Onto Innovation (ONTO) 10-Q 5 Aug 21 2021 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information Document - shares	6 Months Ended
	Jun. 26, 2021	Jul. 12, 2021
Cover [Abstract]
Entity Registrant Name	ONTO INNOVATION INC.
Trading Symbol	ONTO
Entity Central Index Key	0000704532
Current Fiscal Year End Date	--01-01
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Jun. 26, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q2
Document Quarterly Report	true
Document Transition Report	false
Entity Interactive Data Current	Yes
Amendment Flag	false
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Current Reporting Status	Yes
Entity Shell Company	false
Title of 12(b) Security	Common Stock, $0.001 par value per share
Security Exchange Name	NYSE
Entity Common Stock, Shares Outstanding		49,267,758
Entity File Number	001-39110
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	94-2276314
Entity Address, Address Line One	16 Jonspin Road
Entity Address, City or Town	Wilmington
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	01887
City Area Code	978
Local Phone Number	253-6200

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 26, 2021	Jun. 27, 2020	Jun. 26, 2021	Jun. 27, 2020
Income Statement [Abstract]
Revenue	$ 193,387	$ 134,948	$ 362,666	$ 274,876
Cost of revenue	87,931	63,363	166,741	140,660
Gross profit	105,456	71,585	195,925	134,216
Operating expenses:
Research and development	25,507	22,167	47,471	43,094
Sales and marketing	15,429	11,869	28,533	24,940
General and administrative	16,255	15,916	31,814	36,063
Amortization	12,324	13,703	24,681	27,435
Total operating expenses	69,515	63,655	132,499	131,532
Operating income	35,941	7,930	63,426	2,684
Interest income, net	304	686	665	1,896
Other expense, net	(289)	(1,198)	(1,533)	(1,166)
Income before provision for income taxes	35,956	7,418	62,558	3,414
Provision (benefit) for income taxes	905	(6)	3,394	394
Net income	$ 35,051	$ 7,424	$ 59,164	$ 3,020
Earnings per share:
Basic	$ 0.71	$ 0.15	$ 1.20	$ 0.06
Diluted	$ 0.71	$ 0.15	$ 1.19	$ 0.06
Weighted average shares outstanding:
Basic	49,193	48,736	49,105	49,417
Diluted	49,701	49,014	49,645	49,782

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 26, 2021	Jun. 27, 2020	Jun. 26, 2021	Jun. 27, 2020
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 35,051	$ 7,424	$ 59,164	$ 3,020
Other comprehensive (loss) gain, net of tax:
Change in net unrealized (losses) gains on available-for-sale marketable securities	(567)	795	(698)	269
Change in currency translation adjustments	537	2,495	(1,362)	264
Total other comprehensive (loss) gain, net of tax	(30)	3,290	(2,060)	533
Total comprehensive income	$ 35,021	$ 10,714	$ 57,104	$ 3,553

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 26, 2021	Dec. 26, 2020
Current Assets:
Cash and cash equivalents	$ 134,218	$ 136,720
Marketable securities	276,621	237,002
Accounts receivable, less allowance of $720 and $784	174,662	149,251
Inventories, net	206,981	191,217
Prepaid expenses and other current assets	19,147	17,471
Total current assets	811,629	731,661
Property, plant and equipment, net	88,015	87,950
Goodwill	313,891	306,632
Identifiable intangible assets, net	305,886	318,357
Deferred income taxes	2,263	2,235
Other assets	24,809	21,337
Total assets	1,546,493	1,468,172
Current liabilities:
Accounts payable	46,685	40,183
Accrued liabilities	40,957	37,075
Deferred revenue	21,190	14,334
Other current liabilities	24,336	28,499
Total current liabilities	133,168	120,091
Deferred and other tax liabilities	55,867	55,623
Other non-current liabilities	27,895	27,712
Total liabilities	216,930	203,426
Commitments and contingencies
Stockholders’ equity:
Common stock	49	49
Additional paid-in capital	1,241,680	1,233,967
Accumulated other comprehensive income	2,508	4,568
Retained earnings	85,326	26,162
Total stockholders’ equity	1,329,563	1,264,746
Total liabilities and stockholders’ equity	$ 1,546,493	$ 1,468,172

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) (Unaudited) - USD ($) $ in Thousands	Jun. 26, 2021	Dec. 26, 2020
Statement Of Financial Position [Abstract]
Allowances for doubtful accounts	$ 720	$ 784

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 26, 2021	Jun. 27, 2020
Cash flows from operating activities:
Net income	$ 59,164	$ 3,020
Adjustments to reconcile net income to net cash and cash equivalents provided by operating activities:
Amortization of intangibles	24,681	27,435
Depreciation	7,484	6,240
Share-based compensation	10,997	8,730
Acquired inventory step-up amortization	252	10,173
Provision for inventory valuation	3,706	3,108
Other, net	1,892	1,102
Changes in operating assets and liabilities, net of effects of business acquired	(31,748)	(12,937)
Net cash and cash equivalents provided by operating activities	76,428	46,871
Cash flows from investing activities:
Purchases of marketable securities	(142,072)	(140,364)
Proceeds from sales of marketable securities	102,027	147,473
Cash received from convertible note receivable		2,848
Purchase of business, net of cash acquired	(26,795)
Purchases of property, plant and equipment	(9,558)	(2,609)
Net cash and cash equivalents (used in) provided by investing activities	(76,398)	7,348
Cash flows from financing activities:
Purchase of common stock		(52,000)
Tax payments related to shares withheld for share-based compensation plans	(6,499)	(3,279)
Payment of contingent consideration for acquired business		(435)
Issuance of shares through share-based compensation plans	3,215	179
Net cash and cash equivalents used in financing activities	(3,284)	(55,535)
Effect of exchange rate changes on cash and cash equivalents	752	31
Net decrease in cash and cash equivalents	(2,502)	(1,285)
Cash and cash equivalents at beginning of period	136,720	130,673
Cash and cash equivalents at end of period	134,218	129,388
Supplemental disclosure of cash flow information:
Income taxes paid	$ 4,980	$ 3,463

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings (Accumulated Deficit) [Member]
Balance at Dec. 31, 2019	$ 1,264,026	$ 50	$ 1,269,437	$ (598)	$ (4,863)
Balance, Shares at Dec. 31, 2019		50,184
Repurchase of common stock	(33,614)	$ (1)	(33,613)
Repurchase of common stock, Shares		(1,250)
Net income (loss)	(4,404)				(4,404)
Share-based compensation	3,955		3,955
Issuance of shares through share-based compensation plans	164		164
Issuance of shares through share-based compensation plans, Shares		240
Share-based compensation plan withholdings	(1,565)		(1,565)
Share-based compensation plan withholdings, Shares		(42)
Currency translation	(2,231)			(2,231)
Unrealized gain (loss) on investments	(526)			(526)
Balance at Mar. 28, 2020	1,225,805	$ 49	1,238,378	(3,355)	(9,267)
Balance, shares at Mar. 28, 2020		49,132
Balance at Dec. 31, 2019	1,264,026	$ 50	1,269,437	(598)	(4,863)
Balance, Shares at Dec. 31, 2019		50,184
Net income (loss)	3,020
Currency translation	264
Balance at Jun. 27, 2020	1,221,209	$ 49	1,223,068	(65)	(1,843)
Balance, shares at Jun. 27, 2020		48,724
Balance at Mar. 28, 2020	1,225,805	$ 49	1,238,378	(3,355)	(9,267)
Balance, Shares at Mar. 28, 2020		49,132
Repurchase of common stock	(18,385)		(18,385)
Repurchase of common stock, Shares		(632)
Net income (loss)	7,424				7,424
Share-based compensation	4,775		4,775
Issuance of shares through share-based compensation plans	15		15
Issuance of shares through share-based compensation plans, Shares		279
Share-based compensation plan withholdings	(1,715)		(1,715)
Share-based compensation plan withholdings, Shares		55
Currency translation	2,495			2,495
Unrealized gain (loss) on investments	795			795
Balance at Jun. 27, 2020	1,221,209	$ 49	1,223,068	(65)	(1,843)
Balance, shares at Jun. 27, 2020		48,724
Balance at Dec. 26, 2020	1,264,746	$ 49	1,233,967	4,568	26,162
Balance, Shares at Dec. 26, 2020		48,758
Net income (loss)	24,113				24,113
Share-based compensation	4,890		4,890
Issuance of shares through share-based compensation plans	3,085		3,085
Issuance of shares through share-based compensation plans, Shares		240
Share-based compensation plan withholdings	(2,492)		(2,492)
Share-based compensation plan withholdings, Shares		(41)
Currency translation	(1,899)			(1,899)
Unrealized gain (loss) on investments	(131)			(131)
Balance at Mar. 27, 2021	1,292,312	$ 49	1,239,450	2,538	50,275
Balance, shares at Mar. 27, 2021		48,957
Balance at Dec. 26, 2020	1,264,746	$ 49	1,233,967	4,568	26,162
Balance, Shares at Dec. 26, 2020		48,758
Net income (loss)	59,164
Currency translation	(1,362)
Balance at Jun. 26, 2021	1,329,563	$ 49	1,241,680	2,508	85,326
Balance, shares at Jun. 26, 2021		49,189
Balance at Mar. 27, 2021	1,292,312	$ 49	1,239,450	2,538	50,275
Balance, Shares at Mar. 27, 2021		48,957
Net income (loss)	35,051				35,051
Share-based compensation	6,107		6,107
Issuance of shares through share-based compensation plans	130		130
Issuance of shares through share-based compensation plans, Shares		288
Share-based compensation plan withholdings	(4,007)		(4,007)
Share-based compensation plan withholdings, Shares		56
Currency translation	537			537
Unrealized gain (loss) on investments	(567)			(567)
Balance at Jun. 26, 2021	$ 1,329,563	$ 49	$ 1,241,680	$ 2,508	$ 85,326
Balance, shares at Jun. 26, 2021		49,189

Basis of Presentation

Basis of Presentation	6 Months Ended
	Jun. 26, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Basis of Presentation	NOTE 1. Basis of Presentation The Company operates on a 52- or 53-week fiscal year ending on the Saturday closest to December 31 st The accompanying interim unaudited Condensed Consolidated Financial Statements have been prepared by Onto Innovation Inc. (together with its consolidated subsidiaries, unless otherwise specified or suggested by the context, the “Company,” or “Onto Innovation,” “we,” “our” or “us”) and in the opinion of management reflect all adjustments, consisting of normal recurring accruals, necessary for their fair presentation in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”). Preparing financial statements requires management to make estimates and assumptions that affect amounts reported in the financial statements and accompanying notes. Actual amounts could differ materially from reported amounts. The interim results for the three and six months ended June 26, 2021 are not necessarily indicative of results to be expected for the entire year or any future periods. This interim financial information should be read in conjunction with the financial statements and the notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 26, 2020 (the “2020 Form 10-K”) filed with the Securities and Exchange Commission (“SEC”) on February 19, 2021. The accompanying Condensed Consolidated Balance Sheet at December 26, 2020 has been derived from the audited consolidated financial statements included in the 2020 Form 10-K. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. Significant estimates made by management that are evaluated on an ongoing basis include the allowances for credit losses, excess and obsolete inventory, fair value of assets acquired and liabilities assumed in a business combination, recoverability and useful lives of property, plant and equipment and identifiable intangible assets, recoverability of goodwill, recoverability of deferred tax assets, liabilities for product warranty and contingencies, including litigation reserves, share-based payments and liabilities for tax uncertainties. Actual results could differ from those estimates. These estimates and assumptions are based on historical experience and on various other factors which the Company believes to be reasonable under the circumstances. The Company may engage third-party valuation specialists to assist with estimates related to the valuation of financial instruments, fair value of assets acquired and liabilities assumed in a business combination and stock awards. Such estimates often require the selection of appropriate valuation methodologies and significant judgment. Actual results could differ from these estimates under different assumptions or circumstances and such differences could be material. The Company also assessed the impacts of COVID-19 on the above accounting matters as of June 26, 2021 and through the date of this report. While there was not a material impact as of and for the quarter ended June 26, 2021 and through the date of this report, future actual magnitude and duration of the COVID-19 pandemic, as well as other associated factors, could result in material negative impacts to the Company’s condensed consolidated financial statements in future reporting periods. Recent Accounting Pronouncements Recently Adopted Effective December 27, 2020, the Company adopted Accounting Standards Update (“ASU”) No. 2019-12, “Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes.” This standard simplified the accounting for income taxes by eliminating certain exceptions to the guidance in Topic 740 related to the approach for intraperiod tax allocation, the methodology for calculating income taxes in an interim period and the recognition of deferred tax liabilities for outside basis differences. The new guidance also simplified aspects of the accounting for franchise 2019-12 did not have a significant impact on the Company’s consolidated financial position, results of operations, and cash flows.

Business Combination

Business Combination	6 Months Ended
	Jun. 26, 2021
Business Combinations [Abstract]
Business Combination	NOTE 2. Business Combination Inspectrology, LLC On December 31, 2020, the Company acquired Inspectrology, LLC (“Inspectrology”), a leading supplier of overlay metrology for controlling lithography and etch processes in the compound semiconductor market for $27,015 in cash and a potential earnout of $10,000, subject to achievement of certain revenue targets earned for fiscal 2021 and 2022. As of June 26, 2021, the Company does not believe the earnout criteria will be met. Certain payments, including the earnout, are subject to the principals remaining with the Company for a period of one to three years. The following table summarizes the preliminary fair values of assets acquired and liabilities assumed at the date of acquisition: Cash and cash equivalents $ 220 Account receivables 4,071 Inventories 2,587 Prepaid expenses and other current assets 104 Property, plant and equipment 86 Identifiable intangible assets 12,210 Other assets 3,000 Total assets acquired 22,278 Accounts payable (1,048 ) Payroll and related expenses (512 ) Deferred revenue (386 ) Other current liabilities (576 ) Net assets acquired 19,756 Goodwill 7,259 Total purchase consideration $ 27,015

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 26, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	NOTE 3. Fair Value Measurements Fair Value of Financial Instruments The Company has evaluated the estimated fair value of financial instruments using available market information and valuations as provided by third-party sources. The use of different market assumptions and/or estimation methodologies could have a significant effect on the estimated fair value amounts. The carrying value of cash and cash equivalents, accounts receivable, accounts payable and accrued liabilities approximates fair value because of the short-term maturity of these instruments. Fair Value Hierarchy The Company applies a three-level valuation hierarchy for fair value measurements. This hierarchy prioritizes the inputs into three broad levels. Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities. Level 2 inputs are quoted prices for similar assets and liabilities in active markets or inputs that are observable for the asset or liability, either directly or indirectly through market corroboration, for substantially the full term of the asset or liability. Level 3 inputs are unobservable inputs based on management’s assumptions used to measure assets and liabilities at fair value. A financial asset’s or liability’s fair value measurement classification within the hierarchy is determined based on the lowest level input that is significant to the fair value measurement. The following tables provide the assets and liabilities carried at fair value measured on a recurring basis at June 26, 2021 and December 26, 2020: Fair Value Measurements Using Carrying Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) June 26, 2021 Assets: Available-for-sale debt securities: Municipal notes and bonds $ 142,931 $ — $ 142,931 $ — Asset-backed securities 4,094 — 4,094 — Certificates of deposit 44,021 — 44,021 — Commercial paper 50,979 — 50,979 — Corporate bonds 34,596 — 34,596 — Foreign currency forward contracts 27 — 27 — Total assets $ 276,648 $ — $ 276,648 $ — December 26, 2020 Assets: Available-for-sale debt securities: Municipal notes and bonds $ 124,640 $ — $ 124,640 $ — Asset-backed securities 11,708 — 11,708 — Certificates of deposit 36,373 — 36,373 — Commercial paper 32,699 — 32,699 — Corporate bonds 31,582 — 31,582 — Total assets $ 237,002 $ — $ 237,002 $ — Liabilities: Foreign currency forward contracts 36 — 36 — Total liabilities $ 36 $ — $ 36 $ — Available-for-sale debt securities classified as Level 2 are valued using observable inputs to quoted market prices, benchmark yields, reported trades, broker/dealer quotes or alternative pricing sources with reasonable levels of price transparency. The foreign currency forward contracts are primarily measured based on the foreign currency spot and forward rates quoted by the banks or foreign currency dealers. Investment prices are obtained from third party pricing providers, which model prices utilizing the above observable inputs, for each asset class. See Note 4 for additional discussion regarding the fair value of the Company’s marketable securities.

Marketable Securities

Marketable Securities	6 Months Ended
	Jun. 26, 2021
Marketable Securities [Abstract]
Marketable Securities	NOTE 4. Marketable Securities At June 26, 2021 and December 26, 2020, marketable securities are categorized as follows: Amortized Cost Gross Unrealized Holding Gains Gross Unrealized Holding Losses Fair Value June 26, 2021 Municipal notes and bonds $ 142,821 $ 128 $ 19 $ 142,930 Asset-backed securities 4,090 4 — 4,094 Certificates of deposit 44,003 19 1 44,021 Commercial paper 50,961 19 — 50,980 Corporate bonds 34,651 6 61 34,596 Total marketable securities $ 276,526 $ 176 $ 81 $ 276,621 December 26, 2020 Municipal notes and bonds $ 124,387 $ 257 $ 4 $ 124,640 Asset-backed securities 11,679 29 — 11,708 Certificates of deposit 36,349 24 — 36,373 Commercial paper 32,690 12 3 32,699 Corporate bonds 31,544 50 12 31,582 Total marketable securities $ 236,649 $ 372 $ 19 $ 237,002 The amortized cost and estimated fair value of marketable securities classified by the maturity date listed on the security, regardless of the Condensed Consolidated Balance Sheets classification, is as follows at June 26, 2021 and December 26, 2020: June 26, 2021 December 26, 2020 Amortized Cost Fair Value Amortized Cost Fair Value Due within one year $ 195,632 $ 195,733 $ 170,099 $ 170,321 Due after one through five years 80,894 80,888 66,550 66,681 Due after five through ten years — — — — Due after ten years — — — — Total marketable securities $ 276,526 $ 276,621 $ 236,649 $ 237,002 The following table summarizes the estimated fair value and gross unrealized holding losses of marketable securities, aggregated by investment instrument and period of time in an unrealized loss position, at June 26, 2021 and December 26, 2020: In Unrealized Loss Position For Less Than 12 Months In Unrealized Loss Position For Greater Than 12 Months Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses June 26, 2021 Municipal notes and bonds $ 30,626 $ 19 $ — $ — Certificate of deposit 4,603 1 — — Corporate bonds 24,485 61 — — Total $ 59,714 $ 81 $ — $ — December 26, 2020 Municipal notes and bonds $ 8,641 $ 4 $ — $ — Commercial paper 8,862 3 — — Corporate bonds 14,947 12 — — Total $ 32,450 $ 19 $ — $ — See Note 3 for additional discussion regarding the fair value of the Company’s marketable securities.

Derivative Instruments and Hedg

Derivative Instruments and Hedging Activities	6 Months Ended
	Jun. 26, 2021
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Derivative Instruments and Hedging Activities	NOTE 5. Derivative Instruments and Hedging Activities The Company, when it considers it to be appropriate, enters into forward contracts to hedge the economic exposures arising from foreign currency denominated transactions. At June 26, 2021 and December 26, 2020, these contracts included the future sale of British pound sterling, euro, Israeli shekel, Japanese yen, Korean won, Singapore dollar, Taiwanese dollar, and Chinese renminbi to purchase U.S. dollars. Foreign currency forward contracts are not designated as hedges for accounting purposes and therefore, the change in fair value is recorded in “Other expense, net,” in the Condensed Consolidated Statements of Operations. The Company records its forward contracts at fair value in either prepaid expenses and other current assets or other current liabilities in the Condensed Consolidated Balance Sheets. The dollar equivalent of the U.S. dollar forward contracts and related fair values as of June 26, 2021 and December 26, 2020 were as follows: June 26, 2021 December 26, 2020 Notional amount $ 11,397 $ 37,580 Fair value of asset (liability) $ 27 $ (36 )

Goodwill and Purchased Intangib

Goodwill and Purchased Intangible Assets	6 Months Ended
	Jun. 26, 2021
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and Purchased Intangible Assets	NOTE 6. Goodwill and Purchased Intangible Assets Goodwill The changes in the carrying amount of goodwill are as follows: Balance at December 26, 2020 $ 306,632 Goodwill acquired during the period (Note 2) 7,259 Balance at June 26, 2021 $ 313,891 Intangible Assets Purchased intangible assets as of June 26, 2021 and December 26, 2020 are as follows: Gross Carrying Amount Accumulated Amortization Net June 26, 2021 Finite-lived intangibles: Developed technology $ 331,747 $ 132,270 $ 199,477 Customer and distributor relationships 74,701 23,267 51,434 Trademarks and trade names 14,361 5,986 8,375 Total finite-lived intangible assets 420,809 161,523 259,286 In-process research and development 46,600 — 46,600 Total identifiable intangible assets $ 467,409 $ 161,523 $ 305,886 December 26, 2020 Finite-lived intangibles: Developed technology $ 326,877 $ 110,851 $ 216,026 Customer and distributor relationships 69,261 20,654 48,607 Trademarks and trade names 12,461 5,337 7,124 Total finite-lived intangible assets 408,599 136,842 271,757 In-process research and development 46,600 — 46,600 Total identifiable intangible assets $ 455,199 $ 136,842 $ 318,357 Assuming no change in the gross carrying value of identifiable intangible assets and estimated lives, future estimated amortization expenses are: Expected Amortization Fiscal Year: Expense 2021 (remainder) $ 24,548 2022 48,830 2023 48,355 2024 42,669 2025 26,119 2026 24,926 Thereafter 43,839 Total $ 259,286

Balance Sheet Details

Balance Sheet Details	6 Months Ended
	Jun. 26, 2021
Balance Sheet Detail [Abstract]
Balance Sheet Details	NOTE 7. Balance Sheet Details Inventories Inventories, net are comprised of the following: June 26, 2021 December 26, 2020 Materials $ 128,389 $ 124,926 Work-in-process 54,706 44,829 Finished goods 23,886 21,462 Total inventories, net $ 206,981 $ 191,217 Property, Plant and Equipment Property, plant and equipment, net is comprised of the following: June 26, 2021 December 26, 2020 Machinery and equipment $ 57,061 $ 52,833 Land and building 48,188 47,544 Computer equipment and software 15,651 15,549 Leasehold improvements 13,759 12,927 Furniture and fixtures 3,985 4,013 138,644 132,866 Accumulated depreciation and amortization (50,629 ) (44,916 ) Total property, plant and equipment, net $ 88,015 $ 87,950 Other assets Other assets is comprised of the following: June 26, 2021 December 26, 2020 Operating lease right-of-use assets $ 20,449 $ 19,669 Other 4,360 1,668 Total other assets $ 24,809 $ 21,337 Accrued liabilities Accrued liabilities is comprised of the following: June 26, 2021 December 26, 2020 Payroll and related expenses $ 32,026 $ 30,270 Warranty 7,611 6,062 Other 1,320 743 Total accrued liabilities $ 40,957 $ 37,075 Other current liabilities Other current liabilities is comprised of the following: June 26, 2021 December 26, 2020 Customer deposits $ 10,949 $ 15,177 Current operating lease obligations 5,121 4,470 Income tax payable 1,076 4,109 Accrued professional fees 1,259 1,184 Other 5,931 3,559 Total other current liabilities $ 24,336 $ 28,499 Other non-current liabilities Other non-current liabilities is comprised of the following: June 26, 2021 December 26, 2020 Non-current operating lease obligations $ 16,365 $ 16,455 Unrecognized tax benefits (including interest) 2,765 3,812 Deferred revenue 1,716 1,292 Other 7,049 6,153 Total other non-current liabilities $ 27,895 $ 27,712

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 26, 2021
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	NOTE 8. Commitments and Contingencies Factoring The Company maintains arrangements under which eligible accounts receivable in Japan are sold without recourse to unrelated third-party financial institutions. The Company sold $6,226 of receivables during the six months ended June 26, 2021. These receivables were not included in the condensed consolidated balance sheets as the criteria for sale treatment had been met. There were no material gains or losses on the sale of such receivables. There were no amounts due from such third-party financial institutions at June 26, 2021. Intellectual Property Indemnification Obligations The Company has entered into agreements with customers that include limited intellectual property indemnification obligations that are customary in the industry. These guarantees generally require the Company to compensate the other party for certain damages and costs incurred as a result of third-party intellectual property claims arising from these transactions. The nature of the intellectual property indemnification obligations prevents the Company from making a reasonable estimate of the maximum potential amount it could be required to pay to its customers. Historically, the Company has not made any indemnification payments under such agreements, and no amount has been accrued in the accompanying consolidated financial statements with respect to these indemnification guarantees. Warranty Reserves The Company generally provides a warranty on its products for a period of 12 to 14 months against defects in material and workmanship. The Company estimates the costs that may be incurred during the warranty period and records a liability in the amount of such costs at the time revenue is recognized. The Company’s estimate is based primarily on historical experience. The Company periodically assesses the adequacy of its recorded warranty liabilities and adjusts the amounts as necessary. Settlements of warranty reserves are generally associated with sales that occurred during the 12 to 14 months prior to the period-end and warranty accruals are related to sales during the same year. Changes in the Company’s warranty reserves are as follows: Six Months Ended June 26, June 27, 2021 2020 Balance, beginning of the period $ 6,485 $ 6,348 Accruals 3,560 2,794 Warranty liability assumed in acquisition 407 — Usage (2,229 ) (2,327 ) Balance, end of the period $ 8,223 $ 6,815 Warranty reserves are reported in the Condensed Consolidated Balance Sheets under the captions “Accrued liabilities” and “Other non-current liabilities.” Legal Matters From time to time, the Company is subject to legal proceedings and claims in the ordinary course of business. The following reflects an overview of the material developments with regard to the Company’s pending material legal proceedings. Optical Solutions Inc. v. Nanometrics Incorporated (Case No. 18-cv-00417-BLF): On August 2, 2017, Nanometrics was named as defendant in a complaint filed in New Hampshire Superior Court (the “Complaint”). The Complaint, brought by Optical Solutions, Inc. (“OSI”), alleges claims arising from a purported exclusive purchase contract between OSI and Nanometrics pertaining to certain products. The relief sought is the award of damages in an amount to be proven at trial, attorney’s fees and cost as well as other relief the court deems just and proper. On September 18, 2017, Nanometrics removed the action to the United States District Court for the District of New Hampshire (the “District of New Hampshire”). On September 25, 2017, Nanometrics moved to transfer the Complaint to the United States District Court for the Northern District of California (the “Northern District of California”). On December 20, 2017, Nanometrics filed its complaint against OSI in the California Superior Court for the County of Santa Clara alleging claims arising from OSI’s breach of certain purchase orders. The relief sought is the award of damages in an amount to be proven at trial including pre- and post-judgment interest, punitive damages, restitution for benefits unjustly received by OSI, attorney’s fees and cost as well as other relief the court deems just and proper. Nanometrics’ complaint was later removed by OSI to the Northern District of California. On May 29, 2018, the District of New Hampshire issued an order granting Nanometrics’ motion to transfer the Complaint to the Northern District of California and denying Nanometrics’ motion to dismiss the Complaint without prejudice. On June 14, 2018, the Complaint was consolidated with Nanometrics’ complaint against OSI. On August 9, 2018, OSI filed an Amended Complaint. On September 19, 2018, Nanometrics filed a motion to dismiss OSI’s Amended Complaint for failure to state a claim. Nanometrics’ motion to dismiss was heard on February 28, 2019. On March 5, 2019, the Northern District of California granted Nanometrics’ motion to dismiss with leave to amend. OSI filed a Second Amended Complaint on March 29, 2019. Nanometrics filed a motion to dismiss OSI’s Second Amended Complaint on May 31, 2019. In October 2019, Nanometrics was renamed Onto Innovation Inc. as a result of the Merger. Thereafter, the Company’s second motion to dismiss was heard on November 14, 2019. On November 26, 2019, the Northern District of California granted the Company’s motion to dismiss with leave to amend. OSI filed a Third Amended Complaint on January 21, 2020. On March 2, 2020, the Company filed a motion to dismiss OSI’s Third Amended Complaint and a hearing on the motion was held on June 11, 2020. On June 23, 2020, the Northern District of California granted the Company’s motion to dismiss with prejudice with regard to two claims asserted by OSI and dismissed two other claims asserted by OSI with leave to amend. Thereafter, on July 7, 2020, OSI filed a Fourth Amended Complaint. On August 14, 2020, the Company filed a motion to dismiss with regard to one of the two remaining claims. On December 1, 2020, the Northern District of California denied this final motion to dismiss and as a result the Company filed its Answer in this matter on December 22, 2020. This matter is currently in discovery. The Northern District of California granted a joint stipulation that discovery cutoff is September 3, 2022 and the trial date is set for December 4, 2023. At this time, the loss contingency in this matter is remote and the Company does not anticipate the outcome of the matter to have a material impact on its financial position, results of operations, or cash flows. Line of Credit The Company has a credit agreement with a bank that provides for a line of credit which is secured by the marketable securities the Company has with the bank. The Company is permitted to borrow up to 70% of the value of eligible securities held at the time the line of credit is accessed. The available line of credit as of June 26, 2021 was approximately $99.4 million with an available interest rate of 1.8%. The credit agreement is available to the Company until such time that either party terminates the arrangement at their discretion. The Company has not utilized the line of credit to date.

Revenue

Revenue	6 Months Ended
	Jun. 26, 2021
Revenue From Contract With Customer [Abstract]
Revenue	NOTE 9. Revenue The following table represents a disaggregation of revenue by timing of revenue: Three Months Ended Six Months Ended June 26, June 27, June 26, June 27, 2021 2020 2021 2020 Point-in-time $ 182,133 $ 131,796 $ 343,294 $ 265,541 Over-time 11,254 3,152 19,372 9,335 Total revenue $ 193,387 $ 134,948 $ 362,666 $ 274,876 See Note 15 for additional discussion of the Company’s disaggregated revenue in detail. Contract Liabilities The Company records contract liabilities when the customer has been billed in advance of the Company completing its performance obligations. These amounts are recorded as deferred revenue in the Condensed Consolidated Balance Sheets. Changes in deferred revenue were as follows: Three Months Ended Six Months Ended June 26, June 27, June 26, June 27, 2021 2020 2021 2020 Balance, beginning of the period $ 22,429 $ 18,032 $ 15,626 $ 15,093 Deferred revenue assumed in acquisition — — 386 — Deferral of revenue 15,117 8,818 34,348 23,252 Recognition of deferred revenue (14,640 ) (8,956 ) (27,454 ) (20,451 ) Balance, end of the period $ 22,906 $ 17,894 $ 22,906 $ 17,894

Share-Based Compensation

Share-Based Compensation	6 Months Ended
	Jun. 26, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Share-Based Compensation	NOTE 10. Share-Based Compensation Restricted Stock Unit Activity A summary of the Company’s restricted stock unit activity with respect to the six months ended June 26, 2021 is as follows: Number of Shares Weighted Average Grant Date Fair Value Nonvested at December 26, 2020 964 $ 31.37 Granted 285 $ 69.47 Vested (404 ) $ 30.74 Forfeited (46 ) $ 37.61 Nonvested at June 26, 2021 799 $ 45.67 As of June 26, 2021 and December 26, 2020, there was $27,391 and $19,135 of total unrecognized compensation cost related to restricted stock units granted under the Company’s stock plans, respectively. That cost is expected to be recognized over a weighted average period of 1.8 years and 1.7 years for June 26, 2021 and December 26, 2020, respectively.

Other Expense, Net

Other Expense, Net	6 Months Ended
	Jun. 26, 2021
Other Income Expense [Abstract]
Other Expense, Net	NOTE 11. Other Expense, Net Other expense, net, is comprised of the following: Three Months Ended Six Months Ended June 26, June 27, June 26, June 27, 2021 2020 2021 2020 Foreign currency exchange losses, net $ (328 ) $ (1,271 ) $ (1,599 ) $ (1,305 ) Other 39 73 66 139 Total other expense, net $ (289 ) $ (1,198 ) $ (1,533 ) $ (1,166 )

Income Taxes

Income Taxes	6 Months Ended
	Jun. 26, 2021
Income Tax Disclosure [Abstract]
Income Taxes	NOTE 12. Income Taxes The following table provides details of income taxes: Three Months Ended Six Months Ended June 26, June 27, June 26, June 27, 2021 2020 2021 2020 Income before income taxes $ 35,956 $ 7,418 $ 62,558 $ 3,414 Provision (benefit) for income taxes $ 905 $ (6 ) $ 3,394 $ 394 Effective tax rate 3 % 0 % 5 % 12 % The income tax provision for the three and six months ended June 26, 2021 was computed based on the Company’s annual forecast of profit by jurisdiction and forecasted effective tax rate for the year. The increase in the Company’s income tax provision for the three and six months ended June 26, 2021 as compared to the three and six months ended June 27, 2020 is primarily due to an increase in quarterly earnings, offset by (i) an increase in the Foreign Derived Intangible Income (“FDII”) deduction, (ii) an increase in the excess tax benefit associated with equity compensation, and (iii) a release of reserves due to expiration of the applicable statute of limitations. The Company’s recorded effective tax rate is less than the U.S. statutory rate primarily due to projected FDII deductions and federal research and development tax credits. The Company currently has a partial valuation allowance recorded against certain foreign and state net operating loss and credit carryforwards where the realizability of such deferred tax assets is substantially in doubt. Each quarter, the Company assesses the likelihood that it will be able to recover its deferred tax assets. The Company considers available evidence, both positive and negative, including forecasted earnings in assessing its need for a valuation allowance. As a result of the Company’s analysis, it concluded that it is more likely than not that a portion of its deferred tax assets will not be realized. Therefore, the Company continues to provide a valuation allowance against certain deferred tax assets. The Company continues to monitor available evidence and may reverse some or all of its remaining valuation allowance in future periods, if appropriate. The Company has a recorded valuation allowance against a certain portion of its deferred tax assets of $14,254 and $14,238 as of June 26, 2021 and December 26, 2020, respectively.

Earnings Per Share

Earnings Per Share	6 Months Ended
	Jun. 26, 2021
Earnings Per Share [Abstract]
Earnings Per Share	NOTE 13. Earnings Per Share Basic earnings per share is calculated using the weighted average number of shares of common stock outstanding during the period. Restricted stock units, employee stock purchase grants and stock options are included in the calculation of diluted earnings per share, except when their effect would be anti-dilutive. The Company’s basic and diluted earnings per share amounts are as follows: Three Months Ended Six Months Ended June 26, June 27, June 26, June 27, 2021 2020 2021 2020 Numerator: Net income $ 35,051 $ 7,424 $ 59,164 $ 3,020 Denominator: Basic earnings per share - weighted average shares outstanding 49,193 48,736 49,105 49,417 Effect of potential dilutive securities: Employee stock options, employee stock purchase grants and restricted stock units - dilutive shares 508 278 540 365 Diluted earnings per share - weighted average shares outstanding 49,701 49,014 49,645 49,782 Earnings per share: Basic $ 0.71 $ 0.15 $ 1.20 $ 0.06 Diluted $ 0.71 $ 0.15 $ 1.19 $ 0.06

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	6 Months Ended
	Jun. 26, 2021
Accumulated Other Comprehensive Income Loss Net Of Tax [Abstract]
Accumulated Other Comprehensive Income	NOTE 14. Accumulated Other Comprehensive Income The components of accumulated other comprehensive income, net of tax, at June 26, 2021, as well as the activity for the six months ended June 26, 2021, were as follows: Foreign currency translation adjustments Net unrealized gains (losses) on available-for-sale marketable securities Accumulated other comprehensive income Balance at December 26, 2020 $ 4,479 $ 89 $ 4,568 Net current period other comprehensive loss (1,362 ) (698 ) (2,060 ) Reclassifications — — — Balance at June 26, 2021 $ 3,117 $ (609 ) $ 2,508

Segment Reporting and Geographi

Segment Reporting and Geographic Information	6 Months Ended
	Jun. 26, 2021
Segment Reporting [Abstract]
Segment Reporting and Geographic Information	NOTE 15. Segment Reporting and Geographic Information The Company is engaged in the design, development, manufacture and support of high-performance control metrology, defect inspection, lithography and data analysis systems used by microelectronics device manufacturers. The Company and its subsidiaries currently operate in a single operating segment: the design, development, manufacture and support of high-performance process control defect inspection and metrology, lithography and process control software systems used by microelectronics device manufacturers. Therefore, the Company has one reportable segment. The Company’s chief operating decision maker is the Chief Executive Officer (the “CEO”). The CEO allocates resources and assesses performance of the business and other activities at the reportable segment level. The following table lists the different sources of revenue: Three Months Ended Six Months Ended June 26, June 27, June 26, June 27, 2021 2020 2021 2020 Systems and software $ 162,898 84 % $ 108,247 80 % $ 304,407 84 % $ 222,577 81 % Parts 18,697 10 % 16,329 12 % 36,115 10 % 29,904 11 % Services 11,792 6 % 10,372 8 % 22,144 6 % 22,395 8 % Total revenue $ 193,387 100 % $ 134,948 100 % $ 362,666 100 % $ 274,876 100 % The Company’s significant operations outside the United States include sales, service and application offices in Asia and Europe. For geographical revenue reporting, revenue is attributed to the geographic location to which the product is shipped. Revenue by geographic region is as follows: Three Months Ended Six Months Ended June 26, June 27, June 26, June 27, 2021 2020 2021 2020 Revenue from third parties: South Korea $ 41,299 $ 22,964 $ 91,828 $ 43,721 Taiwan 48,501 31,997 84,793 67,178 China 42,274 27,001 68,053 58,384 United States 25,700 22,378 51,180 42,026 Europe 14,446 10,089 31,832 25,158 Japan 17,386 13,908 25,251 28,935 Southeast Asia 3,781 6,611 9,729 9,474 Total revenue $ 193,387 $ 134,948 $ 362,666 $ 274,876 The following customers accounted for 10% or more of total revenue for the indicated periods: Six Months Ended June 26, June 27, 2021 2020 Samsung Semiconductor 22 % 18 % Taiwan Semiconductor Manufacturing Co. Ltd. 16 % 17 %

Share Repurchase Authorization

Share Repurchase Authorization	6 Months Ended
	Jun. 26, 2021
Share Repurchase Program [Abstract]
Share Repurchase Authorization	NOTE 16. Share Repurchase Authorization In November 2020, the Onto Innovation Board of Directors approved a new share repurchase authorization, which allows the Company to repurchase up to $100,000 worth of shares of its common stock. Repurchases may be made through both public market and private transactions from time to time with shares purchased being subsequently retired. At June 26, 2021, there was $100,000 available for future share repurchases under this share repurchase authorization. The following table summarizes the Company’s share repurchases for the periods indicated: Three Months Ended Six Months Ended June 26, June 27, June 26, June 27, 2021 2020 2021 2020 Shares of common stock repurchased — 632 — 1,882 Cost of shares repurchased $ — $ 18,385 $ — $ 52,000 Average price paid per share $ — $ 29.08 $ — $ 27.62

Basis of Presentation (Policies

Basis of Presentation (Policies)	6 Months Ended
	Jun. 26, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. Significant estimates made by management that are evaluated on an ongoing basis include the allowances for credit losses, excess and obsolete inventory, fair value of assets acquired and liabilities assumed in a business combination, recoverability and useful lives of property, plant and equipment and identifiable intangible assets, recoverability of goodwill, recoverability of deferred tax assets, liabilities for product warranty and contingencies, including litigation reserves, share-based payments and liabilities for tax uncertainties. Actual results could differ from those estimates. These estimates and assumptions are based on historical experience and on various other factors which the Company believes to be reasonable under the circumstances. The Company may engage third-party valuation specialists to assist with estimates related to the valuation of financial instruments, fair value of assets acquired and liabilities assumed in a business combination and stock awards. Such estimates often require the selection of appropriate valuation methodologies and significant judgment. Actual results could differ from these estimates under different assumptions or circumstances and such differences could be material. The Company also assessed the impacts of COVID-19 on the above accounting matters as of June 26, 2021 and through the date of this report. While there was not a material impact as of and for the quarter ended June 26, 2021 and through the date of this report, future actual magnitude and duration of the COVID-19 pandemic, as well as other associated factors, could result in material negative impacts to the Company’s condensed consolidated financial statements in future reporting periods.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Recently Adopted Effective December 27, 2020, the Company adopted Accounting Standards Update (“ASU”) No. 2019-12, “Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes.” This standard simplified the accounting for income taxes by eliminating certain exceptions to the guidance in Topic 740 related to the approach for intraperiod tax allocation, the methodology for calculating income taxes in an interim period and the recognition of deferred tax liabilities for outside basis differences. The new guidance also simplified aspects of the accounting for franchise 2019-12 did not have a significant impact on the Company’s consolidated financial position, results of operations, and cash flows.

Business Combination (Tables)

Business Combination (Tables)	6 Months Ended
	Jun. 26, 2021
Business Combinations [Abstract]
Summary of Preliminary Fair Values of Assets Acquired and Liabilities Assumed	The following table summarizes the preliminary fair values of assets acquired and liabilities assumed at the date of acquisition: Cash and cash equivalents $ 220 Account receivables 4,071 Inventories 2,587 Prepaid expenses and other current assets 104 Property, plant and equipment 86 Identifiable intangible assets 12,210 Other assets 3,000 Total assets acquired 22,278 Accounts payable (1,048 ) Payroll and related expenses (512 ) Deferred revenue (386 ) Other current liabilities (576 ) Net assets acquired 19,756 Goodwill 7,259 Total purchase consideration $ 27,015

Fair Value Measurements - (Tabl

Fair Value Measurements - (Tables)	6 Months Ended
	Jun. 26, 2021
Fair Value Disclosures [Abstract]
Schedule of Assets and Liabilities Carried at Fair Value Measured on a Recurring Basis	The following tables provide the assets and liabilities carried at fair value measured on a recurring basis at June 26, 2021 and December 26, 2020: Fair Value Measurements Using Carrying Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) June 26, 2021 Assets: Available-for-sale debt securities: Municipal notes and bonds $ 142,931 $ — $ 142,931 $ — Asset-backed securities 4,094 — 4,094 — Certificates of deposit 44,021 — 44,021 — Commercial paper 50,979 — 50,979 — Corporate bonds 34,596 — 34,596 — Foreign currency forward contracts 27 — 27 — Total assets $ 276,648 $ — $ 276,648 $ — December 26, 2020 Assets: Available-for-sale debt securities: Municipal notes and bonds $ 124,640 $ — $ 124,640 $ — Asset-backed securities 11,708 — 11,708 — Certificates of deposit 36,373 — 36,373 — Commercial paper 32,699 — 32,699 — Corporate bonds 31,582 — 31,582 — Total assets $ 237,002 $ — $ 237,002 $ — Liabilities: Foreign currency forward contracts 36 — 36 — Total liabilities $ 36 $ — $ 36 $ —

Marketable Securities - (Tables

Marketable Securities - (Tables)	6 Months Ended
	Jun. 26, 2021
Marketable Securities [Abstract]
Schedule of Marketable Securities by Category	At June 26, 2021 and December 26, 2020, marketable securities are categorized as follows: Amortized Cost Gross Unrealized Holding Gains Gross Unrealized Holding Losses Fair Value June 26, 2021 Municipal notes and bonds $ 142,821 $ 128 $ 19 $ 142,930 Asset-backed securities 4,090 4 — 4,094 Certificates of deposit 44,003 19 1 44,021 Commercial paper 50,961 19 — 50,980 Corporate bonds 34,651 6 61 34,596 Total marketable securities $ 276,526 $ 176 $ 81 $ 276,621 December 26, 2020 Municipal notes and bonds $ 124,387 $ 257 $ 4 $ 124,640 Asset-backed securities 11,679 29 — 11,708 Certificates of deposit 36,349 24 — 36,373 Commercial paper 32,690 12 3 32,699 Corporate bonds 31,544 50 12 31,582 Total marketable securities $ 236,649 $ 372 $ 19 $ 237,002
Schedule of Amortized Cost and Estimated Fair Value of Marketable Securities Classified by Maturity Date	The amortized cost and estimated fair value of marketable securities classified by the maturity date listed on the security, regardless of the Condensed Consolidated Balance Sheets classification, is as follows at June 26, 2021 and December 26, 2020: June 26, 2021 December 26, 2020 Amortized Cost Fair Value Amortized Cost Fair Value Due within one year $ 195,632 $ 195,733 $ 170,099 $ 170,321 Due after one through five years 80,894 80,888 66,550 66,681 Due after five through ten years — — — — Due after ten years — — — — Total marketable securities $ 276,526 $ 276,621 $ 236,649 $ 237,002
Summary of Estimated Fair Value and Gross Unrealized Holding Losses of Marketable Securities in Unrealized Loss Position	The following table summarizes the estimated fair value and gross unrealized holding losses of marketable securities, aggregated by investment instrument and period of time in an unrealized loss position, at June 26, 2021 and December 26, 2020: In Unrealized Loss Position For Less Than 12 Months In Unrealized Loss Position For Greater Than 12 Months Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses June 26, 2021 Municipal notes and bonds $ 30,626 $ 19 $ — $ — Certificate of deposit 4,603 1 — — Corporate bonds 24,485 61 — — Total $ 59,714 $ 81 $ — $ — December 26, 2020 Municipal notes and bonds $ 8,641 $ 4 $ — $ — Commercial paper 8,862 3 — — Corporate bonds 14,947 12 — — Total $ 32,450 $ 19 $ — $ —

Derivative Instruments and He_2

Derivative Instruments and Hedging Activities (Tables)	6 Months Ended
	Jun. 26, 2021
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Forward Contracts and Related Fair Values	The dollar equivalent of the U.S. dollar forward contracts and related fair values as of June 26, 2021 and December 26, 2020 were as follows: June 26, 2021 December 26, 2020 Notional amount $ 11,397 $ 37,580 Fair value of asset (liability) $ 27 $ (36 )

Goodwill and Purchased Intang_2

Goodwill and Purchased Intangible Assets (Tables)	6 Months Ended
	Jun. 26, 2021
Goodwill And Intangible Assets Disclosure [Abstract]
Changes in the Carrying Amount of Goodwill	The changes in the carrying amount of goodwill are as follows: Balance at December 26, 2020 $ 306,632 Goodwill acquired during the period (Note 2) 7,259 Balance at June 26, 2021 $ 313,891
Schedule of Purchased Intangible Assets	Intangible Assets Purchased intangible assets as of June 26, 2021 and December 26, 2020 are as follows: Gross Carrying Amount Accumulated Amortization Net June 26, 2021 Finite-lived intangibles: Developed technology $ 331,747 $ 132,270 $ 199,477 Customer and distributor relationships 74,701 23,267 51,434 Trademarks and trade names 14,361 5,986 8,375 Total finite-lived intangible assets 420,809 161,523 259,286 In-process research and development 46,600 — 46,600 Total identifiable intangible assets $ 467,409 $ 161,523 $ 305,886 December 26, 2020 Finite-lived intangibles: Developed technology $ 326,877 $ 110,851 $ 216,026 Customer and distributor relationships 69,261 20,654 48,607 Trademarks and trade names 12,461 5,337 7,124 Total finite-lived intangible assets 408,599 136,842 271,757 In-process research and development 46,600 — 46,600 Total identifiable intangible assets $ 455,199 $ 136,842 $ 318,357
Schedule of Estimated Future Amortization Expenses	Assuming no change in the gross carrying value of identifiable intangible assets and estimated lives, future estimated amortization expenses are: Expected Amortization Fiscal Year: Expense 2021 (remainder) $ 24,548 2022 48,830 2023 48,355 2024 42,669 2025 26,119 2026 24,926 Thereafter 43,839 Total $ 259,286

Balance Sheet Details (Tables)

Balance Sheet Details (Tables)	6 Months Ended
	Jun. 26, 2021
Balance Sheet Detail [Abstract]
Schedule of Inventories	Inventories, net are comprised of the following: June 26, 2021 December 26, 2020 Materials $ 128,389 $ 124,926 Work-in-process 54,706 44,829 Finished goods 23,886 21,462 Total inventories, net $ 206,981 $ 191,217
Schedule of Property, Plant and Equipment, Net	Property, plant and equipment, net is comprised of the following: June 26, 2021 December 26, 2020 Machinery and equipment $ 57,061 $ 52,833 Land and building 48,188 47,544 Computer equipment and software 15,651 15,549 Leasehold improvements 13,759 12,927 Furniture and fixtures 3,985 4,013 138,644 132,866 Accumulated depreciation and amortization (50,629 ) (44,916 ) Total property, plant and equipment, net $ 88,015 $ 87,950
Schedule of Other Assets	Other assets is comprised of the following: June 26, 2021 December 26, 2020 Operating lease right-of-use assets $ 20,449 $ 19,669 Other 4,360 1,668 Total other assets $ 24,809 $ 21,337
Schedule of Accrued Liabilities	Accrued liabilities is comprised of the following: June 26, 2021 December 26, 2020 Payroll and related expenses $ 32,026 $ 30,270 Warranty 7,611 6,062 Other 1,320 743 Total accrued liabilities $ 40,957 $ 37,075
Schedule of Other Current Liabilities	Other current liabilities is comprised of the following: June 26, 2021 December 26, 2020 Customer deposits $ 10,949 $ 15,177 Current operating lease obligations 5,121 4,470 Income tax payable 1,076 4,109 Accrued professional fees 1,259 1,184 Other 5,931 3,559 Total other current liabilities $ 24,336 $ 28,499
Schedule of Other Non-Current Liabilities	Other non-current liabilities is comprised of the following: June 26, 2021 December 26, 2020 Non-current operating lease obligations $ 16,365 $ 16,455 Unrecognized tax benefits (including interest) 2,765 3,812 Deferred revenue 1,716 1,292 Other 7,049 6,153 Total other non-current liabilities $ 27,895 $ 27,712

Commitments and Contingencies (

Commitments and Contingencies (Tables)	6 Months Ended
	Jun. 26, 2021
Commitments And Contingencies Disclosure [Abstract]
Schedule of Changes in Warranty Reserves	Changes in the Company’s warranty reserves are as follows: Six Months Ended June 26, June 27, 2021 2020 Balance, beginning of the period $ 6,485 $ 6,348 Accruals 3,560 2,794 Warranty liability assumed in acquisition 407 — Usage (2,229 ) (2,327 ) Balance, end of the period $ 8,223 $ 6,815

Revenue (Tables)

Revenue (Tables)	6 Months Ended
	Jun. 26, 2021
Revenue From Contract With Customer [Abstract]
Schedule of Disaggregation of Revenue	The following table represents a disaggregation of revenue by timing of revenue: Three Months Ended Six Months Ended June 26, June 27, June 26, June 27, 2021 2020 2021 2020 Point-in-time $ 182,133 $ 131,796 $ 343,294 $ 265,541 Over-time 11,254 3,152 19,372 9,335 Total revenue $ 193,387 $ 134,948 $ 362,666 $ 274,876
Schedule of Changes in Deferred Revenue	Changes in deferred revenue were as follows: Three Months Ended Six Months Ended June 26, June 27, June 26, June 27, 2021 2020 2021 2020 Balance, beginning of the period $ 22,429 $ 18,032 $ 15,626 $ 15,093 Deferred revenue assumed in acquisition — — 386 — Deferral of revenue 15,117 8,818 34,348 23,252 Recognition of deferred revenue (14,640 ) (8,956 ) (27,454 ) (20,451 ) Balance, end of the period $ 22,906 $ 17,894 $ 22,906 $ 17,894

Share-Based Compensation - (Tab

Share-Based Compensation - (Tables)	6 Months Ended
	Jun. 26, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Restricted Stock Unit Activity	A summary of the Company’s restricted stock unit activity with respect to the six months ended June 26, 2021 is as follows: Number of Shares Weighted Average Grant Date Fair Value Nonvested at December 26, 2020 964 $ 31.37 Granted 285 $ 69.47 Vested (404 ) $ 30.74 Forfeited (46 ) $ 37.61 Nonvested at June 26, 2021 799 $ 45.67

Other Expense, Net (Tables)

Other Expense, Net (Tables)	6 Months Ended
	Jun. 26, 2021
Other Income Expense [Abstract]
Schedule of Other Expense, Net	Other expense, net, is comprised of the following: Three Months Ended Six Months Ended June 26, June 27, June 26, June 27, 2021 2020 2021 2020 Foreign currency exchange losses, net $ (328 ) $ (1,271 ) $ (1,599 ) $ (1,305 ) Other 39 73 66 139 Total other expense, net $ (289 ) $ (1,198 ) $ (1,533 ) $ (1,166 )

Income Taxes - (Tables)

Income Taxes - (Tables)	6 Months Ended
	Jun. 26, 2021
Income Tax Disclosure [Abstract]
Details of Income Tax	The following table provides details of income taxes: Three Months Ended Six Months Ended June 26, June 27, June 26, June 27, 2021 2020 2021 2020 Income before income taxes $ 35,956 $ 7,418 $ 62,558 $ 3,414 Provision (benefit) for income taxes $ 905 $ (6 ) $ 3,394 $ 394 Effective tax rate 3 % 0 % 5 % 12 %

Earnings Per Share (Tables)

Earnings Per Share (Tables)	6 Months Ended
	Jun. 26, 2021
Earnings Per Share [Abstract]
Schedule of Basic and Diluted Earnings Per Share	The Company’s basic and diluted earnings per share amounts are as follows: Three Months Ended Six Months Ended June 26, June 27, June 26, June 27, 2021 2020 2021 2020 Numerator: Net income $ 35,051 $ 7,424 $ 59,164 $ 3,020 Denominator: Basic earnings per share - weighted average shares outstanding 49,193 48,736 49,105 49,417 Effect of potential dilutive securities: Employee stock options, employee stock purchase grants and restricted stock units - dilutive shares 508 278 540 365 Diluted earnings per share - weighted average shares outstanding 49,701 49,014 49,645 49,782 Earnings per share: Basic $ 0.71 $ 0.15 $ 1.20 $ 0.06 Diluted $ 0.71 $ 0.15 $ 1.19 $ 0.06

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Tables)	6 Months Ended
	Jun. 26, 2021
Accumulated Other Comprehensive Income Loss Net Of Tax [Abstract]
Components of Accumulated Other Comprehensive Income, Net of Tax	The components of accumulated other comprehensive income, net of tax, at June 26, 2021, as well as the activity for the six months ended June 26, 2021, were as follows: Foreign currency translation adjustments Net unrealized gains (losses) on available-for-sale marketable securities Accumulated other comprehensive income Balance at December 26, 2020 $ 4,479 $ 89 $ 4,568 Net current period other comprehensive loss (1,362 ) (698 ) (2,060 ) Reclassifications — — — Balance at June 26, 2021 $ 3,117 $ (609 ) $ 2,508

Segment Reporting and Geograp_2

Segment Reporting and Geographic Information - (Tables)	6 Months Ended
	Jun. 26, 2021
Segment Reporting [Abstract]
Schedule of Revenue from External Customers by Products and Services	The following table lists the different sources of revenue: Three Months Ended Six Months Ended June 26, June 27, June 26, June 27, 2021 2020 2021 2020 Systems and software $ 162,898 84 % $ 108,247 80 % $ 304,407 84 % $ 222,577 81 % Parts 18,697 10 % 16,329 12 % 36,115 10 % 29,904 11 % Services 11,792 6 % 10,372 8 % 22,144 6 % 22,395 8 % Total revenue $ 193,387 100 % $ 134,948 100 % $ 362,666 100 % $ 274,876 100 %
Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area	For geographical revenue reporting, revenue is attributed to the geographic location to which the product is shipped. Revenue by geographic region is as follows: Three Months Ended Six Months Ended June 26, June 27, June 26, June 27, 2021 2020 2021 2020 Revenue from third parties: South Korea $ 41,299 $ 22,964 $ 91,828 $ 43,721 Taiwan 48,501 31,997 84,793 67,178 China 42,274 27,001 68,053 58,384 United States 25,700 22,378 51,180 42,026 Europe 14,446 10,089 31,832 25,158 Japan 17,386 13,908 25,251 28,935 Southeast Asia 3,781 6,611 9,729 9,474 Total revenue $ 193,387 $ 134,948 $ 362,666 $ 274,876
Schedule of Revenue by Major Customer by Reporting Segments	The following customers accounted for 10% or more of total revenue for the indicated periods: Six Months Ended June 26, June 27, 2021 2020 Samsung Semiconductor 22 % 18 % Taiwan Semiconductor Manufacturing Co. Ltd. 16 % 17 %

Share Repurchase Authorization

Share Repurchase Authorization (Tables)	6 Months Ended
	Jun. 26, 2021
Share Repurchase Program [Abstract]
Summary of Share Repurchases	The following table summarizes the Company’s share repurchases for the periods indicated: Three Months Ended Six Months Ended June 26, June 27, June 26, June 27, 2021 2020 2021 2020 Shares of common stock repurchased — 632 — 1,882 Cost of shares repurchased $ — $ 18,385 $ — $ 52,000 Average price paid per share $ — $ 29.08 $ — $ 27.62

Business Combination - Textual

Business Combination - Textual (Details) - Inspectrology, LLC [Member] - USD ($) $ in Thousands	Dec. 31, 2020	Jun. 26, 2021
Business Acquisition [Line Items]
Business acquisition, date of acquisition	Dec. 31, 2020
Business acquisition, cash consideration	$ 27,015
Business combination potential earnout payment	$ 10,000
Minimum [Member]
Business Acquisition [Line Items]
Business combination potential earnout subject to principal remaining period		1 year
Maximum [Member]
Business Acquisition [Line Items]
Business combination potential earnout subject to principal remaining period		3 years

Business Combination - Summary

Business Combination - Summary of Preliminary Fair Values of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Jun. 26, 2021	Mar. 27, 2021	Dec. 31, 2020	Dec. 26, 2020
Business Acquisition [Line Items]
Goodwill	$ 313,891	$ 313,891		$ 306,632
Inspectrology, LLC [Member]
Business Acquisition [Line Items]
Cash and cash equivalents			$ 220
Account receivables			4,071
Inventories			2,587
Prepaid expenses and other current assets			104
Property, plant and equipment			86
Identifiable intangible assets			12,210
Other assets			3,000
Total assets acquired			22,278
Accounts payable			(1,048)
Payroll and related expenses			(512)
Deferred revenue			(386)
Other current liabilities			(576)
Net assets acquired			19,756
Goodwill			7,259
Total purchase consideration			$ 27,015

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Carried at Fair Value Measured on a Recurring Basis (Details) - USD ($) $ in Thousands	Jun. 26, 2021	Dec. 26, 2020
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale debt securities	$ 276,621	$ 237,002
Carrying Value [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Foreign currency forward contracts	27
Total assets	276,648	237,002
Foreign currency forward contracts		36
Total liabilities		36
Carrying Value [Member] | Fair Value, Measurements, Recurring [Member] | Municipal notes and bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale debt securities	142,931	124,640
Carrying Value [Member] | Fair Value, Measurements, Recurring [Member] | Asset-backed securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale debt securities	4,094	11,708
Carrying Value [Member] | Fair Value, Measurements, Recurring [Member] | Certificates of deposits [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale debt securities	44,021	36,373
Carrying Value [Member] | Fair Value, Measurements, Recurring [Member] | Commercial paper [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale debt securities	50,979	32,699
Carrying Value [Member] | Fair Value, Measurements, Recurring [Member] | Corporate bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale debt securities	34,596	31,582
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Foreign currency forward contracts	0
Total assets	0	0
Foreign currency forward contracts		0
Total liabilities		0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fair Value, Measurements, Recurring [Member] | Municipal notes and bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale debt securities	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fair Value, Measurements, Recurring [Member] | Asset-backed securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale debt securities	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fair Value, Measurements, Recurring [Member] | Certificates of deposits [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale debt securities	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fair Value, Measurements, Recurring [Member] | Commercial paper [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale debt securities	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fair Value, Measurements, Recurring [Member] | Corporate bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale debt securities	0	0
Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Foreign currency forward contracts	27
Total assets	276,648	237,002
Foreign currency forward contracts		36
Total liabilities		36
Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member] | Municipal notes and bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale debt securities	142,931	124,640
Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member] | Asset-backed securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale debt securities	4,094	11,708
Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member] | Certificates of deposits [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale debt securities	44,021	36,373
Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member] | Commercial paper [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale debt securities	50,979	32,699
Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member] | Corporate bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale debt securities	34,596	31,582
Significant Unobservable Inputs (Level 3) [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Foreign currency forward contracts	0
Total assets	0	0
Foreign currency forward contracts		0
Total liabilities		0
Significant Unobservable Inputs (Level 3) [Member] | Fair Value, Measurements, Recurring [Member] | Municipal notes and bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale debt securities	0	0
Significant Unobservable Inputs (Level 3) [Member] | Fair Value, Measurements, Recurring [Member] | Asset-backed securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale debt securities	0	0
Significant Unobservable Inputs (Level 3) [Member] | Fair Value, Measurements, Recurring [Member] | Certificates of deposits [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale debt securities	0	0
Significant Unobservable Inputs (Level 3) [Member] | Fair Value, Measurements, Recurring [Member] | Commercial paper [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale debt securities	0	0
Significant Unobservable Inputs (Level 3) [Member] | Fair Value, Measurements, Recurring [Member] | Corporate bonds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Available-for-sale debt securities	$ 0	$ 0

Marketable Securities - Schedul

Marketable Securities - Schedule of Marketable Securities by Category (Details) - USD ($) $ in Thousands	Jun. 26, 2021	Dec. 26, 2020
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 276,526	$ 236,649
Gross Unrealized Holding Gains	176	372
Gross Unrealized Holding Losses	81	19
Fair Value	276,621	237,002
Municipal notes and bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	142,821	124,387
Gross Unrealized Holding Gains	128	257
Gross Unrealized Holding Losses	19	4
Fair Value	142,930	124,640
Asset-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	4,090	11,679
Gross Unrealized Holding Gains	4	29
Gross Unrealized Holding Losses	0	0
Fair Value	4,094	11,708
Certificates of deposits [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	44,003	36,349
Gross Unrealized Holding Gains	19	24
Gross Unrealized Holding Losses	1	0
Fair Value	44,021	36,373
Commercial paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	50,961	32,690
Gross Unrealized Holding Gains	19	12
Gross Unrealized Holding Losses	0	3
Fair Value	50,980	32,699
Corporate bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	34,651	31,544
Gross Unrealized Holding Gains	6	50
Gross Unrealized Holding Losses	61	12
Fair Value	$ 34,596	$ 31,582

Marketable Securities - Sched_2

Marketable Securities - Schedule of Amortized Cost and Estimated Fair Value of Marketable Securities Classified by Maturity Date (Details) - USD ($) $ in Thousands	Jun. 26, 2021	Dec. 26, 2020
Available For Sale Securities Debt Maturities Fair Value [Abstract]
Amortized Cost, Due within one year	$ 195,632	$ 170,099
Amortized Cost, Due after one through five years	80,894	66,550
Amortized Cost, Due after five through ten years	0	0
Amortized Cost, Due after ten years	0	0
Amortized Cost	276,526	236,649
Fair Value, Due within one year	195,733	170,321
Fair Value, Due after one through five years	80,888	66,681
Fair Value, Due after five through ten years	0	0
Fair Value, Due after ten years	0	0
Fair Value, Total marketable securities	$ 276,621	$ 237,002

Marketable Securities - Summary

Marketable Securities - Summary of Estimated Fair Value and Gross Unrealized Holding Losses of Marketable Securities in Unrealized Loss Position (Details) - USD ($) $ in Thousands	Jun. 26, 2021	Dec. 26, 2020
Schedule of Available-for-sale Securities [Line Items]
In Unrealized Loss Position For Less Than 12 Months, Fair Value	$ 59,714	$ 32,450
In Unrealized Loss Position For Less Than 12 Months, Gross Unrealized Losses	81	19
In Unrealized Loss Position For Greater Than 12 Months, Fair Value	0	0
In Unrealized Loss Position For Greater Than 12 Months, Gross Unrealized Losses	0	0
Municipal notes and bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
In Unrealized Loss Position For Less Than 12 Months, Fair Value	30,626	8,641
In Unrealized Loss Position For Less Than 12 Months, Gross Unrealized Losses	19	4
In Unrealized Loss Position For Greater Than 12 Months, Fair Value	0	0
In Unrealized Loss Position For Greater Than 12 Months, Gross Unrealized Losses	0	0
Certificates of deposits [Member]
Schedule of Available-for-sale Securities [Line Items]
In Unrealized Loss Position For Less Than 12 Months, Fair Value	4,603
In Unrealized Loss Position For Less Than 12 Months, Gross Unrealized Losses	1
In Unrealized Loss Position For Greater Than 12 Months, Fair Value	0
In Unrealized Loss Position For Greater Than 12 Months, Gross Unrealized Losses	0
Commercial paper [Member]
Schedule of Available-for-sale Securities [Line Items]
In Unrealized Loss Position For Less Than 12 Months, Fair Value		8,862
In Unrealized Loss Position For Less Than 12 Months, Gross Unrealized Losses		3
In Unrealized Loss Position For Greater Than 12 Months, Fair Value		0
In Unrealized Loss Position For Greater Than 12 Months, Gross Unrealized Losses		0
Corporate bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
In Unrealized Loss Position For Less Than 12 Months, Fair Value	24,485	14,947
In Unrealized Loss Position For Less Than 12 Months, Gross Unrealized Losses	61	12
In Unrealized Loss Position For Greater Than 12 Months, Fair Value	0	0
In Unrealized Loss Position For Greater Than 12 Months, Gross Unrealized Losses	$ 0	$ 0

Derivative Instruments and He_3

Derivative Instruments and Hedging Activities - Forward Contracts and Related Fair Values (Details) - USD ($) $ in Thousands	Jun. 26, 2021	Dec. 26, 2020
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Notional amount	$ 11,397	$ 37,580
Fair value of asset (liability)	$ 27	$ (36)

Goodwill and Purchased Intang_3

Goodwill and Purchased Intangible Assets - Changes in the Carrying Amount of Goodwill (Details) $ in Thousands	6 Months Ended
	Jun. 26, 2021USD ($)
Goodwill Roll Forward
Beginning balance	$ 306,632
Goodwill acquired during the period (Note 2)	7,259
Ending balance	$ 313,891

Goodwill and Purchased Intang_4

Goodwill and Purchased Intangible Assets - Schedule of Purchased Intangible Assets (Details) - USD ($) $ in Thousands	Jun. 26, 2021	Dec. 26, 2020
Finite Lived Intangible Assets [Line Items]
Finite-lived intangibles assets, Gross Carrying Amount	$ 420,809	$ 408,599
Finite-lived intangibles assets, Accumulated Amortization	161,523	136,842
Finite-lived intangibles assets, Net	259,286	271,757
Identifiable intangibles assets, Gross Carrying Amount	467,409	455,199
Identifiable intangibles assets, Accumulated Amortization	161,523	136,842
Identifiable intangibles assets, Net	305,886	318,357
Developed technology [Member]
Finite Lived Intangible Assets [Line Items]
Finite-lived intangibles assets, Gross Carrying Amount	331,747	326,877
Finite-lived intangibles assets, Accumulated Amortization	132,270	110,851
Finite-lived intangibles assets, Net	199,477	216,026
Customer and distributor relationships [Member]
Finite Lived Intangible Assets [Line Items]
Finite-lived intangibles assets, Gross Carrying Amount	74,701	69,261
Finite-lived intangibles assets, Accumulated Amortization	23,267	20,654
Finite-lived intangibles assets, Net	51,434	48,607
Trademarks and trade names [Member]
Finite Lived Intangible Assets [Line Items]
Finite-lived intangibles assets, Gross Carrying Amount	14,361	12,461
Finite-lived intangibles assets, Accumulated Amortization	5,986	5,337
Finite-lived intangibles assets, Net	8,375	7,124
In-process research and development [Member]
Finite Lived Intangible Assets [Line Items]
Identifiable intangibles assets, Gross Carrying Amount	46,600	46,600
Identifiable intangibles assets, Net	$ 46,600	$ 46,600

Goodwill and Purchased Intang_5

Goodwill and Purchased Intangible Assets - Schedule of Estimated Future Amortization Expenses (Details) - USD ($) $ in Thousands	Jun. 26, 2021	Dec. 26, 2020
Finite Lived Intangible Assets Future Amortization Expense [Abstract]
2021 (remainder)	$ 24,548
2022	48,830
2023	48,355
2024	42,669
2025	26,119
2026	24,926
Thereafter	43,839
Finite-lived intangibles assets, Net	$ 259,286	$ 271,757

Balance Sheet Details - Schedul

Balance Sheet Details - Schedule of Inventories (Details) - USD ($) $ in Thousands	Jun. 26, 2021	Dec. 26, 2020
Inventory Details [Abstract]
Materials	$ 128,389	$ 124,926
Work-in-process	54,706	44,829
Finished goods	23,886	21,462
Total inventories, net	$ 206,981	$ 191,217

Balance Sheet Details - Sched_2

Balance Sheet Details - Schedule of Property, Plant and Equipment, Net (Details) - USD ($) $ in Thousands	Jun. 26, 2021	Dec. 26, 2020
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	$ 138,644	$ 132,866
Accumulated depreciation and amortization	(50,629)	(44,916)
Total property, plant and equipment, net	88,015	87,950
Land and building [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	48,188	47,544
Machinery and equipment [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	57,061	52,833
Furniture and fixtures [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	3,985	4,013
Computer equipment and software [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	15,651	15,549
Leasehold improvements [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	$ 13,759	$ 12,927

Balance Sheet Details - Sched_3

Balance Sheet Details - Schedule of Other Assets (Details) - USD ($) $ in Thousands	Jun. 26, 2021	Dec. 26, 2020
Other Assets [Abstract]
Operating lease right-of-use assets	$ 20,449	$ 19,669
Other	4,360	1,668
Total other assets	$ 24,809	$ 21,337

Balance Sheet Details - Sched_4

Balance Sheet Details - Schedule of Accrued Liabilities (Details) - USD ($) $ in Thousands	Jun. 26, 2021	Dec. 26, 2020
Accrued Liabilities Current [Abstract]
Payroll and related expenses	$ 32,026	$ 30,270
Warranty	7,611	6,062
Other	1,320	743
Total accrued liabilities	$ 40,957	$ 37,075

Balance Sheet Details - Sched_5

Balance Sheet Details - Schedule of Other Current Liabilities (Details) - USD ($) $ in Thousands	Jun. 26, 2021	Dec. 26, 2020
Other Liabilities Current [Abstract]
Customer deposits	$ 10,949	$ 15,177
Current operating lease obligations	$ 5,121	$ 4,470
Operating Lease Liability Current Statement Of Financial Position [Extensible List]	onto:OperatingLeaseLiabilityCurrentMember	onto:OperatingLeaseLiabilityCurrentMember
Income tax payable	$ 1,076	$ 4,109
Accrued professional fees	1,259	1,184
Other	5,931	3,559
Total other current liabilities	$ 24,336	$ 28,499

Balance Sheet Details - Sched_6

Balance Sheet Details - Schedule of Other Non-Current Liabilities (Details) - USD ($) $ in Thousands	Jun. 26, 2021	Dec. 26, 2020
Other Liabilities Noncurrent [Abstract]
Non-current operating lease obligations	$ 16,365	$ 16,455
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	onto:OperatingLeaseLiabilityNonCurrentMember	onto:OperatingLeaseLiabilityNonCurrentMember
Unrecognized tax benefits (including interest)	$ 2,765	$ 3,812
Deferred revenue	1,716	1,292
Other	7,049	6,153
Total other non-current liabilities	$ 27,895	$ 27,712

Commitments and Contingencies -

Commitments and Contingencies - Textual (Details)	6 Months Ended
	Jun. 26, 2021USD ($)
Commitments And Contingencies [Line Items]
Sold receivables amount	$ 6,226,000
Due from unrelated third parties	0
Liabilities recorded for obligations	$ 0
Percentage of maximum borrowing capacity of value of eligible securities	70.00%
Available line of credit	$ 99,400,000
Available interest rate on line of credit	1.80%
Minimum [Member]
Commitments And Contingencies [Line Items]
Warranty period	12 months
Maximum [Member]
Commitments And Contingencies [Line Items]
Warranty period	14 months

Commitments and Contingencies_2

Commitments and Contingencies - Schedule of Changes in Warranty Reserves (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 26, 2021	Jun. 27, 2020
Commitments And Contingencies Disclosure [Abstract]
Balance, beginning of the period	$ 6,485	$ 6,348
Accruals	3,560	2,794
Warranty liability assumed in acquisition	407
Usage	(2,229)	(2,327)
Balance, end of the period	$ 8,223	$ 6,815

Revenue - Schedule of Disaggreg

Revenue - Schedule of Disaggregation of Revenue by Timing of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 26, 2021	Jun. 27, 2020	Jun. 26, 2021	Jun. 27, 2020
Disaggregation Of Revenue [Line Items]
Total revenue	$ 193,387	$ 134,948	$ 362,666	$ 274,876
Transferred at Point in Time [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	182,133	131,796	343,294	265,541
Transferred over Time [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	$ 11,254	$ 3,152	$ 19,372	$ 9,335

Revenue - Schedule of Changes i

Revenue - Schedule of Changes in Deferred Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 26, 2021	Jun. 27, 2020	Jun. 26, 2021	Jun. 27, 2020
Deferred Revenue Disclosure [Abstract]
Balance, beginning of the period	$ 22,429	$ 18,032	$ 15,626	$ 15,093
Deferred revenue assumed in acquisition			386
Deferral of revenue	15,117	8,818	34,348	23,252
Recognition of deferred revenue	(14,640)	(8,956)	(27,454)	(20,451)
Balance, end of the period	$ 22,906	$ 17,894	$ 22,906	$ 17,894

Share-Based Compensation - Summ

Share-Based Compensation - Summary of Restricted Stock Unit Activity (Details) - Restricted Stock Units (RSUs) [Member]	6 Months Ended
	Jun. 26, 2021$ / sharesshares
Activity for RSUs [Roll Forward]
Number of Shares, Beginning balance (in shares) | shares	964,000
Number of Shares, Granted (in shares) | shares	285,000
Number of Shares, Vested (in shares) | shares	(404,000)
Number of Shares, Forfeited (in shares) | shares	(46,000)
Number of Shares, Ending balance (in shares) | shares	799,000
Weighted Average Grant Date Fair Value for RSUs [Roll Forward]
Weighted Average Grant Date Fair Value, Beginning balance (in dollars per share) | $ / shares	$ 31.37
Weighted Average Grant Date Fair Value, Granted (in dollars per share) | $ / shares	69.47
Weighted Average Grant Date Fair Value, Vested (in dollars per share) | $ / shares	30.74
Weighted Average Grant Date Fair Value, Forfeited (in dollars per share) | $ / shares	37.61
Weighted Average Grant Date Fair Value, Ending balance (in dollars per share) | $ / shares	$ 45.67

Share-Based Compensation - Text

Share-Based Compensation - Textual (Details) - Restricted Stock Units (RSUs) [Member] - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 26, 2021	Dec. 26, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total unrecognized compensation cost related to restricted stock units granted	$ 27,391	$ 19,135
Unrecognized compensation cost related to restricted stock units, weighted average period	1 year 9 months 18 days	1 year 8 months 12 days

Other Expense, Net - Schedule o

Other Expense, Net - Schedule of Other Expense, Net (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 26, 2021	Jun. 27, 2020	Jun. 26, 2021	Jun. 27, 2020
Other Income Expense [Abstract]
Foreign currency exchange losses, net	$ (328)	$ (1,271)	$ (1,599)	$ (1,305)
Other	39	73	66	139
Total other expense, net	$ (289)	$ (1,198)	$ (1,533)	$ (1,166)

Income Taxes - Details of Incom

Income Taxes - Details of Income Tax (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 26, 2021	Jun. 27, 2020	Jun. 26, 2021	Jun. 27, 2020
Income Tax Disclosure [Abstract]
Income before income taxes	$ 35,956	$ 7,418	$ 62,558	$ 3,414
Provision (benefit) for income taxes	$ 905	$ (6)	$ 3,394	$ 394
Effective tax rate	3.00%	0.00%	5.00%	12.00%

Income Taxes - Textual (Details

Income Taxes - Textual (Details) - USD ($) $ in Thousands	Jun. 26, 2021	Dec. 26, 2020
Income Tax Disclosure [Abstract]
Deferred tax assets, valuation allowance	$ 14,254	$ 14,238

Earnings Per Share - Schedule o

Earnings Per Share - Schedule of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 26, 2021	Mar. 27, 2021	Jun. 27, 2020	Mar. 28, 2020	Jun. 26, 2021	Jun. 27, 2020
Earnings Per Share [Abstract]
Net income	$ 35,051	$ 24,113	$ 7,424	$ (4,404)	$ 59,164	$ 3,020
Basic earnings per share - weighted average shares outstanding	49,193		48,736		49,105	49,417
Employee stock options, employee stock purchase grants and restricted stock units - dilutive shares	508		278		540	365
Diluted earnings per share - weighted average shares outstanding	49,701		49,014		49,645	49,782
Earnings per share:
Basic	$ 0.71		$ 0.15		$ 1.20	$ 0.06
Diluted	$ 0.71		$ 0.15		$ 1.19	$ 0.06

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income - Components of Accumulated Other Comprehensive Income, Net of Tax (Details) $ in Thousands	6 Months Ended
	Jun. 26, 2021USD ($)
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	$ 1,264,746
Balance	1,329,563
Accumulated Foreign Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	4,479
Net current period other comprehensive loss	(1,362)
Reclassifications	0
Balance	3,117
Accumulated Net Unrealized Gains (Losses) on Available-for-sale Marketable Securities [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	89
Net current period other comprehensive loss	(698)
Reclassifications	0
Balance	(609)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	4,568
Net current period other comprehensive loss	(2,060)
Reclassifications	0
Balance	$ 2,508

Segment Reporting and Geograp_3

Segment Reporting and Geographic Information - Additional Information (Details)	6 Months Ended
	Jun. 26, 2021Segment
Segment Reporting [Abstract]
Number of reportable segments	1

Segment Reporting and Geograp_4

Segment Reporting and Geographic Information - Schedule of Revenue from External Customers by Products and Services (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 26, 2021	Jun. 27, 2020	Jun. 26, 2021	Jun. 27, 2020
Segment Reporting Information [Line Items]
Total revenue	$ 193,387	$ 134,948	$ 362,666	$ 274,876
Sales [Member] | Product [Member]
Segment Reporting Information [Line Items]
Concentration risk, percentage	100.00%	100.00%	100.00%	100.00%
Systems and Software [Member]
Segment Reporting Information [Line Items]
Total revenue	$ 162,898	$ 108,247	$ 304,407	$ 222,577
Systems and Software [Member] | Sales [Member] | Product [Member]
Segment Reporting Information [Line Items]
Concentration risk, percentage	84.00%	80.00%	84.00%	81.00%
Parts Revenue [Member]
Segment Reporting Information [Line Items]
Total revenue	$ 18,697	$ 16,329	$ 36,115	$ 29,904
Parts Revenue [Member] | Sales [Member] | Product [Member]
Segment Reporting Information [Line Items]
Concentration risk, percentage	10.00%	12.00%	10.00%	11.00%
Service Revenue [Member]
Segment Reporting Information [Line Items]
Total revenue	$ 11,792	$ 10,372	$ 22,144	$ 22,395
Service Revenue [Member] | Sales [Member] | Product [Member]
Segment Reporting Information [Line Items]
Concentration risk, percentage	6.00%	8.00%	6.00%	8.00%

Segment Reporting and Geograp_5

Segment Reporting and Geographic Information - Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 26, 2021	Jun. 27, 2020	Jun. 26, 2021	Jun. 27, 2020
Segment Reporting Information [Line Items]
Total revenue	$ 193,387	$ 134,948	$ 362,666	$ 274,876
South Korea [Member]
Segment Reporting Information [Line Items]
Total revenue	41,299	22,964	91,828	43,721
Taiwan [Member]
Segment Reporting Information [Line Items]
Total revenue	48,501	31,997	84,793	67,178
China [Member]
Segment Reporting Information [Line Items]
Total revenue	42,274	27,001	68,053	58,384
United States [Member]
Segment Reporting Information [Line Items]
Total revenue	25,700	22,378	51,180	42,026
Europe [Member]
Segment Reporting Information [Line Items]
Total revenue	14,446	10,089	31,832	25,158
Japan [Member]
Segment Reporting Information [Line Items]
Total revenue	17,386	13,908	25,251	28,935
Southeast Asia [Member]
Segment Reporting Information [Line Items]
Total revenue	$ 3,781	$ 6,611	$ 9,729	$ 9,474

Segment Reporting and Geograp_6

Segment Reporting and Geographic Information - Schedule of Revenue by Major Customer by Reporting Segments (Details) - Customer Concentration Risk [Member] - Sales [Member]	6 Months Ended
	Jun. 26, 2021	Jun. 27, 2020
Samsung Semiconductor [Member]
Concentration Risk [Line Items]
Customer concentration risk percentage	22.00%	18.00%
Taiwan Semiconductor Manufacturing Co. Ltd. [Member]
Concentration Risk [Line Items]
Customer concentration risk percentage	16.00%	17.00%

Share Repurchase Authorizatio_2

Share Repurchase Authorization - Textual (Details) - USD ($)	Jun. 26, 2021	Nov. 30, 2020
Shares Repurchase Authorization [Line Items]
Amount available for future repurchase	$ 100,000,000
Maximum [Member]
Shares Repurchase Authorization [Line Items]
Stock repurchase, authorized amount		$ 100,000,000

Share Repurchase Authorizatio_3

Share Repurchase Authorization - Summary of Share Repurchases (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 27, 2020	Jun. 27, 2020
Disclosure Share Repurchase Authorization Summary Of Stock Repurchases Details [Abstract]
Shares of common stock repurchased	632,000	1,882,000
Cost of shares repurchased	$ 18,385	$ 52,000
Average price paid per share	$ 29.08	$ 27.62