IPG Photonics (IPGP) 10-Q 3 Nov 21 2021 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2021	Nov. 02, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2021
Document Transition Report	false
Entity File Number	001-33155
Entity Registrant Name	IPG PHOTONICS CORP
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	04-3444218
Entity Address, Address Line One	50 Old Webster Road
Entity Address, City or Town	Oxford
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	01540
City Area Code	508
Local Phone Number	373-1100
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Trading Symbol	IPGP
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 (in shares)		53,308,856
Amendment Flag	false
Document Fiscal Period Focus	Q3
Document Fiscal Year Focus	2021
Current Fiscal Year End Date	--12-31
Entity Central Index Key	0001111928

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 794,904	$ 876,231
Short-term investments	724,103	514,835
Accounts receivable, net	272,699	264,321
Inventories	435,070	364,993
Prepaid income taxes	34,482	69,893
Prepaid expenses and other current assets	63,917	57,804
Total current assets	2,325,175	2,148,077
Deferred income taxes, net	49,008	43,197
Goodwill	38,705	41,366
Intangible assets, net	55,786	62,114
Property, plant and equipment, net	624,576	597,527
Other assets	50,660	43,419
Total assets	3,143,910	2,935,700
Current liabilities:
Current portion of long-term debt	18,788	3,810
Accounts payable	52,428	25,748
Accrued expenses and other current liabilities	208,915	176,740
Income taxes payable	12,709	8,280
Total current liabilities	292,840	214,578
Deferred income taxes and other long-term liabilities	94,897	92,854
Long-term debt, net of current portion	16,328	34,157
Total liabilities	404,065	341,589
Commitments and contingencies (Note 12)
IPG Photonics Corporation equity:
Common stock, $0.0001 par value, 175,000,000 shares authorized; 55,738,779 and 53,305,485 shares issued and outstanding, respectively, at September 30, 2021; 55,461,246 and 53,427,234 shares issued and outstanding, respectively, at December 31, 2020.	6	6
Treasury stock, at cost, 2,433,294 and 2,034,012 shares held at September 30, 2021 and December 31, 2020, respectively.	(381,685)	(303,614)
Additional paid-in capital	894,264	854,301
Retained earnings	2,401,520	2,188,191
Accumulated other comprehensive loss	(174,753)	(146,065)
Total IPG Photonics Corporation equity	2,739,352	2,592,819
Non-controlling interests	493	1,292
Total equity	2,739,845	2,594,111
Total liabilities and equity	$ 3,143,910	$ 2,935,700

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized	175,000,000	175,000,000
Common stock, shares issued	55,738,779	55,461,246
Common stock, shares outstanding	53,305,485	53,427,234
Treasury stock (in shares)	2,433,294	2,034,012

Condensed Consolidated Statemen

Condensed Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement [Abstract]
Net sales	$ 379,150	$ 318,441	$ 1,096,393	$ 864,094
Cost of sales	193,276	165,649	566,000	471,977
Gross profit	185,874	152,792	530,393	392,117
Operating expenses:
Sales and marketing	20,688	17,332	58,764	53,341
Research and development	34,277	31,710	102,807	95,132
General and administrative	32,557	29,038	93,715	82,561
Goodwill impairment	0	44,589	0	44,589
Impairment of long-lived assets and other restructuring charges	0	12	0	1,177
Gain on foreign exchange	(3,634)	(11,302)	(7,973)	(18,101)
Total operating expenses	83,888	111,379	247,313	258,699
Operating income	101,986	41,413	283,080	133,418
Other (expense) income, net:
Interest (expense) income, net	(288)	1,168	(1,190)	6,097
Other (expense) income, net	(211)	(59)	70	581
Total other (expense) income	(499)	1,109	(1,120)	6,678
Income before provision for income taxes	101,487	42,522	281,960	140,096
Provision for income taxes	26,788	6,992	69,362	29,434
Net income	74,699	35,530	212,598	110,662
Less: net (loss) income attributable to non-controlling interests	(703)	(74)	(731)	429
Net income attributable to IPG Photonics Corporation common stockholders	$ 75,402	$ 35,604	$ 213,329	$ 110,233
Net income attributable to IPG Photonics Corporation per common share:
Basic (in dollars per share)	$ 1.41	$ 0.67	$ 3.99	$ 2.07
Diluted (in dollars per share)	$ 1.40	$ 0.66	$ 3.95	$ 2.05
Weighted average common shares outstanding:
Basic (in shares)	53,387,175	53,098,366	53,500,507	53,136,226
Diluted (in shares)	53,833,752	53,663,640	54,053,343	53,690,805

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 74,699	$ 35,530	$ 212,598	$ 110,662
Other comprehensive income, net of tax:
Translation adjustments	(15,558)	(8,562)	(28,921)	(46,445)
Adjustment for net gain realized and included in net income	0	(232)	0	(232)
Unrealized gain (loss) on derivatives	46	(551)	165	(516)
Total other comprehensive loss	(15,512)	(9,345)	(28,756)	(47,193)
Comprehensive income	59,187	26,185	183,842	63,469
Less: comprehensive (loss) income attributable to non-controlling interests	(869)	(93)	(799)	144
Comprehensive income attributable to IPG Photonics Corporation	$ 60,056	$ 26,278	$ 184,641	$ 63,325

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash flows from operating activities:
Net income	$ 212,598	$ 110,662
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	72,127	71,188
Deferred income taxes	(4,757)	(10,122)
Stock-based compensation	28,536	26,394
Goodwill impairment	0	44,589
Impairment of long-lived assets	0	671
Unrealized gain on foreign currency transactions	(4,313)	(21,759)
Other	5,828	6,823
Provisions for inventory, warranty and bad debt	50,364	42,559
Changes in assets and liabilities that provided (used) cash, net of acquisitions:
Accounts receivable	(12,281)	2,308
Inventories	(105,384)	(34,213)
Prepaid expenses and other assets	(8,823)	(2,065)
Accounts payable	26,296	8,819
Accrued expenses and other liabilities	7,963	(17,492)
Income and other taxes payable	37,002	(28,345)
Net cash provided by operating activities	305,156	200,017
Cash flows from investing activities:
Purchases of and deposits on property, plant and equipment	(93,857)	(61,871)
Proceeds from sales of property, plant and equipment	859	689
Purchases of short-term investments	(1,437,193)	(732,729)
Proceeds from short-term investments	1,226,445	697,816
Other	(1,078)	17
Net cash used in investing activities	(304,824)	(96,078)
Cash flows from financing activities:
Principal payments on long-term borrowings	(2,851)	(2,798)
Proceeds from issuance of common stock under employee stock option and purchase plans less payments for taxes related to net share settlement of equity awards	11,427	16,767
Purchase of treasury stock, at cost	(78,071)	(37,884)
Payment of purchase price holdback from business combination	(2,624)	(1,650)
Net cash used in financing activities	(72,119)	(25,565)
Effect of changes in exchange rates on cash, cash equivalents and restricted cash	(11,862)	4,692
Net (decrease) increase in cash, cash equivalents and restricted cash	(83,649)	83,066
Cash, cash equivalents and restricted cash — Beginning of period	878,553	682,984
Cash and cash equivalents — End of period	794,904	766,050
Supplemental disclosure of cash flow information:
Cash paid for interest	1,932	1,650
Cash paid for income taxes	35,982	65,895
Non-cash transactions:
Demonstration units transferred from inventory to other assets	4,245	6,724
Inventory transferred to machinery and equipment	1,965	2,362
Changes in accounts payable related to property, plant and equipment	1,461	1,248
Leased assets obtained in exchange for new operating lease liabilities	$ 2,500	$ 2,764

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Equity - USD ($) $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Common Stock	Treasury Stock	Additional Paid-In Capital	Retained Earnings	Retained EarningsCumulative Effect, Period of Adoption, Adjustment	Accumulated Other Comprehensive (Loss) Income	Non- controlling Interest
Balance, beginning of year (in shares) at Dec. 31, 2019			53,010,875	1,732,352
Balance, beginning of period at Dec. 31, 2019	$ 2,402,443	$ (115)	$ 5	$ (265,730)	$ 785,636	$ 2,028,734	$ (115)	$ (146,919)	$ 717
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options and vesting of RSU's and PSU's (in shares)			514,717
Exercise of stock options and vesting of RSUs and PSUs	14,217		$ 1		14,216
Common stock issued under employee stock purchase plan (in shares)			20,484
Common stock issued under employee stock purchase plan	2,550				2,550
Purchased common stock (in shares)			(301,660)	(301,660)
Purchased common stock	(37,884)			$ (37,884)
Stock-based compensation	26,394				26,394
Net income	110,662					110,233			429
Foreign currency translation adjustments	(46,445)							(46,160)	(285)
Unrealized gain (loss) on derivatives, net of tax	(516)							(516)
Adjustment for net gain realized and included in net income	(232)							(232)
Balance, end of period (in shares) at Sep. 30, 2020			53,244,416	2,034,012
Balance, end of period at Sep. 30, 2020	2,471,074		$ 6	$ (303,614)	828,796	2,138,852		(193,827)	861
Balance, beginning of year (in shares) at Jun. 30, 2020			53,182,148	1,972,540
Balance, beginning of period at Jun. 30, 2020	2,437,306		$ 6	$ (293,960)	811,559	2,103,248		(184,501)	954
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options and vesting of RSU's and PSU's (in shares)			123,740
Exercise of stock options and vesting of RSUs and PSUs	8,497				8,497
Purchased common stock (in shares)			(61,472)	(61,472)
Purchased common stock	(9,654)			$ (9,654)
Stock-based compensation	8,740				8,740
Net income	35,530					35,604			(74)
Foreign currency translation adjustments	(8,562)							(8,543)	(19)
Unrealized gain (loss) on derivatives, net of tax	(551)							(551)
Adjustment for net gain realized and included in net income	(232)							(232)
Balance, end of period (in shares) at Sep. 30, 2020			53,244,416	2,034,012
Balance, end of period at Sep. 30, 2020	2,471,074		$ 6	$ (303,614)	828,796	2,138,852		(193,827)	861
Balance, beginning of year (in shares) at Dec. 31, 2020			53,427,234	2,034,012
Balance, beginning of period at Dec. 31, 2020	2,594,111		$ 6	$ (303,614)	854,301	2,188,191		(146,065)	1,292
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options and vesting of RSU's and PSU's (in shares)			262,462
Exercise of stock options and vesting of RSUs and PSUs	8,727				8,727
Common stock issued under employee stock purchase plan (in shares)			15,071
Common stock issued under employee stock purchase plan	2,700				2,700
Purchased common stock (in shares)			(399,282)	(399,282)
Purchased common stock	(78,071)			$ (78,071)
Stock-based compensation	28,536				28,536
Net income	212,598					213,329			(731)
Foreign currency translation adjustments	(28,921)							(28,853)	(68)
Unrealized gain (loss) on derivatives, net of tax	165							165
Adjustment for net gain realized and included in net income	0
Balance, end of period (in shares) at Sep. 30, 2021			53,305,485	2,433,294
Balance, end of period at Sep. 30, 2021	2,739,845		$ 6	$ (381,685)	894,264	2,401,520		(174,753)	493
Balance, beginning of year (in shares) at Jun. 30, 2021			53,491,889	2,233,789
Balance, beginning of period at Jun. 30, 2021	2,706,280		$ 6	$ (345,345)	883,546	2,326,118		(159,407)	1,362
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options and vesting of RSU's and PSU's (in shares)			13,101
Exercise of stock options and vesting of RSUs and PSUs	860				860
Purchased common stock (in shares)			(199,505)	(199,505)
Purchased common stock	(36,340)			$ (36,340)
Stock-based compensation	9,858				9,858
Net income	74,699					75,402			(703)
Foreign currency translation adjustments	(15,558)							(15,392)	(166)
Unrealized gain (loss) on derivatives, net of tax	46							46
Adjustment for net gain realized and included in net income	0
Balance, end of period (in shares) at Sep. 30, 2021			53,305,485	2,433,294
Balance, end of period at Sep. 30, 2021	$ 2,739,845		$ 6	$ (381,685)	$ 894,264	$ 2,401,520		$ (174,753)	$ 493

Basis of Presentation and Signi

Basis of Presentation and Significant Accounting Policies	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES	BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES Basis of Presentation — The accompanying unaudited condensed consolidated financial statements have been prepared by IPG Photonics Corporation, or "IPG", "its" or the "Company". Certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America have been condensed or omitted pursuant to the rules and regulations of the Securities and Exchange Commission ("SEC"). The condensed consolidated financial statements include the Company's accounts and those of its subsidiaries. All intercompany balances have been eliminated in consolidation. These condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto in the Company's Annual Report on Form 10-K for the year ended December 31, 2020. In the opinion of the Company's management, the financial information for the interim periods presented reflects all adjustments necessary for a fair presentation of the Company's financial position, results of operations and cash flows. The results reported in these condensed consolidated financial statements are not necessarily indicative of results that may be expected for the entire year. Accounts Receivable and Allowance for Doubtful Accounts — The Company maintains an allowance for doubtful accounts to provide for the estimated amount of accounts receivable that will not be collected. The allowance is based upon an estimate of expected credit losses over the life of outstanding receivables. The estimate involves an assessment of customer creditworthiness, historical payment experience, an assumption of future expected credit losses, and the age of outstanding receivables. Activity related to the allowance for doubtful accounts was as follows: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Balance, beginning of period $ 2,251 $ 1,999 $ 2,156 $ 2,547 Provision for bad debts, net of (recoveries) (295) 143 (154) (206) Uncollectable accounts written off — (1) (59) (72) Foreign currency translation (15) (80) (2) (208) Balance, end of period $ 1,941 $ 2,061 $ 1,941 $ 2,061 Subsequent Events — The Company has considered the impact of subsequent events through the filing date of these financial statements. There were no events through the filing date of these financial statements required to be disclosed.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
RECENT ACCOUNTING PRONOUNCEMENTS	RECENT ACCOUNTING PRONOUNCEMENTS Adopted Pronouncements — In December 2019, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2019-12, "Simplifying the Accounting for Income Taxes" ("ASU 2019-12"), which modifies ASC 740 to simplify the accounting for income taxes. The Company adopted ASU 2019-12 as of January 1, 2021. The impact from adopting this standard was immaterial. In June 2016, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2016-13, "Measurement of Credit Losses on Financial Instruments" ("ASU 2016-13"), which adds an impairment model (known as the current expected credit loss ("CECL") model) that is based on expected losses rather than incurred losses. Under the new guidance, an entity recognizes as an allowance for its estimate of expected credit losses, which the FASB believes will result in more timely recognition of such losses. The ASU is also intended to reduce the complexity by decreasing the number of credit impairment models that entities use to account for debt instruments. The Company adopted ASU 2016-03, along with its subsequent clarifications, as of January 1, 2020. The cumulative effect of the changes made to the Company's condensed consolidated January 1, 2020 balance sheet for the adoption of ASU 2016-13 was as follows: Balance at Adoption of Balance at December 31, 2019 ASU 2016-13 January 1, 2020 Balance Sheet Accounts receivable, net $ 238,479 $ (148) $ 238,331 Deferred income taxes, net 31,395 33 31,428 Retained earnings 2,028,734 (115) 2,028,619 Other Pronouncements Currently Under Evaluation — In March 2020, the FASB issued ASU No. 2020-04, "Reference Rate Reform (Topic 848)" ("ASU 2020-04"), which offers optional expedients related to contracts, hedging relationships, and other transactions that reference LIBOR or another reference rate expected to be discontinued because of reference rate reform. ASU 2020-04, along with its subsequent clarifications, is effective from March 12, 2020 through December 31, 2022. The Company is currently evaluating the standard but does not expect that it will have a material effect on its condensed consolidated financial statements, if adopted.

Revenue From Contracts With Cus

Revenue From Contracts With Customers	9 Months Ended
	Sep. 30, 2021
Revenue from Contract with Customer [Abstract]
REVENUE FROM CONTRACTS WITH CUSTOMERS	REVENUE FROM CONTRACTS WITH CUSTOMERS Sales are derived from products for different applications: fiber lasers, diode lasers, systems and accessories for materials processing; fiber lasers, diodes and amplifiers for advanced applications; fiber amplifiers and transceivers for communications applications; and fiber lasers, systems and fibers for medical applications. The following tables represent a disaggregation of revenue from contracts with customers: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Sales by Application Materials processing $ 346,045 $ 290,028 $ 1,008,939 $ 779,810 Other applications 33,105 28,413 87,454 84,284 Total $ 379,150 $ 318,441 $ 1,096,393 $ 864,094 Sales by Product High Power Continuous Wave ("CW") Lasers $ 177,787 $ 184,387 $ 538,013 $ 461,181 Medium Power CW Lasers 24,520 11,756 58,579 33,701 Pulsed Lasers 59,051 34,975 176,219 109,391 Quasi-Continuous Wave ("QCW") Lasers 16,312 15,079 45,503 38,660 Laser and Non-Laser Systems 32,523 20,841 89,236 64,417 Other Revenue including Amplifiers, Service, Parts, Accessories and Change in Deferred Revenue 68,957 51,403 188,843 156,744 Total $ 379,150 $ 318,441 $ 1,096,393 $ 864,094 Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Sales by Geography North America $ 81,605 $ 52,732 $ 221,123 $ 173,972 Europe: Germany 26,832 16,163 74,840 51,208 Other including Eastern Europe/CIS 79,777 54,907 212,709 158,686 Asia and Australia: China 137,211 148,049 436,119 361,864 Japan 14,286 12,884 35,485 41,241 Other 35,844 31,227 106,608 70,924 Rest of World 3,595 2,479 9,509 6,199 Total $ 379,150 $ 318,441 $ 1,096,393 $ 864,094 Timing of Revenue Recognition Goods and services transferred at a point in time $ 364,677 $ 308,474 $ 1,054,554 $ 824,069 Goods and services transferred over time 14,473 9,967 41,839 40,025 Total $ 379,150 $ 318,441 $ 1,096,393 $ 864,094 One of the Company's customers accounted for 23% and 21% of the Company's net accounts receivable as of September 30, 2021 and December 31, 2020, respectively. The Company enters into contracts to sell lasers and spare parts, for which revenue is generally recognized upon shipment or delivery, depending on the terms of the contract. The Company also provides installation services and extended warranties. The Company frequently receives consideration from a customer prior to transferring goods to the customer under the terms of a sales contract. The Company records customer deposits related to these prepayments, which represent a contract liability. The Company also records deferred revenue related to installation services when consideration is received before the services have been performed. The standalone selling price for installation services is determined based on the estimated number of days of service technician time required for installation at standard service rates. The Company recognizes customer deposits and deferred revenue as net sales after control of the goods or services has been transferred to the customer and all revenue recognition criteria are met. The Company bills customers for extended warranties upon entering into the agreement with the customer, resulting in deferred revenue that is recognized over the period of the extended warranty contract. The Company recognizes revenue over time on contracts for the sale of robotics systems. The timing of customer payments on these contracts generally differs from the timing of revenue recognized. If revenue recognized exceeds customer payments, a contract asset is recorded and if customer payments exceed revenue recognized, a contract liability is recorded. Contract assets are included within prepaid expense and other current assets on the condensed consolidated balance sheets. Contract liabilities are included within accrued expenses and other current liabilities on the condensed consolidated balance sheets. Certain deferred revenues related to extended warranties in excess one year from the balance sheet date are included within deferred income taxes and other long-term liabilities on the condensed consolidated balance sheets. The following table reflects the changes in the Company's contract assets and liabilities for the nine months ended September 30, 2021 and 2020: September 30, December 31, September 30, December 31, 2021 2020 Change 2020 2019 Change Contract assets Contract assets $ 7,510 $ 8,999 $ (1,489) $ 6,771 $ 9,645 $ (2,874) Contract liabilities Contract liabilities - current 80,694 71,246 9,448 57,034 59,531 (2,497) Contract liabilities - long-term 2,737 2,189 548 2,121 1,820 301 During the three months ended September 30, 2021 and 2020 the Company recognized revenue of $10,172 and $10,179, respectively, that was included in contract liabilities at the beginning of each period. During the nine months ended September 30, 2021 and 2020 the Company recognized revenue of $58,069 and $41,622, respectively, that was included in contract liabilities at the beginning of each period. The Company has elected the practical expedient in ASC 606-10-50-14, whereby the performance obligations for contracts with an original expected duration of one year or less are not disclosed. The following table represents the Company's remaining performance obligations from contracts that are recognized over time as of September 30, 2021: Remaining Performance Obligations 2021 (a) 2022 2023 2024 2025 Thereafter Total Revenue expected to be recognized for extended warranty agreements $ 1,965 $ 2,841 $ 1,102 $ 842 $ 386 $ 64 $ 7,200 Revenue to be earned over time from contracts to sell robotic systems 16,849 17,679 — — — — 34,528 Total $ 18,814 $ 20,520 $ 1,102 $ 842 $ 386 $ 64 $ 41,728 (a) For the three-month period beginning October 1, 2021.

Restricted Cash

Restricted Cash	9 Months Ended
	Sep. 30, 2021
Cash and Cash Equivalents [Abstract]
RESTRICTED CASH	RESTRICTED CASH The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the condensed consolidated balance sheets to the total of the same amounts shown in the condensed consolidated statements of cash flows. September 30, December 31, 2021 2020 2020 2019 Cash and cash equivalents $ 794,904 $ 763,920 $ 876,231 $ 680,070 Restricted cash included in prepaid expenses and other current assets — 2,130 2,322 — Restricted cash included in other assets — — — 2,914 Cash, cash equivalents and restricted cash in the condensed consolidated statements of cash flows $ 794,904 $ 766,050 $ 878,553 $ 682,984

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	FAIR VALUE MEASUREMENTS The Company's financial instruments consist of cash equivalents, short-term investments, accounts receivable, accounts payable, drawings on revolving lines of credit, long-term debt, interest rate swaps and contingent purchase consideration. The valuation techniques used to measure fair value are based upon observable and unobservable inputs. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect internal market assumptions. These two types of inputs create the following fair value hierarchy: Level 1, defined as observable inputs such as quoted prices for identical instruments in active markets; Level 2, defined as inputs other than quoted prices in active markets that are either directly or indirectly observable; and Level 3, defined as unobservable inputs for which little or no market data exists, therefore requiring an entity to develop its own assumptions. The Company classifies its financial instruments according to the prescribed criteria. The carrying amounts of money market fund deposits, term deposits, accounts receivable, accounts payable and drawings on revolving lines of credit are considered reasonable estimates of their fair market value due to the short maturity of most of these instruments or as a result of the competitive market interest rates, which have been negotiated. The fair value of the Company's bond securities is based upon quoted prices for instruments with identical terms in active markets. The Company's commercial paper securities reported at fair value are based upon model-driven valuations in which all significant inputs are observable or can be derived from or corroborated by observable market data for substantially the full term of the asset or liability, and are therefore classified as Level 2. The following table presents fair value information related to the Company's assets and liabilities measured at amortized cost on the condensed consolidated balance sheets with the exception of the interest rate swap and contingent purchase consideration, which are measured at fair value: Fair Value Measurements at September 30, 2021 Total Level 1 Level 2 Level 3 Assets Cash equivalents: Money market fund deposits and term deposits $ 252,630 $ 252,630 $ — $ — Commercial paper 60,692 — 60,692 — Corporate bonds 13,690 — 13,690 — Short-term investments: Commercial paper 570,645 — 570,645 — Corporate bonds 142,349 — 142,349 — Municipal bonds 8,065 — 8,065 — Certificates of deposit 3,000 — 3,000 — Total $ 1,051,071 $ 252,630 $ 798,441 $ — Liabilities Long-term debt $ 35,266 $ — $ 35,266 $ — Contingent purchase consideration 1,406 — — 1,406 Interest rate swap 388 — 388 — Total $ 37,060 $ — $ 35,654 $ 1,406 Fair Value Measurements at December 31, 2020 Total Level 1 Level 2 Level 3 Assets Cash equivalents: Money market fund deposits and term deposits $ 218,984 $ 218,984 $ — $ — Commercial paper 162,749 — 162,749 — Corporate bonds 29,010 — 29,010 — U.S. Treasury and agency obligations 6,999 — 6,999 — Short-term investments: Commercial paper 368,665 — 368,665 — Corporate bonds 88,171 — 88,171 — U.S. Treasury and agency obligations 49,996 — 49,996 — Municipal bonds 7,997 — 7,997 — Total $ 932,571 $ 218,984 $ 713,587 $ — Liabilities Long-term debt $ 38,402 $ — $ 38,402 $ — Contingent purchase consideration 1,963 — — 1,963 Interest rate swaps 603 — 603 — Total $ 40,968 $ — $ 39,005 $ 1,963 Short-term investments consist of liquid investments including commercial paper, corporate bonds, municipal bonds and certificates of deposit with original maturities of greater than three months but less than one year and are recorded at amortized cost. There were no impairments for the investments considered held-to-maturity during the quarters ended September 30, 2021 and 2020. There were no current expected credit loss allowances for the investments considered held-to-maturity at September 30, 2021 and 2020. The Company holds highly-rated held-to-maturity instruments that are within one year of maturity. The following table presents the effective maturity dates of debt investments, which are held-to-maturity: September 30, 2021 December 31, 2020 Book Value Fair Value Book Value Fair Value Investment maturity Less than 1 year $ 724,103 $ 724,059 $ 514,835 $ 514,829 The Company entered into an interest rate swap that is designated as a cash flow hedge associated with a long-term note issued during the second quarter of 2016 that will terminate with the long-term note in May 2023. The fair value at September 30, 2021 for the interest rate swap considered pricing models whose inputs are observable for the securities held by the Company. At September 30, 2021 and December 31, 2020, the Company's long-term notes consisted of a variable rate note and a fixed rate note, and are reported at amortized cost on the condensed consolidated balance sheets. For disclosure purposes, the fair value of the long-term notes was estimated using a discounted cash flow model using observable market interest rates and is classified as level 2. Based on the discounted cash flow model, the fair values of the long-term notes, including the current portion, at September 30, 2021 and December 31, 2020 were $35,266 and $38,402 respectively, as compared to the book value of $35,116 and $37,967, respectively. The fair values of contingent purchase consideration at September 30, 2021 and December 31, 2020 were determined using an income approach at the respective business combination date and at the reporting date. The approach is based on significant inputs that are not observable in the market and include key assumptions such as assessing the probability of meeting certain milestones required to earn the contingent purchase consideration. The following table presents information about the Company's movement in Level 3 assets and liabilities measured at fair value: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Auction rate securities Balance, beginning of period $ — $ 596 $ — $ 592 Redemptions — (596) — (596) Change in fair value and accretion — — — 4 Balance, end of period $ — $ — $ — $ — Contingent purchase consideration Balance, beginning of period $ 1,529 $ — $ 1,963 $ 273 Cash payments — — (466) (272) Foreign exchange adjustment (123) — (91) (1) Balance, end of period $ 1,406 $ — $ 1,406 $ —

Inventories

Inventories	9 Months Ended
	Sep. 30, 2021
Inventory Disclosure [Abstract]
INVENTORIES	INVENTORIES Inventories consist of the following: September 30, December 31, 2021 2020 Components and raw materials $ 247,929 $ 190,775 Work-in-process 33,335 47,251 Finished goods 153,806 126,967 Total $ 435,070 $ 364,993 The Company recorded inventory provisions totaling $7,882 and $11,514 for the three months ended September 30, 2021 and 2020, respectively and $23,529 and $25,955 for the nine months ended September 30, 2021 and 2020. These provisions relate to the recoverability of the value of inventories due to technological changes and excess quantities. These provisions are reported as a reduction to components and raw materials and finished components and devices.

Goodwill and Intangibles

Goodwill and Intangibles	9 Months Ended
	Sep. 30, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
GOODWILL AND INTANGIBLES	GOODWILL AND INTANGIBLES The following table sets forth the changes in the carrying amount of goodwill: Nine Months Ended September 30, 2021 2020 Balance at January 1 $ 41,366 $ 82,092 Adjustment to goodwill during measurement period (2,205) — Foreign exchange adjustment (456) 228 Impairment losses — (44,589) Balance at September 30 $ 38,705 $ 37,731 During the fourth quarter of 2020, the Company acquired Pi-Tecnologia S.A. ("PiTec"), which is located in Brazil, to support development in advanced photonics. The acquisition price was $2,717, of which $906 was paid at closing and the remainder of which may be earned over three years based on achievement of certain financial targets. The acquisition date contingent purchase consideration amount was $1,811. The Company paid $466 of the contingent purchase consideration on January 31, 2021. The liabilities related to the contingent purchase consideration were included in accrued expenses and other current liabilities and deferred taxes and other long-term liabilities as of September 30, 2021 and December 31, 2020. During the first quarter of 2021, the Company finalized the purchase price allocations related to the intangible assets, which resulted in adjusting the amounts that were provisionally reported as goodwill to intangible assets for customer relationships and production know-how. This adjustment reduced goodwill by $2,205, increased intangible assets by $2,929 and increased deferred tax liabilities by $724. After completion of the purchase price allocations, the $724 excess of the acquisition consideration over the fair value of assets acquired and liabilities assumed was recorded to goodwill. The goodwill arising from this acquisition will not be deductible for tax purposes. Intangible assets, subject to amortization, consisted of the following: September 30, 2021 December 31, 2020 Gross Carrying Amount Accumulated Net Weighted- Average Lives Gross Carrying Amount Accumulated Net Weighted- Customer relationships $ 59,804 $ (22,149) $ 37,655 10 years $ 58,041 $ (17,674) $ 40,367 11 years Technology, trademark and trade name 40,601 (25,002) 15,599 7 years 40,518 (20,949) 19,569 7 years Production know-how 10,449 (8,604) 1,845 7 years 9,325 (8,167) 1,158 7 years Patents 8,036 (7,349) 687 8 years 8,036 (7,016) 1,020 8 years Total $ 118,890 $ (63,104) $ 55,786 $ 115,920 $ (53,806) $ 62,114 Amortization expense for the three months ended September 30, 2021 and 2020 was $3,051 and $2,947, respectively. Amortization expense for the nine months ended September 30, 2021 and 2020 was $9,387 and $9,029, respectively. The estimated future amortization expense for intangibles for the remainder of 2021 and subsequent years is as follows: 2021 (a) 2022 2023 2024 2025 Thereafter Total $ 3,050 $ 11,459 10,552 $ 8,025 $ 6,518 $ 16,182 $ 55,786 (a) For the three-month period beginning October 1, 2021.

Accrued Expenses and Other Liab

Accrued Expenses and Other Liabilities	9 Months Ended
	Sep. 30, 2021
Payables and Accruals [Abstract]
ACCRUED EXPENSES AND OTHER LIABILITIES	ACCRUED EXPENSES AND OTHER LIABILITIES Accrued expenses and other liabilities consist of the following: September 30, December 31, 2021 2020 Contract liabilities $ 80,694 $ 71,246 Accrued compensation 81,078 62,785 Current portion of accrued warranty 25,650 24,345 Short-term lease liabilities 5,217 5,778 Other 16,276 12,586 Total $ 208,915 $ 176,740

Product Warranties

Product Warranties	9 Months Ended
	Sep. 30, 2021
Product Warranties Disclosures [Abstract]
PRODUCT WARRANTIES	PRODUCT WARRANTIESThe Company typically provides one Activity related to the warranty accrual was as follows: Nine Months Ended September 30, 2021 2020 Balance at January 1 $ 45,669 $ 48,866 Provision for warranty accrual 26,535 16,255 Warranty claims (21,576) (20,992) Foreign currency translation (1,774) 822 Balance at September 30 $ 48,854 $ 44,951 Accrued warranty reported in the accompanying condensed consolidated financial statements as of September 30, 2021 and December 31, 2020 consisted of $25,650 and $24,345 in accrued expenses and other liabilities, respectively, and $23,204 and $21,324 in deferred income taxes and other long-term liabilities, respectively.

Financing Arrangements

Financing Arrangements	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
FINANCING ARRANGEMENTS	FINANCING ARRANGEMENTS The Company's borrowings under existing financing arrangements consist of the following: September 30, December 31, 2021 2020 Total debt $ 35,116 $ 37,967 Less: current portion (18,788) (3,810) Long-term debt, net of current portion $ 16,328 $ 34,157 Term Debt: At September 30, 2021, the Company has an unsecured long-term note with an outstanding principal balance of $17,516, of which, $1,188 is the current portion. The interest on this unsecured long-term note is variable at 1.20% above LIBOR and is fixed using an interest rate swap at 2.85% per annum. The unsecured long-term note matures in May 2023, at which time the outstanding principal balance will be $15,438. Also at September 30, 2021, the Company has another long-term note that is secured by its corporate aircraft with an outstanding principal balance of $17,600, all of which is current. The interest on this collateralized long-term note is fixed at 2.74% per annum. The collateralized long-term note matures in July 2022, at which time the outstanding principal balance will be $15,375. The future principal payments for the Company’s Notes as of September 30, 2021 are as follows: 2021 (a) $ 959 2022 18,126 2023 16,031 Total $ 35,116 (a) For the three-month period beginning October 1, 2021. Revolving Line of Credit Facilities:

Derivative Financial Instrument

Derivative Financial Instruments	9 Months Ended
	Sep. 30, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
DERIVATIVE FINANCIAL INSTRUMENTS	DERIVATIVE FINANCIAL INSTRUMENTS The Company's only outstanding derivative financial instrument is an interest rate swap that is classified as a cash flow hedge of its variable rate debt. The fair value amounts in the condensed consolidated balance sheets were: September 30, December 31, 2021 2020 Notional amounts (1) $ 17,516 $ 18,406 Fair values: Deferred income taxes and other long-term liabilities $ 388 $ 603 (1) Notional amounts represent the gross contract/notional amount of the derivatives outstanding. The derivative gains and losses in the condensed consolidated financial statements related to the Company's current and previous interest rate swap contracts were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Effective portion recognized in other comprehensive income, pretax: Interest rate swap $ 60 $ (723) $ 215 $ (679)

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIESFrom time to time, the Company may be involved in disputes and legal proceedings in the ordinary course of its business. These proceedings may include allegations of infringement of intellectual property, commercial disputes and employment matters. As of September 30, 2021 and through the filing date of these condensed consolidated financial statements, the Company has no legal proceedings ongoing that management estimates could have a material effect on the Company's condensed consolidated financial statements.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2021
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES The effective tax rates were 26.4% and 16.4% for the three months ended September 30, 2021 and 2020, respectively, and 24.6% and 21.0% for the nine months ended September 30, 2021, and 2020, respectively. There were net discrete tax benefits of $1,424 and $727 for the three months ended September 30, 2021 and 2020, respectively, and $5,849 and $6,658 for the nine months ended September 30, 2021 and 2020, respectively, which were primarily related to the tax deductions for equity-based compensation that exceeded compensation expense recognized for books and to provision to return adjustments for the prior year. The primary reasons for the increase in the tax rate from the prior year is due in part to the higher level of income in 2021 which means the benefits from equity based compensation and tax credits provided a lower percentage benefit and in part to the impact to the third quarter 2020 tax rate from new regulations for the Global Intangible Low-Taxed Income (“GILTI”) provisions of US tax law issued in July 2020, which allowed companies to elect out of GILTI for high taxed foreign income. This change substantially reduced the tax rate in that quarter as it reduced the annual effective rate applied to year to date income; the impact of that reduced rate applied to income earned in the first two quarters of 2020 reduced the tax expense in the third quarter of 2020. The Company accounts for its uncertain tax positions in accordance with the accounting standards for income taxes. The Company classifies interest and penalties related to unrecognized tax benefits as a component of the provision for income taxes. The following is a summary of the activity of the Company’s unrecognized tax benefits for nine months ended September 30, 2021 and 2020: Nine Months Ended September 30, 2021 2020 Balance at January 1, $ 14,706 $ 11,416 Additions for tax positions in current period 4,000 2,000 Foreign currency translation 92 (938) Balance at September 30, $ 18,798 $ 12,478

Net Income Attributable to IPG

Net Income Attributable to IPG Photonics Corporation Per Common Share	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
NET INCOME ATTRIBUTABLE TO IPG PHOTONICS CORPORATION PER COMMON SHARE	NET INCOME ATTRIBUTABLE TO IPG PHOTONICS CORPORATION PER COMMON SHARE The following table sets forth the computation of diluted net income attributable to IPG Photonics Corporation per common share following the treasury stock method: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Net income attributable to IPG Photonics Corporation common stockholders $ 75,402 $ 35,604 $ 213,329 $ 110,233 Basic weighted average common shares 53,387,175 53,098,366 53,500,507 53,136,226 Dilutive effect of common stock equivalents 446,577 565,274 552,836 554,579 Diluted weighted average common shares 53,833,752 53,663,640 54,053,343 53,690,805 Basic net income attributable to IPG Photonics Corporation per common share $ 1.41 $ 0.67 $ 3.99 $ 2.07 Diluted net income attributable to IPG Photonics Corporation per common share $ 1.40 $ 0.66 $ 3.95 $ 2.05 The computation of diluted weighted average common shares excludes common stock equivalents including non-qualified stock options, performance stock units ("PSUs"), restricted stock units ("RSUs") and employee stock purchase plan ("ESPP") because the effect of including them would be anti-dilutive. The weighted average anti-dilutive shares outstanding for the three and nine months ended September 30, 2021 and 2020 were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Non-qualified stock options 225,684 528,257 202,077 555,816 Restricted stock units 128,402 28,905 100,066 36,169 Performance stock units 30,142 — 24,732 19,791 Employee stock purchase plan — 5,462 — 16,387 Total weighed average anti-dilutive shares outstanding 384,228 562,624 326,875 628,163 On May 5, 2020, the Company announced that its Board of Directors authorized the purchase of up to $200,000 of IPG common stock. This authorization is separate from, and in addition to, the Company's $125,000 stock repurchase program authorized in February 2019. Under the February 2019 authorization, IPG may repurchase shares of common stock in an amount not to exceed the lesser of the number of shares issued to employees and directors under the Company's various employee and director equity compensation and employee stock purchase plans from January 1, 2019 through December 31, 2020 or $125,000. Under the 2020 authorization, the Company may purchase shares up to $200,000. In both purchase authorizations, share limits are exclusive of fees, commissions or other expenses. Share repurchases may be made periodically in open-market transactions using the Company's working capital and are subject to market conditions, legal

Basis of Presentation and Sig_2

Basis of Presentation and Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation — The accompanying unaudited condensed consolidated financial statements have been prepared by IPG Photonics Corporation, or "IPG", "its" or the "Company". Certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America have been condensed or omitted pursuant to the rules and regulations of the Securities and Exchange Commission ("SEC"). The condensed consolidated financial statements include the Company's accounts and those of its subsidiaries. All intercompany balances have been eliminated in consolidation. These condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto in the Company's Annual Report on Form 10-K for the year ended December 31, 2020.
Accounts Receivable and Allowance for Doubtful Accounts	Accounts Receivable and Allowance for Doubtful Accounts — The Company maintains an allowance for doubtful accounts to provide for the estimated amount of accounts receivable that will not be collected. The allowance is based upon an estimate of expected credit losses over the life of outstanding receivables. The estimate involves an assessment of customer creditworthiness, historical payment experience, an assumption of future expected credit losses, and the age of outstanding receivables.
Subsequent Events	Subsequent Events — The Company has considered the impact of subsequent events through the filing date of these financial statements. There were no events through the filing date of these financial statements required to be disclosed.
Adopted Pronouncements And Other Pronouncements Currently Under Evaluation	Adopted Pronouncements — In December 2019, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2019-12, "Simplifying the Accounting for Income Taxes" ("ASU 2019-12"), which modifies ASC 740 to simplify the accounting for income taxes. The Company adopted ASU 2019-12 as of January 1, 2021. The impact from adopting this standard was immaterial. In June 2016, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2016-13, "Measurement of Credit Losses on Financial Instruments" ("ASU 2016-13"), which adds an impairment model (known as the current expected credit loss ("CECL") model) that is based on expected losses rather than incurred losses. Under the new guidance, an entity recognizes as an allowance for its estimate of expected credit losses, which the FASB believes will result in more timely recognition of such losses. The ASU is also intended to reduce the complexity by decreasing the number of credit impairment models that entities use to account for debt instruments. The Company adopted ASU 2016-03, along with its subsequent clarifications, as of January 1, 2020. The cumulative effect of the changes made to the Company's condensed consolidated January 1, 2020 balance sheet for the adoption of ASU 2016-13 was as follows: Balance at Adoption of Balance at December 31, 2019 ASU 2016-13 January 1, 2020 Balance Sheet Accounts receivable, net $ 238,479 $ (148) $ 238,331 Deferred income taxes, net 31,395 33 31,428 Retained earnings 2,028,734 (115) 2,028,619 Other Pronouncements Currently Under Evaluation — In March 2020, the FASB issued ASU No. 2020-04, "Reference Rate Reform (Topic 848)" ("ASU 2020-04"), which offers optional expedients related to contracts, hedging relationships, and other transactions that reference LIBOR or another reference rate expected to be discontinued because of reference rate reform. ASU 2020-04, along with its subsequent clarifications, is effective from March 12, 2020 through December 31, 2022. The Company is currently evaluating the standard but does not expect that it will have a material effect on its condensed consolidated financial statements, if adopted.

Basis of Presentation and Sig_3

Basis of Presentation and Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Allowance for Doubtful Accounts	Activity related to the allowance for doubtful accounts was as follows: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Balance, beginning of period $ 2,251 $ 1,999 $ 2,156 $ 2,547 Provision for bad debts, net of (recoveries) (295) 143 (154) (206) Uncollectable accounts written off — (1) (59) (72) Foreign currency translation (15) (80) (2) (208) Balance, end of period $ 1,941 $ 2,061 $ 1,941 $ 2,061

Recent Accounting Pronounceme_2

Recent Accounting Pronouncements (Tables)	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Cumulative Effect of Change to Balance Sheet	The cumulative effect of the changes made to the Company's condensed consolidated January 1, 2020 balance sheet for the adoption of ASU 2016-13 was as follows: Balance at Adoption of Balance at December 31, 2019 ASU 2016-13 January 1, 2020 Balance Sheet Accounts receivable, net $ 238,479 $ (148) $ 238,331 Deferred income taxes, net 31,395 33 31,428 Retained earnings 2,028,734 (115) 2,028,619

Revenue From Contracts With C_2

Revenue From Contracts With Customers (Tables)	9 Months Ended
	Sep. 30, 2021
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following tables represent a disaggregation of revenue from contracts with customers: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Sales by Application Materials processing $ 346,045 $ 290,028 $ 1,008,939 $ 779,810 Other applications 33,105 28,413 87,454 84,284 Total $ 379,150 $ 318,441 $ 1,096,393 $ 864,094 Sales by Product High Power Continuous Wave ("CW") Lasers $ 177,787 $ 184,387 $ 538,013 $ 461,181 Medium Power CW Lasers 24,520 11,756 58,579 33,701 Pulsed Lasers 59,051 34,975 176,219 109,391 Quasi-Continuous Wave ("QCW") Lasers 16,312 15,079 45,503 38,660 Laser and Non-Laser Systems 32,523 20,841 89,236 64,417 Other Revenue including Amplifiers, Service, Parts, Accessories and Change in Deferred Revenue 68,957 51,403 188,843 156,744 Total $ 379,150 $ 318,441 $ 1,096,393 $ 864,094 Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Sales by Geography North America $ 81,605 $ 52,732 $ 221,123 $ 173,972 Europe: Germany 26,832 16,163 74,840 51,208 Other including Eastern Europe/CIS 79,777 54,907 212,709 158,686 Asia and Australia: China 137,211 148,049 436,119 361,864 Japan 14,286 12,884 35,485 41,241 Other 35,844 31,227 106,608 70,924 Rest of World 3,595 2,479 9,509 6,199 Total $ 379,150 $ 318,441 $ 1,096,393 $ 864,094 Timing of Revenue Recognition Goods and services transferred at a point in time $ 364,677 $ 308,474 $ 1,054,554 $ 824,069 Goods and services transferred over time 14,473 9,967 41,839 40,025 Total $ 379,150 $ 318,441 $ 1,096,393 $ 864,094
Changes in Contract Assets and Liabilities	The following table reflects the changes in the Company's contract assets and liabilities for the nine months ended September 30, 2021 and 2020: September 30, December 31, September 30, December 31, 2021 2020 Change 2020 2019 Change Contract assets Contract assets $ 7,510 $ 8,999 $ (1,489) $ 6,771 $ 9,645 $ (2,874) Contract liabilities Contract liabilities - current 80,694 71,246 9,448 57,034 59,531 (2,497) Contract liabilities - long-term 2,737 2,189 548 2,121 1,820 301
Schedule of Remaining Performance Obligations	The following table represents the Company's remaining performance obligations from contracts that are recognized over time as of September 30, 2021: Remaining Performance Obligations 2021 (a) 2022 2023 2024 2025 Thereafter Total Revenue expected to be recognized for extended warranty agreements $ 1,965 $ 2,841 $ 1,102 $ 842 $ 386 $ 64 $ 7,200 Revenue to be earned over time from contracts to sell robotic systems 16,849 17,679 — — — — 34,528 Total $ 18,814 $ 20,520 $ 1,102 $ 842 $ 386 $ 64 $ 41,728 (a) For the three-month period beginning October 1, 2021.

Restricted Cash (Tables)

Restricted Cash (Tables)	9 Months Ended
	Sep. 30, 2021
Cash and Cash Equivalents [Abstract]
Schedule of Cash and Cash Equivalents	The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the condensed consolidated balance sheets to the total of the same amounts shown in the condensed consolidated statements of cash flows. September 30, December 31, 2021 2020 2020 2019 Cash and cash equivalents $ 794,904 $ 763,920 $ 876,231 $ 680,070 Restricted cash included in prepaid expenses and other current assets — 2,130 2,322 — Restricted cash included in other assets — — — 2,914 Cash, cash equivalents and restricted cash in the condensed consolidated statements of cash flows $ 794,904 $ 766,050 $ 878,553 $ 682,984
Schedule of Restricted Cash	The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the condensed consolidated balance sheets to the total of the same amounts shown in the condensed consolidated statements of cash flows. September 30, December 31, 2021 2020 2020 2019 Cash and cash equivalents $ 794,904 $ 763,920 $ 876,231 $ 680,070 Restricted cash included in prepaid expenses and other current assets — 2,130 2,322 — Restricted cash included in other assets — — — 2,914 Cash, cash equivalents and restricted cash in the condensed consolidated statements of cash flows $ 794,904 $ 766,050 $ 878,553 $ 682,984

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Assets and Liabilities Measured at Fair Value	The following table presents fair value information related to the Company's assets and liabilities measured at amortized cost on the condensed consolidated balance sheets with the exception of the interest rate swap and contingent purchase consideration, which are measured at fair value: Fair Value Measurements at September 30, 2021 Total Level 1 Level 2 Level 3 Assets Cash equivalents: Money market fund deposits and term deposits $ 252,630 $ 252,630 $ — $ — Commercial paper 60,692 — 60,692 — Corporate bonds 13,690 — 13,690 — Short-term investments: Commercial paper 570,645 — 570,645 — Corporate bonds 142,349 — 142,349 — Municipal bonds 8,065 — 8,065 — Certificates of deposit 3,000 — 3,000 — Total $ 1,051,071 $ 252,630 $ 798,441 $ — Liabilities Long-term debt $ 35,266 $ — $ 35,266 $ — Contingent purchase consideration 1,406 — — 1,406 Interest rate swap 388 — 388 — Total $ 37,060 $ — $ 35,654 $ 1,406 Fair Value Measurements at December 31, 2020 Total Level 1 Level 2 Level 3 Assets Cash equivalents: Money market fund deposits and term deposits $ 218,984 $ 218,984 $ — $ — Commercial paper 162,749 — 162,749 — Corporate bonds 29,010 — 29,010 — U.S. Treasury and agency obligations 6,999 — 6,999 — Short-term investments: Commercial paper 368,665 — 368,665 — Corporate bonds 88,171 — 88,171 — U.S. Treasury and agency obligations 49,996 — 49,996 — Municipal bonds 7,997 — 7,997 — Total $ 932,571 $ 218,984 $ 713,587 $ — Liabilities Long-term debt $ 38,402 $ — $ 38,402 $ — Contingent purchase consideration 1,963 — — 1,963 Interest rate swaps 603 — 603 — Total $ 40,968 $ — $ 39,005 $ 1,963
Schedule of Effective Maturity Dates of Held to Maturity Investments	The following table presents the effective maturity dates of debt investments, which are held-to-maturity: September 30, 2021 December 31, 2020 Book Value Fair Value Book Value Fair Value Investment maturity Less than 1 year $ 724,103 $ 724,059 $ 514,835 $ 514,829
Fair Value, Assets Measured on Recurring Basis	The following table presents information about the Company's movement in Level 3 assets and liabilities measured at fair value: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Auction rate securities Balance, beginning of period $ — $ 596 $ — $ 592 Redemptions — (596) — (596) Change in fair value and accretion — — — 4 Balance, end of period $ — $ — $ — $ — Contingent purchase consideration Balance, beginning of period $ 1,529 $ — $ 1,963 $ 273 Cash payments — — (466) (272) Foreign exchange adjustment (123) — (91) (1) Balance, end of period $ 1,406 $ — $ 1,406 $ —
Fair Value, Liabilities Measured on Recurring Basis	The following table presents information about the Company's movement in Level 3 assets and liabilities measured at fair value: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Auction rate securities Balance, beginning of period $ — $ 596 $ — $ 592 Redemptions — (596) — (596) Change in fair value and accretion — — — 4 Balance, end of period $ — $ — $ — $ — Contingent purchase consideration Balance, beginning of period $ 1,529 $ — $ 1,963 $ 273 Cash payments — — (466) (272) Foreign exchange adjustment (123) — (91) (1) Balance, end of period $ 1,406 $ — $ 1,406 $ —

Inventories (Tables)

Inventories (Tables)	9 Months Ended
	Sep. 30, 2021
Inventory Disclosure [Abstract]
Components of Inventories	Inventories consist of the following: September 30, December 31, 2021 2020 Components and raw materials $ 247,929 $ 190,775 Work-in-process 33,335 47,251 Finished goods 153,806 126,967 Total $ 435,070 $ 364,993

Goodwill and Intangibles (Table

Goodwill and Intangibles (Tables)	9 Months Ended
	Sep. 30, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	The following table sets forth the changes in the carrying amount of goodwill: Nine Months Ended September 30, 2021 2020 Balance at January 1 $ 41,366 $ 82,092 Adjustment to goodwill during measurement period (2,205) — Foreign exchange adjustment (456) 228 Impairment losses — (44,589) Balance at September 30 $ 38,705 $ 37,731
Schedule of Intangible Assets	Intangible assets, subject to amortization, consisted of the following: September 30, 2021 December 31, 2020 Gross Carrying Amount Accumulated Net Weighted- Average Lives Gross Carrying Amount Accumulated Net Weighted- Customer relationships $ 59,804 $ (22,149) $ 37,655 10 years $ 58,041 $ (17,674) $ 40,367 11 years Technology, trademark and trade name 40,601 (25,002) 15,599 7 years 40,518 (20,949) 19,569 7 years Production know-how 10,449 (8,604) 1,845 7 years 9,325 (8,167) 1,158 7 years Patents 8,036 (7,349) 687 8 years 8,036 (7,016) 1,020 8 years Total $ 118,890 $ (63,104) $ 55,786 $ 115,920 $ (53,806) $ 62,114
Estimated Future Amortization Expense for Intangibles	The estimated future amortization expense for intangibles for the remainder of 2021 and subsequent years is as follows: 2021 (a) 2022 2023 2024 2025 Thereafter Total $ 3,050 $ 11,459 10,552 $ 8,025 $ 6,518 $ 16,182 $ 55,786 (a) For the three-month period beginning October 1, 2021.

Accrued Expenses and Other Li_2

Accrued Expenses and Other Liabilities (Tables)	9 Months Ended
	Sep. 30, 2021
Payables and Accruals [Abstract]
Components of Accrued Expenses and Other Liabilities	Accrued expenses and other liabilities consist of the following: September 30, December 31, 2021 2020 Contract liabilities $ 80,694 $ 71,246 Accrued compensation 81,078 62,785 Current portion of accrued warranty 25,650 24,345 Short-term lease liabilities 5,217 5,778 Other 16,276 12,586 Total $ 208,915 $ 176,740

Product Warranties (Tables)

Product Warranties (Tables)	9 Months Ended
	Sep. 30, 2021
Product Warranties Disclosures [Abstract]
Summary of Product Warranty Activity	Activity related to the warranty accrual was as follows: Nine Months Ended September 30, 2021 2020 Balance at January 1 $ 45,669 $ 48,866 Provision for warranty accrual 26,535 16,255 Warranty claims (21,576) (20,992) Foreign currency translation (1,774) 822 Balance at September 30 $ 48,854 $ 44,951

Financing Arrangements (Tables)

Financing Arrangements (Tables)	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Borrowings Under Existing Financing Arrangements	The Company's borrowings under existing financing arrangements consist of the following: September 30, December 31, 2021 2020 Total debt $ 35,116 $ 37,967 Less: current portion (18,788) (3,810) Long-term debt, net of current portion $ 16,328 $ 34,157
Schedule of Future Principal Payments	The future principal payments for the Company’s Notes as of September 30, 2021 are as follows: 2021 (a) $ 959 2022 18,126 2023 16,031 Total $ 35,116 (a) For the three-month period beginning October 1, 2021.

Derivative Financial Instrume_2

Derivative Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Fair Value of Derivatives	The fair value amounts in the condensed consolidated balance sheets were: September 30, December 31, 2021 2020 Notional amounts (1) $ 17,516 $ 18,406 Fair values: Deferred income taxes and other long-term liabilities $ 388 $ 603 (1) Notional amounts represent the gross contract/notional amount of the derivatives outstanding.
Derivative Gains (Losses) In The Consolidated Statements Of Income Related To Interest Rate Swap Contracts	The derivative gains and losses in the condensed consolidated financial statements related to the Company's current and previous interest rate swap contracts were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Effective portion recognized in other comprehensive income, pretax: Interest rate swap $ 60 $ (723) $ 215 $ (679)

Income Taxes (Tables)

Income Taxes (Tables)	9 Months Ended
	Sep. 30, 2021
Income Tax Disclosure [Abstract]
Schedule of Unrecognized Tax Benefits	The following is a summary of the activity of the Company’s unrecognized tax benefits for nine months ended September 30, 2021 and 2020: Nine Months Ended September 30, 2021 2020 Balance at January 1, $ 14,706 $ 11,416 Additions for tax positions in current period 4,000 2,000 Foreign currency translation 92 (938) Balance at September 30, $ 18,798 $ 12,478

Net Income Attributable to IP_2

Net Income Attributable to IPG Photonics Corporation Per Common Share (Tables)	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Computation of Diluted Net Income Per Share	The following table sets forth the computation of diluted net income attributable to IPG Photonics Corporation per common share following the treasury stock method: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Net income attributable to IPG Photonics Corporation common stockholders $ 75,402 $ 35,604 $ 213,329 $ 110,233 Basic weighted average common shares 53,387,175 53,098,366 53,500,507 53,136,226 Dilutive effect of common stock equivalents 446,577 565,274 552,836 554,579 Diluted weighted average common shares 53,833,752 53,663,640 54,053,343 53,690,805 Basic net income attributable to IPG Photonics Corporation per common share $ 1.41 $ 0.67 $ 3.99 $ 2.07 Diluted net income attributable to IPG Photonics Corporation per common share $ 1.40 $ 0.66 $ 3.95 $ 2.05
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	The weighted average anti-dilutive shares outstanding for the three and nine months ended September 30, 2021 and 2020 were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Non-qualified stock options 225,684 528,257 202,077 555,816 Restricted stock units 128,402 28,905 100,066 36,169 Performance stock units 30,142 — 24,732 19,791 Employee stock purchase plan — 5,462 — 16,387 Total weighed average anti-dilutive shares outstanding 384,228 562,624 326,875 628,163

Basis of Presentation and Sig_4

Basis of Presentation and Significant Accounting Policies (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	$ 2,251	$ 1,999	$ 2,156	$ 2,547
Provision for bad debts, net of (recoveries)	(295)	143	(154)	(206)
Uncollectable accounts written off	0	(1)	(59)	(72)
Foreign currency translation	(15)	(80)	(2)	(208)
Balance, end of period	$ 1,941	$ 2,061	$ 1,941	$ 2,061

Recent Accounting Pronounceme_3

Recent Accounting Pronouncements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Sep. 30, 2021	Dec. 31, 2020
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts receivable, net	$ 238,479	$ 272,699	$ 264,321
Deferred income taxes, net	31,395	49,008	43,197
Retained earnings	$ 2,028,734	$ 2,401,520	$ 2,188,191
Accounting standards update	Accounting Standards Update 2016-13 [Member]
Cumulative Effect, Period of Adoption, Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts receivable, net	$ (148)
Deferred income taxes, net	33
Retained earnings	(115)
Cumulative Effect, Period of Adoption, Adjusted Balance
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts receivable, net	238,331
Deferred income taxes, net	31,428
Retained earnings	$ 2,028,619

Revenue From Contracts With C_3

Revenue From Contracts With Customers (Disaggregation of Revenue, By Application) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Sales by Application
Total	$ 379,150	$ 318,441	$ 1,096,393	$ 864,094
Materials processing
Sales by Application
Total	346,045	290,028	1,008,939	779,810
Other applications
Sales by Application
Total	$ 33,105	$ 28,413	$ 87,454	$ 84,284

Revenue From Contracts With C_4

Revenue From Contracts With Customers (Disaggregation of Revenue, By Product) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation of Revenue [Line Items]
Total	$ 379,150	$ 318,441	$ 1,096,393	$ 864,094
High Power Continuous Wave ("CW") Lasers
Disaggregation of Revenue [Line Items]
Total	177,787	184,387	538,013	461,181
Medium Power CW Lasers
Disaggregation of Revenue [Line Items]
Total	24,520	11,756	58,579	33,701
Pulsed Lasers
Disaggregation of Revenue [Line Items]
Total	59,051	34,975	176,219	109,391
Quasi-Continuous Wave ("QCW") Lasers
Disaggregation of Revenue [Line Items]
Total	16,312	15,079	45,503	38,660
Laser and Non-Laser Systems
Disaggregation of Revenue [Line Items]
Total	32,523	20,841	89,236	64,417
Other Revenue including Amplifiers, Service, Parts, Accessories and Change in Deferred Revenue
Disaggregation of Revenue [Line Items]
Total	$ 68,957	$ 51,403	$ 188,843	$ 156,744

Revenue From Contracts With C_5

Revenue From Contracts With Customers (Disaggregation of Revenue, By Geography) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Sales by Geography
Total	$ 379,150	$ 318,441	$ 1,096,393	$ 864,094
North America
Sales by Geography
Total	81,605	52,732	221,123	173,972
Germany
Sales by Geography
Total	26,832	16,163	74,840	51,208
Other including Eastern Europe/CIS
Sales by Geography
Total	79,777	54,907	212,709	158,686
China
Sales by Geography
Total	137,211	148,049	436,119	361,864
Japan
Sales by Geography
Total	14,286	12,884	35,485	41,241
Other
Sales by Geography
Total	35,844	31,227	106,608	70,924
Rest of World
Sales by Geography
Total	$ 3,595	$ 2,479	$ 9,509	$ 6,199

Revenue From Contracts With C_6

Revenue From Contracts With Customers (Disaggregation of Revenue, By Timing) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Timing of Revenue Recognition
Total	$ 379,150	$ 318,441	$ 1,096,393	$ 864,094
Goods and services transferred at a point in time
Timing of Revenue Recognition
Total	364,677	308,474	1,054,554	824,069
Goods and services transferred over time
Timing of Revenue Recognition
Total	$ 14,473	$ 9,967	$ 41,839	$ 40,025

Revenue From Contracts With C_7

Revenue From Contracts With Customers (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Concentration Risk [Line Items]
Revenue recognized that was included in the contract liability balance at the beginning of the period	$ 10,172	$ 10,179	$ 58,069	$ 41,622
One Customer | Customer Concentration Risk | Accounts Receivable
Concentration Risk [Line Items]
Concentration risk, percentage			23.00%		21.00%

Revenue From Contracts With C_8

Revenue From Contracts With Customers (Changes in Contract Assets and Contract Liabilities) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Contract assets
Contract assets	$ 7,510	$ 6,771	$ 8,999	$ 9,645
Contract assets, change	(1,489)	(2,874)
Contract liabilities
Contract liabilities - current	80,694	57,034	71,246	59,531
Contract liabilities - current, change	9,448	(2,497)
Contract liabilities - long-term	2,737	2,121	$ 2,189	$ 1,820
Contract liabilities - long-term, change	$ 548	$ 301

Revenue From Contracts With C_9

Revenue From Contracts With Customers (Schedule of Remaining Performance Obligations) (Details) $ in Thousands	Sep. 30, 2021USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations	$ 41,728
Revenue expected to be recognized for extended warranty agreements
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations	7,200
Revenue to be earned over time from contracts to sell robotic systems
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations	34,528
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations	$ 18,814
Remaining performance obligations, expected timing	3 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-10-01 | Revenue expected to be recognized for extended warranty agreements
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations	$ 1,965
Remaining performance obligations, expected timing	3 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-10-01 | Revenue to be earned over time from contracts to sell robotic systems
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations	$ 16,849
Remaining performance obligations, expected timing	3 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations	$ 20,520
Remaining performance obligations, expected timing	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01 | Revenue expected to be recognized for extended warranty agreements
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations	$ 2,841
Remaining performance obligations, expected timing	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01 | Revenue to be earned over time from contracts to sell robotic systems
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations	$ 17,679
Remaining performance obligations, expected timing	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations	$ 1,102
Remaining performance obligations, expected timing	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01 | Revenue expected to be recognized for extended warranty agreements
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations	$ 1,102
Remaining performance obligations, expected timing	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01 | Revenue to be earned over time from contracts to sell robotic systems
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations	$ 0
Remaining performance obligations, expected timing	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations	$ 842
Remaining performance obligations, expected timing	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01 | Revenue expected to be recognized for extended warranty agreements
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations	$ 842
Remaining performance obligations, expected timing	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01 | Revenue to be earned over time from contracts to sell robotic systems
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations	$ 0
Remaining performance obligations, expected timing	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations	$ 386
Remaining performance obligations, expected timing	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01 | Revenue expected to be recognized for extended warranty agreements
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations	$ 386
Remaining performance obligations, expected timing	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01 | Revenue to be earned over time from contracts to sell robotic systems
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations	$ 0
Remaining performance obligations, expected timing	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations	$ 64
Remaining performance obligations, expected timing	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01 | Revenue expected to be recognized for extended warranty agreements
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations	$ 64
Remaining performance obligations, expected timing	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01 | Revenue to be earned over time from contracts to sell robotic systems
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations	$ 0
Remaining performance obligations, expected timing	1 year

Restricted Cash (Details)

Restricted Cash (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Dec. 31, 2019
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents	$ 794,904	$ 876,231	$ 763,920	$ 680,070
Restricted cash included in prepaid expenses and other current assets	0	2,322	2,130	0
Restricted cash included in other assets	0	0	0	2,914
Cash, cash equivalents and restricted cash in the condensed consolidated statements of cash flows	$ 794,904	$ 878,553	$ 766,050	$ 682,984

Restricted Cash - Narrative (De

Restricted Cash - Narrative (Details) $ in Thousands	Mar. 31, 2021USD ($)
Cash and Cash Equivalents [Abstract]
Restricted cash released	$ 2,127

Fair Value Measurements (Assets

Fair Value Measurements (Assets and Liabilities Measured at Fair Value) (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Assets
Total	$ 1,051,071	$ 932,571
Liabilities
Long-term debt	35,266	38,402
Contingent purchase consideration	1,406	1,963
Interest rate swap	388	603
Total	37,060	40,968
Level 1
Assets
Total	252,630	218,984
Liabilities
Long-term debt	0	0
Contingent purchase consideration	0	0
Interest rate swap	0	0
Total	0	0
Level 2
Assets
Total	798,441	713,587
Liabilities
Long-term debt	35,266	38,402
Contingent purchase consideration	0	0
Interest rate swap	388	603
Total	35,654	39,005
Level 3
Assets
Total	0	0
Liabilities
Long-term debt	0	0
Contingent purchase consideration	1,406	1,963
Interest rate swap	0	0
Total	1,406	1,963
Money market fund deposits and term deposits
Assets
Cash equivalents	252,630	218,984
Money market fund deposits and term deposits | Level 1
Assets
Cash equivalents	252,630	218,984
Money market fund deposits and term deposits | Level 2
Assets
Cash equivalents	0	0
Money market fund deposits and term deposits | Level 3
Assets
Cash equivalents	0	0
Commercial paper
Assets
Cash equivalents	60,692	162,749
Commercial paper | Level 1
Assets
Cash equivalents	0	0
Commercial paper | Level 2
Assets
Cash equivalents	60,692	162,749
Commercial paper | Level 3
Assets
Cash equivalents	0	0
Corporate bonds
Assets
Cash equivalents	13,690	29,010
Short-term investments	142,349	88,171
Corporate bonds | Level 1
Assets
Cash equivalents	0	0
Short-term investments	0	0
Corporate bonds | Level 2
Assets
Cash equivalents	13,690	29,010
Short-term investments	142,349	88,171
Corporate bonds | Level 3
Assets
Cash equivalents	0	0
Short-term investments	0	0
Municipal bonds
Assets
Short-term investments	8,065	7,997
Municipal bonds | Level 1
Assets
Short-term investments	0	0
Municipal bonds | Level 2
Assets
Short-term investments	8,065	7,997
Municipal bonds | Level 3
Assets
Short-term investments	0	0
Commercial paper
Assets
Short-term investments	570,645	368,665
Commercial paper | Level 1
Assets
Short-term investments	0	0
Commercial paper | Level 2
Assets
Short-term investments	570,645	368,665
Commercial paper | Level 3
Assets
Short-term investments	0	0
U.S. Treasury and agency obligations
Assets
Cash equivalents		6,999
Short-term investments		49,996
U.S. Treasury and agency obligations | Level 1
Assets
Cash equivalents		0
Short-term investments		0
U.S. Treasury and agency obligations | Level 2
Assets
Cash equivalents		6,999
Short-term investments		49,996
U.S. Treasury and agency obligations | Level 3
Assets
Cash equivalents		0
Short-term investments		$ 0
Certificates of deposit
Assets
Short-term investments	3,000
Certificates of deposit | Level 1
Assets
Short-term investments	0
Certificates of deposit | Level 2
Assets
Short-term investments	3,000
Certificates of deposit | Level 3
Assets
Short-term investments	$ 0

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Details) - USD ($)	3 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity impairment	$ 0	$ 0
Long-term debt, fair value	35,266,000		$ 38,402,000
Long-term debt, book value	35,116,000		$ 37,967,000
Held-to-maturity Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Allowance for credit loss	$ 0	$ 0

Fair Value Measurements (Schedu

Fair Value Measurements (Schedule of Effective Maturity Dates of Held to Maturity Investments) (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Investment maturity
Held-to-maturity maturities, less than 1 year, book value	$ 724,103	$ 514,835
Held-to-maturity maturities, less than 1 year, fair value	$ 724,059	$ 514,829

Fair Value Measurements (Fair V

Fair Value Measurements (Fair Value of Auction Rate Securities and Contingent Purchase Consideration) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Auction rate securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	$ 0	$ 596	$ 0	$ 592
Redemptions	0	(596)	0	(596)
Change in fair value and accretion	0	0	0	4
Balance, end of period	0	0	0	0
Contingent purchase consideration
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	1,529	0	1,963	273
Cash payments	0	0	(466)	(272)
Foreign exchange adjustment	(123)	0	(91)	(1)
Balance, end of period	$ 1,406	$ 0	$ 1,406	$ 0

Inventories (Components Of Inve

Inventories (Components Of Inventories) (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Inventory Disclosure [Abstract]
Components and raw materials	$ 247,929	$ 190,775
Work-in-process	33,335	47,251
Finished goods	153,806	126,967
Total	$ 435,070	$ 364,993

Inventories (Narrative) (Detail

Inventories (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Inventory Disclosure [Abstract]
Inventory provisions	$ 7,882	$ 11,514	$ 23,529	$ 25,955

Goodwill and Intangibles (Sched

Goodwill and Intangibles (Schedule of Changes) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Goodwill [Roll Forward]
Balance at January 1			$ 41,366	$ 82,092
Adjustment to goodwill during measurement period			(2,205)	0
Foreign exchange adjustment			(456)	228
Goodwill impairment	$ 0	$ (44,589)	0	(44,589)
Balance at September 30	$ 38,705	$ 37,731	$ 38,705	$ 37,731

Goodwill and Intangibles (Narra

Goodwill and Intangibles (Narrative) (Details) - USD ($) $ in Thousands	Jan. 31, 2021	Sep. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Business combination, payment period				3 years
Adjustment to goodwill during measurement period						$ (2,205)	$ 0
Goodwill		$ 38,705		$ 41,366	$ 37,731	38,705	37,731	$ 82,092
Amortization expense		3,051			2,947	9,387	9,029
Pi-Tecnologia S.A.
Finite-Lived Intangible Assets [Line Items]
Consideration transferred				2,717
Payments to acquire businesses, gross				906
Business combination, contingent consideration, liability				$ 1,811
Adjustment to goodwill during measurement period			$ (2,205)
Finite-lived intangible assets, period increase			2,929
Deferred tax liabilities, goodwill			724
Goodwill			$ 724
Contingent Purchase Consideration
Finite-Lived Intangible Assets [Line Items]
Fair value, measurement with unobservable inputs reconciliation, recurring basis, liability, purchases		$ 0			$ 0	$ 466	$ 272
Contingent Purchase Consideration | Pi-Tecnologia S.A.
Finite-Lived Intangible Assets [Line Items]
Fair value, measurement with unobservable inputs reconciliation, recurring basis, liability, purchases	$ 466

Goodwill and Intangibles (Intan

Goodwill and Intangibles (Intangible Assets) (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 118,890	$ 115,920
Accumulated Amortization	(63,104)	(53,806)
Net  Carrying Amount	55,786	62,114
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	59,804	58,041
Accumulated Amortization	(22,149)	(17,674)
Net  Carrying Amount	$ 37,655	$ 40,367
Weighted- Average  Lives	10 years	11 years
Technology, trademark and trade name
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 40,601	$ 40,518
Accumulated Amortization	(25,002)	(20,949)
Net  Carrying Amount	$ 15,599	$ 19,569
Weighted- Average  Lives	7 years	7 years
Production know-how
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 10,449	$ 9,325
Accumulated Amortization	(8,604)	(8,167)
Net  Carrying Amount	$ 1,845	$ 1,158
Weighted- Average  Lives	7 years	7 years
Patents
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 8,036	$ 8,036
Accumulated Amortization	(7,349)	(7,016)
Net  Carrying Amount	$ 687	$ 1,020
Weighted- Average  Lives	8 years	8 years

Goodwill and Intangibles (Estim

Goodwill and Intangibles (Estimated Future Amortization Expense for Intangibles) (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
2021	$ 3,050
2022	11,459
2023	10,552
2024	8,025
2025	6,518
Thereafter	16,182
Net  Carrying Amount	$ 55,786	$ 62,114

Accrued Expenses and Other Li_3

Accrued Expenses and Other Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Dec. 31, 2019
Payables and Accruals [Abstract]
Contract liabilities	$ 80,694	$ 71,246	$ 57,034	$ 59,531
Accrued compensation	81,078	62,785
Current portion of accrued warranty	25,650	24,345
Short-term lease liabilities	5,217	5,778
Other	16,276	12,586
Total	$ 208,915	$ 176,740

Product Warranties (Narrative)

Product Warranties (Narrative) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Product Warranty Liability [Line Items]
Accrued warranty reported in accrued expenses and other liabilities	$ 25,650	$ 24,345
Accrued warranty reported in other long-term liabilities	$ 23,204	$ 21,324
Minimum
Product Warranty Liability [Line Items]
Service warranties on lasers and amplifiers	1 year
Maximum
Product Warranty Liability [Line Items]
Service warranties on lasers and amplifiers	5 years

Product Warranties (Summary of

Product Warranties (Summary of Product Warranty Activity) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Movement in Standard and Extended Product Warranty, Increase (Decrease) [Roll Forward]
Balance at January 1	$ 45,669	$ 48,866
Provision for warranty accrual	26,535	16,255
Warranty claims	(21,576)	(20,992)
Foreign currency translation	(1,774)	822
Balance at September 30	$ 48,854	$ 44,951

Financing Arrangements (Borrowi

Financing Arrangements (Borrowings Under Existing Financing Arrangements) (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Debt Disclosure [Abstract]
Total debt	$ 35,116	$ 37,967
Less: current portion	(18,788)	(3,810)
Long-term debt, net of current portion	$ 16,328	$ 34,157

Financing Arrangements (Narrati

Financing Arrangements (Narrative) (Details) € in Thousands	9 Months Ended
	Sep. 30, 2021USD ($)	May 31, 2023USD ($)	Jul. 31, 2022USD ($)	Sep. 30, 2021EUR (€)	Dec. 31, 2020USD ($)
Debt Instrument [Line Items]
Total unused credit lines and overdraft facilities	$ 129,578,000
Unsecured Debt | Scenario, Forecast
Debt Instrument [Line Items]
Amount due on long-term note		$ 15,438,000
Unsecured Debt | Interest rate swap
Debt Instrument [Line Items]
Fixed interest rate swap	2.85%			2.85%
Unsecured Debt | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Variable interest rate	1.20%
Secured Debt
Debt Instrument [Line Items]
Amount due on long-term note	$ 17,600,000
Fixed interest rate swap	2.74%			2.74%
Secured Debt | Scenario, Forecast
Debt Instrument [Line Items]
Amount due on long-term note			$ 15,375,000
Long-term notes | Unsecured Debt
Debt Instrument [Line Items]
Amount due on long-term note	$ 17,516,000
Current portion of long-term note	1,188,000
U.S. line-of-credit
Debt Instrument [Line Items]
Line of credit	0				$ 0
Guarantees issued	2,731,000				3,300,000
U.S. line-of-credit | Letter of Credit
Debt Instrument [Line Items]
Borrowing capacity	75,000,000
Euro line-of-credit
Debt Instrument [Line Items]
Line of credit	0				0
Guarantees issued	2,373,000				3,424,000
Euro line-of-credit | Letter of Credit
Debt Instrument [Line Items]
Borrowing capacity	57,944,000			€ 50,000
Euro overdraft facility
Debt Instrument [Line Items]
Line of credit	0				$ 0
Euro overdraft facility | Letter of Credit
Debt Instrument [Line Items]
Borrowing capacity	$ 1,738,000			€ 1,500

Financing Arrangements (Future

Financing Arrangements (Future Principal Payments) (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Debt Disclosure [Abstract]
2021	$ 959
2022	18,126
2023	16,031
Total debt	$ 35,116	$ 37,967

Derivative Financial Instrume_3

Derivative Financial Instruments (Fair Value) (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Derivatives, Fair Value [Line Items]
Deferred income taxes and other long-term liabilities	$ 388	$ 603
Derivative designated as a cash flow hedge | Interest rate swap
Derivatives, Fair Value [Line Items]
Derivative, notional amount	17,516	18,406
Derivative designated as a cash flow hedge | Interest rate swap | Other Noncurrent Liabilities
Derivatives, Fair Value [Line Items]
Deferred income taxes and other long-term liabilities	$ 388	$ 603

Derivative Financial Instrume_4

Derivative Financial Instruments (Derivative Gains (Losses) in the Consolidated Statements of Income Related to Interest Rate Swap Contracts) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Interest rate swap | Derivative designated as a cash flow hedge
Derivative Instruments, Gain (Loss) [Line Items]
Effective portion recognized in other comprehensive income, interest rate swap	$ 60	$ (723)	$ 215	$ (679)

Commitments and Contingencies (

Commitments and Contingencies (Details)	Sep. 30, 2021USD ($)
Commitments and Contingencies Disclosure [Abstract]
Legal proceedings	$ 0

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Tax Disclosure [Abstract]
Effective tax rate	26.40%	16.40%	24.60%	21.00%
Share-based payment arrangement, tax benefit	$ 1,424	$ 727	$ 5,849	$ 6,658

Income Taxes (Schedule of Unrec

Income Taxes (Schedule of Unrecognized Tax Benefits) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at January 1,	$ 14,706	$ 11,416
Additions for tax positions in current period	4,000	2,000
Foreign currency translation	92
Foreign currency translation		(938)
Balance at September 30,	$ 18,798	$ 12,478

Net Income Attributable to IP_3

Net Income Attributable to IPG Photonics Corporation Per Common Share (Computation of Diluted Net Income) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Earnings Per Share [Abstract]
Net income attributable to IPG Photonics Corporation common stockholders	$ 75,402	$ 35,604	$ 213,329	$ 110,233
Basic weighted average common shares	53,387,175	53,098,366	53,500,507	53,136,226
Dilutive effect of common stock equivalents (in shares)	446,577	565,274	552,836	554,579
Diluted weighted average common shares	53,833,752	53,663,640	54,053,343	53,690,805
Basic net income attributable to IPG Photonics Corporation per common share (in dollars per share)	$ 1.41	$ 0.67	$ 3.99	$ 2.07
Diluted net income attributable to IPG Photonics Corporation per common share (in dollars per share)	$ 1.40	$ 0.66	$ 3.95	$ 2.05

Net Income Attributable to IP_4

Net Income Attributable to IPG Photonics Corporation Per Common Share (Anti Dilutive Shares Excluded From EPS) (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Excluded from computation of diluted weighted average common shares	384,228	562,624	326,875	628,163
Stock Options | Non-qualified Plan
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Excluded from computation of diluted weighted average common shares	225,684	528,257	202,077	555,816
Restricted Stock Units, RSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Excluded from computation of diluted weighted average common shares	128,402	28,905	100,066	36,169
Performance Stock Units, PSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Excluded from computation of diluted weighted average common shares	30,142	0	24,732	19,791
Employee Stock Purchase Plan, ESPP
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Excluded from computation of diluted weighted average common shares	0	5,462	0	16,387

Net Income Attributable to IP_5

Net Income Attributable to IPG Photonics Corporation Per Common Share (Narrative) (Details) - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2021	May 05, 2020	Feb. 28, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Decrease in weighted average number of shares outstanding treasury stock	91,001	(132,295)
2020 Program
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Share repurchase authorized amount			$ 200,000,000
Stock repurchased during period (in shares)	199,505	399,282
Stock repurchase average price (in dollars per share)	$ 182.12	$ 195.5
Remaining repurchase amount	$ 168,000,000	$ 168,000,000
2019 Program
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Share repurchase authorized amount				$ 125,000,000