Axcelis (ACLS) 10-Q 2 Nov 23 2023 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2023	Oct. 31, 2023
Document and Entity Information
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Sep. 30, 2023
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		32,747,459
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q3
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		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Revenue:
Total revenue	$ 292,326	$ 229,175	$ 820,316	$ 653,947
Cost of revenue:
Total cost of revenue	162,642	125,854	466,911	361,678
Gross profit	129,684	103,321	353,405	292,269
Operating expenses:
Research and development	24,093	20,563	71,996	56,267
Sales and marketing	16,465	14,573	46,146	38,567
General and administrative	17,446	14,983	48,519	41,163
Total operating expenses	58,004	50,119	166,661	135,997
Income from operations	71,680	53,202	186,744	156,272
Other income (expense):
Interest income	4,580	1,111	12,824	1,558
Interest expense	(1,325)	(1,333)	(4,027)	(4,101)
Other, net	(1,260)	(7,971)	(4,348)	(14,640)
Total other income (expense)	1,995	(8,193)	4,449	(17,183)
Income before income taxes	73,675	45,009	191,193	139,089
Income tax provision	7,744	4,726	15,986	13,002
Net income	$ 65,931	$ 40,283	$ 175,207	$ 126,087
Net income per share:
Basic	$ 2.01	$ 1.22	$ 5.35	$ 3.81
Diluted	$ 1.99	$ 1.21	$ 5.28	$ 3.75
Shares used in computing net income per share:
Basic weighted average shares of common stock	32,807	33,011	32,775	33,116
Diluted weighted average shares of common stock	33,159	33,389	33,208	33,638
Product
Revenue:
Total revenue	$ 283,367	$ 221,540	$ 795,047	$ 631,998
Cost of revenue:
Total cost of revenue	154,798	118,992	444,311	342,387
Services
Revenue:
Total revenue	8,959	7,635	25,269	21,949
Cost of revenue:
Total cost of revenue	$ 7,844	$ 6,862	$ 22,600	$ 19,291

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Consolidated Statements of Comprehensive Income
Net income	$ 65,931	$ 40,283	$ 175,207	$ 126,087
Other comprehensive loss:
Foreign currency translation adjustments	(1,231)	(3,690)	(2,192)	(7,561)
Amortization of actuarial net gain and other adjustments from pension plan, net of tax		8		25
Total other comprehensive loss	(1,231)	(3,682)	(2,192)	(7,536)
Comprehensive income	$ 64,700	$ 36,601	$ 173,015	$ 118,551

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 142,300	$ 185,595
Short-term investments	318,710	246,571
Accounts receivable, net	192,327	169,773
Inventories, net	312,223	242,406
Prepaid expenses and other current assets	49,481	33,300
Total current assets	1,015,041	877,645
Property, plant and equipment, net	47,169	39,664
Operating lease assets	31,082	12,146
Finance lease assets, net	16,981	17,942
Long-term restricted cash	6,650	752
Deferred income taxes	44,323	31,701
Other assets	40,448	33,791
Total assets	1,201,694	1,013,641
Current liabilities:
Accounts payable	60,061	62,346
Accrued compensation	26,535	35,540
Warranty	11,464	8,299
Income taxes	582	4,304
Deferred revenue	148,299	123,471
Current portion of finance lease obligation	1,438	1,229
Other current liabilities	12,799	12,943
Total current liabilities	261,178	248,132
Long-term finance lease obligation	44,070	45,185
Long-term deferred revenue	53,730	31,306
Other long-term liabilities	41,745	21,762
Total liabilities	400,723	346,385
Commitments and contingencies (Note 16)
Stockholders' equity:
Common stock, $0.001 par value, 75,000 shares authorized; 32,772 shares issued and outstanding at September 30, 2023; 32,775 shares issued and outstanding at December 31, 2022	33	33
Additional paid-in capital	543,577	550,299
Retained earnings	261,521	118,892
Accumulated other comprehensive loss	(4,160)	(1,968)
Total stockholders' equity	800,971	667,256
Total liabilities and stockholders' equity	$ 1,201,694	$ 1,013,641

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares shares in Thousands	Sep. 30, 2023	Dec. 31, 2022
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	32,772	32,775
Common stock, shares outstanding	32,772	32,775

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, 2021	33,240
Balance at Dec. 31, 2021	$ 33	$ 559,883	$ (22,722)	$ 1,765	$ 538,959
Increase (Decrease) in Stockholders' Equity
Net income			41,614		41,614
Foreign currency translation adjustments				(1,186)	(1,186)
Change in pension obligation				9	9
Exercise of stock options (in shares)	41
Exercise of stock options		491			491
Issuance of common stock on restricted stock units, net of shares withheld (in shares)	67
Issuance of common stock on restricted stock units, net of shares withheld		(3,315)			(3,315)
Stock-based compensation expense		2,701			2,701
Repurchase of common stock (in shares)	(284)
Repurchase of common stock		(5,127)	(14,873)		(20,000)
Balance (in shares) at Mar. 31, 2022	33,064
Balance at Mar. 31, 2022	$ 33	554,633	4,019	588	559,273
Balance (in shares) at Dec. 31, 2021	33,240
Balance at Dec. 31, 2021	$ 33	559,883	(22,722)	1,765	538,959
Increase (Decrease) in Stockholders' Equity
Net income					126,087
Foreign currency translation adjustments					(7,561)
Change in pension obligation					25
Balance (in shares) at Sep. 30, 2022	32,937
Balance at Sep. 30, 2022	$ 33	549,735	70,893	(5,771)	614,890
Balance (in shares) at Mar. 31, 2022	33,064
Balance at Mar. 31, 2022	$ 33	554,633	4,019	588	559,273
Increase (Decrease) in Stockholders' Equity
Net income			44,189		44,189
Foreign currency translation adjustments				(2,685)	(2,685)
Change in pension obligation				8	8
Exercise of stock options (in shares)	25
Exercise of stock options		298			298
Issuance of stock under Employee Stock Purchase Plan (in shares)	15
Issuance of stock under Employee Stock Purchase Plan		711			711
Issuance of common stock on restricted stock units, net of shares withheld (in shares)	205
Issuance of common stock on restricted stock units, net of shares withheld		(5,896)			(5,896)
Stock-based compensation expense		3,527			3,527
Repurchase of common stock (in shares)	(215)
Repurchase of common stock		(3,872)	(8,626)		(12,498)
Balance (in shares) at Jun. 30, 2022	33,094
Balance at Jun. 30, 2022	$ 33	549,401	39,582	(2,089)	586,927
Increase (Decrease) in Stockholders' Equity
Net income			40,283		40,283
Foreign currency translation adjustments				(3,690)	(3,690)
Change in pension obligation				8	8
Exercise of stock options (in shares)	30
Exercise of stock options		367			367
Issuance of common stock on restricted stock units, net of shares withheld (in shares)	8
Issuance of common stock on restricted stock units, net of shares withheld		(70)			(70)
Stock-based compensation expense		3,562			3,562
Repurchase of common stock (in shares)	(195)
Repurchase of common stock		(3,525)	(8,972)		(12,497)
Balance (in shares) at Sep. 30, 2022	32,937
Balance at Sep. 30, 2022	$ 33	549,735	70,893	(5,771)	614,890
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, 2022	32,775
Balance at Dec. 31, 2022	$ 33	550,299	118,892	(1,968)	667,256
Increase (Decrease) in Stockholders' Equity
Net income					175,207
Foreign currency translation adjustments					(2,192)
Balance (in shares) at Sep. 30, 2023	32,772
Balance at Sep. 30, 2023	$ 33	543,577	261,521	(4,160)	800,971
Balance (in shares) at Mar. 31, 2023	32,726
Balance at Mar. 31, 2023	$ 33	547,692	156,014	(1,918)	701,821
Increase (Decrease) in Stockholders' Equity
Net income			61,579		61,579
Foreign currency translation adjustments				(1,011)	(1,011)
Issuance of stock under Employee Stock Purchase Plan (in shares)	6
Issuance of stock under Employee Stock Purchase Plan		957			957
Issuance of common stock on restricted stock units, net of shares withheld (in shares)	199
Issuance of common stock on restricted stock units, net of shares withheld		(11,558)			(11,558)
Stock-based compensation expense		4,749			4,749
Repurchase of common stock (in shares)	(95)
Repurchase of common stock		(1,720)	(10,780)		(12,500)
Balance (in shares) at Jun. 30, 2023	32,836
Balance at Jun. 30, 2023	$ 33	540,120	206,813	(2,929)	744,037
Increase (Decrease) in Stockholders' Equity
Net income			65,931		65,931
Foreign currency translation adjustments				(1,231)	(1,231)
Issuance of common stock on restricted stock units, net of shares withheld (in shares)	7
Issuance of common stock on restricted stock units, net of shares withheld		(349)			(349)
Stock-based compensation expense		5,082			5,082
Repurchase of common stock (in shares)	(71)
Repurchase of common stock		(1,276)	(11,223)		(12,499)
Balance (in shares) at Sep. 30, 2023	32,772
Balance at Sep. 30, 2023	$ 33	$ 543,577	$ 261,521	$ (4,160)	$ 800,971

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Cash flows from operating activities
Net income	$ 175,207	$ 126,087
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	9,488	8,614
Deferred income taxes	(12,623)	6,416
Stock-based compensation expense	13,030	9,790
Provision for doubtful accounts	749
Provision for excess and obsolete inventory	3,912	3,292
Accretion of discounts and premiums on marketable securities	(8,463)
Currency loss on foreign denominated transactions	7,487
Changes in operating assets and liabilities:
Accounts receivable	(26,674)	(77,449)
Inventories	(79,494)	(49,699)
Prepaid expenses and other current assets	(16,493)	(4,861)
Accounts payable and other current liabilities	(8,916)	17,695
Deferred revenue	47,704	54,814
Income taxes	(3,672)	(274)
Other assets and liabilities	(9,948)	(1,202)
Net cash provided by operating activities	91,294	93,223
Cash flows from investing activities
Expenditures for property, plant and equipment and capitalized software	(10,503)	(6,876)
Purchase of short-term investments	(271,583)	(33,576)
Maturities of short-term investments	207,907
Net cash used in investing activities	(74,179)	(40,452)
Cash flows from financing activities
Net settlement on restricted stock grants	(15,814)	(9,281)
Repurchase of common stock	(37,498)	(44,995)
Proceeds from Employee Stock Purchase Plan purchases	957	711
Principal payments on finance lease obligation	(915)	(728)
Proceeds from exercise of stock options	25	1,156
Net cash used in financing activities	(53,245)	(53,137)
Effect of exchange rate changes on cash and cash equivalents	(1,267)	13,987
Net (decrease) increase in cash, cash equivalents and restricted cash	(37,397)	13,621
Cash, cash equivalents and restricted cash at beginning of period	186,347	295,680
Cash, cash equivalents and restricted cash at end of period	$ 148,950	$ 309,301

Nature of Business

Nature of Business	9 Months Ended
	Sep. 30, 2023
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, 2022 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 September 30, 2023, there have been no material changes in the Company’s significant accounting policies. 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, 2022. ​

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2023
Stock-Based Compensation
Stock-Based Compensation	Note 2. Stock-Based Compensation ​ We maintain the Axcelis Technologies, Inc. 2012 Equity Incentive Plan, as amended (the “2012 Equity Plan”), an Internal Revenue Code Section 423 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 Annual Report on Form 10-K for the year ended December 31, 2022. ​ We recognized stock-based compensation expense of $5.1 million and $3.6 million for the three-month periods ended September 30, 2023 and 2022, respectively. We recognized stock-based compensation expense of $13.0 million and $9.8 million for the nine-month periods ended September 30, 2023 and 2022, respectively. These amounts include compensation expense related to RSUs, non-qualified stock options and stock issued to participants under the 2020 Employee Stock Purchase Plan (the “2020 ESPP”). ​ In the three-month period ended September 30, 2023, we issued 7,320 shares of common stock upon vesting of RSUs. In the three-month period ended September 30, 2022, we issued 38,507 shares of common stock upon vesting of RSUs and stock option exercises. In the three-month period ended September 30, 2023, we received no proceeds in connection with the exercise of stock options. In the three-month period ended September 30, 2022, we received proceeds of $0.4 million in connection with the exercise of stock options. ​ In the nine-month periods ended September 30, 2023 and 2022, we issued 0.3 million and 0.4 million shares of common stock, respectively, upon stock option exercises, purchases under the 2020 ESPP and vesting of RSUs. In the nine-month periods ended September 30, 2023 and 2022, we received proceeds of $1.0 million and $1.9 million, respectively, in connection with the exercise of stock options and purchases under the 2020 ESPP.

Leases

Leases	9 Months Ended
	Sep. 30, 2023
Leases
Leases	Note 3. 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 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ ​ ​ Leases Classification ​ 2023 2022 ​ Assets ​ ​ (in thousands) ​ ​ Operating leases Operating lease assets ​ $ 31,082 ​ $ 12,146 ​ ​ ​ Finance lease Finance lease assets* ​ 16,981 ​ 17,942 ​ ​ ​ Total leased assets ​ ​ $ 48,063 ​ $ 30,088 ​ ​ ​ Liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Current ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating Other current liabilities ​ $ 5,001 ​ $ 5,367 ​ ​ ​ Finance Current portion of finance lease obligation ​ ​ 1,438 ​ ​ 1,229 ​ ​ ​ Non-current ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating Other long-term liabilities ​ ​ 25,850 ​ ​ 6,931 ​ ​ ​ Finance Finance lease obligation ​ 44,070 ​ 45,185 ​ ​ ​ Total lease liabilities ​ ​ $ 76,359 ​ $ 58,712 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ *Finance lease assets are recorded net of accumulated depreciation of $46.7 million and include $0.6 million of prepaid financing costs as of September 30, 2023. Finance lease assets are recorded net of accumulated depreciation of $45.9 million and include $0.6 million of prepaid financing costs as of December 31, 2022. ​ ​ ​ ​ ​ square foot logistics and flex manufacturing center in Beverly, Massachusetts became fully operational in the third quarter of 2023. Operating lease expense and depreciation and interest expense relating to our finance lease obligation are recognized within our consolidated statement of operations for the three and nine months ended September 30, 2023 and 2022 as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Nine months ended ​ ​ ​ ​ September 30, ​ September 30, ​ ​ Lease cost Classification ​ 2023 2022 2023 2022 ​ Operating lease cost ​ ​ (in thousands) ​ Product / services* Cost of revenue ​ $ 2,041 ​ $ 1,462 ​ $ 5,328 ​ $ 3,978 ​ ​ Research and development Operating expenses ​ 183 ​ 54 ​ 426 ​ 186 ​ ​ Sales and marketing* Operating expenses ​ 419 ​ 369 ​ 1,231 ​ 1,155 ​ ​ General and administrative* Operating expenses ​ 298 ​ 253 ​ 813 ​ 773 ​ ​ Total operating lease cost ​ ​ $ 2,941 ​ $ 2,138 ​ $ 7,798 ​ $ 6,092 ​ ​ Finance lease cost ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Depreciation of leased assets Cost of revenue, Research and development, Sales and marketing and General and administrative ​ $ 324 ​ $ 325 ​ $ 961 ​ $ 973 ​ ​ Interest on lease liabilities Interest expense ​ 1,214 ​ 1,245 ​ 3,668 ​ 3,754 ​ ​ Total finance lease cost ​ ​ $ 1,538 ​ $ 1,570 ​ $ 4,629 ​ $ 4,727 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total lease cost ​ ​ $ 4,479 ​ $ 3,708 ​ $ 12,427 ​ $ 10,819 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ * 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 $1.6 million for the three and nine months ended September 30, 2023, respectively, and includes short-term lease and variable lease costs of approximately $0.4 million and $1.4 million for the three and nine months ended September 30, 2022, respectively. ​ ​ ​ ​ one ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Finance ​ Operating Total Maturity of Lease Liabilities ​ Leases ​ Leases ​ Leases ​ ​ ​ (in thousands) ​ 2023 ​ $ 1,531 ​ $ 2,117 ​ $ 3,648 ​ 2024 ​ 6,252 ​ 6,248 ​ 12,500 ​ 2025 ​ 5,930 ​ 4,761 ​ 10,691 ​ 2026 ​ 6,008 ​ 3,471 ​ 9,479 ​ 2027 ​ ​ 6,128 ​ ​ 2,502 ​ ​ 8,630 ​ Thereafter ​ ​ 61,586 ​ ​ 25,123 ​ ​ 86,709 ​ Total lease payments ​ $ 87,435 ​ $ 44,222 ​ $ 131,657 ​ Less interest portion* ​ ​ (41,927) ​ ​ (13,371) ​ ​ (55,298) ​ Finance lease and operating lease obligations ​ $ 45,508 ​ $ 30,851 ​ $ 76,359 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ * 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. ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ Lease term and discount rate 2023 ​ Weighted-average remaining lease term (years): ​ ​ ​ ​ Operating leases ​ ​ 11.6 ​ Finance leases ​ 13.3 ​ Weighted-average discount rate: ​ ​ ​ ​ Operating leases ​ 5.5% ​ Finance leases ​ 10.5% ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine months ended September 30, ​ Cash paid for amounts included in the measurement of lease liabilities 2023 2022 ​ ​ ​ (in thousands) ​ Operating cash outflows from operating leases ​ $ 7,798 ​ $ 6,092 ​ Operating cash outflows from finance leases ​ 3,668 ​ 3,754 ​ Financing cash outflows from finance leases ​ 915 ​ 728 ​ Operating lease assets obtained in exchange for operating lease liabilities ​ 25,697 ​ 5,494 ​ Finance lease assets obtained in exchange for new finance lease liabilities ​ — ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

Revenue

Revenue	9 Months Ended
	Sep. 30, 2023
Revenue
Revenue	Note 4. Revenue ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Nine months ended ​ ​ September 30, ​ September 30, ​ ​ 2023 ​ 2022 ​ 2023 ​ 2022 ​ ​ (in thousands) Systems ​ $ 231,454 ​ $ 171,092 ​ $ 641,825 ​ $ 488,243 Aftermarket ​ ​ 60,872 ​ ​ 58,083 ​ ​ 178,491 ​ ​ 165,704 Total Revenue ​ $ 292,326 ​ $ 229,175 ​ $ 820,316 ​ $ 653,947 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Nine months ended ​ ​ September 30, ​ September 30, ​ ​ 2023 ​ 2022 ​ 2023 ​ 2022 ​ ​ (in thousands) North America ​ $ 51,563 ​ $ 36,036 ​ $ 134,647 ​ $ 95,633 Asia Pacific ​ ​ 185,194 ​ ​ 166,342 ​ ​ 582,238 ​ ​ 484,286 Europe ​ ​ 55,569 ​ ​ 26,797 ​ ​ 103,431 ​ ​ 74,028 Total Revenue ​ $ 292,326 ​ $ 229,175 ​ $ 820,316 ​ $ 653,947 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ ​ 2023 ​ 2022 ​ ​ (in thousands) Contract liabilities ​ $ 202,029 ​ $ 154,777 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Nine months ended ​ ​ September 30, September 30, ​ ​ 2023 ​ 2022 ​ 2023 ​ 2022 ​ ​ (in thousands) Balance, beginning of the period ​ $ 182,540 ​ $ 71,549 ​ $ 154,777 ​ $ 68,436 Deferral of revenue ​ ​ 62,787 ​ ​ 70,706 ​ ​ 154,216 ​ ​ 108,472 Recognition of deferred revenue ​ ​ (43,298) ​ ​ (19,666) ​ ​ (106,964) ​ ​ (54,319) Balance, end of the period ​ $ 202,029 ​ $ 122,589 ​ $ 202,029 ​ $ 122,589 ​

Receivables and Allowances for

Receivables and Allowances for Credit Losses	9 Months Ended
	Sep. 30, 2023
Receivables and Allowances for Credit Losses
Receivables and Allowances for Credit Losses	Note 5. 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 $0.7 million in bad debt expense for the three and nine-month periods ended September 30, 2023. We did not have any allowance or incur any credit losses or recoveries for the three and nine-month periods ended September 30, 2022. As of September 30, 2023 and 2022, respectively, we had no provision for credit losses. ​ ​

Computation of Net Earnings per

Computation of Net Earnings per Share	9 Months Ended
	Sep. 30, 2023
Computation of Net Earnings per Share
Computation of Net Earnings per Share	Note 6. 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 ​ Nine months ended ​ ​ ​ September 30, ​ September 30, ​ ​ 2023 2022 2023 2022 ​ ​ (in thousands, except per share amounts) ​ Net income available to common stockholders ​ $ 65,931 ​ $ 40,283 ​ $ 175,207 ​ $ 126,087 ​ Weighted average shares of common stock outstanding used in computing basic income per share ​ 32,807 ​ 33,011 ​ 32,775 ​ 33,116 ​ Incremental options and RSUs ​ 352 ​ 378 ​ 433 ​ 522 ​ Weighted average shares of common stock used in computing diluted net income per share ​ 33,159 ​ 33,389 ​ 33,208 ​ 33,638 ​ Net income per share ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic ​ $ 2.01 ​ $ 1.22 ​ $ 5.35 ​ $ 3.81 ​ Diluted ​ $ 1.99 ​ $ 1.21 ​ $ 5.28 ​ $ 3.75 ​ ​ ​ Diluted weighted average shares of common stock outstanding does not include 734 and 5,046 common equivalent shares issuable with respect to outstanding equity awards for the three-month periods ended September 30, 2023 and 2022, respectively, or 2,598 and 6,692 common equivalent shares issuable with respect to outstanding equity awards for the nine-month periods ended September 30, 2023 and 2022, respectively, as their effect would have been anti-dilutive.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss	9 Months Ended
	Sep. 30, 2023
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Loss	Note 7. Accumulated Other Comprehensive Loss ​ The following table presents the changes in accumulated other comprehensive loss, net of tax, by component, for the nine months ended September 30, 2023: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Foreign Defined benefit ​ ​ ​ ​ currency ​ pension plan ​ Total ​ ​ (in thousands) Balance at December 31, 2022 ​ $ (1,994) ​ $ 26 ​ $ (1,968) ​ Other comprehensive loss and pension reclassification ​ (2,192) ​ — ​ (2,192) ​ Balance at September 30, 2023 ​ $ (4,186) ​ $ 26 ​ $ (4,160) ​ ​

Cash, cash equivalents and rest

Cash, cash equivalents and restricted cash	9 Months Ended
	Sep. 30, 2023
Cash, cash equivalents and restricted cash
Cash, cash equivalents and restricted cash	Note 8. 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: ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ ​ 2023 ​ ​ 2022 ​ ​ (in thousands) ​ Cash and cash equivalents $ 142,300 ​ $ 185,595 ​ Long-term restricted cash ​ 6,650 ​ ​ 752 ​ Total cash, cash equivalents and restricted cash $ 148,950 ​ $ 186,347 ​ ​ As of September 30, 2023, 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 12 for further discussion on the $5.9 million cash collateral.

Inventories, net

Inventories, net	9 Months Ended
	Sep. 30, 2023
Inventories, net
Inventories, net	Note 9. Inventories, net ​ The components of inventories are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ ​ 2023 2022 ​ ​ (in thousands) ​ Raw materials ​ $ 226,601 ​ $ 187,313 ​ Work in process ​ 55,825 ​ 35,069 ​ Finished goods (completed systems) ​ 29,797 ​ 20,024 ​ Inventories, net ​ $ 312,223 ​ $ 242,406 ​ ​ 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 the Company’s 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	9 Months Ended
	Sep. 30, 2023
Product Warranty
Product Warranty	Note 10. 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 defer the portion of systems revenue attributable to the fair value of 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: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine months ended ​ ​ ​ September 30, ​ ​ 2023 2022 ​ ​ (in thousands) ​ Balance at January 1 (beginning of year) ​ $ 10,487 ​ $ 6,924 ​ Warranties issued during the period ​ 9,072 ​ 7,454 ​ Settlements made during the period ​ (7,746) ​ (4,633) ​ Changes in estimate of liability for pre-existing warranties during the period ​ 2,043 ​ (78) ​ Balance at September 30 (end of period) ​ $ 13,856 ​ $ 9,667 ​ ​ ​ ​ ​ ​ ​ ​ ​ Amount classified as current ​ $ 11,464 ​ $ 8,482 ​ Amount classified as long-term (within other long-term liabilities) ​ 2,392 ​ 1,185 ​ Total warranty liability ​ $ 13,856 ​ $ 9,667 ​ ​

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2023
Fair Value Measurements
Fair Value Measurements	Note 11. 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: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 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) ​ $ 114,475 ​ $ — ​ $ — ​ $ 114,475 ​ Short-term investments (U.S. Government Securities and Agency Investments) ​ ​ 318,202 ​ ​ — ​ ​ — ​ ​ 318,202 ​ Total ​ $ 432,677 ​ $ — ​ $ — ​ $ 432,677 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ ​ 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) ​ $ 111,771 ​ $ 25,000 ​ $ — ​ $ 136,771 ​ Short-term investments (U.S. Government Securities and Agency Investments) ​ ​ 245,247 ​ ​ — ​ ​ — ​ ​ 245,247 ​ Total ​ $ 357,018 ​ $ 25,000 ​ $ — ​ $ 382,018 ​ ​ (c) Other Financial Instruments ​ The carrying amounts reflected in the consolidated balance sheets for accounts receivable, prepaid expenses and other current assets and non-current assets, restricted cash, accounts payable and accrued expenses approximate fair value due to their short-term maturities.

Financing Arrangements

Financing Arrangements	9 Months Ended
	Sep. 30, 2023
Financing Arrangements
Financing Arrangements	Note 12. 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 $45.5 million as of September 30, 2023. 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 September 30, 2023, we had a security deposit of $5.9 million related to this lease. ​ On April 5, 2023 we terminated the Senior Secured Credit Facilities Credit Agreement, as amended (the “Credit Agreement”), with Silicon Valley Bank that we entered into on July 31, 2020. The Credit Agreement provided for a revolving credit facility covering borrowings and letters of credit in an aggregate principal amount not to exceed $40.0 million. Our obligations under the Credit Agreement were secured by a security interest, senior to any current and future debts and to any security interest, in all of our rights, title, and interest in, to and under substantially all of our assets, subject to limited exceptions, including permitted liens. Upon termination, these liens and all other obligations under the credit agreement, were released. A letter of credit issued by Silicon Valley Bank, a division of First Citizens Bank & Trust Company (successor by purchase to the Federal Deposit Insurance Corporation as Receiver for Silicon Valley Bridge Bank, N.A.) as successor to Silicon Valley Bank, remains outstanding in the amount of $5.9 million, securing our lease on our corporate headquarters. This letter of credit was transitioned to a cash collateral arrangement on March 30, 2023, and was classified as long-term restricted cash on our balance sheet at September 30, 2023.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2023
Income Taxes
Income Taxes	Note 13. Income Taxes ​ Income tax expense was $7.7 million for the three months ended September 30, 2023, compared to $4.7 million for the three months ended September 30, 2022. The $3.0 million increase was primarily due to an increase in pre-tax income partially offset by the tax deduction related to foreign sales taxed at a lower rate. Income tax expense was $16.0 million for the nine months ended September 30, 2023, compared to $13.0 million for the nine months ended September 30, 2022. The $3.0 million increase was primarily due to an increase in pre-tax income partially offset by the tax deduction related to stock based compensation and additional research and development tax credit. ​ The effective tax rate for the three and nine months ended September 30, 2023 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 $44.3 million and $31.7 million as of September 30, 2023 and December 31, 2022, 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 September 30, 2023, we have recorded a $10.6 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	9 Months Ended
	Sep. 30, 2023
Concentration of Risk
Concentration of Risk	Note 14. Concentration of Risk ​ For the three months ended September 30, 2023, no individual customer accounted for greater than ten percent of total revenue. For the three months ended September 30, 2022, one customer accounted for 13.8% of total revenue. ​ For the nine months ended September 30, 2023, one customer accounted for 10.7% of total revenue. For the nine months ended September 30, 2022, one customer accounted for 14.8% of total revenue. ​ At September 30, 2023, three customers accounted for 11.8%, 11.0%, and 10.2% of accounts receivable, respectively. At December 31, 2022, two customers accounted for 19.4% and 11.5% of accounts receivable, respectively.

Share Repurchase

Share Repurchase	9 Months Ended
	Sep. 30, 2023
Share Repurchase
Share Repurchase	Note 15. 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 nine months ended September 30, 2023, we repurchased 0.3 million shares at an average cost of $137.54 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.

Contingencies

Contingencies	9 Months Ended
	Sep. 30, 2023
Contingencies
Contingencies	Note 16. 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.

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2023
Leases
Schedule of operating and finance lease right-of-use assets and related lease obligations	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ ​ ​ Leases Classification ​ 2023 2022 ​ Assets ​ ​ (in thousands) ​ ​ Operating leases Operating lease assets ​ $ 31,082 ​ $ 12,146 ​ ​ ​ Finance lease Finance lease assets* ​ 16,981 ​ 17,942 ​ ​ ​ Total leased assets ​ ​ $ 48,063 ​ $ 30,088 ​ ​ ​ Liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Current ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating Other current liabilities ​ $ 5,001 ​ $ 5,367 ​ ​ ​ Finance Current portion of finance lease obligation ​ ​ 1,438 ​ ​ 1,229 ​ ​ ​ Non-current ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating Other long-term liabilities ​ ​ 25,850 ​ ​ 6,931 ​ ​ ​ Finance Finance lease obligation ​ 44,070 ​ 45,185 ​ ​ ​ Total lease liabilities ​ ​ $ 76,359 ​ $ 58,712 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ *Finance lease assets are recorded net of accumulated depreciation of $46.7 million and include $0.6 million of prepaid financing costs as of September 30, 2023. Finance lease assets are recorded net of accumulated depreciation of $45.9 million and include $0.6 million of prepaid financing costs as of December 31, 2022. ​ ​ ​ ​
Schedule of lease costs	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Nine months ended ​ ​ ​ ​ September 30, ​ September 30, ​ ​ Lease cost Classification ​ 2023 2022 2023 2022 ​ Operating lease cost ​ ​ (in thousands) ​ Product / services* Cost of revenue ​ $ 2,041 ​ $ 1,462 ​ $ 5,328 ​ $ 3,978 ​ ​ Research and development Operating expenses ​ 183 ​ 54 ​ 426 ​ 186 ​ ​ Sales and marketing* Operating expenses ​ 419 ​ 369 ​ 1,231 ​ 1,155 ​ ​ General and administrative* Operating expenses ​ 298 ​ 253 ​ 813 ​ 773 ​ ​ Total operating lease cost ​ ​ $ 2,941 ​ $ 2,138 ​ $ 7,798 ​ $ 6,092 ​ ​ Finance lease cost ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Depreciation of leased assets Cost of revenue, Research and development, Sales and marketing and General and administrative ​ $ 324 ​ $ 325 ​ $ 961 ​ $ 973 ​ ​ Interest on lease liabilities Interest expense ​ 1,214 ​ 1,245 ​ 3,668 ​ 3,754 ​ ​ Total finance lease cost ​ ​ $ 1,538 ​ $ 1,570 ​ $ 4,629 ​ $ 4,727 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total lease cost ​ ​ $ 4,479 ​ $ 3,708 ​ $ 12,427 ​ $ 10,819 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ * 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 $1.6 million for the three and nine months ended September 30, 2023, respectively, and includes short-term lease and variable lease costs of approximately $0.4 million and $1.4 million for the three and nine months ended September 30, 2022, respectively. ​ ​
Schedule of future minimum operating and finance leases	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Finance ​ Operating Total Maturity of Lease Liabilities ​ Leases ​ Leases ​ Leases ​ ​ ​ (in thousands) ​ 2023 ​ $ 1,531 ​ $ 2,117 ​ $ 3,648 ​ 2024 ​ 6,252 ​ 6,248 ​ 12,500 ​ 2025 ​ 5,930 ​ 4,761 ​ 10,691 ​ 2026 ​ 6,008 ​ 3,471 ​ 9,479 ​ 2027 ​ ​ 6,128 ​ ​ 2,502 ​ ​ 8,630 ​ Thereafter ​ ​ 61,586 ​ ​ 25,123 ​ ​ 86,709 ​ Total lease payments ​ $ 87,435 ​ $ 44,222 ​ $ 131,657 ​ Less interest portion* ​ ​ (41,927) ​ ​ (13,371) ​ ​ (55,298) ​ Finance lease and operating lease obligations ​ $ 45,508 ​ $ 30,851 ​ $ 76,359 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ * 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	​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ Lease term and discount rate 2023 ​ Weighted-average remaining lease term (years): ​ ​ ​ ​ Operating leases ​ ​ 11.6 ​ Finance leases ​ 13.3 ​ Weighted-average discount rate: ​ ​ ​ ​ Operating leases ​ 5.5% ​ Finance leases ​ 10.5% ​ ​ ​ ​ ​ ​
Schedule of cash outflows by lease type	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine months ended September 30, ​ Cash paid for amounts included in the measurement of lease liabilities 2023 2022 ​ ​ ​ (in thousands) ​ Operating cash outflows from operating leases ​ $ 7,798 ​ $ 6,092 ​ Operating cash outflows from finance leases ​ 3,668 ​ 3,754 ​ Financing cash outflows from finance leases ​ 915 ​ 728 ​ Operating lease assets obtained in exchange for operating lease liabilities ​ 25,697 ​ 5,494 ​ Finance lease assets obtained in exchange for new finance lease liabilities ​ — ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

Revenue (Tables)

Revenue (Tables)	9 Months Ended
	Sep. 30, 2023
Revenue
Schedule of revenue by discipline	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Nine months ended ​ ​ September 30, ​ September 30, ​ ​ 2023 ​ 2022 ​ 2023 ​ 2022 ​ ​ (in thousands) Systems ​ $ 231,454 ​ $ 171,092 ​ $ 641,825 ​ $ 488,243 Aftermarket ​ ​ 60,872 ​ ​ 58,083 ​ ​ 178,491 ​ ​ 165,704 Total Revenue ​ $ 292,326 ​ $ 229,175 ​ $ 820,316 ​ $ 653,947
Schedule of revenue by geographic markets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Nine months ended ​ ​ September 30, ​ September 30, ​ ​ 2023 ​ 2022 ​ 2023 ​ 2022 ​ ​ (in thousands) North America ​ $ 51,563 ​ $ 36,036 ​ $ 134,647 ​ $ 95,633 Asia Pacific ​ ​ 185,194 ​ ​ 166,342 ​ ​ 582,238 ​ ​ 484,286 Europe ​ ​ 55,569 ​ ​ 26,797 ​ ​ 103,431 ​ ​ 74,028 Total Revenue ​ $ 292,326 ​ $ 229,175 ​ $ 820,316 ​ $ 653,947
Schedule of Contract liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ ​ 2023 ​ 2022 ​ ​ (in thousands) Contract liabilities ​ $ 202,029 ​ $ 154,777 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Nine months ended ​ ​ September 30, September 30, ​ ​ 2023 ​ 2022 ​ 2023 ​ 2022 ​ ​ (in thousands) Balance, beginning of the period ​ $ 182,540 ​ $ 71,549 ​ $ 154,777 ​ $ 68,436 Deferral of revenue ​ ​ 62,787 ​ ​ 70,706 ​ ​ 154,216 ​ ​ 108,472 Recognition of deferred revenue ​ ​ (43,298) ​ ​ (19,666) ​ ​ (106,964) ​ ​ (54,319) Balance, end of the period ​ $ 202,029 ​ $ 122,589 ​ $ 202,029 ​ $ 122,589

Computation of Net Earnings p_2

Computation of Net Earnings per Share (Tables)	9 Months Ended
	Sep. 30, 2023
Computation of Net Earnings per Share
Schedule of components of net income per share	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ Nine months ended ​ ​ ​ September 30, ​ September 30, ​ ​ 2023 2022 2023 2022 ​ ​ (in thousands, except per share amounts) ​ Net income available to common stockholders ​ $ 65,931 ​ $ 40,283 ​ $ 175,207 ​ $ 126,087 ​ Weighted average shares of common stock outstanding used in computing basic income per share ​ 32,807 ​ 33,011 ​ 32,775 ​ 33,116 ​ Incremental options and RSUs ​ 352 ​ 378 ​ 433 ​ 522 ​ Weighted average shares of common stock used in computing diluted net income per share ​ 33,159 ​ 33,389 ​ 33,208 ​ 33,638 ​ Net income per share ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic ​ $ 2.01 ​ $ 1.22 ​ $ 5.35 ​ $ 3.81 ​ Diluted ​ $ 1.99 ​ $ 1.21 ​ $ 5.28 ​ $ 3.75 ​

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Loss (Tables)	9 Months Ended
	Sep. 30, 2023
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, 2022 ​ $ (1,994) ​ $ 26 ​ $ (1,968) ​ Other comprehensive loss and pension reclassification ​ (2,192) ​ — ​ (2,192) ​ Balance at September 30, 2023 ​ $ (4,186) ​ $ 26 ​ $ (4,160) ​ ​

Cash, cash equivalents and re_2

Cash, cash equivalents and restricted cash (Tables)	9 Months Ended
	Sep. 30, 2023
Cash, cash equivalents and restricted cash
Schedule of reconciliation of cash, cash equivalents and restricted cash	​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ ​ 2023 ​ ​ 2022 ​ ​ (in thousands) ​ Cash and cash equivalents $ 142,300 ​ $ 185,595 ​ Long-term restricted cash ​ 6,650 ​ ​ 752 ​ Total cash, cash equivalents and restricted cash $ 148,950 ​ $ 186,347 ​

Inventories, net (Tables)

Inventories, net (Tables)	9 Months Ended
	Sep. 30, 2023
Inventories, net
Schedule of components of inventories	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ ​ 2023 2022 ​ ​ (in thousands) ​ Raw materials ​ $ 226,601 ​ $ 187,313 ​ Work in process ​ 55,825 ​ 35,069 ​ Finished goods (completed systems) ​ 29,797 ​ 20,024 ​ Inventories, net ​ $ 312,223 ​ $ 242,406 ​

Product Warranty (Tables)

Product Warranty (Tables)	9 Months Ended
	Sep. 30, 2023
Product Warranty
Schedule of product warranty liability	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine months ended ​ ​ ​ September 30, ​ ​ 2023 2022 ​ ​ (in thousands) ​ Balance at January 1 (beginning of year) ​ $ 10,487 ​ $ 6,924 ​ Warranties issued during the period ​ 9,072 ​ 7,454 ​ Settlements made during the period ​ (7,746) ​ (4,633) ​ Changes in estimate of liability for pre-existing warranties during the period ​ 2,043 ​ (78) ​ Balance at September 30 (end of period) ​ $ 13,856 ​ $ 9,667 ​ ​ ​ ​ ​ ​ ​ ​ ​ Amount classified as current ​ $ 11,464 ​ $ 8,482 ​ Amount classified as long-term (within other long-term liabilities) ​ 2,392 ​ 1,185 ​ Total warranty liability ​ $ 13,856 ​ $ 9,667 ​ ​

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2023
Fair Value Measurements
Schedule of Company's assets and liabilities by level within the fair value hierarchy	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 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) ​ $ 114,475 ​ $ — ​ $ — ​ $ 114,475 ​ Short-term investments (U.S. Government Securities and Agency Investments) ​ ​ 318,202 ​ ​ — ​ ​ — ​ ​ 318,202 ​ Total ​ $ 432,677 ​ $ — ​ $ — ​ $ 432,677 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ ​ 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) ​ $ 111,771 ​ $ 25,000 ​ $ — ​ $ 136,771 ​ Short-term investments (U.S. Government Securities and Agency Investments) ​ ​ 245,247 ​ ​ — ​ ​ — ​ ​ 245,247 ​ Total ​ $ 357,018 ​ $ 25,000 ​ $ — ​ $ 382,018 ​ ​

Stock-Based Compensation (Detai

Stock-Based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended					9 Months Ended
	Sep. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022
Stock-Based Compensation
Stock-based compensation expense	$ 5,100		$ 3,600			$ 13,000	$ 9,800
Proceeds from exercise of stock options						$ 25	$ 1,156
Employee Stock Purchase Plan
Stock-Based Compensation
Exercise of stock options (in shares)						300,000	400,000
Proceeds from exercise of stock options						$ 1,000	$ 1,900
Common Stock
Stock-Based Compensation
Exercise of stock options (in shares)		2,000	30,000	25,000	41,000
Common Stock | Employee Stock Purchase Plan
Stock-Based Compensation
Proceeds from exercise of stock options	$ 0		$ 400
Common Stock | Restricted Stock Units
Stock-Based Compensation
Exercise of stock options (in shares)	7,320
Common Stock | Stock Options and Restricted Stock Units
Stock-Based Compensation
Exercise of stock options (in shares)						38,507

Leases (Details)

Leases (Details)	9 Months Ended
	Sep. 30, 2023
Lessee, Lease, Description [Line Items]
Option to extend	true
Minimum
Lessee, Lease, Description [Line Items]
Renewal term	1 year
Maximum
Lessee, Lease, Description [Line Items]
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	Sep. 30, 2023	Dec. 31, 2022
Leases
Operating lease assets	$ 31,082	$ 12,146
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Operating lease assets	Operating lease assets
Finance lease assets	$ 16,981	$ 17,942
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Finance lease assets	Finance lease assets
Total leased assets	$ 48,063	$ 30,088
Operating liabilities current	$ 5,001	$ 5,367
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Other Liabilities, Current	Other Liabilities, Current
Finance liabilities current	$ 1,438	$ 1,229
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	Finance liabilities current	Finance liabilities current
Operating liabilities noncurrent	$ 25,850	$ 6,931
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Other Liabilities, Noncurrent	Other Liabilities, Noncurrent
Finance liabilities noncurrent	$ 44,070	$ 45,185
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Finance liabilities noncurrent	Finance liabilities noncurrent
Total lease liabilities	$ 76,359	$ 58,712
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	$ 45,900
Prepaid financing costs	$ 600	$ 600

Leases - Lease Cost (Details)

Leases - Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Lease cost
Total operating lease cost	$ 2,941	$ 2,138	$ 7,798	$ 6,092
Depreciation of leased assets	324	325	961	973
Interest on lease liabilities	1,214	1,245	3,668	3,754
Total finance lease cost	1,538	1,570	4,629	4,727
Total lease cost	4,479	3,708	12,427	10,819
Short-term lease and variable lease costs	600	400	1,600	1,400
Product / Services
Lease cost
Total operating lease cost	2,041	1,462	5,328	3,978
Research and development
Lease cost
Total operating lease cost	183	54	426	186
Sales and marketing*
Lease cost
Total operating lease cost	419	369	1,231	1,155
General and administrative*
Lease cost
Total operating lease cost	$ 298	$ 253	$ 813	$ 773

Leases - Future Minimum Cash Ou

Leases - Future Minimum Cash Outflow and Weighted-average Remaining Lease Term and Discount Rate (Details) $ in Thousands	Sep. 30, 2023 USD ($) ft²	Dec. 31, 2022 USD ($)
Future minimum lease payments finance lease
2023	$ 1,531
2024	6,252
2025	5,930
2026	6,008
2027	6,128
Thereafter	61,586
Total lease payments	87,435
Less interest portion	(41,927)
Finance lease obligations	45,508
Future minimum lease payments operating lease
2023	2,117
2024	6,248
2025	4,761
2026	3,471
2027	2,502
Thereafter	25,123
Total lease payments	44,222
Less interest portion	(13,371)
Operating lease obligations	30,851
Future minimum lease payments finance and operating lease
2023	3,648
2024	12,500
2025	10,691
2026	9,479
2027	8,630
Thereafter	86,709
Total lease payments	131,657
Less interest portion	(55,298)
Total lease liabilities	76,359	$ 58,712
Lease term and discount rate
Right of use asset	31,082	12,146
Prepaid rent	600	600
Operating liabilities noncurrent	$ 25,850	$ 6,931
Finance lease term	22 years
Operating leases -Weighted-average remaining lease term (in years)	11 years 7 months 6 days
Finance leases - Weighted-average remaining lease term (in years)	13 years 3 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	98,500
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	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Leases
Operating cash outflows from operating leases	$ 7,798	$ 6,092
Operating cash outflows from finance leases	3,668	3,754
Financing cash outflows from finance leases	915	728
Operating lease assets obtained in exchange for operating lease liabilities	$ 25,697	$ 5,494

Revenue - Revenue by discipline

Revenue - Revenue by discipline & geographical areas (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Disaggregation of Revenue
Total Revenue	$ 292,326	$ 229,175	$ 820,316	$ 653,947
North America
Disaggregation of Revenue
Total Revenue	51,563	36,036	134,647	95,633
Asia Pacific
Disaggregation of Revenue
Total Revenue	185,194	166,342	582,238	484,286
Europe
Disaggregation of Revenue
Total Revenue	55,569	26,797	103,431	74,028
Systems
Disaggregation of Revenue
Total Revenue	231,454	171,092	641,825	488,243
Aftermarket
Disaggregation of Revenue
Total Revenue	$ 60,872	$ 58,083	$ 178,491	$ 165,704

Revenue - Contract liabilities

Revenue - Contract liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Jun. 30, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Dec. 31, 2021
Revenue
Contract liabilities	$ 202,029	$ 182,540	$ 154,777	$ 122,589	$ 71,549	$ 68,436

Revenue - Deferred revenue (Det

Revenue - Deferred revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Revenue
Balance, beginning of the period	$ 182,540	$ 71,549	$ 154,777	$ 68,436
Deferral of revenue	62,787	70,706	154,216	108,472
Recognition of deferred revenue	(43,298)	(19,666)	(106,964)	(54,319)
Balance, end of the period	$ 202,029	$ 122,589	$ 202,029	$ 122,589

Revenue (Details)

Revenue (Details)	9 Months Ended
	Sep. 30, 2023
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
Payment upon shipment of the system, as a percent	30%
Pre-shipment deposit, as a percent	20%
Systems | Maximum
Disaggregation of Revenue
Payment upon shipment of the system, as a percent	70%
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

Receivables and Allowances fo_2

Receivables and Allowances for Credit Losses - Trade Receivables (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2023	Sep. 30, 2022
Receivables and Allowances for Credit Losses
Bad debt expense	$ 700	$ 700
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						9 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022
Computation of Net Earnings per Share
Net income available to common stockholders	$ 65,931	$ 61,579	$ 47,697	$ 40,283	$ 44,189	$ 41,614	$ 175,207	$ 126,087
Weighted average shares of common stock outstanding used in computing basic income per share	32,807			33,011			32,775	33,116
Incremental options and RSUs	352			378			433	522
Weighted average shares of common stock used in computing diluted net income per share	33,159			33,389			33,208	33,638
Net income per share
Basic	$ 2.01			$ 1.22			$ 5.35	$ 3.81
Diluted	$ 1.99			$ 1.21			$ 5.28	$ 3.75
Anti-dilutive common equivalent shares excluded from calculation	734			5,046			2,598	6,692

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Loss (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2023 USD ($)
Changes in accumulated other comprehensive income, net of tax
Balance at December 31, 2022	$ (1,968)
Other comprehensive loss and pension reclassification	(2,192)
Balance at September 30, 2023	(4,160)
Foreign currency
Changes in accumulated other comprehensive income, net of tax
Balance at December 31, 2022	(1,994)
Other comprehensive loss and pension reclassification	(2,192)
Balance at September 30, 2023	(4,186)
Defined benefit pension plans
Changes in accumulated other comprehensive income, net of tax
Balance at December 31, 2022	26
Balance at September 30, 2023	$ 26

Cash, cash equivalents and re_3

Cash, cash equivalents and restricted cash (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022	Sep. 30, 2022	Dec. 31, 2021
Cash and cash equivalents	$ 142,300	$ 185,595
Long-term restricted cash	6,650	752
Total cash, cash equivalents and restricted cash	148,950	$ 186,347	$ 309,301	$ 295,680
Letter of credit related to workers' compensation insurance	700
Deposit related to customs activity	100
Beverly Property Owner LLC
Cash collateral related to lease obligation	5,900
Revolving credit facility
Restricted cash which relates to support of outstanding letters of credit	$ 6,700

Inventories, net (Details)

Inventories, net (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Inventories, net
Raw materials	$ 226,601	$ 187,313
Work in process	55,825	35,069
Finished goods (completed systems)	29,797	20,024
Inventories, net	$ 312,223	$ 242,406

Product Warranty (Details)

Product Warranty (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Jan. 01, 2023	Dec. 31, 2022	Jan. 01, 2022
Product Warranty
Product warranty period	1 year
Changes in standard product warranty liability
Warranties issued during the period	$ 9,072	$ 7,454
Settlements made during the period	(7,746)	(4,633)
Changes in estimate of liability for pre-existing warranties during the period	2,043	(78)
Balance at September 30 (end of period)	13,856	9,667
Product warranty classification
Amount classified as current	11,464	8,482		$ 8,299
Amount classified as long-term (within other long-term liabilities)	2,392	1,185
Total warranty liability	$ 13,856	$ 9,667	$ 10,487		$ 6,924

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Fair Value Measurements
Short-term investments (money market funds, U.S. Government Securities and Agency Investments)	$ 318,710	$ 246,571
Recurring | Estimate of fair value measurement
Fair Value Measurements
Total	432,677
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)	114,475	136,771
Total		382,018
Recurring | U.S. Government Securities and Agency Investments | Estimate of fair value measurement
Fair Value Measurements
Short-term investments (money market funds, U.S. Government Securities and Agency Investments)	318,202	245,247
Recurring | Level 1
Fair Value Measurements
Total	432,677
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)	114,475	111,771
Total		357,018
Recurring | Level 1 | U.S. Government Securities and Agency Investments
Fair Value Measurements
Short-term investments (money market funds, U.S. Government Securities and Agency Investments)	$ 318,202	245,247
Recurring | Level 2 | 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)		25,000
Total		$ 25,000

Financing Arrangements (Details

Financing Arrangements (Details) - USD ($) $ in Thousands	Jan. 30, 2015	Sep. 30, 2023	Apr. 05, 2023	Dec. 31, 2022
Financing Arrangements
Long-term finance lease obligation		$ 44,070		$ 45,185
Long-term restricted cash		6,650		$ 752
Sale leaseback obligation
Financing Arrangements
Long-term finance lease obligation		45,500
Security deposit		5,900
Beverly Property Owner LLC | Building
Financing Arrangements
Proceeds from sale of corporate headquarters	$ 48,900
Lease term	22 years
Silicon Valley Bank | Revolving credit facility
Financing Arrangements
Maximum borrowing capacity under the credit facility			$ 40,000
Silicon Valley Bank | Sale leaseback obligation | Letter of credit
Financing Arrangements
Long-term restricted cash		$ 5,900

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Valuation allowance
Income tax expense	$ 7,744	$ 4,726	$ 15,986	$ 13,002
Increase (decrease) in income tax expense	3,000		3,000
Deferred tax assets, net	44,323		44,323		$ 31,701
Deferred tax assets valuation allowance	$ 10,600		$ 10,600
Maximum
Valuation allowance
Statutory income tax rate (as a percent)	21%		21%

Concentration of Risk (Details)

Concentration of Risk (Details) - customer	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Total revenue | Customer concentration risk
Concentration of Risk
Number of customers	0	1	1	1
Total revenue | Customer concentration risk | First customer
Concentration of Risk
Percentage of concentration risk		13.80%	10.70%	14.80%
Accounts receivable | Credit concentration risk
Concentration of Risk
Number of customers			3		2
Accounts receivable | Credit concentration risk | First customer
Concentration of Risk
Percentage of concentration risk			11.80%		19.40%
Accounts receivable | Credit concentration risk | Second customer
Concentration of Risk
Percentage of concentration risk			11%		11.50%
Accounts receivable | Credit concentration risk | Third customer
Concentration of Risk
Percentage of concentration risk			10.20%

Share Repurchase (Details)

Share Repurchase (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	9 Months Ended
	Sep. 30, 2023	Aug. 31, 2023	Feb. 28, 2022
Share Repurchase
Share repurchase program common stock authorized amount		$ 200	$ 100
Number of shares repurchased	0.3
Average cost	$ 137.54

Insider Trading Arrangements

Insider Trading Arrangements	9 Months Ended
	Sep. 30, 2023
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