Cognex (CGNX) 10-Q 29 Oct 18 2018 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information	9 Months Ended
	Sep. 30, 2018shares
Document And Entity Information [Abstract]
Entity Registrant Name	COGNEX CORP
Entity Central Index Key	851,205
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Sep. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Common Stock, Shares Outstanding	172,191,187

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Oct. 01, 2017	Sep. 30, 2018	Oct. 01, 2017
Income Statement [Abstract]
Revenue	$ 232,221	$ 266,042	$ 613,052	$ 583,161
Cost of revenue	58,860	68,061	153,227	142,757
Gross margin	173,361	197,981	459,825	440,404
Research, development, and engineering expenses	29,700	26,078	87,664	72,225
Selling, general, and administrative expenses	65,817	61,054	196,266	160,093
Operating income	77,844	110,849	175,895	208,086
Foreign currency gain (loss)	(379)	(127)	(708)	(574)
Investment income	3,937	2,475	10,736	6,625
Other income (expense)	(129)	(445)	(98)	(344)
Income before income tax expense	81,273	112,752	185,825	213,793
Income tax expense (benefit)	837	10,259	11,976	9,334
Net Income	$ 80,436	$ 102,493	$ 173,849	$ 204,459
Net income per weighted-average common and common-equivalent share:
Basic (usd per share)	$ 0.47	$ 0.59	$ 1.01	$ 1.18
Diluted (usd per share)	$ 0.45	$ 0.57	$ 0.98	$ 1.14
Weighted-average common and common-equivalent shares outstanding:
Basic (shares)	172,189	173,234	172,613	173,052
Diluted (shares)	177,245	179,354	178,021	179,124
Cash dividends per common share (usd per share)	$ 0.0450	$ 0.0425	$ 0.1350	$ 0.1225

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Oct. 01, 2017	Sep. 30, 2018	Oct. 01, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 80,436	$ 102,493	$ 173,849	$ 204,459
Cash flow hedges:
Net unrealized gain (loss), net of tax of $0 and ($8) in the three-month periods and net of tax of $0 and ($5) in the nine-month periods, respectively	0	(4)	0	(16)
Reclassification of net realized (gain) loss into current operations	0	(56)	0	(21)
Net change related to cash flow hedges	0	(60)	0	(37)
Available-for-sale investments:
Net unrealized gain (loss), net of tax of $24 and $41 in the three-month periods and net of tax of ($82) and $191 in the nine-month periods, respectively	522	419	(180)	1,237
Reclassification of net realized (gain) loss into current operations	(266)	(263)	(535)	(370)
Net change related to available-for-sale investments	256	156	(715)	867
Foreign currency translation adjustments:
Foreign currency translation adjustments	(1,881)	5,753	(5,078)	18,497
Other comprehensive income (loss), net of tax	(1,625)	5,849	(5,793)	19,327
Total comprehensive income	$ 78,811	$ 108,342	$ 168,056	$ 223,786

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Oct. 01, 2017	Sep. 30, 2018	Oct. 01, 2017
Statement of Comprehensive Income [Abstract]
Tax effect on cash flow hedges	$ 0	$ (8)	$ 0	$ (5)
Tax effect of unrealized gain (loss) on available-for-sale investments	24	41	(82)	191
Tax effect of foreign currency translation adjustment	$ 0	$ 0	$ 0	$ 0

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 107,371	$ 106,582
Short-term investments	420,016	297,961
Accounts receivable, less reserves of $1,508 and $1,568 in 2018 and 2017, respectively	135,441	119,388
Unbilled revenue	13,948	7,454
Inventories	94,035	67,923
Prepaid expenses and other current assets	27,687	30,683
Total current assets	798,498	629,991
Long-term investments	281,929	423,441
Property, plant, and equipment, net	88,930	78,048
Goodwill	113,208	113,208
Intangible assets, net	10,882	13,189
Deferred income taxes	27,376	27,385
Other assets	3,873	2,491
Total assets	1,324,696	1,287,753
Current liabilities:
Accounts payable	22,295	23,463
Accrued expenses	66,632	68,249
Accrued income taxes	8,974	11,503
Deferred revenue and customer deposits	13,252	9,420
Total current liabilities	111,153	112,635
Deferred income taxes	372	312
Reserve for income taxes	6,646	6,488
Accrued income taxes	51,607	66,741
Other non-current liabilities	5,474	5,904
Total liabilities	175,252	192,080
Shareholders’ equity:
Common stock, $.002 par value – Authorized: 300,000 and 200,000 shares in 2018 and 2017, respectively, issued and outstanding: 172,191 and 173,507 shares in 2018 and 2017, respectively	345	347
Additional paid-in capital	518,556	461,338
Retained earnings	670,935	668,587
Accumulated other comprehensive loss, net of tax	(40,392)	(34,599)
Total shareholders’ equity	1,149,444	1,095,673
Total liabilities and shareholders' equity	$ 1,324,696	$ 1,287,753

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Reserves for accounts receivable	$ 1,501	$ 1,568
Common stock, par value	$ 0.002	$ 0.002
Common stock, shares authorized	300,000,000	200,000,000
Common stock, shares issued	172,032,000	173,507,000

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Oct. 01, 2017
Cash flows from operating activities:
Net income	$ 173,849	$ 204,459
Adjustments to reconcile net income to net cash provided by operating activities:
Stock-based compensation expense	31,339	23,355
Depreciation of property, plant, and equipment	13,474	9,811
Amortization of intangible assets	2,307	2,539
Amortization of discounts or premiums on investments	123	188
Realized (gain) loss on sale of investments	(535)	(370)
Revaluation of contingent consideration	(50)	88
Change in deferred income taxes	175	(1,830)
Accounts receivable	(18,136)	(58,379)
Unbilled revenue	(6,542)	(46,010)
Inventories	(27,699)	(18,550)
Prepaid expenses and other current assets	(3,437)	(14,666)
Accounts payable	(1,182)	19,132
Accrued expenses	2,266	8,819
Accrued income taxes	(17,497)	3,724
Deferred revenue and customer deposits	4,841	5,883
Other	(1,604)	1,861
Net cash provided by operating activities	151,692	140,054
Cash flows from investing activities:
Purchases of investments	(616,047)	(415,508)
Maturities and sales of investments	635,119	428,076
Purchases of property, plant, and equipment	(27,356)	(20,044)
Cash paid for acquisition of business	0	(24,118)
Net cash provided by (used in) investing activities	0	(291)
Net cash provided by (used in) investing activities	(8,284)	(31,885)
Cash flows from financing activities:
Issuance of common stock under stock plans	25,882	44,750
Repurchase of common stock	(142,262)	(99,347)
Payment of dividends	(23,283)	(21,236)
Payment of contingent consideration	(1,000)	(1,926)
Net cash provided by (used in) financing activities	(140,663)	(77,759)
Effect of foreign exchange rate changes on cash and cash equivalents	(1,956)	1,298
Net change in cash and cash equivalents	789	31,708
Cash and cash equivalents at beginning of period	106,582	79,641
Cash and cash equivalents at end of period	$ 107,371	$ 111,349

Consolidated Statement of Share

Consolidated Statement of Shareholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss
Increase (Decrease) in Stockholders' Equity
Adjustment as a result of the adoption of ASU 2016-06 Income Taxes - Intra-Entity Transfers Other than Inventory (Note 12)	$ (5,961)			$ (5,961)
Beginning Balance (in shares) at Dec. 31, 2017	173,507	173,507
Beginning Balance at Dec. 31, 2017	$ 1,095,673	$ 347	$ 461,338	668,587	$ (34,599)
Increase (Decrease) in Stockholders' Equity
Issuance of common stock under stock plans (in shares)		1,434
Issuance of common stock under stock plans	25,882	$ 3	25,879
Repurchase of common stock (in shares)		(2,750)
Repurchase of common stock	(142,262)	$ (5)		(142,257)
Stock-based compensation expense	31,339		31,339
Payment of dividends	(23,283)			(23,283)
Net income	173,849			173,849
Net unrealized gain (loss) on available-for-sale investments, net of tax of ($82)	(180)				(180)
Reclassification of net realized (gain) loss on the sale of available-for-sale investments	(535)				(535)
Foreign currency translation adjustment	$ (5,078)				(5,078)
Ending Balance (in shares) at Sep. 30, 2018	172,032	172,191
Ending Balance at Sep. 30, 2018	$ 1,149,444	$ 345	$ 518,556	$ 670,935	$ (40,392)

Consolidated Statement of Sha_2

Consolidated Statement of Shareholders' Equity (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Oct. 01, 2017	Sep. 30, 2018	Oct. 01, 2017
Statement of Stockholders' Equity [Abstract]
Tax effect of unrealized gain (loss) on available-for-sale investments	$ 24	$ 41	$ (82)	$ 191

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies As permitted by the rules of the Securities and Exchange Commission applicable to Quarterly Reports on Form 10-Q, these notes are condensed and do not contain all disclosures required by generally accepted accounting principles (GAAP). As a result of the adoption of ASC 606 "Revenue from Contracts with Customers," Cognex Corporation (the "Company") has provided disclosures related to revenue recognition in this Quarterly Report on Form 10-Q. Reference should be made to the consolidated financial statements and related notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 for a full description of significant accounting policies. In the opinion of the management of the Company, the accompanying consolidated unaudited financial statements contain all adjustments, consisting of normal, recurring adjustments and financial statement reclassifications, necessary to present fairly the Company’s financial position as of September 30, 2018 , and the results of its operations for the three-month and nine-month periods ended September 30, 2018 and October 1, 2017 , and changes in shareholders’ equity, comprehensive income, and cash flows for the periods presented. The results disclosed in the Consolidated Statements of Operations for the three-month and nine-month periods ended September 30, 2018 are not necessarily indicative of the results to be expected for the full year. Revenue Recognition The Company recognizes revenue in accordance with Accounting Standards Codification (ASC) 606, “Revenue from Contracts with Customers.” The core principle of ASC 606 is to recognize revenue in a manner that depicts the transfer of promised goods or services to customers in an amount that reflects the consideration to which the Company expects to be entitled in exchange for those goods or services. The framework in support of this core principle includes: (1) identifying the contract with the customer; (2) identifying the performance obligations in the contract; (3) determining the transaction price; (4) allocating the transaction price to the performance obligations; and (5) recognizing revenue when (or as) the performance obligations are satisfied. Identifying the Contract with the Customer The Company identifies contracts with customers as agreements that create enforceable rights and obligations, which typically take the form of customer contracts or purchase orders. Identifying the Performance Obligations in the Contract The Company identifies performance obligations as promises in contracts to transfer distinct goods or services. Standard products and services that the Company regularly sells separately are accounted for as distinct performance obligations. Application-specific customer solutions that are comprised of a combination of products and services are accounted for as one performance obligation to deliver a total solution to the customer. On-site support services that are provided to the customer after the solution is deployed are accounted for as a separate performance obligation. These solutions are provided to customers in a variety of industries, including the consumer electronics, logistics, and automotive industries. Shipping and handling activities for which the Company is responsible under the terms and conditions of the sale are not accounted for as performance obligations but as fulfillment costs. These activities are required to fulfill the Company’s promise to transfer the goods and are expensed when revenue is recognized. The Company does not assess whether promised goods or services are performance obligations if they are immaterial in the context of the contract. If revenue is recognized before immaterial promises have been completed, then the costs related to such immaterial promises are accrued at the time of sale. Determining the Transaction Price The Company determines the transaction price as the amount of consideration it expects to receive in exchange for transferring promised goods or services to the customer. Amounts collected from customers for sales taxes are excluded from the transaction price. If a contract includes a variable amount, such as a rebate, then the Company estimates the transaction price using either the expected value or the most likely amount of consideration to be received, depending upon the specific facts and circumstances. The Company includes estimated variable consideration in the transaction price only to the extent it is probable that a significant reversal of revenue will not occur when the uncertainty is resolved. The Company updates its estimate of variable consideration at the end of each reporting period to reflect changes in facts and circumstances. Allocating the Transaction Price to the Performance Obligations The Company allocates the transaction price to each performance obligation at contract inception based on a relative stand-alone selling price basis, or the price at which the Company would sell the good or service separately to similar customers in similar circumstances. Recognizing Revenue When (or As) the Performance Obligations are Satisfied The Company recognizes revenue when it transfers the promised goods or services to the customer. Revenue for standard products is recognized at the point in time when the customer obtains control of the goods, which is typically upon delivery when the customer has legal title, physical possession, the risks and rewards of ownership, and an enforceable obligation to pay for the products. Revenue for services, which are not material, is typically recognized over the time the service is provided. Revenue for application-specific customer solutions is recognized at the point in time when the solution is validated, which is the point in time when the Company can objectively determine that the agreed-upon specifications in the contract have been met and the customer will accept the performance obligations in the arrangement. Although the customer may have taken legal title and physical possession of the goods when they arrived at the customer’s designated site, the significant risks and rewards of ownership transfer to the customer only upon validation. Revenue for on-site support services related to these solutions is recognized over the time the service is provided. In certain instances, an arrangement may include customer-specified acceptance provisions or performance guarantees that allow the customer to accept or reject delivered products that do not meet the customer’s specifications. If the Company can objectively determine that control of a good or service has been transferred to the customer in accordance with the agreed-upon specifications in the contract, then customer acceptance is a formality. If acceptance provisions are presumed to be substantive, then revenue is deferred until customer acceptance. For the Company’s standard products and services, revenue recognition and billing typically occur at the same time. For application-specific customer solutions, however, the agreement with the customer may provide for billing terms which differ from revenue recognition criteria, resulting in either deferred revenue or unbilled revenue. Credit assessments are performed to determine payment terms, which vary by region, industry, and customer. Prepayment terms result in contract liabilities for customer deposits. When credit is granted to customers, payment is typically due 30 to 90 days from billing. The Company's contracts have an original expected duration of less than one year, and therefore as a practical expedient, the Company has elected to ignore the impact of the time value of money on a contract and to expense sales commissions. The Company recognizes an asset for costs to fulfill a contract if the costs relate directly to the contract and to future performance, and the costs are expected to be recovered. Management exercises judgment when determining the amount of revenue to be recognized each period. Such judgments include, but are not limited to, assessing the customer’s ability and intention to pay substantially all of the contract consideration when due, determining when two or more contracts should be combined and accounted for as a single contract, determining whether a contract modification has occurred, assessing whether promises are immaterial in the context of the contract, determining whether material promises in a contract represent distinct performance obligations, estimating the transaction price for a contract that contains variable consideration, determining the stand-alone selling price of each performance obligation, determining whether control is transferred over time or at a point in time for performance obligations, and assessing whether formal customer acceptance provisions are substantive.

New Pronouncements

New Pronouncements	9 Months Ended
	Sep. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
New Pronouncements	New Pronouncements Accounting Standards Update (ASU) 2016-02 and 2018-11, "Leases" ASU 2016-02 creates Topic 842, Leases. The objective of this ASU is to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet, and disclosing key information about leasing arrangements. This ASU applies to any entity that enters into a lease, although lessees will see the most significant changes. The main difference between current GAAP and Topic 842 is the recognition of lease assets and lease liabilities on the balance sheet for those leases classified as operating leases under current GAAP. Topic 842 distinguishes between finance leases and operating leases, which are substantially similar to the classification criteria for distinguishing between capital leases and operating leases under current GAAP. For public companies, the guidance in ASU 2016-02 is effective for annual periods beginning after December 15, 2018, and interim periods within those fiscal years. In July 2018, the Financial Accounting Standards Board issued ASU 2018-11 to amend ASU 2016-02 and provided an additional (and optional) transition method to adopt the new lease standard. This transition method allows entities to apply the new lease standard at the adoption date and recognize a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption instead of using the original modified retrospective transition method of adoption which required the restatement of all prior period financial statements. Under this new transition method, the comparative periods presented in the financial statements will continue to be in accordance with current GAAP (Topic 840, Leases). Management will adopt the new lease standard using this new transition method under ASU 2018-11. As of the date of this report, management has determined the scope of leases subject to the new accounting requirements, has selected a software package to assist with compliance, and has reviewed all leases in scope. Management is in the process of completing the implementation of the lease accounting software, training relevant employees, and finalizing the internal lease accounting policy and the related processes, internal controls, and disclosures. Accounting Standards Update (ASU) 2016-13, "Financial Instruments - Measurement of Credit Losses" ASU 2016-13 applies to all reporting entities holding financial assets that are not accounted for at fair value through net income (debt securities). The amendments in this ASU eliminate the probable initial recognition threshold to recognize a credit loss under current GAAP and, instead, reflect an entity’s current estimate of all expected credit losses. In addition, this ASU broadens the information an entity must consider in developing the credit loss estimate, including the use of reasonable and supportable forecasted information. The amendments in this ASU require that credit losses on available-for-sale debt securities be presented as an allowance rather than as a write-down and an entity will be able to record reversals of credit losses in current period net income. For public companies, the guidance in ASU 2016-13 is effective for annual periods beginning after December 15, 2019, and interim periods within those fiscal years. This ASU should 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. Management does not expect ASU 2016-13 to have a material impact on the Company's financial statements and disclosures. Accounting Standards Update (ASU) 2017-08, "Receivables - Nonrefundable Fees and Other Costs - Premium Amortization on Purchased Callable Debt Securities" ASU 2017-08 applies to all reporting entities that hold investments in callable debt securities that have an amortized cost basis in excess of the amount that is repayable by the issuer at the earliest call date (that is, at a premium). The amendments in this ASU shorten the amortization period for certain callable debt securities held at a premium. Specifically, the amendments require the premium to be amortized to the earliest call date. The amendments do not require an accounting change for securities held at a discount; the discount continues to be amortized to maturity. Under current GAAP, premiums and discounts on callable debt securities generally are amortized to the maturity date. If that callable debt security is subsequently called, the entity records a loss equal to the unamortized premium. The amendments in this ASU more closely align the amortization period of premiums and discounts to expectations incorporated in market pricing on the underlying securities. For public companies, the amendments in ASU 2017-08 are effective for annual periods beginning after December 15, 2019, and interim reporting periods within fiscal years beginning after December 15, 2020. This ASU should be applied on a modified retrospective basis through a cumulative-effect adjustment directly to retained earnings as of the beginning of the period of adoption, and, in the period of adoption, the entity is required to provide disclosures about the change in accounting principle. Early adoption is permitted, including adoption in an interim period. Management does not expect ASU 2017-08 to have a material impact on the Company's financial statements and disclosures. Accounting Standards Update (ASU) 2017-12, "Derivatives and Hedging - Targeted Improvements to Accounting for Hedging Activities" ASU 2017-12 applies to all reporting entities that elect to apply hedge accounting. The hedge accounting requirements under current GAAP sometimes do not permit an entity to properly recognize the economic results of the hedging strategy in the financial statements, and they are difficult to understand and interpret. The amendments in this ASU make certain targeted improvements to simplify the application of the hedge accounting guidance. Also, they better align the risk management activities and financial reporting for hedging relationships through changes to both 1) the designation and measurement guidance for qualifying hedging relationships and 2) the presentation of hedge results. For public companies, the amendments in ASU 2017-12 are effective for annual reporting periods beginning after December 15, 2018, and interim reporting periods within those fiscal years. Early adoption is permitted including adoption in any interim period after issuance of the ASU. All transition requirements and elections should be applied to hedging relationships existing on the date of adoption. The entity should apply a cumulative-effect adjustment related to eliminating the separate measurement of ineffectiveness to accumulated other comprehensive income with a corresponding adjustment to the opening balance of retained earnings as of the beginning of the fiscal year that an entity adopts the amendments in this ASU. The amended presentation and disclosure guidance is required only prospectively. Management does not expect ASU 2017-12 to have a material impact on the Company's financial statements and disclosures. Accounting Standards Update (ASU) 2018-01, "Land Easement Practical Expedient for Transition to Topic 842" ASU 2018-01 applies to entities with land easements that exist or expired before an entity’s adoption of Topic 842, provided that the entity does not account for those land easements as leases under Topic 840. The amendments in this ASU permit an entity to elect an optional transition practical expedient to not evaluate under Topic 842 land easements that exist or expired before the entity’s adoption of Topic 842 and that were not previously accounted for as leases under Topic 840. An entity that elects this practical expedient should apply the practical expedient consistently to all of its existing or expired land easements that were not previously accounted for as leases under Topic 840. Once an entity adopts Topic 842, it should apply that Topic prospectively to all new (or modified) land easements to determine whether the arrangement should be accounted for as a lease. An entity that does not elect this practical expedient should evaluate all existing or expired land easements in connection with the adoption of the new lease requirements in Topic 842 to assess whether they meet the definition of a lease. The amendments in this ASU affect the amendments in ASU 2016-02, which are not yet effective but may be early adopted. The effective date and transition requirements for the amendments are the same as the effective date and transition requirements in ASU 2016-02, which is for annual periods beginning after December 15, 2018, and interim periods within those fiscal years. Management does not expect ASU 2018-01 to have a material impact on the Company's financial statements and disclosures. Accounting Standards Update (ASU) 2018-02, "Income Statement - Reporting Comprehensive Income" ASU 2018-02 applies to entities required to apply the provisions of Topic 220, Income Statement - Reporting Comprehensive Income, and has items of other comprehensive income for which the related tax effects are presented in other comprehensive income as required by GAAP. The amendments in this ASU allow a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act of 2017 (the "Tax Act"). Consequently, the amendments eliminate the stranded tax effects resulting from the Tax Act and will improve the usefulness of information reported to financial statement users. However, because the amendments only relate to the reclassification of the income tax effects of the Tax Act, the underlying guidance that requires the effect of a change in tax laws or rates to be included in income from continuing operations is not affected. The amendments in this ASU also require certain disclosures about stranded tax effects. The amendments in this ASU are effective for all entities for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. Early adoption of the amendments in this ASU is permitted, including adoption in any interim period. The amendments in this ASU should be applied either in the period of adoption or retrospectively to each period (or periods) in which the effect of the change in the U.S. federal corporate income tax rate in the Tax Act is recognized. Management does not expect ASU 2018-02 to have a material impact on the Company's financial statements and disclosures. Accounting Standards Update (ASU) 2018-07, "Compensation - Stock Compensation - Improvements to Nonemployee Share-Based Payment Accounting" ASU 2018-07 applies to all entities that enter into share-based payment transactions for acquiring goods and services from nonemployees. The amendments in this ASU expand the scope of Topic 718, Compensation - Stock Compensation, to include share-based payments transactions to nonemployees. Changes to the accounting for nonemployee awards as a result of this ASU include: 1) equity-classified nonemployee share-based payment awards are measured at the grant date, instead of the previous requirement to remeasure the awards through the performance completion date, 2) for awards with performance conditions, compensation cost is recognized when the achievement of the performance condition is probable, rather than upon achievement, and 3) the current requirement to reassess the classification (equity or liability) for nonemployee awards upon vesting is eliminated. This ASU clarifies that Topic 718 does not apply to financing transactions or awards granted to customers as part of a contract accounted for under Topic 606, Revenue from Contracts with Customers. The amendments in this ASU are effective for public business entities for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. An entity should only remeasure liability-classified awards that have not been settled by the date of adoption and equity-classified awards for which the measurement date has not been established through a cumulative-effect adjustment to retained earnings as of the beginning of the fiscal year of adoption. Management does not expect ASU 2018-07 to have a material impact on the Company's financial statements and disclosures. Accounting Standards Update (ASU) 2018-15, "Intangibles - Goodwill and Other - Internal-Use Software" ASU 2018-15 applies to entities that are a customer in a hosting arrangement that is a service contract. The amendments in this ASU align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. Accordingly, the amendments in this ASU require an entity in a hosting arrangement that is a service contract to follow the guidance in Subtopic 350-40 to determine which implementation costs to capitalize as an asset related to the service contract and which costs to expense. Further, it requires the entity to expense the capitalized implementation costs over the term of the hosting arrangement. In addition, it requires the presentation of the expenses related to the capitalized implementation costs in the same line item in the statement of income as the fees associated with the hosting element of the arrangement and the classification of the payments for the capitalized implementation costs in the statement of cash flows in the same manner as the payments made for the fees associated with the hosting element. The amendments in this ASU are effective for public entities for fiscal years beginning after December 15, 2019, and interim periods within those fiscal years, with early adoption permitted. Management does not expect ASU 2018-15 to have a material impact on the Company's financial statement and disclosures.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Financial Assets and Liabilities that are Measured at Fair Value on a Recurring Basis The following table summarizes the financial assets and liabilities required to be measured at fair value on a recurring basis as of September 30, 2018 (in thousands): Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Assets: Money market instruments $ 2,717 $ — $ — Corporate bonds — 314,106 — Treasury bills — 226,058 — Asset-backed securities — 131,549 — Sovereign bonds — 14,437 — Agency bonds — 8,909 — Municipal bonds — 6,886 — Economic hedge forward contracts — 21 — Liabilities: Economic hedge forward contracts — 91 — Contingent consideration liabilities — — 2,507 The Company’s money market instruments are reported at fair value based upon the daily market price for identical assets in active markets, and are therefore classified as Level 1. The Company’s debt securities and forward contracts are reported at fair value based upon model-driven valuations in which all significant inputs are observable or can be derived from or corroborated by observable market data for substantially the full term of the asset or liability, and are therefore classified as Level 2. Management is responsible for estimating the fair value of these financial assets and liabilities, and in doing so, considers valuations provided by a large, third-party pricing service. For debt securities, this service maintains regular contact with market makers, brokers, dealers, and analysts to gather information on market movement, direction, trends, and other specific data. They use this information to structure yield curves for various types of debt securities and arrive at the daily valuations. The Company's forward contracts are typically traded or executed in over-the-counter markets with a high degree of pricing transparency. The market participants are generally large commercial banks. The Company did not record an other-than-temporary impairment of these financial assets during the nine -month period ended September 30, 2018 . The Company's contingent consideration liabilities are reported at fair value based upon probability-adjusted present values of the consideration expected to be paid using significant inputs that are not observable in the market and are therefore classified as Level 3. Key assumptions used in these estimates include probability assessments with respect to the likelihood of achieving certain revenue milestones. The fair values of these contingent consideration liabilities were calculated using discount rates consistent with the level of risk of achievement, and are remeasured each reporting period with changes in fair value recorded in "Other income (expense)" on the Consolidated Statements of Operations. The following table summarizes the activity for the Company's liability measured at fair value using Level 3 inputs for the nine-month period ended September 30, 2018 (in thousands): Balance as of December 31, 2017 $ 3,557 Fair value adjustment to Manatee contingent consideration (1,350 ) Fair value adjustment to GVi contingent consideration 1,130 Fair value adjustment to Chiaro contingent consideration 170 Payment of GVi contingent consideration (1,000 ) Balance as of September 30, 2018 $ 2,507 Non-financial Assets that are Measured at Fair Value on a Non-recurring Basis Non-financial assets such as property, plant and equipment, goodwill, and intangible assets are required to be measured at fair value only when an impairment loss is recognized. The Company did not record an impairment charge related to these assets during the nine -month periods ended September 30, 2018 and October 1, 2017.

Cash, Cash Equivalents, and Inv

Cash, Cash Equivalents, and Investments	9 Months Ended
	Sep. 30, 2018
Cash and Cash Equivalents [Abstract]
Cash, Cash Equivalents, and Investments	Cash, Cash Equivalents, and Investments Cash, cash equivalents, and investments consisted of the following (in thousands): September 30, 2018 December 31, 2017 Cash $ 104,654 $ 97,951 Money market instruments 2,717 8,631 Cash and cash equivalents 107,371 106,582 Treasury bills 193,347 150,371 Corporate bonds 138,099 47,395 Asset-backed securities 71,438 59,203 Sovereign bonds 8,119 21,579 Municipal bonds 6,044 8,805 Agency bonds 2,969 10,608 Short-term investments 420,016 297,961 Corporate bonds 176,007 296,014 Asset-backed securities 60,111 71,727 Treasury bills 32,711 23,459 Sovereign bonds 6,318 13,147 Agency bonds 5,940 14,890 Municipal bonds 842 4,204 Long-term investments 281,929 423,441 $ 809,316 $ 827,984 Treasury bills consist of debt securities issued by the U.S. government; corporate bonds consist of debt securities issued by both domestic and foreign companies; asset-backed securities consist of debt securities collateralized by pools of receivables or loans with credit enhancement; sovereign bonds consist of direct debt issued by foreign governments; municipal bonds consist of debt securities issued by state and local government entities; and agency bonds consist of domestic or foreign obligations of government agencies and government sponsored enterprises that have government backing. All securities are denominated in U.S. Dollars. The following table summarizes the Company’s available-for-sale investments as of September 30, 2018 (in thousands): Amortized Gross Gross Fair Value Short-term: Treasury bills $ 193,631 $ — $ (284 ) $ 193,347 Corporate bonds 138,383 56 (340 ) 138,099 Asset-backed securities 71,646 1 (209 ) 71,438 Sovereign bonds 8,172 — (53 ) 8,119 Municipal bonds 6,050 — (6 ) 6,044 Agency bonds 2,969 — — 2,969 Long-term: Corporate bonds 175,881 469 (343 ) 176,007 Asset-backed securities 60,276 33 (198 ) 60,111 Treasury bills 32,718 7 (14 ) 32,711 Sovereign bonds 6,286 32 — 6,318 Agency bonds 5,930 10 — 5,940 Municipal bonds 855 — (13 ) 842 $ 702,797 $ 608 $ (1,460 ) $ 701,945 The following table summarizes the Company’s gross unrealized losses and fair values for available-for-sale investments in an unrealized loss position as of September 30, 2018 (in thousands): Unrealized Loss Position For: Less than 12 Months 12 Months or Greater Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Treasury bills $ 137,108 $ (174 ) $ 63,030 $ (124 ) $ 200,138 $ (298 ) Corporate bonds 116,028 (386 ) 42,922 (297 ) 158,950 (683 ) Asset-backed securities 57,678 (207 ) 38,256 (200 ) 95,934 (407 ) Sovereign bonds 3,527 (6 ) 4,592 (47 ) 8,119 (53 ) Municipal bonds 2,854 (6 ) 842 (13 ) 3,696 (19 ) $ 317,195 $ (779 ) $ 149,642 $ (681 ) $ 466,837 $ (1,460 ) As of September 30, 2018 , the Company did not recognize any other-than-temporary impairment of these investments. In its evaluation, management considered the type of security, the credit rating of the security, the length of time the security has been in a loss position, the size of the loss position, the Company's intent and ability to hold the security to expected recovery of value, and other meaningful information. The Company does not intend to sell, and is unlikely to be required to sell, any of these available-for-sale investments before their effective maturity or market price recovery. The Company recorded gross realized gains and gross realized losses on the sale of debt securities totaling $283,000 and $17,000 , respectively, during the three-month period ended September 30, 2018 and $306,000 and $43,000 , respectively, during the three-month period ended October 1, 2017 . The Company recorded gross realized gains and gross realized losses on the sale of debt securities totaling $646,000 and $111,000 , respectively, during the nine-month period ended September 30, 2018 and $449,000 and $79,000 , respectively, during the nine-month period ended October 1, 2017 . These gains and losses are included in "Investment income" on the Consolidated Statement of Operations. Prior to the sale of these securities, unrealized gains and losses for these debt securities, net of tax, are recorded in shareholders’ equity as accumulated other comprehensive income (loss). The following table presents the effective maturity dates of the Company’s available-for-sale investments as of September 30, 2018 (in thousands): <1 year 1-2 Years 2-3 Years 3-4 Years 4-5 Years 5-7 Years Total Corporate bonds $ 138,099 $ 80,605 $ 68,684 $ 22,429 $ 1,434 $ 2,855 $ 314,106 Treasury bills 193,347 32,711 — — — — 226,058 Asset-backed securities 71,438 30,840 5,431 12,102 5,138 6,600 131,549 Sovereign bonds 8,119 6,318 — — — — 14,437 Agency bonds 2,969 — — 5,940 — — 8,909 Municipal bonds 6,044 842 — — — — 6,886 $ 420,016 $ 151,316 $ 74,115 $ 40,471 $ 6,572 $ 9,455 $ 701,945

Inventories

Inventories	9 Months Ended
	Sep. 30, 2018
Inventory Disclosure [Abstract]
Inventories	Inventories Inventories consisted of the following (in thousands): September 30, 2018 December 31, 2017 Raw materials $ 46,660 $ 33,927 Work-in-process 4,071 2,114 Finished goods 43,304 31,882 $ 94,035 $ 67,923

Intangible Assets

Intangible Assets	9 Months Ended
	Sep. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets	Intangible Assets Amortized intangible assets consisted of the following (in thousands): Gross Carrying Value Accumulated Amortization Net Carrying Value Distribution networks $ 38,060 $ 38,060 $ — Completed technologies 13,687 6,010 7,677 Customer relationships 8,607 5,587 3,020 Non-compete agreements 370 185 185 Balance as of September 30, 2018 $ 60,724 $ 49,842 $ 10,882 Gross Carrying Value Accumulated Amortization Net Carrying Value Distribution networks $ 38,060 $ 38,060 $ — Completed technologies 13,687 4,181 9,506 Customer relationships 8,607 5,202 3,405 Non-compete agreements 370 92 278 Balance as of December 31, 2017 $ 60,724 $ 47,535 $ 13,189 As of September 30, 2018, estimated future amortization expense related to intangible assets is as follows (in thousands): Year Ended December 31, Amount Remainder of fiscal 2018 $ 769 2019 2,701 2020 2,185 2021 2,017 2022 1,691 2023 989 Thereafter 530 $ 10,882

Warranty Obligations

Warranty Obligations	9 Months Ended
	Sep. 30, 2018
Product Warranties Disclosures [Abstract]
Warranty Obligations	Warranty Obligations The Company records the estimated cost of fulfilling product warranties at the time of sale based upon historical costs to fulfill claims. Obligations may also be recorded subsequent to the time of sale whenever specific events or circumstances impacting product quality become known that would not have been taken into account using historical data. While we engage in extensive product quality programs and processes, including actively monitoring and evaluating the quality of our component suppliers and third-party contract manufacturers, the Company’s warranty obligation is affected by product failure rates, material usage, and service delivery costs incurred in correcting a product failure. An adverse change in any of these factors may result in the need for additional warranty provisions. Warranty obligations are included in “Accrued expenses” on the Consolidated Balance Sheets. The changes in the warranty obligation were as follows (in thousands): Balance as of December 31, 2017 $ 4,701 Provisions for warranties issued during the period 3,376 Fulfillment of warranty obligations (3,223 ) Foreign exchange rate changes (117 ) Balance as of September 30, 2018 $ 4,737

Derivative Instruments

Derivative Instruments	9 Months Ended
	Sep. 30, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments	Derivative Instruments The Company’s foreign currency risk management strategy is principally designed to mitigate the potential financial impact of changes in the value of transactions and balances denominated in foreign currencies resulting from changes in foreign currency exchange rates. Currently, the Company enters into two types of hedges to manage this risk. The first are economic hedges which utilize foreign currency forward contracts with maturities of up to 45 days to manage the exposure to fluctuations in foreign currency exchange rates arising primarily from foreign-denominated receivables and payables. The gains and losses on these derivatives are intended to be offset by the changes in the fair value of the assets and liabilities being hedged. These economic hedges are not designated as hedging instruments for hedge accounting treatment. The second are cash flow hedges which utilize foreign currency forward contracts with maturities of up to 18 months to hedge specific forecasted transactions of the Company's foreign subsidiaries with the goal of protecting the Company's budgeted revenues and expenses against foreign currency exchange rate changes compared to its budgeted rates. These cash flow hedges are designated as hedging instruments for hedge accounting treatment. The Company had the following outstanding forward contracts (in thousands): September 30, 2018 December 31, 2017 Currency Notional USD Notional USD Derivatives Not Designated as Hedging Instruments: Euro 19,500 $ 22,602 — $ — Japanese Yen 455,000 4,018 455,000 4,049 British Pound 2,100 2,742 1,650 2,232 Hungarian Forint 700,000 2,513 545,000 2,110 Korean Won 2,050,000 1,847 1,825,000 1,708 Taiwanese Dollar 49,000 1,615 37,725 1,278 Canadian Dollar 800 616 — — Singapore Dollar 760 557 — — Swiss Franc — — 1,365 1,401 Information regarding the fair value of the outstanding forward contracts was as follows (in thousands): Asset Derivatives Liability Derivatives Balance Fair Value Balance Fair Value Sheet September 30, 2018 December 31, 2017 Sheet September 30, 2018 December 31, 2017 Derivatives Not Designated as Hedging Instruments: Economic hedge forward contracts Prepaid expenses and other current assets $ 21 $ 16 Accrued expenses $ 91 $ 13 The following table presents the gross activity for all derivative assets and liabilities which were presented on a net basis on the Consolidated Balance Sheets due to the right of offset with each counterparty (in thousands): Asset Derivatives Liability Derivatives September 30, 2018 December 31, 2017 September 30, 2018 December 31, 2017 Gross amounts of recognized assets $ 21 $ 16 Gross amounts of recognized liabilities $ 91 $ 13 Gross amounts offset — — Gross amounts offset — — Net amount of assets presented $ 21 $ 16 Net amount of liabilities presented $ 91 $ 13 Information regarding the effect of derivative instruments on the consolidated financial statements was as follows (in thousands): Location in Financial Statements Three-months Ended Nine-months Ended September 30, 2018 October 1, 2017 September 30, 2018 October 1, 2017 Derivatives Designated as Hedging Instruments: Gains (losses) recorded in shareholders' equity (effective portion) Accumulated other comprehensive income (loss), net of tax $ — $ — $ — $ — Gains (losses) reclassified from accumulated other comprehensive income (loss) into current operations (effective portion) Revenue $ — $ 56 $ — $ 10 Research, development, and engineering expenses — — — 3 Selling, general, and administrative expenses — — — 8 Total gains (losses) reclassified from accumulated other comprehensive income (loss) into current operations $ — $ 56 $ — $ 21 Gains (losses) recognized in current operations (ineffective portion and discontinued derivatives) Foreign currency gain (loss) $ — $ — $ — $ — Derivatives Not Designated as Hedging Instruments: Gains (losses) recognized in current operations Foreign currency gain (loss) $ 299 $ 43 $ (366 ) $ 139

Revenue Recognition

Revenue Recognition	9 Months Ended
	Sep. 30, 2018
Revenue from Contract with Customer [Abstract]
Revenue Recognition	Revenue Recognition On January 1, 2018, the Company adopted Accounting Standards Codification (ASC) 606, "Revenue from Contracts with Customers," using the full retrospective method to present all periods reported on a consistent basis. Accordingly, prior-period results have been restated to apply the provisions of this ASC. As a result of this adoption, revenue for software-only products sold as part of multiple-deliverable arrangements are no longer deferred when vendor-specific objective evidence of fair value does not exist for the undelivered elements of the arrangement. This change results in earlier recognition of revenue. In addition, certain of the Company’s product accessory sales, which were reported on a net basis, are now reported on a gross basis as a result of applying the expanded guidance in the new standard related to principal versus agent considerations. This change results in the Company reporting higher revenue and higher cost of revenue when these sales are reported on a gross basis, although the gross margin dollars do not change. Furthermore, for arrangements that include customer-specified acceptance criteria, revenue is recognized when the Company can objectively determine that control has been transferred to the customer in accordance with the agreed-upon specifications in the contract, which may occur before formal customer acceptance. This change primarily impacts revenue recognition for arrangements in the logistics industry where certain customer solutions include installed products and results in earlier recognition of revenue. The adoption of the standard impacted our previously-reported results as follows (in thousands): Statement of Operations Three-months Ended Nine-months Ended October 1, 2017 October 1, 2017 As previously reported Adjustment As restated As previously reported Adjustment As restated Revenue $ 259,739 $ 6,303 $ 266,042 $ 567,585 $ 15,576 $ 583,161 Cost of revenue 62,360 5,701 68,061 128,056 14,701 142,757 Gross margin 197,379 602 197,981 439,529 875 440,404 Operating income 110,247 602 110,849 207,211 875 208,086 Income before income tax expense 112,150 602 112,752 212,918 875 213,793 Income tax expense (benefit) 9,802 457 10,259 8,843 491 9,334 Net income $ 102,348 $ 145 $ 102,493 $ 204,075 $ 384 $ 204,459 Net income per weighted-average common and common-equivalent share: Basic $ 0.59 $ — $ 0.59 $ 1.18 $ — $ 1.18 Diluted $ 0.57 $ — $ 0.57 $ 1.14 $ — $ 1.14 Balance Sheet December 31, 2017 As previously reported Adjustment As restated Prepaid expenses and other current assets $ 30,800 $ (117 ) $ 30,683 Accrued income taxes 11,391 112 11,503 Deferred revenue and customer deposits 9,969 (549 ) 9,420 Retained earnings 668,267 320 668,587 The following table summarizes disaggregated revenue information by geographic area based upon the customer's country of domicile (in thousands): Three-months Ended Nine-months Ended September 30, 2018 October 1, 2017 September 30, 2018 October 1, 2017 Europe $ 115,592 $ 146,230 $ 242,161 $ 252,386 Americas 58,830 54,902 189,859 155,977 Greater China 32,796 35,546 101,130 84,764 Other Asia 25,003 29,364 79,902 90,034 $ 232,221 $ 266,042 $ 613,052 $ 583,161 The following table summarizes disaggregated revenue information by revenue type (in thousands): Three-months Ended Nine-months Ended September 30, 2018 October 1, 2017 September 30, 2018 October 1, 2017 Standard products and services $ 150,993 $ 159,981 $ 493,019 $ 453,464 Application-specific customer solutions 81,228 106,061 120,033 129,697 $ 232,221 $ 266,042 $ 613,052 $ 583,161 Costs to Fulfill a Contract Costs to fulfill a contract are included in "Prepaid expenses and other current assets" on the Consolidated Balance Sheet and amounted to $6,811,000 and $3,230,000 as of September 30, 2018 and December 31, 2017, respectively. Accounts Receivable, Contract Assets, and Contract Liabilities Accounts receivable represent amounts billed and currently due from customers which are reported at their net estimated realizable value. The Company maintains reserves against its accounts receivable for potential credit losses. Credit losses recognized on accounts receivable were immaterial for the three-month and nine-month periods ended September 30, 2018 and October 1, 2017, respectively. Contract assets consist of unbilled revenue which arises when revenue is recognized in advance of billing for certain application-specific customer solutions contracts. Contract liabilities consist of deferred revenue and customer deposits which arise when amounts are billed to or collected from customers in advance of revenue recognition. The following table summarizes the deferred revenue and customer deposits activity for the nine-month period ended September 30, 2018 (in thousands): Amount Balance as of December 31, 2017 $ 9,420 Increases to deferred revenue and customer deposits 55,408 Recognition of revenue (50,590 ) Foreign exchange rate changes (986 ) Balance as of September 30, 2018 $ 13,252 As a practical expedient, the Company has elected not to disclose the aggregate amount of the transaction price allocated to unsatisfied performance obligations, as our contracts have an original expected duration of less than one year.

Stock-Based Compensation Expens

Stock-Based Compensation Expense	9 Months Ended
	Sep. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation Expense	Stock-Based Compensation Expense The Company’s share-based payments that result in compensation expense consist of stock option grants and restricted stock awards. As of September 30, 2018 , the Company had 20,246,002 shares available for grant. Stock options are granted with an exercise price equal to the market value of the Company’s common stock at the grant date and generally vest over four or five years based upon continuous service and expire ten years from the grant date. Vesting of restricted stock awards may be based on continuing employment and/or achievement of pre-established performance goals and objectives. Vesting for performance-based restricted stock awards and time-based restricted stock awards must not be less than one year and three years, respectively; however, awards with time-based vesting may become vested incrementally over such three-year period. The following table summarizes the Company’s stock option activity for the nine -month period ended September 30, 2018 : Shares (in thousands) Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (in years) Aggregate Intrinsic Value (in thousands) Outstanding as of December 31, 2017 12,726 $ 25.24 Granted 2,318 55.66 Exercised (1,434 ) 18.06 Forfeited or expired (429 ) 33.24 Outstanding as of September 30, 2018 13,181 $ 31.11 7.48 $ 329,301 Exercisable as of September 30, 2018 4,327 $ 20.14 6.01 $ 154,377 Options vested or expected to vest as of September 30, 2018 (1) 11,916 $ 29.99 7.37 $ 310,772 (1) In addition to the vested options, the Company expects a portion of the unvested options to vest at some point in the future. Options expected to vest are calculated by applying an estimated forfeiture rate to the unvested options. The fair values of stock options granted in each period presented were estimated using the following weighted-average assumptions: Three-months Ended Nine-months Ended September 30, 2018 October 1, 2017 September 30, 2018 October 1, 2017 Risk-free rate 2.9 % 2.4 % 2.9 % 2.4 % Expected dividend yield 0.32 % 0.39 % 0.32 % 0.39 % Expected volatility 39 % 41 % 39 % 41 % Expected term (in years) 5.4 5.1 5.3 5.3 Risk-free rate The risk-free rate was based upon a treasury instrument whose term was consistent with the contractual term of the option. Expected dividend yield Generally, the current dividend yield is calculated by annualizing the cash dividend declared by the Company’s Board of Directors and dividing that result by the closing stock price on the grant date. Expected volatility The expected volatility was based upon a combination of historical volatility of the Company’s common stock over the contractual term of the option and implied volatility for traded options of the Company’s stock. Expected term The expected term was derived from the binomial lattice model from the impact of events that trigger exercises over time. The Company stratifies its employee population into two groups: one consisting of senior management and another consisting of all other employees. The Company currently applies an estimated annual forfeiture rate of 8% to all unvested options for senior management and a rate of 12% for all other employees. Each year during the first quarter, the company revises its estimated forfeiture rate. This resulted in an increase to compensation expense of $1,283,000 in 2018 and a decrease to compensation expense of $673,000 in 2017. The weighted-average grant-date fair values of stock options granted during the three-month periods ended September 30, 2018 and October 1, 2017 were $22.52 and $14.80 , respectively. The weighted-average grant-date fair values of stock options granted during the nine-month periods ended September 30, 2018 and October 1, 2017 were $21.70 and $14.97 , respectively. The total intrinsic values of stock options exercised for the three-month periods ended September 30, 2018 and October 1, 2017 were $17,985,000 and $28,462,000 , respectively. The total intrinsic values of stock options exercised for the nine-month periods ended September 30, 2018 and October 1, 2017 were $50,975,000 and $100,913,000 , respectively. The total fair values of stock options vested for the three-month periods ended September 30, 2018 and October 1, 2017 were $997,000 and $844,000 , respectively. The total fair values of stock options vested for the nine-month periods ended September 30, 2018 and October 1, 2017 were $27,557,000 and $19,557,000 , respectively. As of September 30, 2018 , total unrecognized compensation expense related to non-vested stock options was $50,387,000 , which is expected to be recognized over a weighted-average period of 1.61 years. The following table summarizes the Company's restricted stock activity for the nine-month period ended September 30, 2018 : Shares (in thousands) Weighted-Average Grant Fair Value Aggregate Intrinsic Value (in thousands) Nonvested as of December 31, 2017 20 $ 17.03 Granted Vested (20 ) 17.03 993 Forfeited or expired Nonvested as of September 30, 2018 — $ — $ — The fair values of restricted stock awards granted were determined based upon the market value of the Company's common stock at the time of grant. The initial cost was then amortized over the period of vesting until the restrictions lapsed. These restricted shares became fully vested in 2018. Participants were entitled to dividends on the restricted stock awards, but only received those amounts if the shares vested. The sale or transfer of these shares was restricted during the vesting period. The total stock-based compensation expense and the related income tax benefit recognized for the three-month period ended September 30, 2018 were $9,143,000 and $1,654,000 , respectively, and for the three-month period ended October 1, 2017 were $8,026,000 and $2,639,000 , respectively. The total stock-based compensation expense and the related income tax benefit recognized for the nine-month period ended September 30, 2018 were $31,339,000 and $5,608,000 , respectively, and for the nine-month period ended October 1, 2017 were $23,355,000 and $7,661,000 , respectively. No compensation expense was capitalized as of September 30, 2018 or December 31, 2017 . The following table presents the stock-based compensation expense by caption for each period presented on the Consolidated Statements of Operations (in thousands): Three-months Ended Nine-months Ended September 30, 2018 October 1, 2017 September 30, 2018 October 1, 2017 Cost of revenue $ 544 $ 520 $ 1,898 $ 1,404 Research, development, and engineering 3,197 2,765 11,166 8,090 Selling, general, and administrative 5,402 4,741 18,275 13,861 $ 9,143 $ 8,026 $ 31,339 $ 23,355

Stock Repurchase Program

Stock Repurchase Program	9 Months Ended
	Sep. 30, 2018
Equity [Abstract]
Stock Repurchase Program	Stock Repurchase Program In April 2017, the Company's Board of Directors authorized the repurchase of $100,000,000 of the Company's common stock. As of September 30, 2018, the Company had repurchased 1,744,000 shares at a cost of $100,000,000 under this program, including 803,000 shares at a cost of $45,200,000 in the three-month period ended April 1, 2018. Stock repurchases under this April 2017 program were completed in the three-month period ended April 1, 2018. In February 2018, the Company's Board of Directors authorized the repurchase of an additional $150,000,000 of the Company's common stock. As of September 30, 2018, the Company had repurchased 1,947,000 shares at a cost of $97,062,000 under this program, leaving a remaining authorized balance of $52,938,000 . Total stock repurchases in the nine-month period ended September 30, 2018 amounted to $142,262,000 . The Company may repurchase shares under this program in future periods depending upon a variety of factors, including, among other things, the impact of dilution from employee stock options, stock price, share availability, and cash requirements.

Taxes

Taxes	9 Months Ended
	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Taxes	Taxes A reconciliation of the United States federal statutory corporate tax rate to the Company’s income tax expense, or effective tax rate, was as follows: Three-months Ended Nine-months Ended September 30, 2018 October 1, 2017 September 30, 2018 October 1, 2017 Income tax provision at federal statutory corporate tax rate 21 % 35 % 21 % 35 % State income taxes, net of federal benefit 1 % 1 % 1 % 1 % Foreign tax rate differential (7 )% (18 )% (7 )% (18 )% Tax credit — % (1 )% — % (1 )% Discrete tax benefit related to Tax Act 2017 (9 )% — % (4 )% — % Discrete tax benefit related to stock option exercises (4 )% (7 )% (5 )% (13 )% Other discrete tax events (2 )% (2 )% (1 )% (1 )% Other 1 % 1 % 1 % 1 % Income tax provision 1 % 9 % 6 % 4 % On December 22, 2017, the United States Congress passed and the President signed into law the Tax Cuts and Jobs Act of 2017 (Tax Act). The Tax Act included a decrease in the U.S. federal statutory corporate tax rate from 35% to 21% , a one-time transition tax on unrepatriated foreign earnings, and limits on certain deductions. The Securities and Exchange Commission (SEC) released Staff Accounting Bulletin (SAB) No. 118 to provide guidance to companies on how to implement the accounting and disclosure changes as a result of the Tax Act. The Company made what it considered to be a reasonable estimate of the impact of the Tax Act in its financial statements for the year ended December 31, 2017. In the third quarter of 2018, the Company revised its estimate of the impact of the Tax Act based on additional regulatory guidance. The effective tax rate, as a result, was reduced by 9 percentage points and 4 percentage points for the three-month and nine-month period ended September 30, 2018, respectively. This significant estimate is highly judgmental and changes to this estimate could result in material charges or credits in future reporting periods. The Company will continue to review the guidance at the Federal and State levels through the end of 2018 and additional revisions to the estimates of the impact of the Tax Act may be required in the fourth quarter of 2018 as regulatory guidance continues to develop, specifically at the individual State level. The Tax Act subjects the Company to current tax on Global Intangible Low-Taxed Income (GILTI) earned by certain foreign subsidiaries. The Company has made an accounting policy election to provide for the tax expense related to GILTI in the year the tax is incurred rather than recognize deferred taxes for these temporary differences. The majority of income earned outside of the United States is permanently reinvested to provide funds for international expansion. The Company is tax resident in numerous jurisdictions around the world and has identified its major jurisdictions as the United States, Ireland, and China. The statutory tax rate is 12.5% in Ireland and 25% in China, compared to the U.S. federal statutory corporate tax rate of 21% . International rights to certain of the Company's intellectual property are held by a subsidiary whose legal jurisdiction does not tax this income, resulting in a foreign effective tax rate that is lower than the above mentioned statutory rates, although the reduced taxes overseas have been partially offset by changes in U.S. tax law. These differences resulted in a decrease in the effective tax rate by 7 percentage points for the three-month and nine -month periods ended September 30, 2018 , and a decrease in the effective tax rate by 18 percentage points for the three-month and nine-month periods ended October 1, 2017 . The excess tax benefit arising from the difference between the deduction for tax purposes and the compensation cost recognized for financial reporting purposes from stock option exercises resulted in a decrease of the effective tax rate by 4 and 7 percentage points for the three-month periods ended September 30, 2018 and October 1, 2017 , respectively, and a decrease of the effective tax rate by 5 and 13 percentage points for the nine -month periods ended September 30, 2018 and October 1, 2017 , respectively. Certain reserves for income taxes and other provision-to-return adjustments resulted in a decrease of the effective tax rate by 2 percentage points for both the three-month periods ended September 30, 2018 and October 1, 2017 and a decrease of the effective tax rate by 1 percentage point for both the nine-month periods ended September 30, 2018 and October 1, 2017. On January 1, 2018, the Company adopted Accounting Standard Update (ASU) 2016-16, "Income Taxes - Intra-Entity Transfers of Assets Other than Inventory." This Update requires the recognition of deferred income taxes for an intra-entity transfer of an asset other than inventory. As a result of this ASU, the Company recorded $5,961,000 through a cumulative-effect adjustment directly to retained earnings at the beginning of fiscal year 2018. During the nine -month period ended September 30, 2018 , the Company recorded a $204,000 increase in reserves for income taxes, net of deferred tax benefit. Estimated interest and penalties included in these amounts totaled $33,000 for the nine -month period ended September 30, 2018 . The Company’s reserve for income taxes, including gross interest and penalties, was $7,674,000 as of September 30, 2018 , which included $6,646,000 classified as a non-current liability and $1,028,000 recorded as a reduction to non-current deferred tax assets. The amount of gross interest and penalties included in these balances was $773,000 . If the Company’s tax positions were sustained or the statutes of limitations related to certain positions expired, these reserves would be released and income tax expense would be reduced in a future period. As a result of the expiration of certain statutes of limitations, there is a potential that a portion of these reserves could be released, which would decrease income tax expense by approximately $1,200,000 to $1,300,000 over the next twelve months. The Company has defined its major tax jurisdictions as the United States, Ireland, and China, and within the United States, Massachusetts. Within the United States, the tax years 2015 through 2017 remain open to examination by the Internal Revenue Service and various state tax authorities. The tax years 2014 through 2017 remain open to examination by various taxing authorities in other jurisdictions in which the Company operates.

Weighted-Average Shares

Weighted-Average Shares	9 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
Weighted-Average Shares	Weighted-Average Shares Weighted-average shares were calculated as follows (in thousands): Three-months Ended Nine-months Ended September 30, 2018 October 1, 2017 September 30, 2018 October 1, 2017 Basic weighted-average common shares outstanding 172,189 173,234 172,613 173,052 Effect of dilutive stock options 5,056 6,120 5,408 6,072 Weighted-average common and common-equivalent shares outstanding 177,245 179,354 178,021 179,124 Stock options to purchase 2,796,000 and 2,353,000 shares of common stock, on a weighted-average basis, were outstanding during the three-month and nine-month periods ended September 30, 2018, respectively, and 466,000 and 3,108,000 for the same periods in 2017, but were not included in the calculation of dilutive net income per share because they were anti-dilutive.

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2018
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events On October 29, 2018, the Company’s Board of Directors declared a cash dividend of $0.050 per share. The dividend is payable November 30, 2018 to all shareholders of record as of the close of business on November 16, 2018 . In addition, on October 29, 2018, the Company's Board of Directors authorized the repurchase of an additional $200,000,000 of the Company's common stock. This new authorization will commence once the Company completes the February 2018 program.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Revenue Recognition	Revenue Recognition The Company recognizes revenue in accordance with Accounting Standards Codification (ASC) 606, “Revenue from Contracts with Customers.” The core principle of ASC 606 is to recognize revenue in a manner that depicts the transfer of promised goods or services to customers in an amount that reflects the consideration to which the Company expects to be entitled in exchange for those goods or services. The framework in support of this core principle includes: (1) identifying the contract with the customer; (2) identifying the performance obligations in the contract; (3) determining the transaction price; (4) allocating the transaction price to the performance obligations; and (5) recognizing revenue when (or as) the performance obligations are satisfied. Identifying the Contract with the Customer The Company identifies contracts with customers as agreements that create enforceable rights and obligations, which typically take the form of customer contracts or purchase orders. Identifying the Performance Obligations in the Contract The Company identifies performance obligations as promises in contracts to transfer distinct goods or services. Standard products and services that the Company regularly sells separately are accounted for as distinct performance obligations. Application-specific customer solutions that are comprised of a combination of products and services are accounted for as one performance obligation to deliver a total solution to the customer. On-site support services that are provided to the customer after the solution is deployed are accounted for as a separate performance obligation. These solutions are provided to customers in a variety of industries, including the consumer electronics, logistics, and automotive industries. Shipping and handling activities for which the Company is responsible under the terms and conditions of the sale are not accounted for as performance obligations but as fulfillment costs. These activities are required to fulfill the Company’s promise to transfer the goods and are expensed when revenue is recognized. The Company does not assess whether promised goods or services are performance obligations if they are immaterial in the context of the contract. If revenue is recognized before immaterial promises have been completed, then the costs related to such immaterial promises are accrued at the time of sale. Determining the Transaction Price The Company determines the transaction price as the amount of consideration it expects to receive in exchange for transferring promised goods or services to the customer. Amounts collected from customers for sales taxes are excluded from the transaction price. If a contract includes a variable amount, such as a rebate, then the Company estimates the transaction price using either the expected value or the most likely amount of consideration to be received, depending upon the specific facts and circumstances. The Company includes estimated variable consideration in the transaction price only to the extent it is probable that a significant reversal of revenue will not occur when the uncertainty is resolved. The Company updates its estimate of variable consideration at the end of each reporting period to reflect changes in facts and circumstances. Allocating the Transaction Price to the Performance Obligations The Company allocates the transaction price to each performance obligation at contract inception based on a relative stand-alone selling price basis, or the price at which the Company would sell the good or service separately to similar customers in similar circumstances. Recognizing Revenue When (or As) the Performance Obligations are Satisfied The Company recognizes revenue when it transfers the promised goods or services to the customer. Revenue for standard products is recognized at the point in time when the customer obtains control of the goods, which is typically upon delivery when the customer has legal title, physical possession, the risks and rewards of ownership, and an enforceable obligation to pay for the products. Revenue for services, which are not material, is typically recognized over the time the service is provided. Revenue for application-specific customer solutions is recognized at the point in time when the solution is validated, which is the point in time when the Company can objectively determine that the agreed-upon specifications in the contract have been met and the customer will accept the performance obligations in the arrangement. Although the customer may have taken legal title and physical possession of the goods when they arrived at the customer’s designated site, the significant risks and rewards of ownership transfer to the customer only upon validation. Revenue for on-site support services related to these solutions is recognized over the time the service is provided. In certain instances, an arrangement may include customer-specified acceptance provisions or performance guarantees that allow the customer to accept or reject delivered products that do not meet the customer’s specifications. If the Company can objectively determine that control of a good or service has been transferred to the customer in accordance with the agreed-upon specifications in the contract, then customer acceptance is a formality. If acceptance provisions are presumed to be substantive, then revenue is deferred until customer acceptance. For the Company’s standard products and services, revenue recognition and billing typically occur at the same time. For application-specific customer solutions, however, the agreement with the customer may provide for billing terms which differ from revenue recognition criteria, resulting in either deferred revenue or unbilled revenue. Credit assessments are performed to determine payment terms, which vary by region, industry, and customer. Prepayment terms result in contract liabilities for customer deposits. When credit is granted to customers, payment is typically due 30 to 90 days from billing. The Company's contracts have an original expected duration of less than one year, and therefore as a practical expedient, the Company has elected to ignore the impact of the time value of money on a contract and to expense sales commissions. The Company recognizes an asset for costs to fulfill a contract if the costs relate directly to the contract and to future performance, and the costs are expected to be recovered. Management exercises judgment when determining the amount of revenue to be recognized each period. Such judgments include, but are not limited to, assessing the customer’s ability and intention to pay substantially all of the contract consideration when due, determining when two or more contracts should be combined and accounted for as a single contract, determining whether a contract modification has occurred, assessing whether promises are immaterial in the context of the contract, determining whether material promises in a contract represent distinct performance obligations, estimating the transaction price for a contract that contains variable consideration, determining the stand-alone selling price of each performance obligation, determining whether control is transferred over time or at a point in time for performance obligations, and assessing whether formal customer acceptance provisions are substantive.
New Pronouncements	Accounting Standards Update (ASU) 2016-02 and 2018-11, "Leases" ASU 2016-02 creates Topic 842, Leases. The objective of this ASU is to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet, and disclosing key information about leasing arrangements. This ASU applies to any entity that enters into a lease, although lessees will see the most significant changes. The main difference between current GAAP and Topic 842 is the recognition of lease assets and lease liabilities on the balance sheet for those leases classified as operating leases under current GAAP. Topic 842 distinguishes between finance leases and operating leases, which are substantially similar to the classification criteria for distinguishing between capital leases and operating leases under current GAAP. For public companies, the guidance in ASU 2016-02 is effective for annual periods beginning after December 15, 2018, and interim periods within those fiscal years. In July 2018, the Financial Accounting Standards Board issued ASU 2018-11 to amend ASU 2016-02 and provided an additional (and optional) transition method to adopt the new lease standard. This transition method allows entities to apply the new lease standard at the adoption date and recognize a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption instead of using the original modified retrospective transition method of adoption which required the restatement of all prior period financial statements. Under this new transition method, the comparative periods presented in the financial statements will continue to be in accordance with current GAAP (Topic 840, Leases). Management will adopt the new lease standard using this new transition method under ASU 2018-11. As of the date of this report, management has determined the scope of leases subject to the new accounting requirements, has selected a software package to assist with compliance, and has reviewed all leases in scope. Management is in the process of completing the implementation of the lease accounting software, training relevant employees, and finalizing the internal lease accounting policy and the related processes, internal controls, and disclosures. Accounting Standards Update (ASU) 2016-13, "Financial Instruments - Measurement of Credit Losses" ASU 2016-13 applies to all reporting entities holding financial assets that are not accounted for at fair value through net income (debt securities). The amendments in this ASU eliminate the probable initial recognition threshold to recognize a credit loss under current GAAP and, instead, reflect an entity’s current estimate of all expected credit losses. In addition, this ASU broadens the information an entity must consider in developing the credit loss estimate, including the use of reasonable and supportable forecasted information. The amendments in this ASU require that credit losses on available-for-sale debt securities be presented as an allowance rather than as a write-down and an entity will be able to record reversals of credit losses in current period net income. For public companies, the guidance in ASU 2016-13 is effective for annual periods beginning after December 15, 2019, and interim periods within those fiscal years. This ASU should 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. Management does not expect ASU 2016-13 to have a material impact on the Company's financial statements and disclosures. Accounting Standards Update (ASU) 2017-08, "Receivables - Nonrefundable Fees and Other Costs - Premium Amortization on Purchased Callable Debt Securities" ASU 2017-08 applies to all reporting entities that hold investments in callable debt securities that have an amortized cost basis in excess of the amount that is repayable by the issuer at the earliest call date (that is, at a premium). The amendments in this ASU shorten the amortization period for certain callable debt securities held at a premium. Specifically, the amendments require the premium to be amortized to the earliest call date. The amendments do not require an accounting change for securities held at a discount; the discount continues to be amortized to maturity. Under current GAAP, premiums and discounts on callable debt securities generally are amortized to the maturity date. If that callable debt security is subsequently called, the entity records a loss equal to the unamortized premium. The amendments in this ASU more closely align the amortization period of premiums and discounts to expectations incorporated in market pricing on the underlying securities. For public companies, the amendments in ASU 2017-08 are effective for annual periods beginning after December 15, 2019, and interim reporting periods within fiscal years beginning after December 15, 2020. This ASU should be applied on a modified retrospective basis through a cumulative-effect adjustment directly to retained earnings as of the beginning of the period of adoption, and, in the period of adoption, the entity is required to provide disclosures about the change in accounting principle. Early adoption is permitted, including adoption in an interim period. Management does not expect ASU 2017-08 to have a material impact on the Company's financial statements and disclosures. Accounting Standards Update (ASU) 2017-12, "Derivatives and Hedging - Targeted Improvements to Accounting for Hedging Activities" ASU 2017-12 applies to all reporting entities that elect to apply hedge accounting. The hedge accounting requirements under current GAAP sometimes do not permit an entity to properly recognize the economic results of the hedging strategy in the financial statements, and they are difficult to understand and interpret. The amendments in this ASU make certain targeted improvements to simplify the application of the hedge accounting guidance. Also, they better align the risk management activities and financial reporting for hedging relationships through changes to both 1) the designation and measurement guidance for qualifying hedging relationships and 2) the presentation of hedge results. For public companies, the amendments in ASU 2017-12 are effective for annual reporting periods beginning after December 15, 2018, and interim reporting periods within those fiscal years. Early adoption is permitted including adoption in any interim period after issuance of the ASU. All transition requirements and elections should be applied to hedging relationships existing on the date of adoption. The entity should apply a cumulative-effect adjustment related to eliminating the separate measurement of ineffectiveness to accumulated other comprehensive income with a corresponding adjustment to the opening balance of retained earnings as of the beginning of the fiscal year that an entity adopts the amendments in this ASU. The amended presentation and disclosure guidance is required only prospectively. Management does not expect ASU 2017-12 to have a material impact on the Company's financial statements and disclosures. Accounting Standards Update (ASU) 2018-01, "Land Easement Practical Expedient for Transition to Topic 842" ASU 2018-01 applies to entities with land easements that exist or expired before an entity’s adoption of Topic 842, provided that the entity does not account for those land easements as leases under Topic 840. The amendments in this ASU permit an entity to elect an optional transition practical expedient to not evaluate under Topic 842 land easements that exist or expired before the entity’s adoption of Topic 842 and that were not previously accounted for as leases under Topic 840. An entity that elects this practical expedient should apply the practical expedient consistently to all of its existing or expired land easements that were not previously accounted for as leases under Topic 840. Once an entity adopts Topic 842, it should apply that Topic prospectively to all new (or modified) land easements to determine whether the arrangement should be accounted for as a lease. An entity that does not elect this practical expedient should evaluate all existing or expired land easements in connection with the adoption of the new lease requirements in Topic 842 to assess whether they meet the definition of a lease. The amendments in this ASU affect the amendments in ASU 2016-02, which are not yet effective but may be early adopted. The effective date and transition requirements for the amendments are the same as the effective date and transition requirements in ASU 2016-02, which is for annual periods beginning after December 15, 2018, and interim periods within those fiscal years. Management does not expect ASU 2018-01 to have a material impact on the Company's financial statements and disclosures. Accounting Standards Update (ASU) 2018-02, "Income Statement - Reporting Comprehensive Income" ASU 2018-02 applies to entities required to apply the provisions of Topic 220, Income Statement - Reporting Comprehensive Income, and has items of other comprehensive income for which the related tax effects are presented in other comprehensive income as required by GAAP. The amendments in this ASU allow a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act of 2017 (the "Tax Act"). Consequently, the amendments eliminate the stranded tax effects resulting from the Tax Act and will improve the usefulness of information reported to financial statement users. However, because the amendments only relate to the reclassification of the income tax effects of the Tax Act, the underlying guidance that requires the effect of a change in tax laws or rates to be included in income from continuing operations is not affected. The amendments in this ASU also require certain disclosures about stranded tax effects. The amendments in this ASU are effective for all entities for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. Early adoption of the amendments in this ASU is permitted, including adoption in any interim period. The amendments in this ASU should be applied either in the period of adoption or retrospectively to each period (or periods) in which the effect of the change in the U.S. federal corporate income tax rate in the Tax Act is recognized. Management does not expect ASU 2018-02 to have a material impact on the Company's financial statements and disclosures. Accounting Standards Update (ASU) 2018-07, "Compensation - Stock Compensation - Improvements to Nonemployee Share-Based Payment Accounting" ASU 2018-07 applies to all entities that enter into share-based payment transactions for acquiring goods and services from nonemployees. The amendments in this ASU expand the scope of Topic 718, Compensation - Stock Compensation, to include share-based payments transactions to nonemployees. Changes to the accounting for nonemployee awards as a result of this ASU include: 1) equity-classified nonemployee share-based payment awards are measured at the grant date, instead of the previous requirement to remeasure the awards through the performance completion date, 2) for awards with performance conditions, compensation cost is recognized when the achievement of the performance condition is probable, rather than upon achievement, and 3) the current requirement to reassess the classification (equity or liability) for nonemployee awards upon vesting is eliminated. This ASU clarifies that Topic 718 does not apply to financing transactions or awards granted to customers as part of a contract accounted for under Topic 606, Revenue from Contracts with Customers. The amendments in this ASU are effective for public business entities for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. An entity should only remeasure liability-classified awards that have not been settled by the date of adoption and equity-classified awards for which the measurement date has not been established through a cumulative-effect adjustment to retained earnings as of the beginning of the fiscal year of adoption. Management does not expect ASU 2018-07 to have a material impact on the Company's financial statements and disclosures. Accounting Standards Update (ASU) 2018-15, "Intangibles - Goodwill and Other - Internal-Use Software" ASU 2018-15 applies to entities that are a customer in a hosting arrangement that is a service contract. The amendments in this ASU align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. Accordingly, the amendments in this ASU require an entity in a hosting arrangement that is a service contract to follow the guidance in Subtopic 350-40 to determine which implementation costs to capitalize as an asset related to the service contract and which costs to expense. Further, it requires the entity to expense the capitalized implementation costs over the term of the hosting arrangement. In addition, it requires the presentation of the expenses related to the capitalized implementation costs in the same line item in the statement of income as the fees associated with the hosting element of the arrangement and the classification of the payments for the capitalized implementation costs in the statement of cash flows in the same manner as the payments made for the fees associated with the hosting element. The amendments in this ASU are effective for public entities for fiscal years beginning after December 15, 2019, and interim periods within those fiscal years, with early adoption permitted. Management does not expect ASU 2018-15 to have a material impact on the Company's financial statement and disclosures.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Assets and Liabilities Measured at Fair Value on a Recurring Basis	The following table summarizes the financial assets and liabilities required to be measured at fair value on a recurring basis as of September 30, 2018 (in thousands): Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Assets: Money market instruments $ 2,717 $ — $ — Corporate bonds — 314,106 — Treasury bills — 226,058 — Asset-backed securities — 131,549 — Sovereign bonds — 14,437 — Agency bonds — 8,909 — Municipal bonds — 6,886 — Economic hedge forward contracts — 21 — Liabilities: Economic hedge forward contracts — 91 — Contingent consideration liabilities — — 2,507
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation	The following table summarizes the activity for the Company's liability measured at fair value using Level 3 inputs for the nine-month period ended September 30, 2018 (in thousands): Balance as of December 31, 2017 $ 3,557 Fair value adjustment to Manatee contingent consideration (1,350 ) Fair value adjustment to GVi contingent consideration 1,130 Fair value adjustment to Chiaro contingent consideration 170 Payment of GVi contingent consideration (1,000 ) Balance as of September 30, 2018 $ 2,507

Cash, Cash Equivalents, and I_2

Cash, Cash Equivalents, and Investments (Tables)	9 Months Ended
	Sep. 30, 2018
Cash and Cash Equivalents [Abstract]
Components of Cash, Cash Equivalents, and Investments	Cash, cash equivalents, and investments consisted of the following (in thousands): September 30, 2018 December 31, 2017 Cash $ 104,654 $ 97,951 Money market instruments 2,717 8,631 Cash and cash equivalents 107,371 106,582 Treasury bills 193,347 150,371 Corporate bonds 138,099 47,395 Asset-backed securities 71,438 59,203 Sovereign bonds 8,119 21,579 Municipal bonds 6,044 8,805 Agency bonds 2,969 10,608 Short-term investments 420,016 297,961 Corporate bonds 176,007 296,014 Asset-backed securities 60,111 71,727 Treasury bills 32,711 23,459 Sovereign bonds 6,318 13,147 Agency bonds 5,940 14,890 Municipal bonds 842 4,204 Long-term investments 281,929 423,441 $ 809,316 $ 827,984
Summary of Available-for-Sale Investments	The following table summarizes the Company’s available-for-sale investments as of September 30, 2018 (in thousands): Amortized Gross Gross Fair Value Short-term: Treasury bills $ 193,631 $ — $ (284 ) $ 193,347 Corporate bonds 138,383 56 (340 ) 138,099 Asset-backed securities 71,646 1 (209 ) 71,438 Sovereign bonds 8,172 — (53 ) 8,119 Municipal bonds 6,050 — (6 ) 6,044 Agency bonds 2,969 — — 2,969 Long-term: Corporate bonds 175,881 469 (343 ) 176,007 Asset-backed securities 60,276 33 (198 ) 60,111 Treasury bills 32,718 7 (14 ) 32,711 Sovereign bonds 6,286 32 — 6,318 Agency bonds 5,930 10 — 5,940 Municipal bonds 855 — (13 ) 842 $ 702,797 $ 608 $ (1,460 ) $ 701,945
Gross Unrealized Losses and Fair Values for Available-for-Sale Investments	The following table summarizes the Company’s gross unrealized losses and fair values for available-for-sale investments in an unrealized loss position as of September 30, 2018 (in thousands): Unrealized Loss Position For: Less than 12 Months 12 Months or Greater Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Treasury bills $ 137,108 $ (174 ) $ 63,030 $ (124 ) $ 200,138 $ (298 ) Corporate bonds 116,028 (386 ) 42,922 (297 ) 158,950 (683 ) Asset-backed securities 57,678 (207 ) 38,256 (200 ) 95,934 (407 ) Sovereign bonds 3,527 (6 ) 4,592 (47 ) 8,119 (53 ) Municipal bonds 2,854 (6 ) 842 (13 ) 3,696 (19 ) $ 317,195 $ (779 ) $ 149,642 $ (681 ) $ 466,837 $ (1,460 )
Effective Maturity Dates of Available-for-Sale Investments	The following table presents the effective maturity dates of the Company’s available-for-sale investments as of September 30, 2018 (in thousands): <1 year 1-2 Years 2-3 Years 3-4 Years 4-5 Years 5-7 Years Total Corporate bonds $ 138,099 $ 80,605 $ 68,684 $ 22,429 $ 1,434 $ 2,855 $ 314,106 Treasury bills 193,347 32,711 — — — — 226,058 Asset-backed securities 71,438 30,840 5,431 12,102 5,138 6,600 131,549 Sovereign bonds 8,119 6,318 — — — — 14,437 Agency bonds 2,969 — — 5,940 — — 8,909 Municipal bonds 6,044 842 — — — — 6,886 $ 420,016 $ 151,316 $ 74,115 $ 40,471 $ 6,572 $ 9,455 $ 701,945

Inventories (Tables)

Inventories (Tables)	9 Months Ended
	Sep. 30, 2018
Inventory Disclosure [Abstract]
Schedule of Inventories	Inventories consisted of the following (in thousands): September 30, 2018 December 31, 2017 Raw materials $ 46,660 $ 33,927 Work-in-process 4,071 2,114 Finished goods 43,304 31,882 $ 94,035 $ 67,923

Intangible Assets (Tables)

Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Intangible Assets	Amortized intangible assets consisted of the following (in thousands): Gross Carrying Value Accumulated Amortization Net Carrying Value Distribution networks $ 38,060 $ 38,060 $ — Completed technologies 13,687 6,010 7,677 Customer relationships 8,607 5,587 3,020 Non-compete agreements 370 185 185 Balance as of September 30, 2018 $ 60,724 $ 49,842 $ 10,882 Gross Carrying Value Accumulated Amortization Net Carrying Value Distribution networks $ 38,060 $ 38,060 $ — Completed technologies 13,687 4,181 9,506 Customer relationships 8,607 5,202 3,405 Non-compete agreements 370 92 278 Balance as of December 31, 2017 $ 60,724 $ 47,535 $ 13,189
Schedule of Intangible Assets, Future Amortization Expense	As of September 30, 2018, estimated future amortization expense related to intangible assets is as follows (in thousands): Year Ended December 31, Amount Remainder of fiscal 2018 $ 769 2019 2,701 2020 2,185 2021 2,017 2022 1,691 2023 989 Thereafter 530 $ 10,882

Warranty Obligations (Tables)

Warranty Obligations (Tables)	9 Months Ended
	Sep. 30, 2018
Product Warranties Disclosures [Abstract]
Changes in Warranty Obligations	The changes in the warranty obligation were as follows (in thousands): Balance as of December 31, 2017 $ 4,701 Provisions for warranties issued during the period 3,376 Fulfillment of warranty obligations (3,223 ) Foreign exchange rate changes (117 ) Balance as of September 30, 2018 $ 4,737

Derivative Instruments (Tables)

Derivative Instruments (Tables)	9 Months Ended
	Sep. 30, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Outstanding Forward Contracts Table	The Company had the following outstanding forward contracts (in thousands): September 30, 2018 December 31, 2017 Currency Notional USD Notional USD Derivatives Not Designated as Hedging Instruments: Euro 19,500 $ 22,602 — $ — Japanese Yen 455,000 4,018 455,000 4,049 British Pound 2,100 2,742 1,650 2,232 Hungarian Forint 700,000 2,513 545,000 2,110 Korean Won 2,050,000 1,847 1,825,000 1,708 Taiwanese Dollar 49,000 1,615 37,725 1,278 Canadian Dollar 800 616 — — Singapore Dollar 760 557 — — Swiss Franc — — 1,365 1,401
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value	Information regarding the fair value of the outstanding forward contracts was as follows (in thousands): Asset Derivatives Liability Derivatives Balance Fair Value Balance Fair Value Sheet September 30, 2018 December 31, 2017 Sheet September 30, 2018 December 31, 2017 Derivatives Not Designated as Hedging Instruments: Economic hedge forward contracts Prepaid expenses and other current assets $ 21 $ 16 Accrued expenses $ 91 $ 13
Offsetting Assets	The following table presents the gross activity for all derivative assets and liabilities which were presented on a net basis on the Consolidated Balance Sheets due to the right of offset with each counterparty (in thousands): Asset Derivatives Liability Derivatives September 30, 2018 December 31, 2017 September 30, 2018 December 31, 2017 Gross amounts of recognized assets $ 21 $ 16 Gross amounts of recognized liabilities $ 91 $ 13 Gross amounts offset — — Gross amounts offset — — Net amount of assets presented $ 21 $ 16 Net amount of liabilities presented $ 91 $ 13
Derivative Instruments, Gain (Loss)	Information regarding the effect of derivative instruments on the consolidated financial statements was as follows (in thousands): Location in Financial Statements Three-months Ended Nine-months Ended September 30, 2018 October 1, 2017 September 30, 2018 October 1, 2017 Derivatives Designated as Hedging Instruments: Gains (losses) recorded in shareholders' equity (effective portion) Accumulated other comprehensive income (loss), net of tax $ — $ — $ — $ — Gains (losses) reclassified from accumulated other comprehensive income (loss) into current operations (effective portion) Revenue $ — $ 56 $ — $ 10 Research, development, and engineering expenses — — — 3 Selling, general, and administrative expenses — — — 8 Total gains (losses) reclassified from accumulated other comprehensive income (loss) into current operations $ — $ 56 $ — $ 21 Gains (losses) recognized in current operations (ineffective portion and discontinued derivatives) Foreign currency gain (loss) $ — $ — $ — $ — Derivatives Not Designated as Hedging Instruments: Gains (losses) recognized in current operations Foreign currency gain (loss) $ 299 $ 43 $ (366 ) $ 139

Revenue Recognition (Tables)

Revenue Recognition (Tables)	9 Months Ended
	Sep. 30, 2018
Revenue from Contract with Customer [Abstract]
Schedule of New Accounting Pronouncements and Changes in Accounting Principles	The adoption of the standard impacted our previously-reported results as follows (in thousands): Statement of Operations Three-months Ended Nine-months Ended October 1, 2017 October 1, 2017 As previously reported Adjustment As restated As previously reported Adjustment As restated Revenue $ 259,739 $ 6,303 $ 266,042 $ 567,585 $ 15,576 $ 583,161 Cost of revenue 62,360 5,701 68,061 128,056 14,701 142,757 Gross margin 197,379 602 197,981 439,529 875 440,404 Operating income 110,247 602 110,849 207,211 875 208,086 Income before income tax expense 112,150 602 112,752 212,918 875 213,793 Income tax expense (benefit) 9,802 457 10,259 8,843 491 9,334 Net income $ 102,348 $ 145 $ 102,493 $ 204,075 $ 384 $ 204,459 Net income per weighted-average common and common-equivalent share: Basic $ 0.59 $ — $ 0.59 $ 1.18 $ — $ 1.18 Diluted $ 0.57 $ — $ 0.57 $ 1.14 $ — $ 1.14 Balance Sheet December 31, 2017 As previously reported Adjustment As restated Prepaid expenses and other current assets $ 30,800 $ (117 ) $ 30,683 Accrued income taxes 11,391 112 11,503 Deferred revenue and customer deposits 9,969 (549 ) 9,420 Retained earnings 668,267 320 668,587
Revenue from External Customers by Geographic Areas	The following table summarizes disaggregated revenue information by geographic area based upon the customer's country of domicile (in thousands): Three-months Ended Nine-months Ended September 30, 2018 October 1, 2017 September 30, 2018 October 1, 2017 Europe $ 115,592 $ 146,230 $ 242,161 $ 252,386 Americas 58,830 54,902 189,859 155,977 Greater China 32,796 35,546 101,130 84,764 Other Asia 25,003 29,364 79,902 90,034 $ 232,221 $ 266,042 $ 613,052 $ 583,161
Revenue from External Customers by Products and Services	The following table summarizes disaggregated revenue information by revenue type (in thousands): Three-months Ended Nine-months Ended September 30, 2018 October 1, 2017 September 30, 2018 October 1, 2017 Standard products and services $ 150,993 $ 159,981 $ 493,019 $ 453,464 Application-specific customer solutions 81,228 106,061 120,033 129,697 $ 232,221 $ 266,042 $ 613,052 $ 583,161
Deferred Revenue, by Arrangement, Disclosure	The following table summarizes the deferred revenue and customer deposits activity for the nine-month period ended September 30, 2018 (in thousands): Amount Balance as of December 31, 2017 $ 9,420 Increases to deferred revenue and customer deposits 55,408 Recognition of revenue (50,590 ) Foreign exchange rate changes (986 ) Balance as of September 30, 2018 $ 13,252

Stock-Based Compensation Expe_2

Stock-Based Compensation Expense (Tables)	9 Months Ended
	Sep. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Stock Option Activity	The following table summarizes the Company’s stock option activity for the nine -month period ended September 30, 2018 : Shares (in thousands) Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (in years) Aggregate Intrinsic Value (in thousands) Outstanding as of December 31, 2017 12,726 $ 25.24 Granted 2,318 55.66 Exercised (1,434 ) 18.06 Forfeited or expired (429 ) 33.24 Outstanding as of September 30, 2018 13,181 $ 31.11 7.48 $ 329,301 Exercisable as of September 30, 2018 4,327 $ 20.14 6.01 $ 154,377 Options vested or expected to vest as of September 30, 2018 (1) 11,916 $ 29.99 7.37 $ 310,772 (1) In addition to the vested options, the Company expects a portion of the unvested options to vest at some point in the future. Options expected to vest are calculated by applying an estimated forfeiture rate to the unvested options.
Weighted-Average Assumptions Used in Estimating Fair Values of Stock Options Granted	The fair values of stock options granted in each period presented were estimated using the following weighted-average assumptions: Three-months Ended Nine-months Ended September 30, 2018 October 1, 2017 September 30, 2018 October 1, 2017 Risk-free rate 2.9 % 2.4 % 2.9 % 2.4 % Expected dividend yield 0.32 % 0.39 % 0.32 % 0.39 % Expected volatility 39 % 41 % 39 % 41 % Expected term (in years) 5.4 5.1 5.3 5.3
Nonvested Restricted Stock Shares Activity	The following table summarizes the Company's restricted stock activity for the nine-month period ended September 30, 2018 : Shares (in thousands) Weighted-Average Grant Fair Value Aggregate Intrinsic Value (in thousands) Nonvested as of December 31, 2017 20 $ 17.03 Granted Vested (20 ) 17.03 993 Forfeited or expired Nonvested as of September 30, 2018 — $ — $ —
Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs	The following table presents the stock-based compensation expense by caption for each period presented on the Consolidated Statements of Operations (in thousands): Three-months Ended Nine-months Ended September 30, 2018 October 1, 2017 September 30, 2018 October 1, 2017 Cost of revenue $ 544 $ 520 $ 1,898 $ 1,404 Research, development, and engineering 3,197 2,765 11,166 8,090 Selling, general, and administrative 5,402 4,741 18,275 13,861 $ 9,143 $ 8,026 $ 31,339 $ 23,355

Taxes (Tables)

Taxes (Tables)	9 Months Ended
	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Reconciliation of United States Federal Statutory Corporate Tax Rate to Company's Effective Tax Rate, or Income Tax Provision	A reconciliation of the United States federal statutory corporate tax rate to the Company’s income tax expense, or effective tax rate, was as follows: Three-months Ended Nine-months Ended September 30, 2018 October 1, 2017 September 30, 2018 October 1, 2017 Income tax provision at federal statutory corporate tax rate 21 % 35 % 21 % 35 % State income taxes, net of federal benefit 1 % 1 % 1 % 1 % Foreign tax rate differential (7 )% (18 )% (7 )% (18 )% Tax credit — % (1 )% — % (1 )% Discrete tax benefit related to Tax Act 2017 (9 )% — % (4 )% — % Discrete tax benefit related to stock option exercises (4 )% (7 )% (5 )% (13 )% Other discrete tax events (2 )% (2 )% (1 )% (1 )% Other 1 % 1 % 1 % 1 % Income tax provision 1 % 9 % 6 % 4 %

Weighted-Average Shares (Tables

Weighted-Average Shares (Tables)	9 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
Calculation of Weighted-Average Shares	Weighted-average shares were calculated as follows (in thousands): Three-months Ended Nine-months Ended September 30, 2018 October 1, 2017 September 30, 2018 October 1, 2017 Basic weighted-average common shares outstanding 172,189 173,234 172,613 173,052 Effect of dilutive stock options 5,056 6,120 5,408 6,072 Weighted-average common and common-equivalent shares outstanding 177,245 179,354 178,021 179,124

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Assets:
Money market instruments	$ 2,717	$ 8,631
Financial assets at fair value	701,945
Corporate Bonds
Assets:
Financial assets at fair value	314,106
Treasury Bills
Assets:
Financial assets at fair value	226,058
Asset-Backed Securities
Assets:
Financial assets at fair value	131,549
Sovereign Bonds
Assets:
Financial assets at fair value	14,437
Agency Bonds
Assets:
Financial assets at fair value	8,909
Municipal Bonds
Assets:
Financial assets at fair value	6,886
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Measurements, Recurring
Assets:
Money market instruments	2,717
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring
Assets:
Money market instruments	0
Economic hedge forward contracts	0
Liabilities:
Economic hedge forward contracts	91
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Corporate Bonds
Assets:
Financial assets at fair value	314,106
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Treasury Bills
Assets:
Financial assets at fair value	226,058
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Asset-Backed Securities
Assets:
Financial assets at fair value	131,549
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Sovereign Bonds
Assets:
Financial assets at fair value	14,437
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Agency Bonds
Assets:
Financial assets at fair value	8,909
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Municipal Bonds
Assets:
Financial assets at fair value	6,886
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring
Liabilities:
Contingent consideration liabilities	$ 2,507

Fair Value Measurements - Liabi

Fair Value Measurements - Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Oct. 01, 2017
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Payment of contingent consideration	$ (1,000)	$ (1,926)
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	3,557
Ending balance	2,507
Manatee | Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liabilities, Fair Value Adjustment	(1,350)
GVi | Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liabilities, Fair Value Adjustment	1,130
Payment of contingent consideration	(1,000)
Chiaro Technologies LLC [Member] | Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liabilities, Fair Value Adjustment	$ 170

Cash, Cash Equivalents, and I_3

Cash, Cash Equivalents, and Investments (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Oct. 01, 2017	Sep. 30, 2018	Oct. 01, 2017
Cash and Cash Equivalents [Abstract]
Gross realized gains on sale of investments	$ 283,000	$ 306,000	$ 646,000	$ 449,000
Gross realized losses on sale of investments	$ 17,000	$ 43,000	$ 111,000	$ 79,000

Cash, Cash Equivalents, and I_4

Cash, Cash Equivalents, and Investments - Components of Cash, Cash Equivalents, and Investments (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Oct. 01, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Cash	$ 104,654	$ 97,951
Money market instruments	2,717	8,631
Cash and cash equivalents	107,371	106,582	$ 111,349	$ 79,641
Short-term investments	420,016	297,961
Long-term investments	281,929	423,441
Total	809,316	827,984
Treasury Bills
Schedule of Available-for-sale Securities [Line Items]
Short-term investments	193,347	150,371
Long-term investments	32,711	23,459
Corporate Bonds
Schedule of Available-for-sale Securities [Line Items]
Short-term investments	138,099	47,395
Long-term investments	176,007	296,014
Asset-Backed Securities
Schedule of Available-for-sale Securities [Line Items]
Short-term investments	71,438	59,203
Long-term investments	60,111	71,727
Sovereign Debt [Member]
Schedule of Available-for-sale Securities [Line Items]
Short-term investments	8,119	21,579
Sovereign Bonds
Schedule of Available-for-sale Securities [Line Items]
Long-term investments	6,318	13,147
Agency Bonds
Schedule of Available-for-sale Securities [Line Items]
Short-term investments	2,969	10,608
Long-term investments	5,940	14,890
Municipal Bonds
Schedule of Available-for-sale Securities [Line Items]
Short-term investments	6,044	8,805
Long-term investments	$ 842	$ 4,204

Cash, Cash Equivalents, and I_5

Cash, Cash Equivalents, and Investments - Summary of Available-for-Sale Investments (Detail) $ in Thousands	Sep. 30, 2018USD ($)
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	$ 702,797
Gross unrealized gains	608
Gross unrealized losses	(1,460)
Fair value	701,945
Agency Bonds | Short-Term Investments
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	2,969
Gross unrealized gains	0
Gross unrealized losses	0
Fair value	2,969
Agency Bonds | Long-Term Investments
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	5,930
Gross unrealized gains	10
Gross unrealized losses	0
Fair value	5,940
Treasury Bills
Schedule of Available-for-sale Securities [Line Items]
Gross unrealized losses	(298)
Treasury Bills | Short-Term Investments
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	193,631
Gross unrealized gains	0
Gross unrealized losses	(284)
Fair value	193,347
Treasury Bills | Long-Term Investments
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	32,718
Gross unrealized gains	7
Gross unrealized losses	(14)
Fair value	32,711
Corporate Bonds
Schedule of Available-for-sale Securities [Line Items]
Gross unrealized losses	(683)
Corporate Bonds | Short-Term Investments
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	138,383
Gross unrealized gains	56
Gross unrealized losses	(340)
Fair value	138,099
Corporate Bonds | Long-Term Investments
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	175,881
Gross unrealized gains	469
Gross unrealized losses	(343)
Fair value	176,007
Asset-Backed Securities
Schedule of Available-for-sale Securities [Line Items]
Gross unrealized losses	(407)
Asset-Backed Securities | Short-Term Investments
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	71,646
Gross unrealized gains	1
Gross unrealized losses	(209)
Fair value	71,438
Asset-Backed Securities | Long-Term Investments
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	60,276
Gross unrealized gains	33
Gross unrealized losses	(198)
Fair value	60,111
Sovereign Bonds
Schedule of Available-for-sale Securities [Line Items]
Gross unrealized losses	(53)
Sovereign Bonds | Short-Term Investments
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	8,172
Gross unrealized gains	0
Gross unrealized losses	(53)
Fair value	8,119
Sovereign Bonds | Long-Term Investments
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	6,286
Gross unrealized gains	32
Gross unrealized losses	0
Fair value	6,318
Municipal Bonds
Schedule of Available-for-sale Securities [Line Items]
Gross unrealized losses	(19)
Municipal Bonds | Short-Term Investments
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	6,050
Gross unrealized gains	0
Gross unrealized losses	(6)
Fair value	6,044
Municipal Bonds | Long-Term Investments
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	855
Gross unrealized gains	0
Gross unrealized losses	(13)
Fair value	$ 842

Cash, Cash Equivalents, and I_6

Cash, Cash Equivalents, and Investments - Gross Unrealized Losses and Fair Values for Available-for-Sale Investments (Detail) $ in Thousands	Sep. 30, 2018USD ($)
Schedule of Available-for-sale Securities [Line Items]
Fair value, less than 12 months	$ 317,195
Unrealized losses, less than 12 months	(779)
Fair value, 12 months or greater	149,642
Unrealized losses, 12 months or greater	(681)
Total fair value	466,837
Total unrealized losses	(1,460)
Treasury Bills
Schedule of Available-for-sale Securities [Line Items]
Fair value, less than 12 months	137,108
Unrealized losses, less than 12 months	(174)
Fair value, 12 months or greater	63,030
Unrealized losses, 12 months or greater	(124)
Total fair value	200,138
Total unrealized losses	(298)
Corporate Bonds
Schedule of Available-for-sale Securities [Line Items]
Fair value, less than 12 months	116,028
Unrealized losses, less than 12 months	(386)
Fair value, 12 months or greater	42,922
Unrealized losses, 12 months or greater	(297)
Total fair value	158,950
Total unrealized losses	(683)
Asset-Backed Securities
Schedule of Available-for-sale Securities [Line Items]
Fair value, less than 12 months	57,678
Unrealized losses, less than 12 months	(207)
Fair value, 12 months or greater	38,256
Unrealized losses, 12 months or greater	(200)
Total fair value	95,934
Total unrealized losses	(407)
Sovereign Bonds
Schedule of Available-for-sale Securities [Line Items]
Fair value, less than 12 months	3,527
Unrealized losses, less than 12 months	(6)
Fair value, 12 months or greater	4,592
Unrealized losses, 12 months or greater	(47)
Total fair value	8,119
Total unrealized losses	(53)
Municipal Bonds
Schedule of Available-for-sale Securities [Line Items]
Fair value, less than 12 months	2,854
Unrealized losses, less than 12 months	(6)
Fair value, 12 months or greater	842
Unrealized losses, 12 months or greater	(13)
Total fair value	3,696
Total unrealized losses	$ (19)

Cash, Cash Equivalents, and I_7

Cash, Cash Equivalents, and Investments - Effective Maturity Dates of Available-for-Sale Investments (Detail) $ in Thousands	Sep. 30, 2018USD ($)
Schedule of Available-for-sale Securities [Line Items]
1 year or less	$ 420,016
1-2 years	151,316
2-3 years	74,115
3-4 years	40,471
4-5 years	6,572
5-7 years	9,455
Fair value	701,945
Corporate Bonds
Schedule of Available-for-sale Securities [Line Items]
1 year or less	138,099
1-2 years	80,605
2-3 years	68,684
3-4 years	22,429
4-5 years	1,434
5-7 years	2,855
Fair value	314,106
Treasury Bills
Schedule of Available-for-sale Securities [Line Items]
1 year or less	193,347
1-2 years	32,711
2-3 years	0
3-4 years	0
4-5 years	0
5-7 years	0
Fair value	226,058
Asset-Backed Securities
Schedule of Available-for-sale Securities [Line Items]
1 year or less	71,438
1-2 years	30,840
2-3 years	5,431
3-4 years	12,102
4-5 years	5,138
5-7 years	6,600
Fair value	131,549
Sovereign Bonds
Schedule of Available-for-sale Securities [Line Items]
1 year or less	8,119
1-2 years	6,318
2-3 years	0
3-4 years	0
4-5 years	0
5-7 years	0
Fair value	14,437
Agency Bonds
Schedule of Available-for-sale Securities [Line Items]
1 year or less	2,969
1-2 years	0
2-3 years	0
3-4 years	5,940
4-5 years	0
5-7 years	0
Fair value	8,909
Municipal Bonds
Schedule of Available-for-sale Securities [Line Items]
1 year or less	6,044
1-2 years	842
2-3 years	0
3-4 years	0
4-5 years	0
5-7 years	0
Fair value	$ 6,886

Inventories - Schedule of Inven

Inventories - Schedule of Inventories (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Inventory Disclosure [Abstract]
Raw materials	$ 46,660	$ 33,927
Work-in-process	4,071	2,114
Finished goods	43,304	31,882
Inventories	$ 94,035	$ 67,923

Intangible Assets (Details)

Intangible Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 60,724	$ 60,724
Accumulated Amortization	49,842	47,535
Net Carrying Value	10,882	13,189
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Remainder of fiscal 2018	769
2,019	2,701
2,020	2,185
2,021	2,017
2,022	1,691
2,023	989
Thereafter	530
Net Carrying Value	10,882	13,189
Distribution networks
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	38,060	38,060
Accumulated Amortization	38,060	38,060
Net Carrying Value	0	0
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Net Carrying Value	0	0
Completed technologies
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	13,687	13,687
Accumulated Amortization	6,010	4,181
Net Carrying Value	7,677	9,506
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Net Carrying Value	7,677	9,506
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	8,607	8,607
Accumulated Amortization	5,587	5,202
Net Carrying Value	3,020	3,405
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Net Carrying Value	3,020	3,405
Non-compete agreements
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	370	370
Accumulated Amortization	185	92
Net Carrying Value	185	278
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Net Carrying Value	$ 185	$ 278

Warranty Obligations - Changes

Warranty Obligations - Changes in Warranty Obligations (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)
Movement in Standard Product Warranty Accrual [Roll Forward]
Beginning balance	$ 4,701
Provisions for warranties issued during the period	3,376
Fulfillment of warranty obligations	(3,223)
Foreign exchange rate changes	(117)
Ending balance	$ 4,737

Derivative Instruments (Detail)

Derivative Instruments (Detail)	9 Months Ended
	Sep. 30, 2018Category
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Number of instruments held	2
Designated as Hedging Instrument
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Maximum length of time hedged in cash flow hedge	18 months
Not Designated as Hedging Instrument
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Remaining maturity of foreign currency derivatives (up to)	45 days

Derivative Instruments - Outsta

Derivative Instruments - Outstanding Forward Contracts Table (Detail) - Not Designated as Hedging Instrument € in Thousands, ₩ in Thousands, ¥ in Thousands, $ in Thousands, $ in Thousands, $ in Thousands, $ in Thousands	Sep. 30, 2018CAD ($)	Sep. 30, 2018SGD ($)	Sep. 30, 2018JPY (¥)	Sep. 30, 2018KRW (₩)	Sep. 30, 2018TWD ($)	Sep. 30, 2018EUR (€)	Sep. 30, 2018USD ($)	Dec. 31, 2017CAD ($)	Dec. 31, 2017SGD ($)	Dec. 31, 2017JPY (¥)	Dec. 31, 2017KRW (₩)	Dec. 31, 2017TWD ($)	Dec. 31, 2017EUR (€)	Dec. 31, 2017USD ($)
Euro Member Countries, Euro
Derivative [Line Items]
Outstanding forward contracts						€ 19,500	$ 22,602						€ 0	$ 0
Japanese Yen
Derivative [Line Items]
Outstanding forward contracts			¥ 455,000				4,018			¥ 455,000				4,049
United Kingdom, Pounds
Derivative [Line Items]
Outstanding forward contracts			2,100				2,742			1,650				2,232
Hungary, Forint
Derivative [Line Items]
Outstanding forward contracts			¥ 700,000				2,513			¥ 545,000				2,110
Korean Won
Derivative [Line Items]
Outstanding forward contracts				₩ 2,050,000			1,847				₩ 1,825,000			1,708
Taiwanese Dollar
Derivative [Line Items]
Outstanding forward contracts					$ 49,000		1,615					$ 37,725		1,278
Canada, Dollars
Derivative [Line Items]
Outstanding forward contracts	$ 800						616	$ 0						0
Singapore Dollar
Derivative [Line Items]
Outstanding forward contracts		$ 760					557		$ 0					0
Switzerland, Francs
Derivative [Line Items]
Outstanding forward contracts		$ 0					$ 0					$ 1,365		$ 1,401

Derivative Instruments - Schedu

Derivative Instruments - Schedule of Derivative Instruments in Statement of Financial Position, Fair Value (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Derivatives, Fair Value [Line Items]
Derivative asset	$ 21	$ 16
Derivative liability	91	13
Not Designated as Hedging Instrument | Prepaid Expenses and Other Current Assets
Derivatives, Fair Value [Line Items]
Derivative asset	21	16
Not Designated as Hedging Instrument | Accrued Expenses
Derivatives, Fair Value [Line Items]
Derivative liability	$ 91	$ 13

Derivative Instruments - Offset

Derivative Instruments - Offsetting Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Gross amounts of recognized assets	$ 21	$ 16
Gross amounts offset	0	0
Net amount of assets presented	21	16
Gross amounts of recognized liabilities	91	13
Gross amounts offset	0	0
Net amount of liabilities presented	$ 91	$ 13

Derivative Instruments - Deriva

Derivative Instruments - Derivative Instruments, Gain (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Oct. 01, 2017	Sep. 30, 2018	Oct. 01, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Total gains (losses) reclassified from accumulated other comprehensive income (loss) into current operations	$ 0	$ 56	$ 0	$ 21
Designated as Hedging Instrument | Accumulated Other Comprehensive Income (Loss), Net of Tax
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recorded in shareholders' equity (effective portion)	0	0	0	0
Designated as Hedging Instrument | Product Revenue
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) reclassified from accumulated other comprehensive income (loss) into current operations (effective portion)	0	56	0	10
Designated as Hedging Instrument | Research, Development, and Engineering Expenses
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) reclassified from accumulated other comprehensive income (loss) into current operations (effective portion)	0	0	0	3
Designated as Hedging Instrument | Selling, General, and Administrative Expenses
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) reclassified from accumulated other comprehensive income (loss) into current operations (effective portion)	0	0	0	8
Designated as Hedging Instrument | Foreign Currency Gain (Loss)
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net	0	0	0	0
Not Designated as Hedging Instrument | Foreign Currency Gain (Loss)
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in current operations	$ 299	$ 43	$ (366)	$ 139

Revenue Recognition - Impact on

Revenue Recognition - Impact on Statement of Operations (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Oct. 01, 2017	Sep. 30, 2018	Oct. 01, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue	$ 232,221	$ 266,042	$ 613,052	$ 583,161
Cost of revenue	58,860	68,061	153,227	142,757
Gross margin	173,361	197,981	459,825	440,404
Operating income	77,844	110,849	175,895	208,086
Income before income tax expense	81,273	112,752	185,825	213,793
Income tax expense (benefit)	837	10,259	11,976	9,334
Net income	$ 80,436	$ 102,493	$ 173,849	$ 204,459
Basic (usd per share)	$ 0.47	$ 0.59	$ 1.01	$ 1.18
Diluted (usd per share)	$ 0.45	$ 0.57	$ 0.98	$ 1.14
As previously reported
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue		$ 259,739		$ 567,585
Cost of revenue		62,360		128,056
Gross margin		197,379		439,529
Operating income		110,247		207,211
Income before income tax expense		112,150		212,918
Income tax expense (benefit)		9,802		8,843
Net income		$ 102,348		$ 204,075
Basic (usd per share)		$ 0.59		$ 1.18
Diluted (usd per share)		$ 0.57		$ 1.14
Accounting Standards Update 2014-09 | Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue		$ 6,303		$ 15,576
Cost of revenue		5,701		14,701
Gross margin		602		875
Operating income		602		875
Income before income tax expense		602		875
Income tax expense (benefit)		457		491
Net income		$ 145		$ 384
Basic (usd per share)		$ 0		$ 0
Diluted (usd per share)		$ 0		$ 0

Revenue Recognition - Impact _2

Revenue Recognition - Impact on Balance Sheet (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Prepaid expenses and other current assets	$ 27,687	$ 30,683
Accrued income taxes	8,974	11,503
Deferred revenue and customer deposits	13,252	9,420
Retained earnings	$ 670,935	668,587
As previously reported
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Prepaid expenses and other current assets		30,800
Accrued income taxes		11,391
Deferred revenue and customer deposits		9,969
Retained earnings		668,267
Adjustment | Accounting Standards Update 2014-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Prepaid expenses and other current assets		(117)
Accrued income taxes		112
Deferred revenue and customer deposits		(549)
Retained earnings		$ 320

Revenue Recognition - Revenue D

Revenue Recognition - Revenue Disaggregated by Geography (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Oct. 01, 2017	Sep. 30, 2018	Oct. 01, 2017
Disaggregation of Revenue [Line Items]
Revenue	$ 232,221	$ 266,042	$ 613,052	$ 583,161
Europe
Disaggregation of Revenue [Line Items]
Revenue	115,592	146,230	242,161	252,386
Americas
Disaggregation of Revenue [Line Items]
Revenue	58,830	54,902	189,859	155,977
Greater China
Disaggregation of Revenue [Line Items]
Revenue	32,796	35,546	101,130	84,764
Other Asia
Disaggregation of Revenue [Line Items]
Revenue	$ 25,003	$ 29,364	$ 79,902	$ 90,034

Revenue Recognition - Revenue_2

Revenue Recognition - Revenue Disaggregated by Products and Services (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Oct. 01, 2017	Sep. 30, 2018	Oct. 01, 2017
Revenue from External Customer [Line Items]
Revenue	$ 232,221	$ 266,042	$ 613,052	$ 583,161
Standard Products and Services
Revenue from External Customer [Line Items]
Revenue	150,993	159,981	493,019	453,464
Application-Specific Customer Solutions
Revenue from External Customer [Line Items]
Revenue	$ 81,228	$ 106,061	$ 120,033	$ 129,697

Revenue Recognition - Additiona

Revenue Recognition - Additional Information (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Revenue from Contract with Customer [Abstract]
Costs to fulfill contract	$ 6,811	$ 3,230

Revenue Recognition - Deferred

Revenue Recognition - Deferred Revenue Activity (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)
Movement in Deferred Revenue [Roll Forward]
Balance as of December 31, 2017	$ 9,420
Increases to deferred revenue and customer deposits	55,408
Recognition of revenue	(50,590)
Foreign exchange rate changes	(986)
Balance as of September 30, 2018	$ 13,252

Stock-Based Compensation Expe_3

Stock-Based Compensation Expense (Detail)	3 Months Ended				9 Months Ended
	Sep. 30, 2018USD ($)group$ / sharesshares	Apr. 01, 2018USD ($)	Oct. 01, 2017USD ($)$ / shares	Apr. 02, 2017USD ($)	Sep. 30, 2018USD ($)group$ / sharesshares	Oct. 01, 2017USD ($)$ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period, performance-based restricted stock, years					1 year
Vesting period, time-based restricted stock, years					3 years
Groups within the employee population | group	2				2
Estimated annual forfeiture rate for unvested options for senior management	8.00%				8.00%
Estimated annual forfeiture rate for unvested options for all other employees	12.00%				12.00%
Increase (decrease) to compensation expense		$ 1,283,000		$ 673,000
Weighted-average grant-date fair values, in dollars per share | $ / shares	$ 22.52		$ 14.80		$ 21.70	$ 14.97
Total intrinsic value	$ 17,985,000		$ 28,462,000		$ 50,975,000	$ 100,913,000
Total fair values of stock options vest	997,000		844,000		27,557,000	19,557,000
Unrecognized compensation expense	50,387,000				$ 50,387,000
Weighted average period to be recognized					1 year 7 months 10 days
Stock-based compensation expense	9,143,000		8,026,000		$ 31,339,000	23,355,000
Tax benefit from compensation expense	1,654,000		$ 2,639,000		5,608,000	$ 7,661,000
Recognized period costs capitalized	$ 0				$ 0
General Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period for stock option plans					4 years
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for grant under stock option plans | shares	20,246,002				20,246,002
Expiration period from grant day					10 years

Stock-Based Compensation Expe_4

Stock-Based Compensation Expense - Summary of Stock Option Activity (Detail) $ / shares in Units, shares in Thousands, $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)$ / sharesshares
Shares (in thousands)
Outstanding, shares | shares	12,726
Granted, shares | shares	2,318
Exercised, shares | shares	(1,434)
Forfeited or expired, shares | shares	(429)
Outstanding, shares | shares	13,181
Exercisable as of reporting date, shares | shares	4,327
Options vested or expected to vest as of reporting date, shares | shares	11,916
Weighted- Average Exercise Price
Outstanding, shares | $ / shares	$ 25.24
Granted, in dollars per share | $ / shares	55.66
Exercised, in dollars per share | $ / shares	18.06
Forfeited or expired, in dollars per share | $ / shares	33.24
Outstanding, shares | $ / shares	31.11
Exercisable as of reporting date, Weighted-Average Exercise Price, in dollars per share | $ / shares	20.14
Weighted- Average Remaining Contractual Term (in years) | $ / shares	$ 29.99
Weighted- Average Remaining Contractual Term (in years)
Outstanding, in years	7 years 5 months 23 days
Exercisable, in years	6 years 4 days
Options vested or expected to vest, in years	7 years 4 months 13 days
Aggregate Intrinsic Value (in thousands)
Outstanding, in dollars | $	$ 329,301
Exercisable, in dollars | $	154,377
Options vested or expected to vest, in dollars | $	$ 310,772

Stock-Based Compensation Expe_5

Stock-Based Compensation Expense - Weighted-Average Assumptions Used in Estimating Fair Values of Stock Options Granted (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Oct. 01, 2017	Sep. 30, 2018	Oct. 01, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Risk-free rate	2.90%	2.40%	2.90%	2.40%
Expected dividend yield	0.32%	0.39%	0.32%	0.39%
Expected volatility	39.00%	41.00%	39.00%	41.00%
Expected term (in years)	5 years 4 months 24 days	5 years 1 month 6 days	5 years 3 months 18 days	5 years 3 months 18 days

Stock-Based Compensation Expe_6

Stock-Based Compensation Expense - Nonvested Restricted Stock Shares Activity (Details) - Restricted Stock $ / shares in Units, shares in Thousands, $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)$ / sharesshares
Shares (in thousands)
Nonvested, shares | shares	20
Granted, shares | shares
Vested, shares | shares	(20)
Forfeited or expired, shares | shares
Nonvested, shares | shares	0
Weighted-Average Grant Fair Value
Nonvested, in dollars per share | $ / shares	$ 17.03
Granted, in dollars per share | $ / shares
Vested, in dollars per share | $ / shares	17.03
Forfeited or expired, in dollars per share | $ / shares
Nonvested, in dollars per share | $ / shares	$ 0
Aggregate Intrinsic Value (in thousands)
Vested | $	$ 993
Nonvested as of September 30, 2018 | $	$ 0

Stock-Based Compensation Expe_7

Stock-Based Compensation Expense - Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Oct. 01, 2017	Sep. 30, 2018	Oct. 01, 2017
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 9,143	$ 8,026	$ 31,339	$ 23,355
Cost of Revenue
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	544	520	1,898	1,404
Research, Development, and Engineering Expenses
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	3,197	2,765	11,166	8,090
Selling, General, and Administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 5,402	$ 4,741	$ 18,275	$ 13,861

Stock Repurchase Program (Detai

Stock Repurchase Program (Detail) - USD ($) shares in Thousands	9 Months Ended
	Sep. 30, 2018	Feb. 28, 2018	Nov. 01, 2015
Equity, Class of Treasury Stock [Line Items]
Stock repurchased during period, value	$ 142,262,000
Repurchase Program April 2017
Equity, Class of Treasury Stock [Line Items]
Authorized common stock to be repurchased			$ 100,000,000
Stock Repurchase Program, Aggregate Number of Shares Repurchased	1,744
Shares repurchased, value	$ 100,000,000
Repurchase of common stock (in shares)	803
Stock repurchased during period, value	$ 45,200,000
Repurchase Program February 2018
Equity, Class of Treasury Stock [Line Items]
Authorized common stock to be repurchased		$ 150,000,000
Repurchase of common stock (in shares)	1,947
Stock repurchased during period, value	$ 97,062,000
Stock repurchase program, remaining authorized repurchase amount	52,938,000
Repurchase Program April 2017 and February 2018
Equity, Class of Treasury Stock [Line Items]
Stock repurchased during period, value	$ 142,262,000

Taxes - Reconciliation of Unite

Taxes - Reconciliation of United States Federal Statutory Corporate Tax Rate to Company's Effective Tax Rate, or Income Tax Provision (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Oct. 01, 2017	Sep. 30, 2018	Oct. 01, 2017
Income Tax Disclosure [Abstract]
Income tax provision at federal statutory corporate tax rate	21.00%	35.00%	21.00%	35.00%
State income taxes, net of federal benefit	1.00%	1.00%	1.00%	1.00%
Foreign tax rate differential	(7.00%)	(18.00%)	(7.00%)	(18.00%)
Tax credit	(0.00%)	(1.00%)	(0.00%)	(1.00%)
Discrete tax benefit related to Tax Act 2017	(9.00%)	0.00%	(4.00%)	0.00%
Discrete tax benefit related to stock option exercises	(4.00%)	(7.00%)	(5.00%)	(13.00%)
Other discrete tax events	(2.00%)	(2.00%)	(1.00%)	(1.00%)
Other	1.00%	1.00%	1.00%	1.00%
Income tax provision	1.00%	9.00%	6.00%	4.00%

Taxes (Detail)

Taxes (Detail) - USD ($) $ in Thousands	Jan. 01, 2018	Sep. 30, 2018	Oct. 01, 2017	Sep. 30, 2018	Oct. 01, 2017	Dec. 31, 2017
Income Tax Contingency [Line Items]
Discrete tax benefit related to Tax Act 2017		(9.00%)	0.00%	(4.00%)	0.00%
Income tax provision at federal statutory corporate tax rate		21.00%	35.00%	21.00%	35.00%
Decrease in effective tax rate		7.00%	18.00%	7.00%	18.00%
Decrease in effective tax rate for difference between deduction for tax purposes and compensation cost recognized from stock option exercises		4.00%	7.00%	5.00%	13.00%
Other discrete tax events		(2.00%)	(2.00%)	(1.00%)	(1.00%)
Increase in reserves for income taxes, net of deferred tax benefit		$ 204		$ 204
Interest and penalties included in reserve				33
Liability for uncertain tax positions		7,674		7,674
Reserve for income taxes classified as a noncurrent iability		6,646		6,646		$ 6,488
Reserve for income taxes classified an noncurrent deferred tax assets		1,028		1,028
Interest and penalties, gross		$ 773		773
Minimum decrease in income tax expense due to release in reserves				1,200
Maximum decrease in income tax expense due to release in reserves				$ 1,300
Tax years open to examination by Internal Revenue Service				2015 through 2017
Tax years open to examination by various taxing authorities for other entities				2014 through 2017
Foreign Tax Authority | Revenue Commissioners, Ireland
Income Tax Contingency [Line Items]
Income tax provision at federal statutory corporate tax rate				12.50%
Foreign Tax Authority | State Administration of Taxation, China
Income Tax Contingency [Line Items]
Income tax provision at federal statutory corporate tax rate				25.00%
Domestic Tax Authority
Income Tax Contingency [Line Items]
Income tax provision at federal statutory corporate tax rate				21.00%
Accounting Standards Update 2016-16
Income Tax Contingency [Line Items]
Cumulative effect on retained earnings, net of tax	$ 5,961

Weighted-Average Shares (Detail

Weighted-Average Shares (Detail) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Oct. 01, 2017	Sep. 30, 2018	Oct. 01, 2017
Earnings Per Share [Abstract]
Stock options to purchase anti-dilutive common stock	2,796,000	466,000	2,353,000	3,108,000

Weighted-Average Shares - Calcu

Weighted-Average Shares - Calculation of Weighted-Average Shares (Detail) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Oct. 01, 2017	Sep. 30, 2018	Oct. 01, 2017
Earnings Per Share [Abstract]
Basic weighted-average common shares outstanding	172,189	173,234	172,613	173,052
Effect of dilutive stock options	5,056	6,120	5,408	6,072
Weighted-average common and common-equivalent shares outstanding	177,245	179,354	178,021	179,124

Subsequent Events (Details)

Subsequent Events (Details) - Subsequent Event	Oct. 29, 2018USD ($)
Subsequent Event [Line Items]
Dividends (in dollars per share)	$ 0.05
Dividends payable, date payable	Nov. 30, 2018
Dividends payable, date of record	Nov. 16, 2018
Stock Repurchase Program, Value	$ 200,000,000