items]
Restructuring charge	$ 0	$ 1,380	$ 2,266
Employee severance and benefits [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring charge	$ 0	$ 1,369	$ 1,163

Restructuring (Details)

Restructuring (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Restructuring Reserve [Roll Forward]
Beginning Balance	$ 256	$ 997	$ 0
Charges	0	1,380	2,266
Cash Payments	(256)	(2,121)	(1,269)
Ending Balance	0	256	997
Employee severance and benefits [Member]
Restructuring Reserve [Roll Forward]
Beginning Balance	0	383	0
Charges	0	1,369	1,163
Cash Payments	0	(1,752)	(780)
Ending Balance	0	0	383
Facility termination costs [Member]
Restructuring Reserve [Roll Forward]
Beginning Balance	249	583	0
Charges	0	0	784
Cash Payments	(249)	(334)	(201)
Ending Balance	0	249	583
Other [Member]
Restructuring Reserve [Roll Forward]
Beginning Balance	7	31	0
Charges	0	11	319
Cash Payments	(7)	(35)	(288)
Ending Balance	$ 0	$ 7	$ 31

Line of Credit and Debt Oblig58

Line of Credit and Debt Obligations - Textual (Details) - Revolving line of credit facility [Member] - USD ($)	12 Months Ended
	Dec. 31, 2016	May 30, 2016
Debt Instrument [Line Items]
Expiration date	May 30, 2016
Maximum amount of credit facility		$ 12,000,000

Commitments and Contingencies -

Commitments and Contingencies - Textual (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Long Term Purchase Commitment [Line Items]
Liabilities recorded for obligations	$ 0	$ 0
Rent expense	1,800,000	1,700,000	$ 2,000,000
Zygo Corporation [Member]
Long Term Purchase Commitment [Line Items]
Payments for royalty	300,000	$ 900,000
Inventories [Member]
Long Term Purchase Commitment [Line Items]
Purchase commitment	$ 30,600,000

Commitments and Contingencies60

Commitments and Contingencies - Future minimum lease payments (Details) $ in Thousands	Dec. 31, 2016USD ($)
Future minimum lease payments under operating leases
2,017	$ 1,562
2,018	1,189
2,019	755
2,020	301
2,021	79
Thereafter	0
Total	$ 3,886

Net Income (Loss) Per Share (De

Net Income (Loss) Per Share (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Reconciliation of the basic and diluted net income per share computations
Weighted average common shares outstanding used in basic net income (loss) per share calculation	24,655	24,059	23,958
Potential dilutive common stock equivalents, using treasury stock method	498	316	0
Weighted average shares used in diluted net income (loss) per share calculation	25,153	24,375	23,958

Net Income (Loss) Per Share - T

Net Income (Loss) Per Share - Textual (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Earnings Per Share [Abstract]
Weighted average common share equivalents consisting of stock options included in the calculation of diluted net income per share	498	316	0
Anti-dilutive common stock equivalents excluded from calculation			400

Stockholders' Equity and Stoc63

Stockholders' Equity and Stock-Based Compensation - Textual (Details)	May 24, 2013shares	Dec. 31, 2016USD ($)$ / sharesshares	Dec. 26, 2015USD ($)$ / sharesshares	Dec. 27, 2014USD ($)$ / sharesshares	May 29, 2012USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock authorized		47,000,000	47,000,000
Common stock, par value per share | $ / shares		$ 0.001	$ 0.001
Shares of preferred stock authorized		3,000,000	3,000,000
Preferred stock, par value per share | $ / shares		$ 0.001	$ 0.001
Number of shares repurchased and retired		0	111,050	362,633
Amount available for repurchase at end of period | $			$ 4,397,000	$ 6,118,000
Weighted average fair value per share of stock options | $ / shares				$ 8.13
Number of options granted		0	0	74,300
Closing stock price | $ / shares		$ 25.06
Intrinsic value of options exercised | $		$ 2,700,000	$ 1,600,000	$ 3,000,000
Fair value of options vested | $		700,000	1,500,000	3,200,000
Unrecognized compensation costs | $		200,000
Excess tax benefit | $		$ 1,000,000	$ 0	$ 0
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum percentage of salary withholdings		10.00%
Purchase price of common stock, percent		85.00%
Shares remaining for issuance under the ESPP		100,000
Shares purchased under the ESPP		212,619	125,504	122,112
Weighted average price of shares issued (in dollars per share) | $ / shares		$ 14.29	$ 13.98	$ 13.76
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average remaining amortization period for unrecognized compensation costs		1 year 9 months 7 days
Shares per unit granted		1.7
Granted (in shares)		476,667	506,459
Unrecognized compensation costs | $		$ 8,000,000
Cancelled (in shares)		54,253	119,033
Restricted Stock Units (RSUs) [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Period of vesting		3 years
Restricted Stock Units (RSUs) [Member] | Key Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)		476,667	506,459
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average remaining amortization period for unrecognized compensation costs		7 months 24 days
Performance-Based Restricted Stock Units (PSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)		67,500	60,000
Percent of granted shares that will vest if target stock price performance is achieved		66.70%
Maximum percent of granted shares that will vest if maximum stock price performance is achieved		100.00%
Cancelled (in shares)		6,667
Performance-Based Restricted Stock Units (PSUs) [Member] | Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Period of vesting		1 year
Performance-Based Restricted Stock Units (PSUs) [Member] | Tranche Two [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Period of vesting		2 years
Performance-Based Restricted Stock Units (PSUs) [Member] | Tranche Three [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Period of vesting		3 years
2012 Share Repurchase Program [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amount available for repurchase at end of period | $		$ 4,400,000
May 29, 2012 Program [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum amount of common stock approved to repurchase, Value | $					$ 20,000,000
2005 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Ratio of restricted stock units against available for grant pool	1.7
Number of shares of common stock authorized	2,600,000	7,292,594
Option term	7 years
2005 Equity Incentive Plan [Member] | Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)		810,334
Cancelled (in shares)		92,230
2005 Equity Incentive Plan [Member] | Performance-Based Restricted Stock Units (PSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)		114,750
Cancelled (in shares)		11,334

Stockholders' Equity and Stoc64

Stockholders' Equity and Stock-Based Compensation - Share Repurchases (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of shares of common stock repurchased	0	111,050	362,633
Weighted average price (in dollars per share)		$ 15.49	$ 14.74
Total cost of repurchase		$ 1,721	$ 5,344
Amount available for repurchase at end of period		$ 4,397	$ 6,118

Stockholders' Equity and Stoc65

Stockholders' Equity and Stock-Based Compensation - Option Plans (Details) - shares	Dec. 31, 2016	May 24, 2013
2005 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Authorized	7,292,594	2,600,000
2002 Non-statutory Stock Option Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Authorized	1,200,000
2000 Employee Stock Option Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Authorized	2,450,000
2000 Director Stock Option Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Authorized	250,000
Accent Optical Technologies, Inc. Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Authorized	205,003

Stockholders' Equity and Stoc66

Stockholders' Equity and Stock-Based Compensation - Stock Options and Employee Stock Purchase Plan Assumptions (Details)	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Stock Options [Member]
Assumption of stock option's fair value
Expected life			4 years 7 months 6 days
Volatility			54.90%
Risk free interest rate			1.54%
Dividends			0.00%
Employee Stock Purchase Plan [Member]
Assumption of stock option's fair value
Expected life	6 months	6 months	6 months
Volatility	38.70%	36.90%	31.20%
Risk free interest rate	0.44%	0.12%	0.54%
Dividends	0.00%	0.00%	0.00%

Stockholders' Equity and Stoc67

Stockholders' Equity and Stock-Based Compensation - Summary of Activity of Stock Options (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Activity of stock option plans [Roll Forward]
Number of Shares Outstanding (Options), Beginning Balance (in shares)	1,059,471	1,382,993
Number of Shares Outstanding (Options), Exercised (in shares)	(442,339)	(229,510)
Number of Shares Outstanding (Options), Cancelled/Forfeited (in shares)	(176,587)	(94,012)	(191,061)
Number of Shares Outstanding (Options), Ending Balance (in shares)	440,545	1,059,471	1,382,993
Number of Shares Outstanding (Options), Exercisable (in shares)	407,920
Weighted average exercise price for stock option plans [Roll Forward]
Weighted Average Exercise Price, Beginning Balance (in dollars per share)	$ 14.61	$ 13.92
Weighted Average Exercise Price, Exercised (in dollars per share)	13.66	9.65
Weighted Average Exercise Price, Cancelled/Forfeited (in dollars per share)	15.83	16.67
Weighted Average Exercise Price, Ending Balance (in dollars per share)	15.06	$ 14.61	$ 13.92
Weighted Average Exercise Price, Exercisable (in dollars per share)	$ 14.94
Weighed Average Remaining Contractual Term, Outstanding	2 years 1 month 13 days	2 years 5 months 19 days	3 years 4 months 28 days
Weighed Average Remaining Contractual Term, Exercisable	2 years
Aggregate Intrinsic Value, Outstanding	$ 4,405	$ 1,920	$ 4,108
Aggregate Intrinsic Value, Exercisable	$ 4,129

Stockholders' Equity and Stoc68

Stockholders' Equity and Stock-Based Compensation - Ranges of Outstanding and Exercisable Options (Details) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number Outstanding (in shares)	440,545	1,059,471	1,382,993
Options Outstanding, Weighted Average Remaining Contractual Life (Years)	2 years 1 month 13 days	2 years 5 months 19 days	3 years 4 months 28 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 15.06	$ 14.61	$ 13.92
Options Exercisable, Number Exercisable (in shares)	407,920
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 14.94
$9.5-$10.46 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, Lower Range Limit	9.5
Exercise Price, Upper Range Limit	$ 10.46
Options Outstanding, Number Outstanding (in shares)	17,400
Options Outstanding, Weighted Average Remaining Contractual Life (Years)	3 months 26 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 10.05
Options Exercisable, Number Exercisable (in shares)	17,400
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 10.05
$11.37-$11.37 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, Lower Range Limit	11.37
Exercise Price, Upper Range Limit	$ 11.37
Options Outstanding, Number Outstanding (in shares)	114,166
Options Outstanding, Weighted Average Remaining Contractual Life (Years)	10 months 17 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 11.37
Options Exercisable, Number Exercisable (in shares)	114,166
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 11.37
$12.98-$15.33 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, Lower Range Limit	12.98
Exercise Price, Upper Range Limit	$ 15.33
Options Outstanding, Number Outstanding (in shares)	45,691
Options Outstanding, Weighted Average Remaining Contractual Life (Years)	3 years 4 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 14.36
Options Exercisable, Number Exercisable (in shares)	38,954
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 14.34
$15.35-$15.74 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, Lower Range Limit	15.35
Exercise Price, Upper Range Limit	$ 15.74
Options Outstanding, Number Outstanding (in shares)	44,437
Options Outstanding, Weighted Average Remaining Contractual Life (Years)	2 years 6 months 29 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 15.65
Options Exercisable, Number Exercisable (in shares)	40,586
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 15.65
$15.85-$15.85 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, Lower Range Limit	15.85
Exercise Price, Upper Range Limit	$ 15.85
Options Outstanding, Number Outstanding (in shares)	60,000
Options Outstanding, Weighted Average Remaining Contractual Life (Years)	3 years 2 months 9 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 15.85
Options Exercisable, Number Exercisable (in shares)	56,250
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 15.85
$15.97-$17.33 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, Lower Range Limit	15.97
Exercise Price, Upper Range Limit	$ 17.33
Options Outstanding, Number Outstanding (in shares)	57,166
Options Outstanding, Weighted Average Remaining Contractual Life (Years)	2 years 3 months 18 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 16.89
Options Exercisable, Number Exercisable (in shares)	48,527
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 16.85
$17.7-$18.27 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, Lower Range Limit	17.7
Exercise Price, Upper Range Limit	$ 18.27
Options Outstanding, Number Outstanding (in shares)	36,935
Options Outstanding, Weighted Average Remaining Contractual Life (Years)	2 years 4 months 2 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 18.12
Options Exercisable, Number Exercisable (in shares)	33,267
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 18.15
$18.51-$18.51 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, Lower Range Limit	18.51
Exercise Price, Upper Range Limit	$ 18.51
Options Outstanding, Number Outstanding (in shares)	13,750
Options Outstanding, Weighted Average Remaining Contractual Life (Years)	4 years 1 month 17 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 18.51
Options Exercisable, Number Exercisable (in shares)	8,333
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 18.51
$18.79-$18.79 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, Lower Range Limit	18.79
Exercise Price, Upper Range Limit	$ 18.79
Options Outstanding, Number Outstanding (in shares)	1,000
Options Outstanding, Weighted Average Remaining Contractual Life (Years)	4 years 2 months 23 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 18.79
Options Exercisable, Number Exercisable (in shares)	437
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 18.79
$19.03-$19.03 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, Lower Range Limit	19.03
Exercise Price, Upper Range Limit	$ 19.03
Options Outstanding, Number Outstanding (in shares)	50,000
Options Outstanding, Weighted Average Remaining Contractual Life (Years)	2 years 1 month 17 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 19.03
Options Exercisable, Number Exercisable (in shares)	50,000
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 19.03
$9.5-$19.03 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, Lower Range Limit	9.5
Exercise Price, Upper Range Limit	$ 19.03
Options Outstanding, Number Outstanding (in shares)	440,545
Options Exercisable, Number Exercisable (in shares)	407,920

Stockholders' Equity and Stoc69

Stockholders' Equity and Stock-Based Compensation - Restricted Stock Unit Activity (Details) - Restricted Stock Units (RSUs) [Member] - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015
Activity for RSUs [Roll Forward]
Number of units Beginning balance (in shares)	713,243	563,337
Number of units, Granted (in shares)	476,667	506,459
Number of units, Released (in shares)	(315,872)	(237,520)
Number of units, Cancelled (in shares)	(54,253)	(119,033)
Number of units, Ending balance (in shares)	819,785	713,243
Weighted Average Fair Value for RSUs [Roll Forward]
Weighted Average Fair Value, Beginning balance (in dollars per share)	$ 15.99	$ 17.90
Weighted Average Fair Value, Granted (in dollars per share)	17.45	15.62
Weighted Average Fair Value, Released (in dollars per share)	16.05	16.59
Weighted Average Fair Value, Cancelled (in dollars per share)	16.29	16.59
Weighted Average Fair Value, Ending balance (in dollars per share)	$ 16.79	$ 15.99

Stockholders' Equity and Stoc70

Stockholders' Equity and Stock-Based Compensation - Performance Stock Units Activity (Details) - Performance-Based Restricted Stock Units (PSUs) [Member] - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015
Activity for PSUs [Roll Forward]
Number of units Beginning balance (in shares)	60,000
Number of units, Granted (in shares)	67,500	60,000
Number of units, Released (in shares)	(13,333)
Number of units, Cancelled (in shares)	(6,667)
Number of units, Ending balance (in shares)	107,500	60,000
Weighted Average Fair Value for PSUs [Roll Forward]
Weighted Average Fair Value, Beginning balance (in dollars per share)	$ 12.23
Weighted Average Fair Value, Granted (in dollars per share)	8.52	$ 12.23
Weighted Average Fair Value, Released (in dollars per share)	12.03
Weighted Average Fair Value, Cancelled (in dollars per share)	12.03
Weighted Average Fair Value, Ending balance (in dollars per share)	$ 9.94	$ 12.23

Stockholders' Equity and Stoc71

Stockholders' Equity and Stock-Based Compensation - Performance Stock Units Valuation Assumptions (Details) - Performance-Based Restricted Stock Units (PSUs) [Member] - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant Date Fair Value Per Share (in dollars per share)	$ 8.52	$ 12.23
Expected Dividend	0.00%	0.00%
Risk free interest rate	0.92%
Range of risk-free interest rates, minimum		0.25%
Range of risk-free interest rates, maximum		1.10%
Range of expected volatilities for peer group, minimum	22.00%	23.00%
Range of expected volatilities for peer group, maximum	93.00%	65.00%

Stockholders' Equity and Stoc72

Stockholders' Equity and Stock-Based Compensation - Stock Option Plans Activity Including Options, RSUs and PSUs (Details) - shares	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Activity of stock option plans including options and RSUs [Roll Forward]
Options granted (in shares)	0	0	(74,300)
Options cancelled (in shares)	176,587	94,012	191,061
Options - expired plan shares (in shares)	(116,192)	(1,800)	(17,491)
Stock Options, RSUs and PSUs [Member]
Activity of stock option plans including options and RSUs [Roll Forward]
Number of Shares Outstanding (Options), Beginning Balance (in shares)	1,916,589	2,464,082	2,937,001
Number of Shares Outstanding (Options), Ending Balance (in shares)	1,334,581	1,916,589	2,464,082
Restricted Stock Units - Equivalent Shares [Member]
Activity of stock option plans including options and RSUs [Roll Forward]
Granted (in shares)	(810,334)	(860,980)	(805,120)
Cancelled (in shares)	92,230	202,356	167,404
RSUs - shares issued to satisfy tax withholding obligations (in shares)	179,117	120,919	65,527
Performance Stock Units - Equivalent Shares [Member]
Activity of stock option plans including options and RSUs [Roll Forward]
Granted (in shares)	(114,750)	(102,000)	0
Cancelled (in shares)	11,334	0	0

Stockholders' Equity and Stoc73

Stockholders' Equity and Stock-Based Compensation - Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense related to employee stock options and employee stock purchases	$ 7,666	$ 6,248	$ 6,752
Cost of products [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense related to employee stock options and employee stock purchases	403	274	268
Cost of service [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense related to employee stock options and employee stock purchases	509	309	287
Research and development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense related to employee stock options and employee stock purchases	1,408	1,036	1,245
Selling [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense related to employee stock options and employee stock purchases	2,046	1,881	1,642
General and administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense related to employee stock options and employee stock purchases	$ 3,300	$ 2,748	3,243
Restructuring [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense related to employee stock options and employee stock purchases			$ 67

Defined Benefit Pension Plan (D

Defined Benefit Pension Plan (Details) - Pension Plans, Defined Benefit [Member] - USD ($) $ in Millions	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 0.2	$ 0.2	$ 0.2
Net funding deficiency of the Benefit Plan	$ 0.4	$ 0.3	$ 0.3

Income Taxes - Income (Loss) Be

Income Taxes - Income (Loss) Before Provision for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Income Tax Disclosure [Abstract]
Domestic	$ 25,372	$ 178	$ (15,691)
Foreign	3,763	5,390	4,070
Income (loss) before income taxes	$ 29,135	$ 5,568	$ (11,621)

Income Taxes - Provision (Benef

Income Taxes - Provision (Benefit) for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Current:
Federal	$ 697	$ 148	$ 358
State	85	3	(151)
Foreign	2,111	2,266	1,327
Total current	2,893	2,417	1,534
Deferred:
Federal	(16,641)	190	17,368
State	(320)	3	550
Foreign	(832)	53	45
Total deferred	(17,793)	246	17,963
Provision (benefit) for income taxes	$ (14,900)	$ 2,663	$ 19,497

Income Taxes - Components of De

Income Taxes - Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 26, 2015
Deferred tax assets:
Reserves and accruals	$ 11,043	$ 13,712
Deferred revenue	349	1,154
Shared based compensation	2,590	3,856
Tax credit carry-forwards	10,112	8,658
Net operating losses	8,434	13,218
Depreciation & amortization	(2,898)	366
Other	(1,252)	94
Total deferred tax assets	28,378	41,058
Less: Valuation allowance	(10,980)	(36,786)
Total deferred tax assets net of valuation allowance	17,398	4,272
Deferred tax liabilities:
Depreciation & amortization	(6)	(2,537)
Other	(14)	(1,137)
Total deferred tax liabilities	(20)	(3,674)
Net deferred tax assets	$ 17,378	$ 598

Income Taxes - Textual (Details

Income Taxes - Textual (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014	Dec. 28, 2013
Operating Loss Carryforwards [Line Items]
Excess benefits due to stock option exercise	$ 200
Excess tax benefits recorded to additional paid in capital	100
Change in amount of operating loss carryforwards valuation allowance	(25,800)	$ 1,600
Decrease in valuation allowance for deferred tax assets	27,400
Undistributed earnings from non-U.S. operations	3,700
Maximum amount company recognize from unrecognized tax benefit	6,477	$ 6,961	$ 6,442	$ 4,436
Unrecognized tax benefits that would impact effective tax rate if recognized	3,700
California [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	26,700
State research and experimental tax credit carryforward	7,800
California [Member] | Excess Tax Benefit Related to Exercise of Stock Option [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	3,100
State research and experimental tax credit carryforward	200
Foreign Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	31,800
Foreign Tax Authority [Member] | Excess Tax Benefit Related to Exercise of Stock Option [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	1,300
Federal [Member]
Operating Loss Carryforwards [Line Items]
State research and experimental tax credit carryforward	$ 8,600

Income Taxes - Income Tax Rate

Income Taxes - Income Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Income Tax Expense Benefit Continuing Operations Income Tax Reconciliation [Abstract]
Income taxes computed at U.S. statutory rate	$ 10,197	$ 1,949	$ (4,067)
State income taxes	223	28	(109)
Foreign tax rate differential	3,502	342	777
Change in valuation allowance	(25,738)	1,648	23,894
Non-deductible Equity Compensation	380	311	242
Tax credits	(3,191)	(1,834)	(2,187)
Domestic production activities deduction	(354)
Liabilities for uncertain tax positions	67	74	118
Other, net	14	145	829
Provision (benefit) for income taxes	$ (14,900)	$ 2,663	$ 19,497

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Reconciliation Of Unrecognized Tax Benefits Excluding Amounts Pertaining To Examined Tax Returns Roll Forward
Unrecognized tax benefits - beginning of the period	$ 6,961	$ 6,442	$ 4,436
Gross increases-tax positions in prior period	23	127	655
Gross decreases-tax positions in prior period	(1,193)	(306)	(123)
Gross increases-current-period tax positions	686	698	1,541
Lapse of statute of limitations		0	(67)
Unrecognized tax benefits - end of the period	$ 6,477	$ 6,961	$ 6,442

Segment, Geographic, Product 81

Segment, Geographic, Product and Significant Customer Information - Revenue Net (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)segment	Dec. 26, 2015USD ($)	Dec. 27, 2014USD ($)
Revenues From External Customers And Long Lived Assets [Line Items]
Number of operating segments | segment	1
Net revenues:
Total net revenues	$ 221,129	$ 187,367	$ 166,443
South Korea [Member]
Net revenues:
Total net revenues	44,735	30,572	41,381
China [Member]
Net revenues:
Total net revenues	43,460	17,373	28,702
Singapore [Member]
Net revenues:
Total net revenues	37,096	17,395	7,905
United States [Member]
Net revenues:
Total net revenues	29,887	36,720	36,123
Taiwan [Member]
Net revenues:
Total net revenues	27,189	46,715	19,790
Japan [Member]
Net revenues:
Total net revenues	26,604	31,140	15,185
Other [Member]
Net revenues:
Total net revenues	$ 12,158	$ 7,452	$ 17,357

Segment, Geographic, Product 82

Segment, Geographic, Product and Significant Customer Information - Long-lived Tangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 26, 2015
Long-lived tangible assets:
Total long-lived tangible assets	$ 44,226	$ 44,493
United States [Member]
Long-lived tangible assets:
Total long-lived tangible assets	42,688	42,581
Taiwan [Member]
Long-lived tangible assets:
Total long-lived tangible assets	818	1,056
South Korea [Member]
Long-lived tangible assets:
Total long-lived tangible assets	554	697
Japan [Member]
Long-lived tangible assets:
Total long-lived tangible assets	57	59
All Other [Member]
Long-lived tangible assets:
Total long-lived tangible assets	$ 109	$ 100

Segment, Geographic, Product 83

Segment, Geographic, Product and Significant Customer Information - Product Revenues (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Segment Reporting Information [Line Items]
Products	$ 185,066	$ 146,945	$ 133,589
Automated Systems [Member]
Segment Reporting Information [Line Items]
Products	127,378	102,386	108,768
Integrated Systems [Member]
Segment Reporting Information [Line Items]
Products	43,846	31,579	15,334
Materials Characterization Systems [Member]
Segment Reporting Information [Line Items]
Products	$ 13,842	$ 12,980	$ 9,487

Segment, Geographic, Product 84

Segment, Geographic, Product and Significant Customer Information - Customers More Than 10% of Accounts Receivable (Details) - Accounts Receivable [Member] - Customer Concentration Risk [Member]	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Taiwan Semiconductor Manufacturing Company Limited [Member]
Customers accounted for 10% or more of total accounts receivable
Customers accounted for 10% or more of total accounts receivable	20.10%	25.60%	20.20%
Samsung Electronics Co. Ltd. [Member]
Customers accounted for 10% or more of total accounts receivable
Customers accounted for 10% or more of total accounts receivable	14.30%		10.00%
Micron Technology, Inc. [Member]
Customers accounted for 10% or more of total accounts receivable
Customers accounted for 10% or more of total accounts receivable	11.80%		23.70%
Intel Corporation [Member]
Customers accounted for 10% or more of total accounts receivable
Customers accounted for 10% or more of total accounts receivable	11.10%
Toshiba Corporation [Member]
Customers accounted for 10% or more of total accounts receivable
Customers accounted for 10% or more of total accounts receivable	10.20%	27.10%
GLOBALFOUNDRIES [Member]
Customers accounted for 10% or more of total accounts receivable
Customers accounted for 10% or more of total accounts receivable			10.20%

Segment, Geographic, Product 85

Segment, Geographic, Product and Significant Customer Information - Customers More Than 10% of Revenues (Details) - Sales Revenue, Net [Member] - Customer Concentration Risk [Member]	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Micron Technology, Inc. [Member]
Net revenues:
Customers accounted for 10% or more of total revenue	20.30%	15.80%	10.40%
Intel Corporation [Member]
Net revenues:
Customers accounted for 10% or more of total revenue	18.00%		12.60%
SK Hynix [Member]
Net revenues:
Customers accounted for 10% or more of total revenue	15.30%	10.70%	12.20%
Taiwan Semiconductor Manufacturing Company Limited [Member]
Net revenues:
Customers accounted for 10% or more of total revenue	10.00%	19.40%
Samsung Electronics Co. Ltd. [Member]
Net revenues:
Customers accounted for 10% or more of total revenue		13.20%	26.90%
Toshiba Corporation [Member]
Net revenues:
Customers accounted for 10% or more of total revenue		10.20%

Schedule II - VALUATION AND Q86

Schedule II - VALUATION AND QUALIFYING ACCOUNTS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Allowance for Doubtful Accounts [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	$ 150	$ 253	$ 293
Additions to Allowance	0	10	0
Charges Utilized/Write-offs	(77)	(113)	(40)
Balance at end of period	73	150	253
Valuation Allowance for Deferred Tax Assets [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	36,786	35,835	11,665
Additions to Allowance	1,643	951	24,170
Charges Utilized/Write-offs	(27,449)	0	0
Balance at end of period	$ 10,980	$ 36,786	$ 35,835