Cognex (CGNX) 10-Q 29 Jul 19 2019 Q2 Quarterly report Financial data

Cover Page

Cover Page	6 Months Ended
	Jun. 30, 2019shares
Cover page.
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2019
Document Transition Report	false
Entity File Number	001-34218
Entity Registrant Name	COGNEX CORP
Entity Central Index Key	0000851205
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Amendment Flag	false
Entity Incorporation, State or Country Code	MA
Entity Tax Identification Number	04-2713778
Entity Address, Address Line One	One Vision Drive
Entity Address, City or Town	Natick
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	01760
City Area Code	508
Local Phone Number	650-3000
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Title of 12(b) Security	Common Stock, par value $.002 per share
Trading Symbol	CGNX
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding	170,660,621

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jul. 01, 2018	Jun. 30, 2019	Jul. 01, 2018
Income Statement [Abstract]
Revenue	$ 199,047	$ 211,264	$ 372,531	$ 380,831
Cost of revenue	50,967	54,169	97,251	94,367
Gross margin	148,080	157,095	275,280	286,464
Research, development, and engineering expenses	28,079	26,888	58,321	57,964
Selling, general, and administrative expenses	68,245	66,752	135,056	130,449
Operating income	51,756	63,455	81,903	98,051
Foreign currency gain (loss)	140	(195)	(108)	(329)
Investment income	5,223	3,559	10,128	6,799
Other income (expense)	(144)	(246)	783	31
Income before income tax expense	56,975	66,573	92,706	104,552
Income tax expense	8,226	10,377	10,853	11,139
Net Income	$ 48,749	$ 56,196	$ 81,853	$ 93,413
Net income per weighted-average common and common-equivalent share:
Basic (usd per share)	$ 0.28	$ 0.33	$ 0.48	$ 0.54
Diluted (usd per share)	$ 0.28	$ 0.32	$ 0.47	$ 0.52
Weighted-average common and common-equivalent shares outstanding:
Basic (shares)	171,318	172,370	171,209	172,825
Diluted (shares)	175,448	177,149	175,528	178,418
Cash dividends per common share (usd per share)	$ 0.050	$ 0.045	$ 0.100	$ 0.090

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jul. 01, 2018	Jun. 30, 2019	Jul. 01, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 48,749	$ 56,196	$ 81,853	$ 93,413
Available-for-sale investments:
Net unrealized gain (loss), net of tax of $239 and $8 in the three-month periods and net of tax of $507 and ($106) in the six-month periods, respectively	2,311	490	4,562	(702)
Reclassification of net realized (gain) loss into current operations	(382)	(247)	(422)	(269)
Net change related to available-for-sale investments	1,929	243	4,140	(971)
Foreign currency translation adjustments:
Foreign currency translation adjustments	(663)	(7,253)	(445)	(3,197)
Other comprehensive income (loss), net of tax	1,266	(7,010)	3,695	(4,168)
Total comprehensive income	$ 50,015	$ 49,186	$ 85,548	$ 89,245

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jul. 01, 2018	Jun. 30, 2019	Jul. 01, 2018
Statement of Comprehensive Income [Abstract]
Tax effect on cash flow hedges	$ 0	$ 0	$ 0	$ 0
Tax effect of unrealized gain (loss) on available-for-sale investments	239	8	507	(106)
Tax effect of foreign currency translation adjustment	$ 0	$ 0	$ 0	$ 0

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 89,104	$ 108,212
Current investments	364,487	427,348
Accounts receivable, less reserves of $1,778 and $1,646 in 2019 and 2018, respectively	107,643	119,172
Unbilled revenue	10,300	8,312
Inventories	72,889	83,282
Prepaid expenses and other current assets	34,451	34,000
Total current assets	678,874	780,326
Non-current investments	408,032	262,039
Property, plant, and equipment, net	89,342	91,396
Operating Lease, Right-of-Use Asset	17,928	0
Goodwill	113,208	113,208
Intangible assets, net	8,575	10,113
Deferred income taxes	28,537	28,660
Other assets	5,424	3,925
Total assets	1,349,920	1,289,667
Current liabilities:
Accounts payable	11,729	16,230
Accrued expenses	48,709	60,220
Accrued income taxes	1,078	5,062
Deferred revenue and customer deposits	18,332	9,845
Operating Lease, Liability, Current	5,835	0
Total current liabilities	85,683	91,357
Operating Lease, Liability, Noncurrent	12,149	0
Deferred income taxes	0	962
Reserve for income taxes	8,091	7,106
Non-current accrued income taxes	51,113	51,113
Other liabilities	1,244	3,866
Total liabilities	158,280	154,404
Preferred Stock, Value, Outstanding	0	0
Shareholders’ equity:
Common stock, $.002 par value – Authorized: 300,000 shares in 2019 and 2018, respectively, issued and outstanding: 170,661 and 170,820 shares in 2019 and 2018, respectively	341	342
Additional paid-in capital	578,871	529,208
Retained earnings	649,234	646,214
Accumulated other comprehensive loss, net of tax	(36,806)	(40,501)
Total shareholders’ equity	1,191,640	1,135,263
Total liabilities and shareholders' equity	$ 1,349,920	$ 1,289,667

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Reserves for accounts receivable	$ 1,778	$ 1,646
Common stock, par value	$ 0.002	$ 0.002
Common stock, shares authorized	300,000,000	300,000,000
Common stock, shares issued	170,661,000	170,820,000

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jul. 01, 2018
Cash flows from operating activities:
Net income	$ 81,853	$ 93,413
Adjustments to reconcile net income to net cash provided by operating activities:
Stock-based compensation expense	23,248	22,196
Depreciation of property, plant, and equipment	10,537	8,874
Amortization of intangible assets	1,538	1,538
Amortization of discounts or premiums on investments	(342)	94
Realized (gain) loss on sale of investments	(422)	(269)
Revaluation of contingent consideration	(863)	(254)
Change in deferred income taxes	(1,311)	(2,385)
Accounts receivable	11,383	(18,779)
Unbilled revenue	(1,989)	3,803
Inventories	10,394	(23,220)
Prepaid expenses and other current assets	(463)	(23,112)
Accounts payable	(4,528)	(10,889)
Accrued expenses	(12,270)	(5,666)
Accrued income taxes	(4,000)	(5,360)
Deferred revenue and customer deposits	8,575	32,470
Other	(1,190)	162
Net cash provided by operating activities	120,150	72,616
Cash flows from investing activities:
Purchases of investments	(664,896)	(336,189)
Maturities and sales of investments	587,175	431,008
Purchases of property, plant, and equipment	(8,969)	(21,675)
Net cash provided by (used in) investing activities	(86,690)	73,144
Cash flows from financing activities:
Issuance of common stock under stock plans	26,417	14,811
Repurchase of common stock	(61,690)	(121,308)
Payment of dividends	(17,146)	(15,524)
Payment of contingent consideration	0	(1,000)
Net cash provided by (used in) financing activities	(52,419)	(123,021)
Effect of foreign exchange rate changes on cash and cash equivalents	(149)	(119)
Net change in cash and cash equivalents	(19,108)	22,620
Cash and cash equivalents at beginning of period	108,212	106,582
Cash and cash equivalents at end of period	$ 89,104	$ 129,202

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
Beginning Balance (in shares) at Dec. 31, 2017		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)		881
Issuance of common stock under stock plans	14,811	$ 2	14,809
Repurchase of common stock (in shares)		(2,356)
Repurchase of common stock	(121,308)	$ (5)		(121,303)
Stock-based compensation expense	22,196		22,196
Payment of dividends	(15,524)			(15,524)
Net income	93,413			93,413
Net unrealized gain (loss) on available-for-sale investments, net of tax of ($106)	(702)				(702)
Reclassification of net realized (gain) loss on the sale of available-for-sale investments	(269)				(269)
Foreign currency translation adjustment	(3,197)				(3,197)
Ending Balance (in shares) at Jul. 01, 2018		172,032
Ending Balance at Jul. 01, 2018	1,079,132	$ 344	498,343	619,212	(38,767)
Beginning Balance (in shares) at Apr. 01, 2018		172,948
Beginning Balance at Apr. 01, 2018	1,077,099	$ 346	485,654	622,856	(31,757)
Increase (Decrease) in Stockholders' Equity
Issuance of common stock under stock plans (in shares)		184
Issuance of common stock under stock plans	3,688	$ 1	3,687
Repurchase of common stock (in shares)		(1,100)
Repurchase of common stock	(52,106)	$ (3)		(52,103)
Stock-based compensation expense	9,002		9,002
Payment of dividends	(7,737)			(7,737)
Net income	56,196			56,196
Net unrealized gain (loss) on available-for-sale investments, net of tax of ($106)	490				490
Reclassification of net realized (gain) loss on the sale of available-for-sale investments	(247)				(247)
Foreign currency translation adjustment	(7,253)				(7,253)
Ending Balance (in shares) at Jul. 01, 2018		172,032
Ending Balance at Jul. 01, 2018	$ 1,079,132	$ 344	498,343	619,212	(38,767)
Beginning Balance (in shares) at Dec. 31, 2018	170,820	170,820
Beginning Balance at Dec. 31, 2018	$ 1,135,263	$ 342	529,208	646,214	(40,501)
Increase (Decrease) in Stockholders' Equity
Issuance of common stock under stock plans (in shares)		1,239
Issuance of common stock under stock plans	26,417	$ 2	26,415
Repurchase of common stock (in shares)		(1,398)
Repurchase of common stock	(61,690)	$ (3)		(61,687)
Stock-based compensation expense	23,248		23,248
Payment of dividends	(17,146)			(17,146)
Net income	81,853			81,853
Net unrealized gain (loss) on available-for-sale investments, net of tax of ($106)	4,562				4,562
Reclassification of net realized (gain) loss on the sale of available-for-sale investments	(422)				(422)
Foreign currency translation adjustment	$ (445)				(445)
Ending Balance (in shares) at Jun. 30, 2019	170,661	170,661
Ending Balance at Jun. 30, 2019	$ 1,191,640	$ 341	578,871	649,234	(36,806)
Beginning Balance (in shares) at Mar. 31, 2019		171,537
Beginning Balance at Mar. 31, 2019	1,188,859	$ 343	555,834	670,754	(38,072)
Increase (Decrease) in Stockholders' Equity
Issuance of common stock under stock plans (in shares)		522
Issuance of common stock under stock plans	12,071	$ 1	12,070
Repurchase of common stock (in shares)		(1,398)
Repurchase of common stock	(61,690)	$ (3)		(61,687)
Stock-based compensation expense	10,967		10,967
Payment of dividends	(8,582)			(8,582)
Net income	48,749			48,749
Net unrealized gain (loss) on available-for-sale investments, net of tax of ($106)	2,311				2,311
Reclassification of net realized (gain) loss on the sale of available-for-sale investments	(382)				(382)
Foreign currency translation adjustment	$ (663)				(663)
Ending Balance (in shares) at Jun. 30, 2019	170,661	170,661
Ending Balance at Jun. 30, 2019	$ 1,191,640	$ 341	$ 578,871	$ 649,234	$ (36,806)

Consolidated Statement of Sha_2

Consolidated Statement of Shareholders' Equity (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jul. 01, 2018	Jun. 30, 2019	Jul. 01, 2018
Statement of Stockholders' Equity [Abstract]
Tax effect of unrealized gain (loss) on available-for-sale investments	$ 239	$ 8	$ 507	$ (106)

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2019
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 842 "Leases," Cognex Corporation (the "Company") has provided new disclosures related to leases 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, 2018 for a full description of other 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 June 30, 2019 , and the results of its operations for the three-month and six-month periods ended June 30, 2019 and July 1, 2018 , 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 six-month periods ended June 30, 2019 are not necessarily indicative of the results to be expected for the full year. Leases The Company accounts for leases in accordance with Accounting Standard Codification (ASC) 842, "Leases." The core principle of ASC 842 is that a lessee should recognize on the balance sheet the assets and liabilities that arise from leases. At inception of a contract, the Company determines whether that contract is or contains a lease. The Company determines whether a contract contains a lease by assessing whether there is an identified asset and whether the contract conveys the right to control the use of the identified asset for a period of time in exchange for consideration. The Company has control of the asset if it has the right to direct the use of the asset and obtains substantially all of the economic benefits from the use of the asset throughout the period of use. As a practical expedient, the Company does not recognize a lease asset or lease liability for leases with a lease term of 12 months or less. In the determination of the lease term, the Company considers the existence of extension or termination options and the probability of those options being exercised. Lease contracts may include lease components and non-lease components, such as common area maintenance and utilities for property leases. As a practical expedient, the Company accounts for the non-lease components together with the lease components as a single lease component for all of its leases. The Company classifies a lease as a finance lease when it meets any of the following criteria at the lease commencement date: a) the lease transfers ownership of the underlying asset to the Company by the end of the lease term; b) the lease grants the Company an option to purchase the underlying asset that the Company is reasonably certain to exercise; c) the lease term is for the major part of the remaining economic life of the underlying asset (the Company considers a major part to be 75% or more of the remaining economic life of the underlying asset); d) the present value of the sum of the lease payments and any residual value guaranteed by the Company equals or exceeds substantially all of the fair value of the underlying asset (the Company considers substantially all the fair value to be 90% or more of the fair value of the underlying asset amount); or e) the underlying asset is of such a specialized nature that it is expected to have no alternative use to the lessor at the end of the lease term. When none of the criteria above are met, the Company classifies the lease as an operating lease. On the lease commencement date, the Company records a lease asset and lease liability on the balance sheet. The lease asset consists of: 1) the amount of the initial lease liability; 2) any lease payments made to the lessor at or before the lease commencement date, minus any lease incentives received; and 3) any initial direct cost incurred by the Company. Initial direct costs are incremental costs of a lease that would not have been incurred if the lease had not been obtained and are capitalized as part of the lease asset. The lease liability equals the present value of the future cash payments discounted using the Company's incremental borrowing rate. The Company’s incremental borrowing rate is the rate of interest that the Company would have to pay to borrow an amount equal to the lease payments over a similar term, which is the three-month London Interbank Offered Rate (LIBOR) plus a 2.5% credit risk spread. Operating lease expense equals the total cash payments recognized on a straight-line basis over the lease term. The amortization of the lease asset is calculated as the straight-line lease expense less the accretion of the interest on the lease liability each period. The lease liability is reduced by the cash payment less the interest each period.

New Pronouncements

New Pronouncements	6 Months Ended
	Jun. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
New Pronouncements	New Pronouncements 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 U.S. 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 annual periods. 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 annual 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) 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 statements and disclosures.

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2019
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 June 30, 2019 (in thousands): Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Assets: Money market instruments $ 3,099 $ — $ — Treasury bills — 307,490 — Corporate bonds — 278,991 — Asset-backed securities — 145,432 — Sovereign bonds — 20,823 — Agency bonds — 13,686 — Municipal bonds — 6,097 — Economic hedge forward contracts — 20 — Liabilities: Economic hedge forward contracts — 13 — Contingent consideration liabilities — — 1,691 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 three-month or six -month periods ended June 30, 2019 and July 1, 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 six-month period ended June 30, 2019 (in thousands): Balance as of December 31, 2018 $ 2,554 Fair value adjustment to GVi contingent consideration (1,019 ) Fair value adjustment to Chiaro contingent consideration 156 Balance as of June 30, 2019 $ 1,691 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 three-month or six -month periods ended June 30, 2019 and July 1, 2018.

Cash, Cash Equivalents, and Inv

Cash, Cash Equivalents, and Investments	6 Months Ended
	Jun. 30, 2019
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): June 30, 2019 December 31, 2018 Cash $ 86,005 $ 104,655 Money market instruments 3,099 3,557 Cash and cash equivalents 89,104 108,212 Treasury bills 138,600 198,477 Asset-backed securities 104,998 78,407 Corporate bonds 101,868 137,871 Agency bonds 7,783 — Sovereign bonds 5,990 8,101 Municipal bonds 5,248 4,492 Current investments 364,487 427,348 Corporate bonds 177,123 162,566 Treasury bills 168,890 32,760 Asset-backed securities 40,434 53,631 Sovereign bonds 14,833 6,316 Agency bonds 5,903 5,921 Municipal bonds 849 845 Non-current investments 408,032 262,039 $ 861,623 $ 797,599 Treasury bills consist of debt securities issued by the U.S. government; asset-backed securities consist of debt securities collateralized by pools of receivables or loans with credit enhancement; corporate bonds consist of debt securities issued by both domestic and foreign companies; agency bonds consist of domestic or foreign obligations of government agencies and government sponsored enterprises that have government backing; sovereign bonds consist of direct debt issued by foreign governments; and municipal bonds consist of debt securities issued by state and local government entities. All securities are denominated in U.S. Dollars. The following table summarizes the Company’s available-for-sale investments as of June 30, 2019 (in thousands): Amortized Gross Gross Fair Value Current: Treasury bills $ 138,217 $ 383 $ — $ 138,600 Asset-backed securities 104,717 317 (36 ) 104,998 Corporate bonds 101,722 182 (36 ) 101,868 Agency bonds 7,780 3 — 7,783 Sovereign bonds 5,979 12 (1 ) 5,990 Municipal bonds 5,241 7 — 5,248 Non-current: Corporate bonds 176,726 537 (140 ) 177,123 Treasury bills 167,653 1,257 (20 ) 168,890 Asset-backed securities 40,198 237 (1 ) 40,434 Sovereign bonds 14,783 50 — 14,833 Agency bonds 5,930 — (27 ) 5,903 Municipal bonds 855 — (6 ) 849 $ 769,801 $ 2,985 $ (267 ) $ 772,519 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 June 30, 2019 (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 Corporate bonds $ 26,243 $ (90 ) $ 42,031 $ (86 ) $ 68,274 $ (176 ) Asset-backed securities 4,378 (1 ) 21,331 (36 ) 25,709 (37 ) Treasury bills 24,855 (20 ) — — 24,855 (20 ) Agency bonds 5,903 (27 ) — — 5,903 (27 ) Sovereign bonds — — 2,689 (1 ) 2,689 (1 ) Municipal bonds — — 849 (6 ) 849 (6 ) $ 61,379 $ (138 ) $ 66,900 $ (129 ) $ 128,279 $ (267 ) As of June 30, 2019 , 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 $394,000 and $12,000 , respectively, during the three-month period ended June 30, 2019 and $308,000 and $61,000 , respectively, during the three-month period ended July 1, 2018 . The Company recorded gross realized gains and gross realized losses on the sale of debt securities totaling $458,000 and $36,000 , respectively, during the six-month period ended June 30, 2019 and $363,000 and $94,000 , respectively, during the six-month period ended July 1, 2018 . These gains and losses are included in "Investment income" on the Consolidated Statements 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 loss. The following table presents the effective maturity dates of the Company’s available-for-sale investments as of June 30, 2019 (in thousands): <1 year 1-2 Years 2-3 Years 3-4 Years 4-5 Years 5-7 Years Total Treasury bills $ 138,600 $ 158,777 $ 10,113 $ — $ — $ — $ 307,490 Corporate bonds 101,868 103,324 65,231 5,710 2,858 — 278,991 Asset-backed securities 104,998 15,771 8,760 11,199 — 4,704 145,432 Sovereign bonds 5,990 14,833 — — — 20,823 Agency bonds 7,783 — — 5,903 — — 13,686 Municipal bonds 5,248 849 — — — — 6,097 $ 364,487 $ 293,554 $ 84,104 $ 22,812 $ 2,858 $ 4,704 $ 772,519

Inventories

Inventories	6 Months Ended
	Jun. 30, 2019
Inventory Disclosure [Abstract]
Inventories	Inventories Inventories consisted of the following (in thousands): June 30, 2019 December 31, 2018 Raw materials $ 32,545 $ 42,738 Work-in-process 4,112 3,435 Finished goods 36,232 37,109 $ 72,889 $ 83,282

Leases

Leases	6 Months Ended
	Jun. 30, 2019
Leases [Abstract]
Leases	Leases On January 1, 2019, the Company adopted Accounting Standards Codification (ASC) 842, “Leases,” using the transition method of adoption, which allowed the Company to apply the standard on a prospective basis with a cumulative-effect adjustment to the opening balance sheet as of the adoption date. Accordingly, the Company recorded lease assets of $ 17,522,000 , current lease liabilities of $ 4,736,000 , and non-current lease liabilities of $ 12,669,000 on its Consolidated Balance Sheet as of January 1, 2019. As part of the adoption, the Company elected a practical expedient package to be applied to all of its leases upon transition, and as a result, the Company did not reassess: 1) whether any expired or existing contracts contain leases; 2) the lease classification for any expired or existing leases; and 3) the accounting for initial direct costs for any existing leases. The Company's leases are primarily leased properties across different worldwide locations where the Company conducts its operations. All of these leases are classified as operating leases. Certain leases may contain options to extend or terminate the lease at the Company's sole discretion. There were no options to extend or terminate that were included in the determination of the lease term for the leases outstanding as of June 30, 2019. Certain leases contain leasehold improvement incentives, retirement obligations, escalating clauses, rent holidays, and variable payments tied to a consumer price index. There were no restrictions or covenants for the leases outstanding as of June 30, 2019. The total operating lease expense for the three-month and six-month periods ended June 30, 2019 was $ 1,742,000 and $3,227,000 , respectively. The total operating lease cash payments for the three-month and six-month periods ended June 30, 2019 was $ 1,669,000 and $3,070,000 , respectively. The total lease expense for leases with a term of twelve months or less for which the Company elected not to recognize a lease asset or lease liability was $ 64,000 and $233,000 for the three-month and six-month periods ended June 30, 2019, respectively. Future operating lease cash payments are as follows (in thousands): Year Ended December 31, Amount Remainder of fiscal 2019 $ 3,387 2020 5,730 2021 4,397 2022 2,890 2023 2,035 2024 842 Thereafter 311 $ 19,592 The discounted present value of the future lease cash payments resulted in a lease liability of $ 17,984,000 as of June 30, 2019. The weighted-average discount rate was 4.8 % for the leases outstanding as of June 30, 2019. The weighted-average remaining lease term was 3.6 years for the leases outstanding as of June 30, 2019. The Company did not have any leases that have not yet commenced but that create significant rights and obligations as of June 30, 2019. The Company owns a building adjacent to its corporate headquarters that is partially occupied with a tenant who has a lease agreement that will expire in 2022. Rental income was $81,000 and $83,000 for the three-month period ended June 30, 2019 and July 1, 2018, respectively. Rental income was $ 158,000 and $ 159,000 for the six-month period ended June 30, 2019 and July 1, 2018, respectively. Future minimum rental receipts under non-cancelable lease agreements are as follows (in thousands): Year Ended December 31, Amount Remainder of fiscal 2019 $ 153 2020 307 2021 307 2022 307 $ 1,074

Intangible Assets

Intangible Assets	6 Months Ended
	Jun. 30, 2019
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 7,839 5,848 Customer relationships 8,607 5,973 2,634 Non-compete agreements 370 277 93 Balance as of June 30, 2019 $ 60,724 $ 52,149 $ 8,575 Gross Carrying Value Accumulated Amortization Net Carrying Value Distribution networks $ 38,060 $ 38,060 $ — Completed technologies 13,687 6,619 7,068 Customer relationships 8,607 5,716 2,891 Non-compete agreements 370 216 154 Balance as of December 31, 2018 $ 60,724 $ 50,611 $ 10,113 As of June 30, 2019, estimated future amortization expense related to intangible assets is as follows (in thousands): Year Ended December 31, Amount Remainder of fiscal 2019 $ 1,163 2020 2,185 2021 2,017 2022 1,691 2023 989 2024 422 Thereafter 108 $ 8,575

Warranty Obligations

Warranty Obligations	6 Months Ended
	Jun. 30, 2019
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, 2018 $ 4,743 Provisions for warranties issued during the period 2,533 Fulfillment of warranty obligations (1,824 ) Balance as of June 30, 2019 $ 5,452

Derivative Instruments

Derivative Instruments	6 Months Ended
	Jun. 30, 2019
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 economic hedges to manage this risk. The economic hedges 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 Company had the following outstanding forward contracts (in thousands): June 30, 2019 December 31, 2018 Currency Notional USD Notional USD Derivatives Not Designated as Hedging Instruments: Euro 19,000 $ 21,681 23,000 $ 26,330 Japanese Yen 400,000 3,717 380,000 3,459 Hungarian Forint 900,000 3,178 750,000 2,685 Korean Won 3,550,000 3,072 3,125,000 2,808 British Pound 2,400 3,055 2,500 3,204 Taiwanese Dollar 50,000 1,617 55,000 1,807 Canadian Dollar 1,100 841 990 726 Singapore Dollar — — 700 514 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 June 30, 2019 December 31, 2018 Sheet June 30, 2019 December 31, 2018 Derivatives Not Designated as Hedging Instruments: Economic hedge forward contracts Prepaid expenses and other current assets $ 20 $ 1 Accrued expenses $ 13 $ 106 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 June 30, 2019 December 31, 2018 June 30, 2019 December 31, 2018 Gross amounts of recognized assets $ 20 $ 1 Gross amounts of recognized liabilities $ 13 $ 106 Gross amounts offset — — Gross amounts offset — — Net amount of assets presented $ 20 $ 1 Net amount of liabilities presented $ 13 $ 106 Information regarding the effect of derivative instruments on the consolidated financial statements was as follows (in thousands): Location in Financial Statements Three-months Ended Six-months Ended June 30, 2019 July 1, 2018 June 30, 2019 July 1, 2018 Derivatives Not Designated as Hedging Instruments: Gains (losses) recognized in current operations Foreign currency gain (loss) $ (439 ) $ (354 ) $ 66 $ (665 )

Revenue Recognition

Revenue Recognition	6 Months Ended
	Jun. 30, 2019
Revenue from Contract with Customer [Abstract]
Revenue Recognition	Revenue Recognition The following table summarizes disaggregated revenue information by geographic area based upon the customer's country of domicile (in thousands): Three-months Ended Six-months Ended June 30, 2019 July 1, 2018 June 30, 2019 July 1, 2018 Americas $ 78,500 $ 71,812 $ 143,656 $ 131,029 Europe 58,881 70,366 118,538 126,569 Greater China 35,782 41,175 58,592 68,334 Other Asia 25,884 27,911 51,745 54,899 $ 199,047 $ 211,264 $ 372,531 $ 380,831 The following table summarizes disaggregated revenue information by revenue type (in thousands): Three-months Ended Six-months Ended June 30, 2019 July 1, 2018 June 30, 2019 July 1, 2018 Standard products and services $ 173,368 $ 183,627 $ 334,420 $ 342,026 Application-specific customer solutions 25,679 27,637 38,111 38,805 $ 199,047 $ 211,264 $ 372,531 $ 380,831 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 $6,852,000 and $3,514,000 as of June 30, 2019 and December 31, 2018, 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 six-month periods ended June 30, 2019 and July 1, 2018, 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 six-month period ended June 30, 2019 (in thousands): Balance as of December 31, 2018 $ 9,845 Increases to deferred revenue and customer deposits 29,883 Recognition of revenue (21,308 ) Foreign exchange rate changes (88 ) Balance as of June 30, 2019 $ 18,332 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	6 Months Ended
	Jun. 30, 2019
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 June 30, 2019 , the Company had 17,363,952 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. The following table summarizes the Company’s stock option activity for the six -month period ended June 30, 2019 : Shares (in thousands) Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (in years) Aggregate Intrinsic Value (in thousands) Outstanding as of December 31, 2018 13,789 $ 31.73 Granted 2,821 51.37 Exercised (1,239 ) 21.32 Forfeited or expired (606 ) 40.27 Outstanding as of June 30, 2019 14,765 $ 36.00 7.42 $ 207,599 Exercisable as of June 30, 2019 5,867 $ 25.12 5.95 $ 138,370 Options vested or expected to vest as of June 30, 2019 (1) 13,214 $ 34.65 7.25 $ 201,420 (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 Six-months Ended June 30, 2019 July 1, 2018 June 30, 2019 July 1, 2018 Risk-free rate 2.7 % 2.9 % 2.7 % 2.9 % Expected dividend yield 0.39 % 0.32 % 0.39 % 0.32 % Expected volatility 37 % 39 % 37 % 39 % Expected term (in years) 5.2 5.4 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 9% 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 a decrease to compensation expense of $499,000 in 2019 and in increase to compensation expense of $1,283,000 in 2018. The weighted-average grant-date fair values of stock options granted during the three-month periods ended June 30, 2019 and July 1, 2018 were $18.68 and $21.63 , respectively. The weighted-average grant-date fair values of stock options granted during the six-month periods ended June 30, 2019 and July 1, 2018 were $18.59 and $21.62 , respectively. The total intrinsic values of stock options exercised for the three-month periods ended June 30, 2019 and July 1, 2018 were $14,220,000 and $4,902,000 , respectively. The total intrinsic values of stock options exercised for the six-month periods ended June 30, 2019 and July 1, 2018 were $36,799,000 and $32,991,000 , respectively. The total fair values of stock options vested for the three-month periods ended June 30, 2019 and July 1, 2018 were $887,000 and $887,000 , respectively. The total fair values of stock options vested for the six-month periods ended June 30, 2019 and July 1, 2018 were $30,859,000 and $26,560,000 , respectively. As of June 30, 2019 , total unrecognized compensation expense related to non-vested stock options was $66,645,000 , which is expected to be recognized over a weighted-average period of 1.88 years. The total stock-based compensation expense and the related income tax benefit recognized for the three-month period ended June 30, 2019 were $10,967,000 and $1,813,000 , respectively, and for the three-month period ended July 1, 2018 were $9,002,000 and $1,607,000 , respectively. The total stock-based compensation expense and the related income tax benefit recognized for the six-month period ended June 30, 2019 were $23,248,000 and $4,035,000 , respectively, and for the six-month period ended July 1, 2018 were $22,196,000 and $3,954,000 , respectively. No compensation expense was capitalized as of June 30, 2019 or December 31, 2018 . 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 Six-months Ended June 30, 2019 July 1, 2018 June 30, 2019 July 1, 2018 Cost of revenue $ 329 $ 557 $ 780 $ 1,354 Research, development, and engineering 3,550 3,154 8,017 7,969 Selling, general, and administrative 7,088 5,291 14,451 12,873 $ 10,967 $ 9,002 $ 23,248 $ 22,196

Stock Repurchase Program

Stock Repurchase Program	6 Months Ended
	Jun. 30, 2019
Equity [Abstract]
Stock Repurchase Program	Stock Repurchase Program In October 2018, the Company's Board of Directors authorized the repurchase of $200,000,000 of the Company's common stock. As of June 30, 2019, the Company repurchased 1,601,000 shares at a cost of $70,312,000 under this program, including 1,398,000 shares at a cost of $61,690,000 in 2019, all of which were repurchased in the three-month period ended June 30, 2019. The Company may repurchase shares under this program in future periods, up to the remaining balance of $129,688,000 , 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	6 Months Ended
	Jun. 30, 2019
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 Six-months Ended June 30, 2019 July 1, 2018 June 30, 2019 July 1, 2018 Income tax expense at U.S. federal statutory corporate tax rate 21 % 21 % 21 % 21 % State income taxes, net of federal benefit 1 % 2 % 1 % 2 % Foreign tax rate differential (7 )% (7 )% (7 )% (7 )% Tax credit (1 )% (1 )% (1 )% (1 )% Discrete tax benefit related to stock options (2 )% (1 )% (4 )% (5 )% Other 2 % 2 % 2 % 1 % Income tax expense 14 % 16 % 12 % 11 % Management has determined that earnings from its legal entity in China will be indefinitely reinvested to provide sufficient local funding for growth, and that earnings from all other jurisdictions will not be indefinitely reinvested. The Company is tax resident in numerous jurisdictions around the world and has identified its major tax 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 all periods presented. 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 in the effective tax rate by 2 and 1 percentage points for the three-month periods ended June 30, 2019 and July 1, 2018 , respectively, and a decrease in the effective tax rate by 4 and 5 percentage points for the six -month periods ended June 30, 2019 and July 1, 2018 , respectively. During the six -month period ended June 30, 2019 , the Company recorded a $952,000 increase in reserves for income taxes, net of deferred tax benefit. Estimated interest and penalties included in these amounts totaled $155,000 for the six -month period ended June 30, 2019 . The Company’s reserve for income taxes, including gross interest and penalties, was $9,119,000 as of June 30, 2019 , which included $8,091,000 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 $1,019,000 . 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 $1,250,000 to $1,350,000 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 2018 remain open to examination by the Internal Revenue Service and various state tax authorities. The tax years 2014 through 2018

Weighted-Average Shares

Weighted-Average Shares	6 Months Ended
	Jun. 30, 2019
Earnings Per Share [Abstract]
Weighted-Average Shares	Weighted-Average Shares Weighted-average shares were calculated as follows (in thousands): Three-months Ended Six-months Ended June 30, 2019 July 1, 2018 June 30, 2019 July 1, 2018 Basic weighted-average common shares outstanding 171,318 172,370 171,209 172,825 Effect of dilutive stock options 4,130 4,779 4,319 5,593 Weighted-average common and common-equivalent shares outstanding 175,448 177,149 175,528 178,418 Stock options to purchase 6,113,000 and 5,503,000 shares of common stock, on a weighted-average basis, were outstanding during the three-month and six-month periods ended June 30, 2019, respectively, and 2,959,000 and 2,032,000 for the same periods in 2018, but were not included in the calculation of dilutive net income per share because they were anti-dilutive.

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2019
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events On July 29, 2019, the Company’s Board of Directors declared a cash dividend of $0.050 per share. The dividend is payable on August 30, 2019 to all shareholders of record as of the close of business on August 16, 2019

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2019
Accounting Policies [Abstract]
Leases	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 842 "Leases," Cognex Corporation (the "Company") has provided new disclosures related to leases 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, 2018 for a full description of other 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 June 30, 2019 , and the results of its operations for the three-month and six-month periods ended June 30, 2019 and July 1, 2018 , 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 six-month periods ended June 30, 2019 are not necessarily indicative of the results to be expected for the full year. Leases The Company accounts for leases in accordance with Accounting Standard Codification (ASC) 842, "Leases." The core principle of ASC 842 is that a lessee should recognize on the balance sheet the assets and liabilities that arise from leases. At inception of a contract, the Company determines whether that contract is or contains a lease. The Company determines whether a contract contains a lease by assessing whether there is an identified asset and whether the contract conveys the right to control the use of the identified asset for a period of time in exchange for consideration. The Company has control of the asset if it has the right to direct the use of the asset and obtains substantially all of the economic benefits from the use of the asset throughout the period of use. As a practical expedient, the Company does not recognize a lease asset or lease liability for leases with a lease term of 12 months or less. In the determination of the lease term, the Company considers the existence of extension or termination options and the probability of those options being exercised. Lease contracts may include lease components and non-lease components, such as common area maintenance and utilities for property leases. As a practical expedient, the Company accounts for the non-lease components together with the lease components as a single lease component for all of its leases. The Company classifies a lease as a finance lease when it meets any of the following criteria at the lease commencement date: a) the lease transfers ownership of the underlying asset to the Company by the end of the lease term; b) the lease grants the Company an option to purchase the underlying asset that the Company is reasonably certain to exercise; c) the lease term is for the major part of the remaining economic life of the underlying asset (the Company considers a major part to be 75% or more of the remaining economic life of the underlying asset); d) the present value of the sum of the lease payments and any residual value guaranteed by the Company equals or exceeds substantially all of the fair value of the underlying asset (the Company considers substantially all the fair value to be 90% or more of the fair value of the underlying asset amount); or e) the underlying asset is of such a specialized nature that it is expected to have no alternative use to the lessor at the end of the lease term. When none of the criteria above are met, the Company classifies the lease as an operating lease. On the lease commencement date, the Company records a lease asset and lease liability on the balance sheet. The lease asset consists of: 1) the amount of the initial lease liability; 2) any lease payments made to the lessor at or before the lease commencement date, minus any lease incentives received; and 3) any initial direct cost incurred by the Company. Initial direct costs are incremental costs of a lease that would not have been incurred if the lease had not been obtained and are capitalized as part of the lease asset. The lease liability equals the present value of the future cash payments discounted using the Company's incremental borrowing rate. The Company’s incremental borrowing rate is the rate of interest that the Company would have to pay to borrow an amount equal to the lease payments over a similar term, which is the three-month London Interbank Offered Rate (LIBOR) plus a 2.5% credit risk spread. Operating lease expense equals the total cash payments recognized on a straight-line basis over the lease term. The amortization of the lease asset is calculated as the straight-line lease expense less the accretion of the interest on the lease liability each period. The lease liability is reduced by the cash payment less the interest each period.
New Pronouncements	ew Pronouncements 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 U.S. 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 annual periods. 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 annual 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) 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 statements and disclosures.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2019
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 June 30, 2019 (in thousands): Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Assets: Money market instruments $ 3,099 $ — $ — Treasury bills — 307,490 — Corporate bonds — 278,991 — Asset-backed securities — 145,432 — Sovereign bonds — 20,823 — Agency bonds — 13,686 — Municipal bonds — 6,097 — Economic hedge forward contracts — 20 — Liabilities: Economic hedge forward contracts — 13 — Contingent consideration liabilities — — 1,691
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 six-month period ended June 30, 2019 (in thousands): Balance as of December 31, 2018 $ 2,554 Fair value adjustment to GVi contingent consideration (1,019 ) Fair value adjustment to Chiaro contingent consideration 156 Balance as of June 30, 2019 $ 1,691

Cash, Cash Equivalents, and I_2

Cash, Cash Equivalents, and Investments (Tables)	6 Months Ended
	Jun. 30, 2019
Cash and Cash Equivalents [Abstract]
Components of Cash, Cash Equivalents, and Investments	Cash, cash equivalents, and investments consisted of the following (in thousands): June 30, 2019 December 31, 2018 Cash $ 86,005 $ 104,655 Money market instruments 3,099 3,557 Cash and cash equivalents 89,104 108,212 Treasury bills 138,600 198,477 Asset-backed securities 104,998 78,407 Corporate bonds 101,868 137,871 Agency bonds 7,783 — Sovereign bonds 5,990 8,101 Municipal bonds 5,248 4,492 Current investments 364,487 427,348 Corporate bonds 177,123 162,566 Treasury bills 168,890 32,760 Asset-backed securities 40,434 53,631 Sovereign bonds 14,833 6,316 Agency bonds 5,903 5,921 Municipal bonds 849 845 Non-current investments 408,032 262,039 $ 861,623 $ 797,599
Summary of Available-for-Sale Investments	The following table summarizes the Company’s available-for-sale investments as of June 30, 2019 (in thousands): Amortized Gross Gross Fair Value Current: Treasury bills $ 138,217 $ 383 $ — $ 138,600 Asset-backed securities 104,717 317 (36 ) 104,998 Corporate bonds 101,722 182 (36 ) 101,868 Agency bonds 7,780 3 — 7,783 Sovereign bonds 5,979 12 (1 ) 5,990 Municipal bonds 5,241 7 — 5,248 Non-current: Corporate bonds 176,726 537 (140 ) 177,123 Treasury bills 167,653 1,257 (20 ) 168,890 Asset-backed securities 40,198 237 (1 ) 40,434 Sovereign bonds 14,783 50 — 14,833 Agency bonds 5,930 — (27 ) 5,903 Municipal bonds 855 — (6 ) 849 $ 769,801 $ 2,985 $ (267 ) $ 772,519
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 June 30, 2019 (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 Corporate bonds $ 26,243 $ (90 ) $ 42,031 $ (86 ) $ 68,274 $ (176 ) Asset-backed securities 4,378 (1 ) 21,331 (36 ) 25,709 (37 ) Treasury bills 24,855 (20 ) — — 24,855 (20 ) Agency bonds 5,903 (27 ) — — 5,903 (27 ) Sovereign bonds — — 2,689 (1 ) 2,689 (1 ) Municipal bonds — — 849 (6 ) 849 (6 ) $ 61,379 $ (138 ) $ 66,900 $ (129 ) $ 128,279 $ (267 )
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 June 30, 2019 (in thousands): <1 year 1-2 Years 2-3 Years 3-4 Years 4-5 Years 5-7 Years Total Treasury bills $ 138,600 $ 158,777 $ 10,113 $ — $ — $ — $ 307,490 Corporate bonds 101,868 103,324 65,231 5,710 2,858 — 278,991 Asset-backed securities 104,998 15,771 8,760 11,199 — 4,704 145,432 Sovereign bonds 5,990 14,833 — — — 20,823 Agency bonds 7,783 — — 5,903 — — 13,686 Municipal bonds 5,248 849 — — — — 6,097 $ 364,487 $ 293,554 $ 84,104 $ 22,812 $ 2,858 $ 4,704 $ 772,519

Inventories (Tables)

Inventories (Tables)	6 Months Ended
	Jun. 30, 2019
Inventory Disclosure [Abstract]
Schedule of Inventories	Inventories consisted of the following (in thousands): June 30, 2019 December 31, 2018 Raw materials $ 32,545 $ 42,738 Work-in-process 4,112 3,435 Finished goods 36,232 37,109 $ 72,889 $ 83,282

Leases (Tables)

Leases (Tables)	6 Months Ended
	Jun. 30, 2019
Leases [Abstract]
Lessor, Operating Lease, Payments to be Received, Maturity [Table Text Block]	Future minimum rental receipts under non-cancelable lease agreements are as follows (in thousands): Year Ended December 31, Amount Remainder of fiscal 2019 $ 153 2020 307 2021 307 2022 307 $ 1,074
Lessee, Operating Lease, Liability, Maturity	Future operating lease cash payments are as follows (in thousands): Year Ended December 31, Amount Remainder of fiscal 2019 $ 3,387 2020 5,730 2021 4,397 2022 2,890 2023 2,035 2024 842 Thereafter 311 $ 19,592

Intangible Assets (Tables)

Intangible Assets (Tables)	6 Months Ended
	Jun. 30, 2019
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 7,839 5,848 Customer relationships 8,607 5,973 2,634 Non-compete agreements 370 277 93 Balance as of June 30, 2019 $ 60,724 $ 52,149 $ 8,575 Gross Carrying Value Accumulated Amortization Net Carrying Value Distribution networks $ 38,060 $ 38,060 $ — Completed technologies 13,687 6,619 7,068 Customer relationships 8,607 5,716 2,891 Non-compete agreements 370 216 154 Balance as of December 31, 2018 $ 60,724 $ 50,611 $ 10,113
Schedule of Intangible Assets, Future Amortization Expense	As of June 30, 2019, estimated future amortization expense related to intangible assets is as follows (in thousands): Year Ended December 31, Amount Remainder of fiscal 2019 $ 1,163 2020 2,185 2021 2,017 2022 1,691 2023 989 2024 422 Thereafter 108 $ 8,575

Warranty Obligations (Tables)

Warranty Obligations (Tables)	6 Months Ended
	Jun. 30, 2019
Product Warranties Disclosures [Abstract]
Changes in Warranty Obligations	The changes in the warranty obligation were as follows (in thousands): Balance as of December 31, 2018 $ 4,743 Provisions for warranties issued during the period 2,533 Fulfillment of warranty obligations (1,824 ) Balance as of June 30, 2019 $ 5,452

Derivative Instruments (Tables)

Derivative Instruments (Tables)	6 Months Ended
	Jun. 30, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Outstanding Forward Contracts Table	The Company had the following outstanding forward contracts (in thousands): June 30, 2019 December 31, 2018 Currency Notional USD Notional USD Derivatives Not Designated as Hedging Instruments: Euro 19,000 $ 21,681 23,000 $ 26,330 Japanese Yen 400,000 3,717 380,000 3,459 Hungarian Forint 900,000 3,178 750,000 2,685 Korean Won 3,550,000 3,072 3,125,000 2,808 British Pound 2,400 3,055 2,500 3,204 Taiwanese Dollar 50,000 1,617 55,000 1,807 Canadian Dollar 1,100 841 990 726 Singapore Dollar — — 700 514
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 June 30, 2019 December 31, 2018 Sheet June 30, 2019 December 31, 2018 Derivatives Not Designated as Hedging Instruments: Economic hedge forward contracts Prepaid expenses and other current assets $ 20 $ 1 Accrued expenses $ 13 $ 106
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 June 30, 2019 December 31, 2018 June 30, 2019 December 31, 2018 Gross amounts of recognized assets $ 20 $ 1 Gross amounts of recognized liabilities $ 13 $ 106 Gross amounts offset — — Gross amounts offset — — Net amount of assets presented $ 20 $ 1 Net amount of liabilities presented $ 13 $ 106
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 Six-months Ended June 30, 2019 July 1, 2018 June 30, 2019 July 1, 2018 Derivatives Not Designated as Hedging Instruments: Gains (losses) recognized in current operations Foreign currency gain (loss) $ (439 ) $ (354 ) $ 66 $ (665 )

Revenue Recognition (Tables)

Revenue Recognition (Tables)	6 Months Ended
	Jun. 30, 2019
Revenue from Contract with Customer [Abstract]
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 Six-months Ended June 30, 2019 July 1, 2018 June 30, 2019 July 1, 2018 Americas $ 78,500 $ 71,812 $ 143,656 $ 131,029 Europe 58,881 70,366 118,538 126,569 Greater China 35,782 41,175 58,592 68,334 Other Asia 25,884 27,911 51,745 54,899 $ 199,047 $ 211,264 $ 372,531 $ 380,831
Revenue from External Customers by Products and Services	The following table summarizes disaggregated revenue information by revenue type (in thousands): Three-months Ended Six-months Ended June 30, 2019 July 1, 2018 June 30, 2019 July 1, 2018 Standard products and services $ 173,368 $ 183,627 $ 334,420 $ 342,026 Application-specific customer solutions 25,679 27,637 38,111 38,805 $ 199,047 $ 211,264 $ 372,531 $ 380,831
Deferred Revenue, by Arrangement, Disclosure	The following table summarizes the deferred revenue and customer deposits activity for the six-month period ended June 30, 2019 (in thousands): Balance as of December 31, 2018 $ 9,845 Increases to deferred revenue and customer deposits 29,883 Recognition of revenue (21,308 ) Foreign exchange rate changes (88 ) Balance as of June 30, 2019 $ 18,332

Stock-Based Compensation Expe_2

Stock-Based Compensation Expense (Tables)	6 Months Ended
	Jun. 30, 2019
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 six -month period ended June 30, 2019 : Shares (in thousands) Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (in years) Aggregate Intrinsic Value (in thousands) Outstanding as of December 31, 2018 13,789 $ 31.73 Granted 2,821 51.37 Exercised (1,239 ) 21.32 Forfeited or expired (606 ) 40.27 Outstanding as of June 30, 2019 14,765 $ 36.00 7.42 $ 207,599 Exercisable as of June 30, 2019 5,867 $ 25.12 5.95 $ 138,370 Options vested or expected to vest as of June 30, 2019 (1) 13,214 $ 34.65 7.25 $ 201,420 (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 Six-months Ended June 30, 2019 July 1, 2018 June 30, 2019 July 1, 2018 Risk-free rate 2.7 % 2.9 % 2.7 % 2.9 % Expected dividend yield 0.39 % 0.32 % 0.39 % 0.32 % Expected volatility 37 % 39 % 37 % 39 % Expected term (in years) 5.2 5.4 5.3 5.3
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 Six-months Ended June 30, 2019 July 1, 2018 June 30, 2019 July 1, 2018 Cost of revenue $ 329 $ 557 $ 780 $ 1,354 Research, development, and engineering 3,550 3,154 8,017 7,969 Selling, general, and administrative 7,088 5,291 14,451 12,873 $ 10,967 $ 9,002 $ 23,248 $ 22,196

Taxes (Tables)

Taxes (Tables)	6 Months Ended
	Jun. 30, 2019
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 Six-months Ended June 30, 2019 July 1, 2018 June 30, 2019 July 1, 2018 Income tax expense at U.S. federal statutory corporate tax rate 21 % 21 % 21 % 21 % State income taxes, net of federal benefit 1 % 2 % 1 % 2 % Foreign tax rate differential (7 )% (7 )% (7 )% (7 )% Tax credit (1 )% (1 )% (1 )% (1 )% Discrete tax benefit related to stock options (2 )% (1 )% (4 )% (5 )% Other 2 % 2 % 2 % 1 % Income tax expense 14 % 16 % 12 % 11 %

Weighted-Average Shares (Tables

Weighted-Average Shares (Tables)	6 Months Ended
	Jun. 30, 2019
Earnings Per Share [Abstract]
Calculation of Weighted-Average Shares	Weighted-average shares were calculated as follows (in thousands): Three-months Ended Six-months Ended June 30, 2019 July 1, 2018 June 30, 2019 July 1, 2018 Basic weighted-average common shares outstanding 171,318 172,370 171,209 172,825 Effect of dilutive stock options 4,130 4,779 4,319 5,593 Weighted-average common and common-equivalent shares outstanding 175,448 177,149 175,528 178,418

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Assets:
Money market instruments	$ 3,099	$ 3,557
Financial assets at fair value	772,519
Corporate Bonds
Assets:
Financial assets at fair value	278,991
Treasury Bills
Assets:
Financial assets at fair value	307,490
Asset-Backed Securities
Assets:
Financial assets at fair value	145,432
Sovereign Bonds
Assets:
Financial assets at fair value	20,823
Agency Bonds
Assets:
Financial assets at fair value	13,686
Municipal Bonds
Assets:
Financial assets at fair value	6,097
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Measurements, Recurring
Assets:
Money market instruments	3,099
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring
Assets:
Money market instruments	0
Economic hedge forward contracts	20
Liabilities:
Economic hedge forward contracts	13
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Corporate Bonds
Assets:
Financial assets at fair value	278,991
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Treasury Bills
Assets:
Financial assets at fair value	307,490
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Asset-Backed Securities
Assets:
Financial assets at fair value	145,432
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Sovereign Bonds
Assets:
Financial assets at fair value	20,823
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Agency Bonds
Assets:
Financial assets at fair value	13,686
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Municipal Bonds
Assets:
Financial assets at fair value	6,097
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring
Liabilities:
Contingent consideration liabilities	$ 1,691

Fair Value Measurements - Liabi

Fair Value Measurements - Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jul. 01, 2018
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Payment of contingent consideration	$ 0	$ (1,000)
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	2,554
Ending balance	1,691
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	(1,019)
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	$ 156

Cash, Cash Equivalents, and I_3

Cash, Cash Equivalents, and Investments (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jul. 01, 2018	Jun. 30, 2019	Jul. 01, 2018
Cash and Cash Equivalents [Abstract]
Gross realized gains on sale of investments	$ 394,000	$ 308,000	$ 458,000	$ 363,000
Gross realized losses on sale of investments	$ 12,000	$ 61,000	$ 36,000	$ 94,000

Cash, Cash Equivalents, and I_4

Cash, Cash Equivalents, and Investments - Components of Cash, Cash Equivalents, and Investments (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018	Jul. 01, 2018	Dec. 31, 2017
Debt Securities, Available-for-sale [Line Items]
Cash	$ 86,005	$ 104,655
Money market instruments	3,099	3,557
Cash and cash equivalents	89,104	108,212	$ 129,202	$ 106,582
Current investments	364,487	427,348
Non-current investments	408,032	262,039
Total	861,623	797,599
Treasury Bills
Debt Securities, Available-for-sale [Line Items]
Current investments	138,600	198,477
Long-term investments	168,890	32,760
Corporate Bonds
Debt Securities, Available-for-sale [Line Items]
Current investments	101,868	137,871
Long-term investments	177,123	162,566
Asset-Backed Securities
Debt Securities, Available-for-sale [Line Items]
Current investments	104,998	78,407
Long-term investments	40,434	53,631
Sovereign Debt [Member]
Debt Securities, Available-for-sale [Line Items]
Current investments	5,990	8,101
Sovereign Bonds
Debt Securities, Available-for-sale [Line Items]
Long-term investments	14,833	6,316
Agency Bonds
Debt Securities, Available-for-sale [Line Items]
Current investments	7,783	0
Long-term investments	5,903	5,921
Municipal Bonds
Debt Securities, Available-for-sale [Line Items]
Current investments	5,248	4,492
Long-term investments	$ 849	$ 845

Cash, Cash Equivalents, and I_5

Cash, Cash Equivalents, and Investments - Summary of Available-for-Sale Investments (Detail) $ in Thousands	Jun. 30, 2019USD ($)
Debt Securities, Available-for-sale [Line Items]
Amortized cost	$ 769,801
Gross unrealized gains	2,985
Gross unrealized losses	(267)
Fair value	772,519
Agency Bonds
Debt Securities, Available-for-sale [Line Items]
Gross unrealized losses	(27)
Agency Bonds | Short-Term Investments
Debt Securities, Available-for-sale [Line Items]
Amortized cost	7,780
Gross unrealized gains	3
Gross unrealized losses	0
Fair value	7,783
Agency Bonds | Long-Term Investments
Debt Securities, Available-for-sale [Line Items]
Amortized cost	5,930
Gross unrealized gains	0
Gross unrealized losses	(27)
Fair value	5,903
Treasury Bills
Debt Securities, Available-for-sale [Line Items]
Gross unrealized losses	(20)
Treasury Bills | Short-Term Investments
Debt Securities, Available-for-sale [Line Items]
Amortized cost	138,217
Gross unrealized gains	383
Gross unrealized losses	0
Fair value	138,600
Treasury Bills | Long-Term Investments
Debt Securities, Available-for-sale [Line Items]
Amortized cost	167,653
Gross unrealized gains	1,257
Gross unrealized losses	(20)
Fair value	168,890
Corporate Bonds
Debt Securities, Available-for-sale [Line Items]
Gross unrealized losses	(176)
Corporate Bonds | Short-Term Investments
Debt Securities, Available-for-sale [Line Items]
Amortized cost	101,722
Gross unrealized gains	182
Gross unrealized losses	(36)
Fair value	101,868
Corporate Bonds | Long-Term Investments
Debt Securities, Available-for-sale [Line Items]
Amortized cost	176,726
Gross unrealized gains	537
Gross unrealized losses	(140)
Fair value	177,123
Asset-Backed Securities
Debt Securities, Available-for-sale [Line Items]
Gross unrealized losses	(37)
Asset-Backed Securities | Short-Term Investments
Debt Securities, Available-for-sale [Line Items]
Amortized cost	104,717
Gross unrealized gains	317
Gross unrealized losses	(36)
Fair value	104,998
Asset-Backed Securities | Long-Term Investments
Debt Securities, Available-for-sale [Line Items]
Amortized cost	40,198
Gross unrealized gains	237
Gross unrealized losses	(1)
Fair value	40,434
Sovereign Bonds
Debt Securities, Available-for-sale [Line Items]
Gross unrealized losses	(1)
Sovereign Bonds | Short-Term Investments
Debt Securities, Available-for-sale [Line Items]
Amortized cost	5,979
Gross unrealized gains	12
Gross unrealized losses	(1)
Fair value	5,990
Sovereign Bonds | Long-Term Investments
Debt Securities, Available-for-sale [Line Items]
Amortized cost	14,783
Gross unrealized gains	50
Gross unrealized losses	0
Fair value	14,833
Municipal Bonds
Debt Securities, Available-for-sale [Line Items]
Gross unrealized losses	(6)
Municipal Bonds | Short-Term Investments
Debt Securities, Available-for-sale [Line Items]
Amortized cost	5,241
Gross unrealized gains	7
Gross unrealized losses	0
Fair value	5,248
Municipal Bonds | Long-Term Investments
Debt Securities, Available-for-sale [Line Items]
Amortized cost	855
Gross unrealized gains	0
Gross unrealized losses	(6)
Fair value	$ 849

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	Jun. 30, 2019USD ($)
Debt Securities, Available-for-sale [Line Items]
Fair value, less than 12 months	$ 61,379
Unrealized losses, less than 12 months	(138)
Fair value, 12 months or greater	66,900
Unrealized losses, 12 months or greater	(129)
Total fair value	128,279
Total unrealized losses	(267)
Treasury Bills
Debt Securities, Available-for-sale [Line Items]
Fair value, less than 12 months	24,855
Unrealized losses, less than 12 months	(20)
Fair value, 12 months or greater	0
Unrealized losses, 12 months or greater	0
Total fair value	24,855
Total unrealized losses	(20)
Agency Bonds
Debt Securities, Available-for-sale [Line Items]
Fair value, less than 12 months	5,903
Unrealized losses, less than 12 months	(27)
Fair value, 12 months or greater	0
Unrealized losses, 12 months or greater	0
Total fair value	5,903
Total unrealized losses	(27)
Corporate Bonds
Debt Securities, Available-for-sale [Line Items]
Fair value, less than 12 months	26,243
Unrealized losses, less than 12 months	(90)
Fair value, 12 months or greater	42,031
Unrealized losses, 12 months or greater	(86)
Total fair value	68,274
Total unrealized losses	(176)
Asset-Backed Securities
Debt Securities, Available-for-sale [Line Items]
Fair value, less than 12 months	4,378
Unrealized losses, less than 12 months	(1)
Fair value, 12 months or greater	21,331
Unrealized losses, 12 months or greater	(36)
Total fair value	25,709
Total unrealized losses	(37)
Sovereign Bonds
Debt Securities, Available-for-sale [Line Items]
Fair value, less than 12 months	0
Unrealized losses, less than 12 months	0
Fair value, 12 months or greater	2,689
Unrealized losses, 12 months or greater	(1)
Total fair value	2,689
Total unrealized losses	(1)
Municipal Bonds
Debt Securities, Available-for-sale [Line Items]
Fair value, less than 12 months	0
Unrealized losses, less than 12 months	0
Fair value, 12 months or greater	849
Unrealized losses, 12 months or greater	(6)
Total fair value	849
Total unrealized losses	$ (6)

Cash, Cash Equivalents, and I_7

Cash, Cash Equivalents, and Investments - Effective Maturity Dates of Available-for-Sale Investments (Detail) $ in Thousands	Jun. 30, 2019USD ($)
Debt Securities, Available-for-sale [Line Items]
1 year or less	$ 364,487
1-2 years	293,554
2-3 years	84,104
3-4 years	22,812
4-5 years	2,858
5-7 years	4,704
Fair value	772,519
Corporate Bonds
Debt Securities, Available-for-sale [Line Items]
1 year or less	101,868
1-2 years	103,324
2-3 years	65,231
3-4 years	5,710
4-5 years	2,858
5-7 years	0
Fair value	278,991
Treasury Bills
Debt Securities, Available-for-sale [Line Items]
1 year or less	138,600
1-2 years	158,777
2-3 years	10,113
3-4 years	0
4-5 years	0
5-7 years	0
Fair value	307,490
Asset-Backed Securities
Debt Securities, Available-for-sale [Line Items]
1 year or less	104,998
1-2 years	15,771
2-3 years	8,760
3-4 years	11,199
4-5 years	0
5-7 years	4,704
Fair value	145,432
Sovereign Bonds
Debt Securities, Available-for-sale [Line Items]
1 year or less	5,990
1-2 years	14,833
2-3 years	0
3-4 years	0
4-5 years	0
5-7 years
Fair value	20,823
Agency Bonds
Debt Securities, Available-for-sale [Line Items]
1 year or less	7,783
1-2 years	0
2-3 years	0
3-4 years	5,903
4-5 years	0
5-7 years	0
Fair value	13,686
Municipal Bonds
Debt Securities, Available-for-sale [Line Items]
1 year or less	5,248
1-2 years	849
2-3 years	0
3-4 years	0
4-5 years	0
5-7 years	0
Fair value	$ 6,097

Inventories - Schedule of Inven

Inventories - Schedule of Inventories (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Inventory Disclosure [Abstract]
Raw materials	$ 32,545	$ 42,738
Work-in-process	4,112	3,435
Finished goods	36,232	37,109
Inventories	$ 72,889	$ 83,282

Leases - Narrative (Details)

Leases - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jul. 01, 2018	Jun. 30, 2019	Jul. 01, 2018	Jan. 01, 2019	Dec. 31, 2018
Leases [Abstract]
Operating Lease, Liability	$ 17,984		$ 17,984
Operating lease, right-of-use asset	17,928		17,928		$ 17,522	$ 0
Operating lease, liability, current	5,835		5,835		4,736	0
Operating lease, liability, noncurrent	12,149		12,149		$ 12,669	$ 0
Operating lease, cost	1,742		3,227
Operating lease, payments	1,669		3,070
Lease, cost	$ 64		$ 233
Operating Lease, Weighted Average Discount Rate, Percent	480.00%		480.00%
Operating Lease, Weighted Average Remaining Lease Term	3 years 7 months 6 days		3 years 7 months 6 days
Operating Lease, Lease Income	$ 81	$ 83	$ 158	$ 159

Leases - Future Minimum Lease P

Leases - Future Minimum Lease Payment Obligations Under Operating Leases (Details) $ in Thousands	Jun. 30, 2019USD ($)
Leases [Abstract]
Remainder of fiscal 2019	$ 3,387
2020	5,730
2021	4,397
2022	2,890
2023	2,035
2024	842
Thereafter	311
Total	$ 19,592

Leases - Future Minimum Rental

Leases - Future Minimum Rental Receipts Under Non-cancelable Lease Agreements (Details) $ in Thousands	Jun. 30, 2019USD ($)
Leases [Abstract]
Lessor, Operating Lease, Payments to be Received, Remainder of Fiscal Year	$ 153
Lessor, Operating Lease, Payments to be Received, Two Years	307
Lessor, Operating Lease, Payments to be Received, Three Years	307
Lessor, Operating Lease, Payments to be Received, Four Years	307
Lessor, Operating Lease, Payments to be Received	$ 1,074

Intangible Assets (Details)

Intangible Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 60,724	$ 60,724
Accumulated Amortization	52,149	50,611
Net Carrying Value	8,575	10,113
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Remainder of fiscal 2019	1,163
2019	2,185
2020	2,017
2021	1,691
2022	989
2023	422
Thereafter	108
Net Carrying Value	8,575	10,113
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	7,839	6,619
Net Carrying Value	5,848	7,068
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Net Carrying Value	5,848	7,068
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	8,607	8,607
Accumulated Amortization	5,973	5,716
Net Carrying Value	2,634	2,891
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Net Carrying Value	2,634	2,891
Non-compete agreements
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	370	370
Accumulated Amortization	277	216
Net Carrying Value	93	154
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Net Carrying Value	$ 93	$ 154

Warranty Obligations - Changes

Warranty Obligations - Changes in Warranty Obligations (Detail) $ in Thousands	6 Months Ended
	Jun. 30, 2019USD ($)
Movement in Standard Product Warranty Accrual [Roll Forward]
Beginning balance	$ 4,743
Provisions for warranties issued during the period	2,533
Fulfillment of warranty obligations	(1,824)
Ending balance	$ 5,452

Derivative Instruments (Detail)

Derivative Instruments (Detail)	6 Months Ended
	Jun. 30, 2019
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	Jun. 30, 2019EUR (€)	Jun. 30, 2019CAD ($)	Jun. 30, 2019SGD ($)	Jun. 30, 2019JPY (¥)	Jun. 30, 2019KRW (₩)	Jun. 30, 2019TWD ($)	Jun. 30, 2019USD ($)	Dec. 31, 2018EUR (€)	Dec. 31, 2018CAD ($)	Dec. 31, 2018SGD ($)	Dec. 31, 2018JPY (¥)	Dec. 31, 2018KRW (₩)	Dec. 31, 2018TWD ($)	Dec. 31, 2018USD ($)
Euro Member Countries, Euro
Derivative [Line Items]
Outstanding forward contracts	€ 19,000						$ 21,681	€ 23,000						$ 26,330
Japanese Yen
Derivative [Line Items]
Outstanding forward contracts				¥ 400,000			3,717				¥ 380,000			3,459
United Kingdom, Pounds
Derivative [Line Items]
Outstanding forward contracts				2,400			3,055				2,500			3,204
Hungary, Forint
Derivative [Line Items]
Outstanding forward contracts				¥ 900,000			3,178				¥ 750,000			2,685
Korean Won
Derivative [Line Items]
Outstanding forward contracts					₩ 3,550,000		3,072					₩ 3,125,000		2,808
Taiwanese Dollar
Derivative [Line Items]
Outstanding forward contracts						$ 50,000	1,617						$ 55,000	1,807
Canada, Dollars
Derivative [Line Items]
Outstanding forward contracts		$ 1,100					841		$ 990					726
Singapore, Dollars
Derivative [Line Items]
Outstanding forward contracts			$ 0				$ 0			$ 700				$ 514

Derivative Instruments - Schedu

Derivative Instruments - Schedule of Derivative Instruments in Statement of Financial Position, Fair Value (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Derivative asset	$ 20	$ 1
Derivative liability	13	106
Not Designated as Hedging Instrument | Prepaid Expenses and Other Current Assets
Derivatives, Fair Value [Line Items]
Derivative asset	20	1
Not Designated as Hedging Instrument | Accrued Expenses
Derivatives, Fair Value [Line Items]
Derivative liability	$ 13	$ 106

Derivative Instruments - Offset

Derivative Instruments - Offsetting Assets (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Gross amounts of recognized assets	$ 20	$ 1
Gross amounts offset	0	0
Net amount of assets presented	20	1
Gross amounts of recognized liabilities	13	106
Gross amounts offset	0	0
Net amount of liabilities presented	$ 13	$ 106

Derivative Instruments - Deriva

Derivative Instruments - Derivative Instruments, Gain (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jul. 01, 2018	Jun. 30, 2019	Jul. 01, 2018
Not Designated as Hedging Instrument | Foreign Currency Gain (Loss)
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recognized in current operations	$ (439)	$ (354)	$ 66	$ (665)

Revenue Recognition - Revenue D

Revenue Recognition - Revenue Disaggregated by Geography (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jul. 01, 2018	Jun. 30, 2019	Jul. 01, 2018
Disaggregation of Revenue [Line Items]
Revenue	$ 199,047	$ 211,264	$ 372,531	$ 380,831
Europe
Disaggregation of Revenue [Line Items]
Revenue	58,881	70,366	118,538	126,569
Americas
Disaggregation of Revenue [Line Items]
Revenue	78,500	71,812	143,656	131,029
Greater China
Disaggregation of Revenue [Line Items]
Revenue	35,782	41,175	58,592	68,334
Other Asia
Disaggregation of Revenue [Line Items]
Revenue	$ 25,884	$ 27,911	$ 51,745	$ 54,899

Revenue Recognition - Revenue_2

Revenue Recognition - Revenue Disaggregated by Products and Services (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jul. 01, 2018	Jun. 30, 2019	Jul. 01, 2018
Revenue from External Customer [Line Items]
Revenue	$ 199,047	$ 211,264	$ 372,531	$ 380,831
Standard Products and Services
Revenue from External Customer [Line Items]
Revenue	173,368	183,627	334,420	342,026
Application-Specific Customer Solutions
Revenue from External Customer [Line Items]
Revenue	$ 25,679	$ 27,637	$ 38,111	$ 38,805

Revenue Recognition - Additiona

Revenue Recognition - Additional Information (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Costs to fulfill contract	$ 6,852	$ 3,514

Revenue Recognition - Deferred

Revenue Recognition - Deferred Revenue Activity (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2019USD ($)
Movement in Deferred Revenue [Roll Forward]
Balance as of December 31, 2018	$ 9,845
Increases to deferred revenue and customer deposits	29,883
Recognition of revenue	(21,308)
Foreign exchange rate changes	(88)
Balance as of June 30, 2019	$ 18,332

Stock-Based Compensation Expe_3

Stock-Based Compensation Expense (Detail)	3 Months Ended				6 Months Ended
	Jun. 30, 2019USD ($)group$ / sharesshares	Jul. 01, 2018USD ($)$ / shares	Apr. 01, 2018USD ($)	Apr. 02, 2017USD ($)	Jun. 30, 2019USD ($)group$ / sharesshares	Jul. 01, 2018USD ($)$ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Groups within the employee population | group	2				2
Estimated annual forfeiture rate for unvested options for senior management	9.00%				9.00%
Estimated annual forfeiture rate for unvested options for all other employees	12.00%				12.00%
Increase (decrease) to compensation expense			$ 499,000	$ 1,283,000
Weighted-average grant-date fair values, in dollars per share | $ / shares	$ 18.68	$ 21.63			$ 18.59	$ 21.62
Total intrinsic value	$ 14,220,000	$ 4,902,000			$ 36,799,000	$ 32,991,000
Total fair values of stock options vest	887,000	887,000			30,859,000	26,560,000
Unrecognized compensation expense	66,645,000				$ 66,645,000
Weighted average period to be recognized					1 year 10 months 17 days
Stock-based compensation expense	10,967,000	9,002,000			$ 23,248,000	22,196,000
Tax benefit from compensation expense	1,813,000	$ 1,607,000			4,035,000	$ 3,954,000
Recognized period costs capitalized	$ 0				$ 0
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for grant under stock option plans | shares	17,363,952				17,363,952
Expiration period from grant day					10 years
Minimum | General Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period for stock option plans					4 years
Maximum | General Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period for stock option plans					5 years

Stock-Based Compensation Expe_4

Stock-Based Compensation Expense - Summary of Stock Option Activity (Detail) $ / shares in Units, shares in Thousands, $ in Thousands	6 Months Ended
	Jun. 30, 2019USD ($)$ / sharesshares
Shares (in thousands)
Outstanding, shares | shares	13,789
Granted, shares | shares	2,821
Exercised, shares | shares	(1,239)
Forfeited or expired, shares | shares	(606)
Outstanding, shares | shares	14,765
Exercisable as of reporting date, shares | shares	5,867
Options vested or expected to vest as of reporting date, shares | shares	13,214
Weighted- Average Exercise Price
Outstanding, shares | $ / shares	$ 31.73
Granted, in dollars per share | $ / shares	51.37
Exercised, in dollars per share | $ / shares	21.32
Forfeited or expired, in dollars per share | $ / shares	40.27
Outstanding, shares | $ / shares	36
Exercisable as of reporting date, Weighted-Average Exercise Price, in dollars per share | $ / shares	25.12
Weighted- Average Remaining Contractual Term (in years) | $ / shares	$ 34.65
Weighted- Average Remaining Contractual Term (in years)
Outstanding, in years	7 years 5 months 1 day
Exercisable, in years	5 years 11 months 12 days
Options vested or expected to vest, in years	7 years 3 months
Aggregate Intrinsic Value (in thousands)
Outstanding, in dollars | $	$ 207,599
Exercisable, in dollars | $	138,370
Options vested or expected to vest, in dollars | $	$ 201,420

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		6 Months Ended
	Jun. 30, 2019	Jul. 01, 2018	Jun. 30, 2019	Jul. 01, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Risk-free rate	2.70%	2.90%	2.70%	2.90%
Expected dividend yield	0.39%	0.32%	0.39%	0.32%
Expected volatility	37.00%	39.00%	37.00%	39.00%
Expected term (in years)	5 years 2 months 12 days	5 years 4 months 24 days	5 years 3 months 18 days	5 years 3 months 18 days

Stock-Based Compensation Expe_6

Stock-Based Compensation Expense - Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jul. 01, 2018	Jun. 30, 2019	Jul. 01, 2018
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 10,967	$ 9,002	$ 23,248	$ 22,196
Cost of Revenue
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	329	557	780	1,354
Research, Development, and Engineering Expenses
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	3,550	3,154	8,017	7,969
Selling, General, and Administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 7,088	$ 5,291	$ 14,451	$ 12,873

Stock Repurchase Program (Detai

Stock Repurchase Program (Detail) - USD ($) shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jul. 01, 2018	Jun. 30, 2019	Jul. 01, 2018	Oct. 29, 2018
Equity, Class of Treasury Stock [Line Items]
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 129,688,000		$ 129,688,000
Stock repurchased during period, value	$ 61,690,000	$ 52,106,000	$ 61,690,000	$ 121,308,000
Repurchase Program October 2018 [Member]
Equity, Class of Treasury Stock [Line Items]
Authorized common stock to be repurchased					$ 200,000,000
Stock Repurchase Program, Aggregate Number of Shares Repurchased	1,601		1,601
Shares repurchased, value	$ 70,312,000		$ 70,312,000
Repurchase of common stock (in shares)			1,398
Stock repurchased during period, value			$ 61,690,000

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		6 Months Ended
	Jun. 30, 2019	Jul. 01, 2018	Jun. 30, 2019	Jul. 01, 2018
Income Tax Disclosure [Abstract]
Income tax expense at U.S. federal statutory corporate tax rate	21.00%	21.00%	21.00%	21.00%
State income taxes, net of federal benefit	1.00%	2.00%	1.00%	2.00%
Foreign tax rate differential	(7.00%)	(7.00%)	(7.00%)	(7.00%)
Tax credit	(1.00%)	(1.00%)	(1.00%)	(1.00%)
Discrete tax benefit related to stock options	(2.00%)	(1.00%)	(4.00%)	(5.00%)
Other	2.00%	2.00%	2.00%	1.00%
Income tax expense	14.00%	16.00%	12.00%	11.00%

Taxes (Detail)

Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jul. 01, 2018	Jun. 30, 2019	Jul. 01, 2018	Dec. 31, 2018
Income Tax Contingency [Line Items]
Income tax expense at U.S. federal statutory corporate tax rate	21.00%	21.00%	21.00%	21.00%
Decrease in effective tax rate	7.00%	7.00%	7.00%	7.00%
Decrease in effective tax rate for difference between deduction for tax purposes and compensation cost recognized from stock option exercises	2.00%	1.00%	4.00%	5.00%
Increase in reserves for income taxes, net of deferred tax benefit	$ 952		$ 952
Interest and penalties included in reserve			155
Liability for uncertain tax positions	9,119		9,119
Reserve for income taxes classified as a noncurrent iability	8,091		8,091		$ 7,106
Reserve for income taxes classified an noncurrent deferred tax assets	1,028		1,028
Interest and penalties, gross	$ 1,019		1,019
Minimum decrease in income tax expense due to release in reserves			1,250
Maximum decrease in income tax expense due to release in reserves			$ 1,350
Tax years open to examination by Internal Revenue Service			2015 through 2018
Tax years open to examination by various taxing authorities for other entities			2014 through 2018
Foreign Tax Authority | Revenue Commissioners, Ireland
Income Tax Contingency [Line Items]
Income tax expense at U.S. federal statutory corporate tax rate			12.50%
Foreign Tax Authority | State Administration of Taxation, China
Income Tax Contingency [Line Items]
Income tax expense at U.S. federal statutory corporate tax rate			25.00%
Domestic Tax Authority
Income Tax Contingency [Line Items]
Income tax expense at U.S. federal statutory corporate tax rate			21.00%

Weighted-Average Shares (Detail

Weighted-Average Shares (Detail) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jul. 01, 2018	Jun. 30, 2019	Jul. 01, 2018
Earnings Per Share [Abstract]
Stock options to purchase anti-dilutive common stock	6,113,000	2,959,000	5,503,000	2,032,000

Weighted-Average Shares - Calcu

Weighted-Average Shares - Calculation of Weighted-Average Shares (Detail) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jul. 01, 2018	Jun. 30, 2019	Jul. 01, 2018
Earnings Per Share [Abstract]
Basic weighted-average common shares outstanding	171,318	172,370	171,209	172,825
Effect of dilutive stock options	4,130	4,779	4,319	5,593
Weighted-average common and common-equivalent shares outstanding	175,448	177,149	175,528	178,418

Subsequent Events (Details)

Subsequent Events (Details) - Subsequent Event	Jul. 29, 2019USD ($)
Subsequent Event [Line Items]
Dividends (in dollars per share)	$ 0.050
Dividends payable, date payable	Aug. 30, 2019
Dividends payable, date of record	Aug. 16, 2019

Uncategorized Items - cgnx-6302

Label	Element	Value
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ (5,961,000)
Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ (5,961,000)