Axcelis (ACLS) 10-Q 2 May 24 2024 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2024	Apr. 30, 2024
Document and Entity Information
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Mar. 31, 2024
Entity File Number	000-30941
Entity Registrant Name	AXCELIS TECHNOLOGIES INC
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	34-1818596
Entity Address, Address Line One	108 Cherry Hill Drive
Entity Address, City or Town	Beverly
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	01915
City Area Code	978
Local Phone Number	787-4000
Title of 12(b) Security	Common Stock, $0.001 par value
Trading Symbol	ACLS
Security Exchange Name	NASDAQ
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
Entity Common Stock, Shares Outstanding		32,532,498
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q1
Entity Central Index Key	0001113232
Amendment Flag	false

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Revenue:
Total revenue	$ 252,372	$ 254,020
Cost of revenue:
Total cost of revenue	136,321	150,001
Gross profit	116,051	104,019
Operating expenses:
Research and development	25,662	23,773
Sales and marketing	17,445	14,144
General and administrative	16,405	14,745
Total operating expenses	59,512	52,662
Income from operations	56,539	51,357
Other income (expense):
Interest income	5,516	3,936
Interest expense	(1,346)	(1,353)
Other, net	(1,710)	(1,038)
Total other income	2,460	1,545
Income before income taxes	58,999	52,902
Income tax provision	7,404	5,205
Net income	$ 51,595	$ 47,697
Net income per share:
Basic	$ 1.58	$ 1.46
Diluted	$ 1.57	$ 1.43
Shares used in computing net income per share:
Basic weighted average shares of common stock	32,638	32,744
Diluted weighted average shares of common stock	32,926	33,293
Product
Revenue:
Total revenue	$ 243,418	$ 246,007
Cost of revenue:
Total cost of revenue	127,912	142,771
Services
Revenue:
Total revenue	8,954	8,013
Cost of revenue:
Total cost of revenue	$ 8,409	$ 7,230

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Consolidated Statements of Comprehensive Income
Net income	$ 51,595	$ 47,697
Other comprehensive (loss) / income:
Foreign currency translation adjustments	(1,731)	50
Amortization of actuarial net gain and other adjustments from pension plan, net of tax	5
Total other comprehensive (loss) / income	(1,726)	50
Comprehensive income	$ 49,869	$ 47,747

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 133,963	$ 167,297
Short-term investments	396,228	338,851
Accounts receivable, net	208,544	217,964
Inventories, net	312,170	306,482
Prepaid expenses and other current assets	54,544	49,397
Total current assets	1,105,449	1,079,991
Property, plant and equipment, net	53,032	53,971
Operating lease assets	29,557	30,716
Finance lease assets, net	16,310	16,632
Long-term restricted cash	6,652	6,654
Deferred income taxes	54,525	53,428
Other assets	41,094	40,575
Total assets	1,306,619	1,281,967
Current liabilities:
Accounts payable	39,853	54,400
Accrued compensation	16,413	31,445
Warranty	14,355	14,098
Income taxes	26,850	6,164
Deferred revenue	164,700	164,677
Current portion of finance lease obligation	1,503	1,511
Other current liabilities	12,894	12,834
Total current liabilities	276,568	285,129
Long-term finance lease obligation	43,328	43,674
Long-term deferred revenue	43,718	46,208
Other long-term liabilities	41,262	42,074
Total liabilities	404,876	417,085
Commitments and contingencies (Note 17)
Stockholders' equity:
Common stock, $0.001 par value, 75,000 shares authorized; 32,605 shares issued and outstanding at March 31, 2024; 32,685 shares issued and outstanding at December 31, 2023	33	33
Additional paid-in capital	546,979	547,189
Retained earnings	358,303	319,506
Accumulated other comprehensive loss	(3,572)	(1,846)
Total stockholders' equity	901,743	864,882
Total liabilities and stockholders' equity	$ 1,306,619	$ 1,281,967

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares shares in Thousands	Mar. 31, 2024	Dec. 31, 2023
Consolidated Balance Sheets
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	75,000	75,000
Common stock, shares issued	32,605	32,685
Common stock, shares outstanding	32,605	32,685

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)	Total
Balance (in shares) at Dec. 31, 2022	32,775
Balance at Dec. 31, 2022	$ 33	$ 550,299	$ 118,892	$ (1,968)	$ 667,256
Increase (Decrease) in Stockholders' Equity
Net income			47,697		47,697
Foreign currency translation adjustments				50	50
Exercise of stock options (in shares)	2
Exercise of stock options		25			25
Issuance of common stock on restricted stock units, net of shares withheld (in shares)	56
Issuance of common stock on restricted stock units, net of shares withheld		(3,907)			(3,907)
Stock-based compensation expense		3,199			3,199
Repurchase of common stock (in shares)	(107)
Repurchase of common stock		(1,924)	(10,575)		(12,499)
Balance (in shares) at Mar. 31, 2023	32,726
Balance at Mar. 31, 2023	$ 33	547,692	156,014	(1,918)	701,821
Balance (in shares) at Dec. 31, 2023	32,685
Balance at Dec. 31, 2023	$ 33	547,189	319,506	(1,846)	864,882
Increase (Decrease) in Stockholders' Equity
Net income			51,595		51,595
Foreign currency translation adjustments				(1,731)	(1,731)
Change in pension obligation, net of tax				5	5
Issuance of common stock on restricted stock units, net of shares withheld (in shares)	42
Issuance of common stock on restricted stock units, net of shares withheld		(2,699)			(2,699)
Stock-based compensation expense		4,690			4,690
Repurchase of common stock (in shares)	(122)
Repurchase of common stock		(2,201)	(12,798)		(14,999)
Balance (in shares) at Mar. 31, 2024	32,605
Balance at Mar. 31, 2024	$ 33	$ 546,979	$ 358,303	$ (3,572)	$ 901,743

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Cash flows from operating activities
Net income	$ 51,595	$ 47,697
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	3,775	3,100
Deferred income taxes	(1,097)	(3,621)
Stock-based compensation expense	4,690	3,199
Provision for doubtful accounts	(459)
Provision for excess and obsolete inventory	1,445	1,069
Accretion of discounts and premiums on marketable securities	(3,306)	(2,840)
Currency loss on foreign denominated transactions	6,560	1,343
Changes in operating assets and liabilities:
Accounts receivable	7,042	(20,762)
Inventories	(11,427)	(21,105)
Prepaid expenses and other current assets	(5,489)	(4,794)
Accounts payable and other current liabilities	(29,118)	(22,976)
Deferred revenue	(1,963)	47,160
Income taxes	21,374	8,891
Other assets and liabilities	(1,399)	(1,802)
Net cash provided by operating activities	42,223	34,559
Cash flows from investing activities
Expenditures for property, plant and equipment and capitalized software	(1,620)	(2,240)
Purchase of short-term investments	(145,121)	(61,809)
Maturities of short-term investments	91,050	31,000
Net cash used in investing activities	(55,691)	(33,049)
Cash flows from financing activities
Net settlement on restricted stock grants	(2,699)	(3,907)
Repurchase of common stock	(14,999)	(12,499)
Principal payments on finance lease obligation	(357)	(289)
Proceeds from exercise of stock options		25
Net cash used in financing activities	(18,055)	(16,670)
Effect of exchange rate changes on cash and cash equivalents	(1,813)	(55)
Net decrease in cash, cash equivalents and restricted cash	(33,336)	(15,215)
Cash, cash equivalents and restricted cash at beginning of period	173,951	186,347
Cash, cash equivalents and restricted cash at end of period	$ 140,615	$ 171,132

Nature of Business

Nature of Business	3 Months Ended
	Mar. 31, 2024
Nature of Business
Nature of Business	Note 1. Nature of Business ​ Axcelis Technologies, Inc. (“Axcelis” or the “Company”) was incorporated in Delaware in 1995 and is a producer of ion implantation equipment used in the fabrication of semiconductor chips in the United States, Europe and Asia. In addition, we provide extensive worldwide aftermarket service and support, including spare parts, equipment upgrades, used equipment and maintenance services to the semiconductor industry. ​ The accompanying unaudited consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by generally accepted accounting principles for complete financial statements. In the opinion of management, all adjustments which are of a normal recurring nature and considered necessary for a fair presentation of these financial statements have been included. Operating results for the interim periods presented are not necessarily indicative of the results that may be expected for other interim periods or for the year as a whole. ​ The balance sheet at December 31, 2023 has been derived from the audited consolidated financial statements at that date but does not include all the information and footnotes required by generally accepted accounting principles for complete financial statements. As of March 31, 2024, there have been no material changes in the Company’s significant accounting policies, other than with respect to the Company’s accounting policy for derivative financial instruments, which it had not held in prior periods, as described in Note 2 below. For further information, refer to the consolidated financial statements and footnotes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2023, filed with the Securities and Exchange Commission (the “SEC”) on February 23, 2024, as amended by Amendment No. 1 thereto, filed with the SEC on February 28, 2024 (as so amended, the “2023 Form 10-K”).

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2024
Summary of Significant Accounting Policies
Summary of Significant Accounting Policies	Note 2. Significant Accounting Policies ​ Derivative instruments ​ ​ We do not offset fair value amounts of derivative instruments. We do not use derivative instruments for speculative purposes.

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2024
Stock Award Plans and Stock Based Compensation
Stock-Based Compensation	Note 3. Stock-Based Compensation ​ We maintain the Axcelis Technologies, Inc. 2012 Equity Incentive Plan, as amended (the “2012 Equity Plan”), which became effective on May 2, 2012, and permits the issuance of options, restricted stock, restricted stock units (“RSUs”) and performance awards to selected employees, directors and consultants of the Company. ​ The 2012 Equity Plan is more fully described in Note 13 to the consolidated financial statements in our 2023 Form 10-K. ​ We recognized stock-based compensation expense of $4.7 million and $3.2 million for the three-month periods ended March 31, 2024 and 2023, respectively. These amounts include compensation expense related to RSUs and non-qualified stock options. ​ In the three-month period ended March 31, 2024, we issued 41,941 shares of common stock upon vesting of RSUs. In the three-month period ended March 31, 2023, we issued 57,604 shares of common stock upon vesting of RSUs and stock option exercises. In the three-month period ended March 31, 2024, we received no proceeds in connection with the exercise of stock options. In the three-month period ended March 31, 2023, we received proceeds of $25.0 thousand in connection with the exercise of stock options.

Leases

Leases	3 Months Ended
	Mar. 31, 2024
Leases
Leases	Note 4. Leases ​ We have operating leases for manufacturing, office space, warehouse space, computer and office equipment and vehicles used in our business operations. We have a finance lease in relation to the 2015 sale-leaseback of our corporate headquarters in Beverly, Massachusetts. We review all agreements to determine if the agreement contains a lease component. An agreement contains a lease component if it provides for the use of a specific physical space or a specific physical item. ​ We recognize operating lease obligations under Accounting Standards Codification Topic 842, Leases options to renew one ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ ​ ​ Leases Classification ​ 2024 2023 ​ Assets ​ ​ (in thousands) ​ ​ Operating leases Operating lease assets ​ $ 29,557 ​ $ 30,716 ​ ​ ​ Finance lease Finance lease assets* ​ 16,310 ​ 16,632 ​ ​ ​ Total leased assets ​ ​ $ 45,867 ​ $ 47,348 ​ ​ ​ Liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Current ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating Other current liabilities ​ $ 4,645 ​ $ 4,978 ​ ​ ​ Finance Current portion of finance lease obligation ​ ​ 1,503 ​ ​ 1,511 ​ ​ ​ Non-current ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating Other long-term liabilities ​ ​ 24,963 ​ ​ 25,724 ​ ​ ​ Finance Finance lease obligation ​ 43,328 ​ 43,674 ​ ​ ​ Total lease liabilities ​ ​ $ 74,439 ​ $ 75,887 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ *Finance lease assets are recorded net of accumulated depreciation of $46.7 million and include $0.6 million of prepaid financing costs as of March 31, 2024. Finance lease assets are recorded net of accumulated depreciation of $46.4 million and include $0.6 million of prepaid financing costs as of December 31, 2023. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ ​ ​ ​ March 31, ​ ​ Lease cost Classification ​ 2024 2023 ​ Operating lease cost ​ ​ (in thousands) ​ Product / services* Cost of revenue ​ $ 1,828 ​ $ 1,466 ​ ​ Research and development Operating expenses ​ 123 ​ 106 ​ ​ Sales and marketing* Operating expenses ​ 451 ​ 396 ​ ​ General and administrative* Operating expenses ​ 194 ​ 276 ​ ​ Total operating lease cost ​ ​ $ 2,596 ​ $ 2,244 ​ ​ Finance lease cost ​ ​ ​ ​ ​ ​ ​ ​ ​ Depreciation of leased assets Cost of revenue, Research and development, Sales and marketing and General and administrative ​ $ 319 ​ $ 319 ​ ​ Interest on lease liabilities Interest expense ​ 1,197 ​ 1,231 ​ ​ Total finance lease cost ​ ​ $ 1,516 ​ $ 1,550 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total lease cost ​ ​ $ 4,112 ​ $ 3,794 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ * Product / services, sales and marketing and general and administrative expense also includes short-term lease and variable lease costs of approximately $0.6 million and $0.5 million for the three months ended March 31, 2024 and 2023, respectively. ​ ​ ​ ​ one ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Finance ​ Operating Total Maturity of Lease Liabilities ​ Leases ​ Leases ​ Leases ​ ​ ​ (in thousands) ​ 2024 ​ $ 4,698 ​ $ 4,979 ​ $ 9,677 ​ 2025 ​ 5,930 ​ 3,484 ​ 9,414 ​ 2026 ​ 6,008 ​ 2,443 ​ 8,451 ​ 2027 ​ 6,128 ​ 1,915 ​ 8,043 ​ 2028 ​ ​ 6,251 ​ ​ 22,730 ​ ​ 28,981 ​ Thereafter ​ ​ 55,336 ​ ​ 42,139 ​ ​ 97,475 ​ Total lease payments ​ $ 84,351 ​ $ 77,690 ​ $ 162,041 ​ Less interest portion* ​ ​ (39,520) ​ ​ (48,082) ​ ​ (87,602) ​ Finance lease and operating lease obligations ​ $ 44,831 ​ $ 29,608 ​ $ 74,439 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ * Finance lease interest calculated using the implied interest rate; operating lease interest calculated using estimated corporate borrowing rate. ​ ​ The table above does not include options to renew lease terms that are not reasonably certain of being exercised. ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ Lease term and discount rate 2024 ​ Weighted-average remaining lease term (years): ​ ​ ​ ​ Operating leases ​ ​ 11.5 ​ Finance leases ​ 12.8 ​ Weighted-average discount rate: ​ ​ ​ ​ Operating leases ​ 5.5% ​ Finance leases ​ 10.5% ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended March 31, Cash paid for amounts included in the measurement of lease liabilities 2024 2023 ​ ​ (in thousands) Operating cash outflows from operating leases ​ $ 2,596 ​ $ 2,244 Operating cash outflows from finance leases ​ 1,197 ​ 1,231 Financing cash outflows from finance leases ​ 357 ​ 289 Operating lease assets obtained in exchange for operating lease liabilities ​ 632 ​ 757 Finance lease assets obtained in exchange for new finance lease liabilities ​ — ​ — ​ ​ ​ ​ ​ ​ ​ ​

Revenue

Revenue	3 Months Ended
	Mar. 31, 2024
Revenue
Revenue	Note 5. Revenue ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ ​ ​ March 31, ​ ​ ​ 2024 ​ 2023 ​ ​ ​ (in thousands) ​ Systems ​ $ 195,432 ​ $ 195,198 ​ Aftermarket ​ ​ 56,940 ​ ​ 58,822 ​ Total Revenue ​ $ 252,372 ​ $ 254,020 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ ​ ​ March 31, ​ ​ ​ 2024 ​ 2023 ​ ​ ​ (in thousands) ​ North America ​ $ 45,503 ​ $ 45,166 ​ Asia Pacific ​ ​ 188,217 ​ ​ 191,103 ​ Europe ​ ​ 18,652 ​ ​ 17,751 ​ Total Revenue ​ $ 252,372 ​ $ 254,020 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ ​ 2024 ​ 2023 ​ ​ (in thousands) Contract liabilities ​ $ 208,418 ​ $ 210,885 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ ​ ​ March 31, ​ ​ 2024 ​ 2023 ​ ​ ​ (in thousands) ​ Balance, beginning of the period ​ $ 210,885 ​ $ 154,777 ​ Deferral of revenue ​ ​ 42,974 ​ ​ 88,048 ​ Recognition of deferred revenue ​ ​ (45,441) ​ ​ (41,100) ​ Balance, end of the period ​ $ 208,418 ​ $ 201,725 ​ ​

Accounts Receivable and Allowan

Accounts Receivable and Allowance for Credit Losses	3 Months Ended
	Mar. 31, 2024
Receivables and Allowances for Credit Losses
Receivables and Allowances for Credit Losses	Note 6. Receivables and Allowances for Credit Losses ​ All trade receivables are reported on the consolidated balance sheets at their amortized cost adjusted for any write-offs and net of allowances for credit losses. ​ We maintain an allowance for credit losses, which represents an estimate of expected losses over the remaining contractual life of our receivables, considering current market conditions and estimates for supportable forecasts when appropriate. The estimate is a result of our ongoing assessments and evaluations of collectability, historical loss experience, and future expectations in estimating credit losses in our receivable portfolio. We use historical loss experience rates and apply them to a related aging analysis while also considering customer and/or economic risk where appropriate. Determination of the proper amount of allowances requires management to exercise judgment about the timing, frequency and severity of credit losses that could materially affect the provision for credit losses and, as a result, net earnings. The allowance takes into consideration numerous quantitative and qualitative factors that include receivable type, historical loss experience, loss migration, delinquency trends, collection experience, current economic conditions, trade restrictions, estimates for supportable forecasts, when appropriate, and credit risk characteristics. ​ We evaluate the credit risk of the customer when extending credit based on a combination of financial and qualitative factors that may affect our customers’ ability to pay. These factors may include the customer’s financial condition, past payment experience, and credit bureau report, as well as the value of the underlying collateral. ​ Management performs detailed reviews of our receivables on a quarterly basis to assess the adequacy of the allowances and to determine if any impairment has occurred. Amounts determined to be uncollectable are charged directly against the allowances, while amounts recovered on previously written-off accounts increase the allowances. Changes to the allowances for credit losses are maintained through adjustments to the provision for credit losses, which are charged to current period earnings. We recorded $0.5 million of recovery of bad debt expense for the three-month period ended March 31, 2024. We did not have any allowance or incur any credit losses or recoveries for the three-month period ended March 31, 2023. As of both March 31, 2024 and 2023, we had no provision for credit losses. ​ ​

Computation of Net Earnings per

Computation of Net Earnings per Share	3 Months Ended
	Mar. 31, 2024
Computation of Net Earnings per Share
Computation of Net Earnings per Share	Note 7. Computation of Net Earnings per Share ​ Basic earnings per share is computed by dividing income available to common stockholders (the numerator) by the weighted-average number of shares of common stock outstanding (the denominator) for the period. The computation of diluted earnings per share is similar to basic earnings per share, except that the denominator is increased by the number of additional shares of common stock that would have been outstanding if the potentially dilutive shares of common stock issuable on exercise of stock options and vesting of RSUs had been issued, calculated using the treasury stock method. ​ The components of net earnings per share are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ ​ ​ March 31, ​ ​ 2024 2023 ​ ​ ​ ​ ​ ​ ​ ​ Net income available to common stockholders ​ $ 51,595 ​ $ 47,697 ​ Weighted average shares of common stock outstanding used in computing basic income per share ​ 32,638 ​ 32,744 ​ Incremental options and RSUs ​ 288 ​ 549 ​ Weighted average shares of common stock used in computing diluted net income per share ​ 32,926 ​ 33,293 ​ Net income per share ​ ​ ​ ​ ​ ​ ​ Basic ​ $ 1.58 ​ $ 1.46 ​ Diluted ​ $ 1.57 ​ $ 1.43 ​ ​ ​ Diluted weighted average shares of common stock outstanding does not include 19,548 and 1,120 common equivalent shares issuable with respect to outstanding equity awards for the three-month periods ended March 31, 2024 and 2023, respectively, as their effect would have been anti-dilutive.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss	3 Months Ended
	Mar. 31, 2024
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Loss	Note 8. Accumulated Other Comprehensive Loss ​ The following table presents the changes in accumulated other comprehensive loss, net of tax, by component, for the three months ended March 31, 2024: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Foreign Defined benefit ​ ​ ​ ​ currency ​ pension plan ​ Total ​ ​ (in thousands) Balance at December 31, 2023 ​ $ (1,956) ​ $ 110 ​ $ (1,846) ​ Other comprehensive loss and pension reclassification ​ (1,731) ​ 5 ​ (1,726) ​ Balance at March 31, 2024 ​ $ (3,687) ​ $ 115 ​ $ (3,572) ​ ​

Cash, cash equivalents and rest

Cash, cash equivalents and restricted cash	3 Months Ended
	Mar. 31, 2024
Cash, cash equivalents and restricted cash
Cash, cash equivalents and restricted cash	Note 9. Cash, cash equivalents and restricted cash ​ The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the consolidated balance sheets to the total of the amounts shown in the statement of cash flows: ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ ​ 2024 ​ ​ 2023 ​ ​ (in thousands) ​ Cash and cash equivalents $ 133,963 ​ $ 167,297 ​ Long-term restricted cash ​ 6,652 ​ ​ 6,654 ​ Total cash, cash equivalents and restricted cash $ 140,615 ​ $ 173,951 ​ ​ As of March 31, 2024, we had $6.7 million in restricted cash representing the total of (i) a $5.9 million cash collateral relating to our lease for our headquarters in Beverly, Massachusetts, (ii) a $0.7 million letter of credit relating to workers’ compensation insurance and (iii) a $0.1 million deposit relating to customs activity. See Note 13 for further discussion on the $5.9 million cash collateral.

Inventories, net

Inventories, net	3 Months Ended
	Mar. 31, 2024
Inventories, net
Inventories, net	Note 10. Inventories, net ​ The components of inventories are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ ​ 2024 2023 ​ ​ (in thousands) ​ Raw materials ​ $ 236,480 ​ $ 231,200 ​ Work in process ​ 47,455 ​ 45,373 ​ Finished goods (completed systems) ​ 28,235 ​ 29,909 ​ Inventories, net ​ $ 312,170 ​ $ 306,482 ​ ​ When recorded, inventory reserves reduce the carrying value of inventories to their net realizable value. We establish inventory reserves when conditions exist that indicate inventory may be in excess of anticipated demand or is obsolete based upon assumptions about future demand for our products or market conditions. We regularly evaluate the ability to realize the value of inventories based on a combination of factors including the following: forecasted sales or usage, estimated product end of life dates, estimated current and future market value and new product introductions. Purchasing and usage alternatives are also explored to mitigate inventory exposure.

Product Warranty

Product Warranty	3 Months Ended
	Mar. 31, 2024
Product Warranty
Product Warranty	Note 11. Product Warranty ​ We generally offer a one-year warranty for all of our systems, the terms and conditions of which vary depending upon the product sold. For all systems sold, we accrue a liability for the estimated cost of standard warranty at the time of system shipment and, if applicable, defer the portion of systems revenue attributable to non-standard warranty. Costs for non-standard warranty are expensed as incurred. Factors that affect our warranty liability include the number of installed units, historical and anticipated product failure rates, material usage and service labor costs. We periodically assess the adequacy of our recorded liability and adjust the amount as necessary. ​ The changes in our standard product warranty liability are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ ​ ​ March 31, ​ ​ 2024 2023 ​ ​ (in thousands) ​ Balance at January 1 (beginning of year) ​ $ 16,757 ​ $ 10,487 ​ Warranties issued during the period ​ 2,809 ​ 2,629 ​ Settlements made during the period ​ (3,022) ​ (2,587) ​ Changes in estimate of liability for pre-existing warranties during the period ​ 88 ​ 865 ​ Balance at March 31 (end of period) ​ $ 16,632 ​ $ 11,394 ​ ​ ​ ​ ​ ​ ​ ​ ​ Amount classified as current ​ $ 14,355 ​ $ 9,599 ​ Amount classified as long-term (within other long-term liabilities) ​ 2,277 ​ 1,795 ​ Total warranty liability ​ $ 16,632 ​ $ 11,394 ​ ​

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2024
Fair Value Measurements
Fair Value Measurements	Note 12. Fair Value Measurements ​ Fair value is defined as the price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. ​ (a) Fair Value Hierarchy ​ The accounting guidance for fair value measurement requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The standard establishes a fair value hierarchy based on the level of independent, objective evidence surrounding the inputs used to measure fair value. A financial instrument’s categorization within the fair value hierarchy is based upon the lowest level of input that is significant to the fair value measurement. The fair value hierarchy is as follows: ​ Level 1 ​ Level 2 ​ Level 3 ​ (b) Fair Value Measurements ​ Our money market funds and short-term investments with initial maturities of three months or less are included in cash and cash equivalents in the consolidated balance sheets. Other investments that have a maturity of greater than three months but less than one year are included within short-term investments in the consolidated balance sheets. ​ The following table sets forth our assets by level within the fair value hierarchy: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2024 ​ ​ Fair Value Measurements ​ Level 1 Level 2 Level 3 Total ​ ​ (in thousands) Assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash equivalents and other short-term investments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash equivalents (money market funds, U.S. Government Securities and Agency Investments) ​ $ 74,229 ​ $ — ​ $ — ​ $ 74,229 ​ Short-term investments (U.S. Government Securities and Agency Investments) ​ ​ 396,154 ​ ​ — ​ ​ — ​ ​ 396,154 ​ Mark-to-market adjustment on forward exchange contracts ​ ​ — ​ ​ 18 ​ ​ — ​ ​ 18 ​ Total ​ $ 470,383 ​ $ 18 ​ $ — ​ $ 470,401 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2023 ​ ​ Fair Value Measurements ​ Level 1 Level 2 Level 3 Total ​ ​ (in thousands) Assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash equivalents and other short-term investments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash equivalents (money market funds, U.S. Government Securities and Agency Investments) ​ $ 118,278 ​ $ — ​ $ — ​ $ 118,278 ​ Short-term investments (U.S. Government Securities and Agency Investments) ​ ​ 339,240 ​ ​ — ​ ​ — ​ ​ 339,240 ​ Total ​ $ 457,518 ​ $ — ​ $ — ​ $ 457,518 ​ ​ (c) Other Financial Instruments ​ The carrying amounts reflected in the consolidated balance sheets for accounts receivable, prepaid expenses, forward currency exchange contracts and other current assets and non-current assets, restricted cash, accounts payable and accrued expenses approximate fair value due to their short-term maturities. ​ (d) Forward Currency Exchange Contracts ​ Beginning in February 2024, we entered into forward currency exchange contracts to minimize the impact of foreign currency fluctuations on our earnings and cash flows. These contracts have month-to-month settlement dates. Any gains or losses on these contracts are reported within Other, net within our Consolidated Statement of Operations. Any open contracts at period end that have settlement dates within one month after the reported period end and any mark-to-market valuation adjustments related to these open contracts are recorded within the current asset or current liability account and any unrealized gain or loss recognized is recorded within Other, net within our Consolidated Statement of Operations. These contracts are measured at fair value using observable market inputs such as forward currency exchange rates and our counterparties’ credit risks. Based on these inputs, the derivative instruments are classified within Level 2 of the valuation hierarchy. At March 31, 2024, the recognized unrealized gain on these forward exchange contracts was approximately $18 thousand and is included in other current assets within our Consolidated Balance Sheets. Based on our continued ability to trade and enter into forward contracts, we consider the markets for our fair value instruments to be active. We evaluated the credit risk associated with the counterparties to these derivative instruments and determined that as of March 31, 2024, such credit risks have not had an adverse impact on the fair value of these instruments.

Financing Arrangements

Financing Arrangements	3 Months Ended
	Mar. 31, 2024
Financing Arrangements
Financing Arrangements	Note 13. Financing Arrangements ​ On January 30, 2015, we sold our corporate headquarters facility in Beverly, Massachusetts for $48.9 million. As part of the sale, we also entered into a 22-year lease agreement of our headquarters facility. This sale-leaseback is accounted for as a financing lease under generally accepted accounting principles and, as such, we have recorded a financing obligation of $44.8 million as of March 31, 2024. The associated lease payments include both an interest component and payment of principal, with the remaining liability being extinguished at the end of the original lease term. As of March 31, 2024, we had a security deposit of $5.9 million related to this lease in the form of a cash collateralized letter of credit issued with UBS Bank USA, which is classified as long-term restricted cash on our balance sheet at March 31, 2024.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2024
Income Taxes
Income Taxes	Note 14. Income Taxes ​ Income tax expense was $7.4 million for the three months ended March 31, 2024, compared to $5.2 million for the three months ended March 31, 2023. The $2.2 million increase was primarily due to an increase in pre-tax income and a decrease in stock compensation deduction partially offset by the tax deduction related to foreign sales taxed at a lower rate. ​ The effective tax rate for the three months ended March 31, 2024 was less than the U.S. statutory rate of 21% due to a forecasted Foreign Derived Intangible Income deduction, Federal research and development tax credits and a favorable discrete item related to equity compensation that reduces the annual tax rate. ​ The deferred income taxes of $54.5 million and $53.4 million as of March 31, 2024 and December 31, 2023, respectively, reflect the net tax effect of temporary differences between the carrying amount of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes, as well as the tax effect of carryforwards. As of March 31, 2024, we have recorded a $10.8 million valuation allowance in the U.S. against certain tax credits and state net operating losses due to the uncertainty of their realization. Realization of our net deferred tax assets is dependent on future taxable income. We believe it is more likely than not that such assets will be realized; however, ultimate realization could be impacted by market conditions and other variables not known or anticipated at this time. ​

Concentration of Risk

Concentration of Risk	3 Months Ended
	Mar. 31, 2024
Concentration of Risk
Concentration of Risk	Note 15. Concentration of Risk ​ For the three months ended March 31, 2024, no individual customer accounted for greater than ten percent of total revenue. For the three months ended March 31, 2023, two customers accounted for 15.2% and 12.9% of total revenue, respectively. ​ At March 31, 2024, no individual customer accounted for greater than ten percent of accounts receivable. At December 31, 2023, one customer accounted for 12.2% of accounts receivable.

Share Repurchase

Share Repurchase	3 Months Ended
	Mar. 31, 2024
Stockholders' Equity
Share Repurchase	Note 16. Share Repurchase ​ In February 2022, our Board of Directors approved stock repurchases of up to $100 million of our common stock. In August 2023, our Board of Directors approved additional funding of $200 million for our stock repurchase program, to be available on full utilization of the $100 million repurchase funding approved in February 2022. During the three months ended March 31, 2024, we repurchased 0.1 million shares at an average cost of $122.99 per share. The timing and actual number of any additional shares to be repurchased under this program will depend on various factors including price, corporate and regulatory requirements, alternative investment opportunities and other market conditions. ​ Repurchased shares are accounted for when the transaction is settled and returned to the status of authorized but unissued shares. Accordingly, on our balance sheet, the repurchase price is deducted from common stock par value and from additional paid-in capital for the excess over par value. If additional paid-in capital has been exhausted, the excess over par value is deducted from retained earnings. Direct costs incurred to acquire the shares are included in the total cost of the shares.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2024
Commitments and Contingencies
Commitments and Contingencies	Note 17. Contingencies ​ (a) Litigation ​ We are from time to time a party to litigation that arises in the normal course of our business operations. We are not presently a party to any litigation that we believe might have a material adverse effect on our business operations. ​ (b) Indemnifications ​ Our system sales agreements typically include provisions under which we agree to take certain actions, provide certain remedies and defend our customers against third-party claims of intellectual property infringement under specified conditions and indemnify customers against any damage and costs awarded in connection with such claims. We have not incurred any material costs as a result of such indemnifications and have not accrued any liabilities related to such obligations in the accompanying consolidated financial statements. ​

Recent Accounting Guidance

Recent Accounting Guidance	3 Months Ended
	Mar. 31, 2024
Summary of Significant Accounting Policies
Recent Accounting Guidance	Note 18. Recent Accounting Guidance ​ In November 2023 the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures (“ASU 2023-07”). ASU 2023-07 is intended to enhance disclosures for significant segment expenses for all public entities required to report segment information in accordance with ASC Topic 280, Segment Reporting (“ASC 280”). ASC 280 requires a public entity to report for each reportable segment a measure of segment profit or loss that its chief operating decision maker (“CODM”) uses to assess segment performance and to make decisions about resource allocations. ASU 2023-07 is intended to improve financial reporting by requiring disclosure of incremental segment information on an annual and interim basis for all public entities to enable investors to develop more useful financial analyses. ASU 2023-07 is effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024. Early adoption is permitted. A public entity should apply ASU 2023-07 retrospectively to all prior periods presented in the consolidated financial statements. We are currently evaluating the impact of ASU 2023- on our future consolidated financial statements and related disclosures. ​ In December 2023 the FASB issued Accounting Standards Update 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures (“ASU 2023-09”). ASU 2023-09 is intended to enhance the transparency and decision usefulness of income tax disclosures. ASU 2023-09 addresses investor requests for enhanced income tax information primarily through changes to the rate reconciliation and income taxes paid information. Early adoption is permitted. A public entity should apply ASU 2023-09 prospectively to all annual periods beginning after December 15, 2024. We are currently evaluating the impact of ASU 2023-09 on our future consolidated financial statements and related disclosures.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2024
Summary of Significant Accounting Policies
Derivative instruments	Derivative instruments ​ ​ We do not offset fair value amounts of derivative instruments. We do not use derivative instruments for speculative purposes.

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2024
Leases
Schedule of operating and finance lease right-of-use assets and related lease obligations	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ ​ ​ Leases Classification ​ 2024 2023 ​ Assets ​ ​ (in thousands) ​ ​ Operating leases Operating lease assets ​ $ 29,557 ​ $ 30,716 ​ ​ ​ Finance lease Finance lease assets* ​ 16,310 ​ 16,632 ​ ​ ​ Total leased assets ​ ​ $ 45,867 ​ $ 47,348 ​ ​ ​ Liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Current ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating Other current liabilities ​ $ 4,645 ​ $ 4,978 ​ ​ ​ Finance Current portion of finance lease obligation ​ ​ 1,503 ​ ​ 1,511 ​ ​ ​ Non-current ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating Other long-term liabilities ​ ​ 24,963 ​ ​ 25,724 ​ ​ ​ Finance Finance lease obligation ​ 43,328 ​ 43,674 ​ ​ ​ Total lease liabilities ​ ​ $ 74,439 ​ $ 75,887 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ *Finance lease assets are recorded net of accumulated depreciation of $46.7 million and include $0.6 million of prepaid financing costs as of March 31, 2024. Finance lease assets are recorded net of accumulated depreciation of $46.4 million and include $0.6 million of prepaid financing costs as of December 31, 2023. ​ ​ ​
Schedule of lease costs	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ ​ ​ ​ March 31, ​ ​ Lease cost Classification ​ 2024 2023 ​ Operating lease cost ​ ​ (in thousands) ​ Product / services* Cost of revenue ​ $ 1,828 ​ $ 1,466 ​ ​ Research and development Operating expenses ​ 123 ​ 106 ​ ​ Sales and marketing* Operating expenses ​ 451 ​ 396 ​ ​ General and administrative* Operating expenses ​ 194 ​ 276 ​ ​ Total operating lease cost ​ ​ $ 2,596 ​ $ 2,244 ​ ​ Finance lease cost ​ ​ ​ ​ ​ ​ ​ ​ ​ Depreciation of leased assets Cost of revenue, Research and development, Sales and marketing and General and administrative ​ $ 319 ​ $ 319 ​ ​ Interest on lease liabilities Interest expense ​ 1,197 ​ 1,231 ​ ​ Total finance lease cost ​ ​ $ 1,516 ​ $ 1,550 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total lease cost ​ ​ $ 4,112 ​ $ 3,794 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ * Product / services, sales and marketing and general and administrative expense also includes short-term lease and variable lease costs of approximately $0.6 million and $0.5 million for the three months ended March 31, 2024 and 2023, respectively. ​ ​
Schedule of future minimum operating and finance leases	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Finance ​ Operating Total Maturity of Lease Liabilities ​ Leases ​ Leases ​ Leases ​ ​ ​ (in thousands) ​ 2024 ​ $ 4,698 ​ $ 4,979 ​ $ 9,677 ​ 2025 ​ 5,930 ​ 3,484 ​ 9,414 ​ 2026 ​ 6,008 ​ 2,443 ​ 8,451 ​ 2027 ​ 6,128 ​ 1,915 ​ 8,043 ​ 2028 ​ ​ 6,251 ​ ​ 22,730 ​ ​ 28,981 ​ Thereafter ​ ​ 55,336 ​ ​ 42,139 ​ ​ 97,475 ​ Total lease payments ​ $ 84,351 ​ $ 77,690 ​ $ 162,041 ​ Less interest portion* ​ ​ (39,520) ​ ​ (48,082) ​ ​ (87,602) ​ Finance lease and operating lease obligations ​ $ 44,831 ​ $ 29,608 ​ $ 74,439 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ * Finance lease interest calculated using the implied interest rate; operating lease interest calculated using estimated corporate borrowing rate. ​
Schedule of weighted-average remaining lease term and discount rates	​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ Lease term and discount rate 2024 ​ Weighted-average remaining lease term (years): ​ ​ ​ ​ Operating leases ​ ​ 11.5 ​ Finance leases ​ 12.8 ​ Weighted-average discount rate: ​ ​ ​ ​ Operating leases ​ 5.5% ​ Finance leases ​ 10.5% ​ ​ ​ ​ ​ ​
Schedule of cash outflows by lease type	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended March 31, Cash paid for amounts included in the measurement of lease liabilities 2024 2023 ​ ​ (in thousands) Operating cash outflows from operating leases ​ $ 2,596 ​ $ 2,244 Operating cash outflows from finance leases ​ 1,197 ​ 1,231 Financing cash outflows from finance leases ​ 357 ​ 289 Operating lease assets obtained in exchange for operating lease liabilities ​ 632 ​ 757 Finance lease assets obtained in exchange for new finance lease liabilities ​ — ​ — ​ ​ ​ ​ ​ ​ ​ ​

Revenue (Tables)

Revenue (Tables)	3 Months Ended
	Mar. 31, 2024
Revenue
Schedule of revenue by discipline	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ ​ ​ March 31, ​ ​ ​ 2024 ​ 2023 ​ ​ ​ (in thousands) ​ Systems ​ $ 195,432 ​ $ 195,198 ​ Aftermarket ​ ​ 56,940 ​ ​ 58,822 ​ Total Revenue ​ $ 252,372 ​ $ 254,020 ​
Schedule of revenue by geographic markets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ ​ ​ March 31, ​ ​ ​ 2024 ​ 2023 ​ ​ ​ (in thousands) ​ North America ​ $ 45,503 ​ $ 45,166 ​ Asia Pacific ​ ​ 188,217 ​ ​ 191,103 ​ Europe ​ ​ 18,652 ​ ​ 17,751 ​ Total Revenue ​ $ 252,372 ​ $ 254,020 ​
Schedule of Contract liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ ​ 2024 ​ 2023 ​ ​ (in thousands) Contract liabilities ​ $ 208,418 ​ $ 210,885 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ ​ ​ March 31, ​ ​ 2024 ​ 2023 ​ ​ ​ (in thousands) ​ Balance, beginning of the period ​ $ 210,885 ​ $ 154,777 ​ Deferral of revenue ​ ​ 42,974 ​ ​ 88,048 ​ Recognition of deferred revenue ​ ​ (45,441) ​ ​ (41,100) ​ Balance, end of the period ​ $ 208,418 ​ $ 201,725 ​

Computation of Net Earnings p_2

Computation of Net Earnings per Share (Tables)	3 Months Ended
	Mar. 31, 2024
Computation of Net Earnings per Share
Schedule of components of net income per share	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ ​ ​ March 31, ​ ​ 2024 2023 ​ ​ ​ ​ ​ ​ ​ ​ Net income available to common stockholders ​ $ 51,595 ​ $ 47,697 ​ Weighted average shares of common stock outstanding used in computing basic income per share ​ 32,638 ​ 32,744 ​ Incremental options and RSUs ​ 288 ​ 549 ​ Weighted average shares of common stock used in computing diluted net income per share ​ 32,926 ​ 33,293 ​ Net income per share ​ ​ ​ ​ ​ ​ ​ Basic ​ $ 1.58 ​ $ 1.46 ​ Diluted ​ $ 1.57 ​ $ 1.43 ​

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Loss (Tables)	3 Months Ended
	Mar. 31, 2024
Accumulated Other Comprehensive Loss
Schedule of changes in accumulated other comprehensive loss, net of tax	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Foreign Defined benefit ​ ​ ​ ​ currency ​ pension plan ​ Total ​ ​ (in thousands) Balance at December 31, 2023 ​ $ (1,956) ​ $ 110 ​ $ (1,846) ​ Other comprehensive loss and pension reclassification ​ (1,731) ​ 5 ​ (1,726) ​ Balance at March 31, 2024 ​ $ (3,687) ​ $ 115 ​ $ (3,572) ​ ​

Cash, cash equivalents and re_2

Cash, cash equivalents and restricted cash (Tables)	3 Months Ended
	Mar. 31, 2024
Cash, cash equivalents and restricted cash
Schedule of reconciliation of cash, cash equivalents and restricted cash	​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ ​ 2024 ​ ​ 2023 ​ ​ (in thousands) ​ Cash and cash equivalents $ 133,963 ​ $ 167,297 ​ Long-term restricted cash ​ 6,652 ​ ​ 6,654 ​ Total cash, cash equivalents and restricted cash $ 140,615 ​ $ 173,951 ​

Inventories, net (Tables)

Inventories, net (Tables)	3 Months Ended
	Mar. 31, 2024
Inventories, net
Schedule of components of inventories	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ ​ 2024 2023 ​ ​ (in thousands) ​ Raw materials ​ $ 236,480 ​ $ 231,200 ​ Work in process ​ 47,455 ​ 45,373 ​ Finished goods (completed systems) ​ 28,235 ​ 29,909 ​ Inventories, net ​ $ 312,170 ​ $ 306,482 ​

Product Warranty (Tables)

Product Warranty (Tables)	3 Months Ended
	Mar. 31, 2024
Product Warranty
Schedule of product warranty liability	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ ​ ​ March 31, ​ ​ 2024 2023 ​ ​ (in thousands) ​ Balance at January 1 (beginning of year) ​ $ 16,757 ​ $ 10,487 ​ Warranties issued during the period ​ 2,809 ​ 2,629 ​ Settlements made during the period ​ (3,022) ​ (2,587) ​ Changes in estimate of liability for pre-existing warranties during the period ​ 88 ​ 865 ​ Balance at March 31 (end of period) ​ $ 16,632 ​ $ 11,394 ​ ​ ​ ​ ​ ​ ​ ​ ​ Amount classified as current ​ $ 14,355 ​ $ 9,599 ​ Amount classified as long-term (within other long-term liabilities) ​ 2,277 ​ 1,795 ​ Total warranty liability ​ $ 16,632 ​ $ 11,394 ​ ​

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2024
Fair Value Measurements
Schedule of Company's assets and liabilities by level within the fair value hierarchy	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2024 ​ ​ Fair Value Measurements ​ Level 1 Level 2 Level 3 Total ​ ​ (in thousands) Assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash equivalents and other short-term investments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash equivalents (money market funds, U.S. Government Securities and Agency Investments) ​ $ 74,229 ​ $ — ​ $ — ​ $ 74,229 ​ Short-term investments (U.S. Government Securities and Agency Investments) ​ ​ 396,154 ​ ​ — ​ ​ — ​ ​ 396,154 ​ Mark-to-market adjustment on forward exchange contracts ​ ​ — ​ ​ 18 ​ ​ — ​ ​ 18 ​ Total ​ $ 470,383 ​ $ 18 ​ $ — ​ $ 470,401 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2023 ​ ​ Fair Value Measurements ​ Level 1 Level 2 Level 3 Total ​ ​ (in thousands) Assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash equivalents and other short-term investments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash equivalents (money market funds, U.S. Government Securities and Agency Investments) ​ $ 118,278 ​ $ — ​ $ — ​ $ 118,278 ​ Short-term investments (U.S. Government Securities and Agency Investments) ​ ​ 339,240 ​ ​ — ​ ​ — ​ ​ 339,240 ​ Total ​ $ 457,518 ​ $ — ​ $ — ​ $ 457,518 ​ ​

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2024 USD ($)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Foreign exchange gains (losses) realized	$ 1,500
Forward exchange contracts
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Notional value of open forward contracts	100,000
Forward exchange contracts | Other current assets
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Unrealized gain on forward exchange contracts	$ 18

Stock-Based Compensation (Detai

Stock-Based Compensation (Details) - USD ($)	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Stock-Based Compensation
Stock-based compensation expense	$ 4,700,000	$ 3,200,000
Proceeds from exercise of stock options		$ 25,000
Common Stock
Stock-Based Compensation
Exercise of stock options (in shares)		2,000
Common Stock | Employee Stock Purchase Plan
Stock-Based Compensation
Proceeds from exercise of stock options	$ 0	$ 25,000
Common Stock | Restricted Stock Units
Stock-Based Compensation
Exercise of stock options (in shares)	41,941
Common Stock | Stock Options and Restricted Stock Units
Stock-Based Compensation
Exercise of stock options (in shares)		57,604

Leases (Details)

Leases (Details)	3 Months Ended
	Mar. 31, 2024
Lease
Option to extend	true
Minimum
Lease
Renewal term	1 year
Maximum
Lease
Renewal term	3 years

Leases - Operating and Finance

Leases - Operating and Finance Lease Right-of-use-assets and Related Lease Obligations (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Leases
Operating lease assets	$ 29,557	$ 30,716
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Operating lease assets	Operating lease assets
Finance lease assets	$ 16,310	$ 16,632
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Finance lease assets	Finance lease assets
Total leased assets	$ 45,867	$ 47,348
Operating liabilities current	$ 4,645	$ 4,978
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Other Liabilities, Current	Other Liabilities, Current
Finance liabilities current	$ 1,503	$ 1,511
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	Finance liabilities current	Finance liabilities current
Operating liabilities noncurrent	$ 24,963	$ 25,724
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Other Liabilities, Noncurrent	Other Liabilities, Noncurrent
Finance liabilities noncurrent	$ 43,328	$ 43,674
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Finance liabilities noncurrent	Finance liabilities noncurrent
Total lease liabilities	$ 74,439	$ 75,887
Operating Lease, Liability, Statement of Financial Position [Extensible List]	Other Liabilities, Current, Other Liabilities, Noncurrent	Other Liabilities, Current, Other Liabilities, Noncurrent
Finance lease, accumulated depreciation	$ 46,700	$ 46,400
Prepaid financing costs	$ 600	$ 600

Leases - Lease Cost (Details)

Leases - Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Lease cost
Total operating lease cost	$ 2,596	$ 2,244
Depreciation of leased assets	319	319
Interest on lease liabilities	1,197	1,231
Total finance lease cost	1,516	1,550
Total lease cost	4,112	3,794
Short-term lease and variable lease costs	600	500
Product / services*
Lease cost
Total operating lease cost	1,828	1,466
Research and development
Lease cost
Total operating lease cost	123	106
Sales and marketing*
Lease cost
Total operating lease cost	451	396
General and administrative*
Lease cost
Total operating lease cost	$ 194	$ 276

Leases - Future Minimum Cash Ou

Leases - Future Minimum Cash Outflow and Weighted-average Remaining Lease Term and Discount Rate (Details) $ in Thousands	Mar. 31, 2024 USD ($) ft²	Dec. 31, 2023 USD ($)
Future minimum lease payments finance lease
2024	$ 4,698
2025	5,930
2026	6,008
2027	6,128
2028	6,251
Thereafter	55,336
Total lease payments	84,351
Less interest portion	(39,520)
Finance lease obligations	44,831
Future minimum lease payments operating lease
2024	4,979
2025	3,484
2026	2,443
2027	1,915
2028	22,730
Thereafter	42,139
Total lease payments	77,690
Less interest portion	(48,082)
Operating lease obligations	29,608
Future minimum lease payments finance and operating lease
2024	9,677
2025	9,414
2026	8,451
2027	8,043
2028	28,981
Thereafter	97,475
Total lease payments	162,041
Less interest portion	(87,602)
Total lease liabilities	74,439	$ 75,887
Lease term and discount rate
Right of use asset	29,557	30,716
Prepaid rent	600	600
Operating liabilities noncurrent	$ 24,963	$ 25,724
Finance lease term	22 years
Operating leases -Weighted-average remaining lease term (in years)	11 years 6 months
Finance leases - Weighted-average remaining lease term (in years)	12 years 9 months 18 days
Operating leases - Weighted-average discount rate	5.50%
Finance leases - Weighted-average discount rate	10.50%
Beverly Property Owner LLC
Lease term and discount rate
Area of Property | ft²	101,800
Minimum
Lease term and discount rate
Operating lease term	1 year
Maximum
Lease term and discount rate
Operating lease term	16 years

Leases - Cash Flow by Lease Typ

Leases - Cash Flow by Lease Type (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Leases
Operating cash outflows from operating leases	$ 2,596	$ 2,244
Operating cash outflows from finance leases	1,197	1,231
Financing cash outflows from finance leases	357	289
Operating lease assets obtained in exchange for operating lease liabilities	$ 632	$ 757

Revenue - Revenue by discipline

Revenue - Revenue by discipline & geographical areas (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Disaggregation of Revenue
Total Revenue	$ 252,372	$ 254,020
North America
Disaggregation of Revenue
Total Revenue	45,503	45,166
Asia Pacific
Disaggregation of Revenue
Total Revenue	188,217	191,103
Europe
Disaggregation of Revenue
Total Revenue	18,652	17,751
Systems
Disaggregation of Revenue
Total Revenue	195,432	195,198
Aftermarket
Disaggregation of Revenue
Total Revenue	$ 56,940	$ 58,822

Revenue - Contract liabilities

Revenue - Contract liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Revenue
Contract liabilities	$ 208,418	$ 210,885	$ 201,725	$ 154,777

Revenue - Deferred revenue (Det

Revenue - Deferred revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Revenue
Balance, beginning of the period	$ 210,885	$ 154,777
Deferral of revenue	42,974	88,048
Recognition of deferred revenue	(45,441)	(41,100)
Balance, end of the period	$ 208,418	$ 201,725

Revenue (Details)

Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Disaggregation of Revenue
Deferred revenue	$ 208,418	$ 210,885	$ 201,725	$ 154,777
Short-term deferred revenue	164,700	164,677
Long-term deferred revenue	$ 43,718	$ 46,208
Systems
Disaggregation of Revenue
Payment upon shipment of the system, as a percent	90%
Payment upon acceptance, as a percent	10%
Systems | Minimum
Disaggregation of Revenue
Pre-shipment deposit, as a percent	20%
Systems | Maximum
Disaggregation of Revenue
Pre-shipment deposit, as a percent	60%
Aftermarket | Minimum
Disaggregation of Revenue
Payment upon delivery of parts, period	30 days
Aftermarket | Maximum
Disaggregation of Revenue
Payment upon delivery of parts, period	60 days

Accounts Receivable and Allow_2

Accounts Receivable and Allowance for Credit Losses - Trade Receivables (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Receivables and Allowances for Credit Losses
Recoveries	$ 500	$ 0
Charge-offs	0	0
Provision for credit losses	$ 0	$ 0

Computation of Net Earnings p_3

Computation of Net Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Computation of Net Earnings per Share
Net income available to common stockholders	$ 51,595	$ 47,697
Weighted average shares of common stock outstanding used in computing basic income per share	32,638	32,744
Incremental options and RSUs	288	549
Weighted average shares of common stock used in computing diluted net income per share	32,926	33,293
Net income per share
Basic	$ 1.58	$ 1.46
Diluted	$ 1.57	$ 1.43
Anti-dilutive common equivalent shares excluded from calculation	19,548	1,120

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Loss (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2024 USD ($)
Changes in accumulated other comprehensive (loss) income, net of tax
Balance at beginning of period	$ (1,846)
Other comprehensive loss and pension reclassification	(1,726)
Balance at end of period	(3,572)
Foreign currency
Changes in accumulated other comprehensive (loss) income, net of tax
Balance at beginning of period	(1,956)
Other comprehensive loss and pension reclassification	(1,731)
Balance at end of period	(3,687)
Defined benefit pension plan
Changes in accumulated other comprehensive (loss) income, net of tax
Balance at beginning of period	110
Other comprehensive loss and pension reclassification	5
Balance at end of period	$ 115

Cash, cash equivalents and re_3

Cash, cash equivalents and restricted cash (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	$ 133,963	$ 167,297
Long-term Restricted Cash	6,652	6,654
Total cash, cash equivalents and restricted cash	140,615	$ 173,951	$ 171,132	$ 186,347
Security Deposit	5,900
Letter of credit related to workers' compensation insurance	700
Deposit related to customs activity	$ 100

Inventories, net (Details)

Inventories, net (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Inventories, net
Raw materials	$ 236,480	$ 231,200
Work in process	47,455	45,373
Finished goods (completed systems)	28,235	29,909
Inventories, net	$ 312,170	$ 306,482

Product Warranty (Details)

Product Warranty (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Product Warranty
Product warranty period	1 year
Changes in standard product warranty liability
Balance at beginning of year	$ 16,757	$ 10,487
Warranties issued during the period	2,809	2,629
Settlements made during the period	(3,022)	(2,587)
Changes in estimate of liability for pre-existing warranties during the period	88	865
Balance at end of period	16,632	11,394
Product warranty classification
Amount classified as current	14,355	9,599	$ 14,098
Amount classified as long-term (within other long-term liabilities)	2,277	1,795
Total warranty liability	$ 16,632	$ 11,394	$ 16,757

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Fair Value Measurements
Short-term investments (U.S. Government Securities and Agency Investments)	$ 396,228	$ 338,851
Forward exchange contracts | Other current assets
Fair Value Measurements
Mark-to-market adjustment on forward exchange contracts	18
Level 2 | Forward exchange contracts | Estimate of fair value measurement | Other current assets
Fair Value Measurements
Mark-to-market adjustment on forward exchange contracts	18
Recurring | Estimate of fair value measurement
Fair Value Measurements
Total	470,401
Recurring | Forward exchange contracts | Estimate of fair value measurement
Fair Value Measurements
Mark-to-market adjustment on forward exchange contracts	18
Recurring | Money market funds, U.S. Government Securities and Agency Investments | Estimate of fair value measurement
Fair Value Measurements
Cash equivalents (money market funds, U.S. Government Securities and Agency Investments)	74,229	118,278
Total		457,518
Recurring | U.S. Government Securities and Agency Investments | Estimate of fair value measurement
Fair Value Measurements
Short-term investments (U.S. Government Securities and Agency Investments)	396,154	339,240
Recurring | Level 1
Fair Value Measurements
Total	470,383
Recurring | Level 1 | Money market funds, U.S. Government Securities and Agency Investments
Fair Value Measurements
Cash equivalents (money market funds, U.S. Government Securities and Agency Investments)	74,229	118,278
Total		457,518
Recurring | Level 1 | U.S. Government Securities and Agency Investments
Fair Value Measurements
Short-term investments (U.S. Government Securities and Agency Investments)	396,154	$ 339,240
Recurring | Level 2
Fair Value Measurements
Total	18
Recurring | Level 2 | Forward exchange contracts
Fair Value Measurements
Mark-to-market adjustment on forward exchange contracts	$ 18

Financing Arrangements (Details

Financing Arrangements (Details) - USD ($) $ in Thousands	Jan. 30, 2015	Mar. 31, 2024	Dec. 31, 2023
Financing Arrangements
Long-term finance lease obligation		$ 43,328	$ 43,674
Security deposit		5,900
Building
Financing Arrangements
Proceeds from sale of corporate headquarters	$ 48,900
Lease term	22 years
Long-term finance lease obligation		44,800
UBS Bank USA
Financing Arrangements
Security deposit		$ 5,900

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Valuation allowance
Income tax expense	$ 7,404	$ 5,205
Increase (decrease) in income tax expense	2,200
Deferred tax assets, net	54,525		$ 53,428
Deferred tax assets valuation allowance	$ 10,800
Maximum
Valuation allowance
Statutory income tax rate (as a percent)	21%

Concentration of Risk (Details)

Concentration of Risk (Details) - customer	3 Months Ended		12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Total revenue | Customer concentration risk
Concentration of Risk
Number of customers	0	2
Total revenue | Customer concentration risk | First customer
Concentration of Risk
Percentage of concentration risk		15.20%
Total revenue | Customer concentration risk | Second customer
Concentration of Risk
Percentage of concentration risk		12.90%
Accounts receivable | Credit concentration risk
Concentration of Risk
Number of customers	0		1
Accounts receivable | Credit concentration risk | First customer
Concentration of Risk
Percentage of concentration risk			12.20%

Share Repurchase (Details)

Share Repurchase (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2024	Aug. 31, 2023	Feb. 28, 2022
Stockholders' Equity
Share repurchase program common stock authorized amount		$ 200	$ 100
Number of shares repurchased	0.1
Average cost	$ 122.99

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Mar. 31, 2024
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false