IPG Photonics (IPGP) 10-Q 5 May 21 2021 Q1 Quarterly report Financial data

Cover Page

Cover Page - shares	3 Months Ended
	Mar. 31, 2021	May 04, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 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)		53,578,610
Amendment Flag	false
Document Fiscal Period Focus	Q1
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	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 896,741	$ 876,231
Short-term investments	548,196	514,835
Accounts receivable, net	252,877	264,321
Inventories	368,149	364,993
Prepaid income taxes	70,421	69,893
Prepaid expenses and other current assets	65,877	57,804
Total current assets	2,202,261	2,148,077
Deferred income taxes, net	41,276	43,197
Goodwill	38,764	41,366
Intangible assets, net	61,768	62,114
Property, plant and equipment, net	600,911	597,527
Other assets	37,971	43,419
Total assets	2,982,951	2,935,700
Current liabilities:
Current portion of long-term debt	3,828	3,810
Accounts payable	44,704	25,748
Accrued expenses and other current liabilities	162,775	176,740
Income taxes payable	3,446	8,280
Total current liabilities	214,753	214,578
Deferred income taxes and other long-term liabilities	94,335	92,854
Long-term debt, net of current portion	33,193	34,157
Total liabilities	342,281	341,589
Commitments and contingencies (Note 12)
IPG Photonics Corporation equity:
Common stock, $0.0001 par value, 175,000,000 shares authorized; 55,672,783 and 53,623,865 shares issued and outstanding, respectively, at March 31, 2021; 55,461,246 and 53,427,234 shares issued and outstanding, respectively, at December 31, 2020.	6	6
Treasury stock, at cost, 2,048,918 and 2,034,012 shares held at March 31, 2021 and December 31, 2020, respectively.	(306,662)	(303,614)
Additional paid-in capital	868,097	854,301
Retained earnings	2,256,318	2,188,191
Accumulated other comprehensive loss	(178,257)	(146,065)
Total IPG Photonics Corporation equity	2,639,502	2,592,819
Non-controlling interests	1,168	1,292
Total equity	2,640,670	2,594,111
Total liabilities and equity	$ 2,982,951	$ 2,935,700

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 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	55,672,783	55,461,246
Common stock, shares outstanding	53,623,865	53,427,234
Treasury stock (in shares)	2,048,918	2,034,012

Condensed Consolidated Statemen

Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Income Statement [Abstract]
Net sales	$ 345,585	$ 249,242
Cost of sales	181,594	146,366
Gross profit	163,991	102,876
Operating expenses:
Sales and marketing	18,883	18,683
Research and development	33,339	31,838
General and administrative	30,092	27,124
(Gain) on foreign exchange	(7,165)	(19,565)
Total operating expenses	75,149	58,080
Operating income	88,842	44,796
Other (expense) income, net:
Interest (expense) income, net	(495)	3,073
Other income, net	253	191
Total other (expense) income	(242)	3,264
Income before provision for income taxes	88,600	48,060
Provision for income taxes	20,378	11,294
Net income	68,222	36,766
Less: net income attributable to non-controlling interests	95	363
Net income attributable to IPG Photonics Corporation common stockholders	$ 68,127	$ 36,403
Earnings Per Share [Abstract]
Basic (in dollars per share)	$ 1.27	$ 0.69
Diluted (in dollars per share)	$ 1.26	$ 0.68
Weighted average common shares outstanding:
Basic (in shares)	53,541	53,075
Diluted (in shares)	54,201	53,676

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 68,222	$ 36,766
Other comprehensive income, net of tax:
Translation adjustments	(32,479)	(73,417)
Unrealized gain on derivatives	68	36
Total other comprehensive (loss)	(32,411)	(73,381)
Comprehensive income (loss)	35,811	(36,615)
Less: comprehensive (loss) income attributable to non-controlling interests	(124)	144
Comprehensive income (loss) attributable to IPG Photonics Corporation	$ 35,935	$ (36,759)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities:
Net income	$ 68,222	$ 36,766
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	23,819	24,099
Deferred income taxes	3,944	(935)
Stock-based compensation	8,815	8,430
Unrealized gain on foreign currency transactions	(7,800)	(19,589)
Other	1,462	1,015
Provisions for inventory, warranty and bad debt	16,685	13,486
Changes in assets and liabilities that provided (used) cash, net of acquisitions:
Accounts receivable	7,360	34,492
Inventories	(20,084)	(10,429)
Prepaid expenses and other assets	(1,052)	(9,119)
Accounts payable	18,980	6,054
Accrued expenses and other liabilities	(17,961)	(6,477)
Income and other taxes payable	(14,847)	(21,012)
Net cash provided by operating activities	87,543	56,781
Cash flows from investing activities:
Purchases of and deposits on property, plant and equipment	(27,421)	(17,801)
Proceeds from sales of property, plant and equipment	130	139
Purchases of short-term investments	(513,564)	(308,195)
Proceeds from short-term investments	480,163	186,024
Other	(2)	79
Net cash used in investing activities	(60,694)	(139,754)
Cash flows from financing activities:
Principal payments on long-term borrowings	(946)	(928)
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	4,981
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		(5,498)
Purchase of treasury stock, at cost	(3,048)	(12,716)
Payment of purchase price holdback from business combination	(2,624)	(1,650)
Net cash used in financing activities	(1,637)	(20,792)
Effect of changes in exchange rates on cash, cash equivalents and restricted cash	(7,024)	(6,878)
Net increase in cash, cash equivalents and restricted cash	18,188	(110,643)
Cash, cash equivalents and restricted cash — Beginning of period	878,553	682,984
Cash and cash equivalents — End of period	896,741	572,341
Supplemental disclosure of cash flow information:
Cash paid for interest	703	447
Cash paid for income taxes	21,340	29,865
Non-cash transactions:
Demonstration units transferred from inventory to other assets	1,109	1,086
Inventory transferred to machinery and equipment	727	1,294
Changes in accounts payable related to property, plant and equipment	863	6,983
Leased assets obtained in exchange for new operating lease liabilities	$ 409	$ 830

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)			225,125
Exercise of stock options and vesting of RSUs and PSUs	(5,497)		$ 1		(5,498)
Purchased common stock (in shares)			(108,819)	(108,819)
Purchased common stock	(12,716)			$ (12,716)
Stock-based compensation	8,430				8,430
Net income	36,766					36,403			363
Foreign currency translation adjustments	(73,417)							(73,198)	(219)
Unrealized gain on derivatives	36							36
Balance, end of period (in shares) at Mar. 31, 2020			53,127,181	1,841,171
Balance, end of period at Mar. 31, 2020	2,355,930		$ 6	$ (278,446)	788,568	2,065,022		(220,081)	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)			211,537
Exercise of stock options and vesting of RSUs and PSUs	4,981				4,981
Purchased common stock (in shares)			(14,906)	(14,906)
Purchased common stock	(3,048)			$ (3,048)
Stock-based compensation	8,815				8,815
Net income	68,222					68,127			95
Foreign currency translation adjustments	(32,479)							(32,260)	(219)
Unrealized gain on derivatives	68							68
Balance, end of period (in shares) at Mar. 31, 2021			53,623,865	2,048,918
Balance, end of period at Mar. 31, 2021	$ 2,640,670		$ 6	$ (306,662)	$ 868,097	$ 2,256,318		$ (178,257)	$ 1,168

Basis of Presentation and Signi

Basis of Presentation and Significant Accounting Policies	3 Months Ended
	Mar. 31, 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 March 31, 2021 2020 Balance, beginning of period $ 2,156 $ 2,547 Provision for bad debts, net of recoveries 188 (187) Foreign currency translation (37) (225) Balance, end of period $ 2,307 $ 2,135 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	3 Months Ended
	Mar. 31, 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	3 Months Ended
	Mar. 31, 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 March 31, 2021 2020 Sales by Application Materials processing $ 317,241 $ 218,074 Other applications 28,344 31,168 Total $ 345,585 $ 249,242 Sales by Product High Power Continuous Wave ("CW") Lasers $ 170,482 $ 119,316 Medium Power CW Lasers 15,882 11,253 Pulsed Lasers 55,395 31,839 Quasi-Continuous Wave ("QCW") Lasers 13,666 9,873 Laser and Non-Laser Systems 27,116 18,634 Other Revenue including Amplifiers, Service, Parts, Accessories and Change in Deferred Revenue 63,044 58,327 Total $ 345,585 $ 249,242 Three Months Ended March 31, 2021 2020 Sales by Geography North America $ 73,384 $ 67,339 Europe: Germany 26,260 17,411 Other including Eastern Europe/CIS 58,593 57,232 Asia and Australia: China 139,833 68,599 Japan 10,877 13,685 Other 33,110 22,823 Rest of World 3,528 2,153 Total $ 345,585 $ 249,242 Timing of Revenue Recognition Goods and services transferred at a point in time $ 332,532 $ 233,436 Goods and services transferred over time 13,053 15,806 Total $ 345,585 $ 249,242 One of the Company's customers accounted for 22% and 21% of the Company's net accounts receivable as of March 31, 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. 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 three months ended March 31, 2021 and 2020: March 31, December 31, March 31, December 31, 2021 2020 Change 2020 2019 Change Contract assets Contract assets $ 7,670 $ 8,999 $ (1,329) $ 8,646 $ 9,645 $ (999) Contract liabilities Contract liabilities - current 69,526 71,246 (1,720) 62,499 59,531 2,968 Contract liabilities - long-term 2,549 2,189 360 2,377 1,820 557 During the three months ended March 31, 2021 and 2020 the Company recognized revenue of $30,378 and $14,995, 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 March 31, 2021: Remaining Performance Obligations 2021 (a) 2022 2023 2024 2025 Thereafter Total Revenue expected to be recognized for extended warranty agreements $ 3,385 $ 1,493 $ 842 $ 589 $ 263 $ 27 $ 6,599 Revenue to be earned over time from contracts to sell robotic systems 15,350 1,405 — — — — 16,755 Total $ 18,735 $ 2,898 $ 842 $ 589 $ 263 $ 27 $ 23,354 (a) For the nine-month period beginning April 1, 2021.

Restricted Cash

Restricted Cash	3 Months Ended
	Mar. 31, 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. March 31, December 31, 2021 2020 2020 2019 Cash and cash equivalents $ 896,741 $ 570,058 $ 876,231 $ 680,070 Restricted cash included in prepaid expenses and other current assets — 2,283 2,322 — Restricted cash included in other assets — — — 2,914 Cash, cash equivalents and restricted cash in the condensed consolidated statements of cash flows $ 896,741 $ 572,341 $ 878,553 $ 682,984

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 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 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 is measured at fair value: Fair Value Measurements at March 31, 2021 Total Level 1 Level 2 Level 3 Assets Cash equivalents: Money market fund deposits and term deposits $ 306,431 $ 306,431 $ — $ — Commercial paper 173,324 — 173,324 — Municipal bonds 7,998 — 7,998 — Corporate bonds 47,703 — 47,703 — Short-term investments: Corporate bonds 56,323 — 56,323 — Commercial paper 475,818 — 475,818 — Certificates of deposit 3,000 3,000 — — U.S. Treasury and agency obligations 13,000 — 13,000 — Total $ 1,083,597 $ 309,431 $ 774,166 $ — Liabilities Long-term debt $ 37,296 $ — $ 37,296 $ — Interest rate swap 514 514 Contingent purchase consideration 1,343 — — 1,343 Total $ 39,153 $ — $ 37,810 $ 1,343 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 $ — $ — U.S. Treasury and agency obligations 6,999 — 6,999 — Commercial paper 162,749 — 162,749 — Corporate bonds 29,010 — 29,010 — Short-term investments: U.S. Treasury and agency obligations 49,996 — 49,996 — Municipal bonds 7,997 — 7,997 — Corporate bonds 88,171 — 88,171 — Commercial paper 368,665 — 368,665 — 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 U.S. government and government agency notes, corporate bonds, commercial paper 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 March 31, 2021 and 2020. There were no current expected credit loss allowances for the investments considered held-to-maturity at March 31, 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: March 31, 2021 December 31, 2020 Book Value Fair Value Book Value Fair Value Investment maturity Less than 1 year $ 548,196 $ 548,141 $ 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 March 31, 2021 for the interest rate swap considered pricing models whose inputs are observable for the securities held by the Company. At March 31, 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 are classified as a level 2. Based on the discounted cash flow model, the fair values of the long-term notes at March 31, 2021 and December 31, 2020 were $37,296 and $38,402 respectively, as compared to the book value of $37,021 and $37,967, respectively. The fair values of contingent purchase consideration at March 31, 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 March 31, 2021 2020 Auction rate securities Balance, beginning of period $ — $ 592 Change in fair value and accretion — 2 Balance, end of period $ — $ 594 Contingent purchase consideration Balance, beginning of period $ 1,963 $ 273 Cash payments (466) (272) Foreign exchange adjustment (154) (1) Balance, end of period $ 1,343 $ —

Inventories

Inventories	3 Months Ended
	Mar. 31, 2021
Inventory Disclosure [Abstract]
INVENTORIES	INVENTORIES Inventories consist of the following: March 31, December 31, 2021 2020 Components and raw materials $ 190,376 $ 190,775 Work-in-process 38,066 47,251 Finished goods 139,707 126,967 Total $ 368,149 $ 364,993 The Company recorded inventory provisions totaling $8,027 and $8,451 for the three months ended March 31, 2021 and 2020, respectively. 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	3 Months Ended
	Mar. 31, 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: Three Months Ended March 31, 2021 2020 Balance at January 1 $ 41,366 $ 82,092 Adjustment to goodwill during measurement period (2,205) — Foreign exchange adjustment (397) (465) Balance at March 31 $ 38,764 $ 81,627 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 March 31, 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: March 31, 2021 December 31, 2020 Gross Accumulated Net Carrying Weighted- Average Lives Gross Carrying Accumulated Net Carrying Weighted- Customer relationships $ 59,740 $ (19,232) $ 40,508 10 years $ 58,041 $ (17,674) $ 40,367 11 years Technology, trademark and trade name 40,443 (22,206) 18,237 7 years 40,518 (20,949) 19,569 7 years Production know-how 10,413 (8,299) 2,114 7 years 9,325 (8,167) 1,158 7 years Patents 8,036 (7,127) 909 8 years 8,036 (7,016) 1,020 8 years Total $ 118,632 $ (56,864) $ 61,768 $ 115,920 $ (53,806) $ 62,114 Amortization expense for the three months ended March 31, 2021 and 2020 was $3,257 and $3,133, 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 $ 9,132 $ 11,409 10,508 $ 8,019 $ 6,505 $ 16,195 $ 61,768 (a) For the nine-month period beginning April 1, 2021.

Accrued Expenses and Other Liab

Accrued Expenses and Other Liabilities	3 Months Ended
	Mar. 31, 2021
Payables and Accruals [Abstract]
ACCRUED EXPENSES AND OTHER LIABILITIES	ACCRUED EXPENSES AND OTHER LIABILITIES Accrued expenses and other liabilities consist of the following: March 31, December 31, 2021 2020 Accrued compensation $ 53,690 $ 62,785 Contract liabilities 69,526 71,246 Current portion of accrued warranty 24,056 24,345 Short-term lease liabilities 5,596 5,778 Other 9,907 12,586 Total $ 162,775 $ 176,740

Product Warranties

Product Warranties	3 Months Ended
	Mar. 31, 2021
Product Warranties Disclosures [Abstract]
PRODUCT WARRANTIES	PRODUCT WARRANTIES The Company typically provides one Activity related to the warranty accrual was as follows:. Three Months Ended March 31, 2021 2020 Balance at January 1 $ 45,669 $ 48,866 Provision for warranty accrual 8,403 5,001 Warranty claims (7,446) (7,241) Foreign currency translation (1,382) (822) Balance at March 31 $ 45,244 $ 45,804 Accrued warranty reported in the accompanying condensed consolidated financial statements as of March 31, 2021 and December 31, 2020 consisted of $24,056 and $24,345 in accrued expenses and other liabilities, respectively, and $21,188 and $21,324 in other long-term liabilities, respectively.

Financing Arrangements

Financing Arrangements	3 Months Ended
	Mar. 31, 2021
Debt Disclosure [Abstract]
FINANCING ARRANGEMENTS	FINANCING ARRANGEMENTS The Company's borrowings under existing financing arrangements consist of the following: March 31, December 31, 2021 2020 Total notes payable $ 37,021 $ 37,967 Less: current portion (3,828) (3,810) Total long-term debt $ 33,193 $ 34,157 Term Debt: At March 31, 2021, the Company has an unsecured long-term note with an outstanding principal balance of $18,109, of which, $1,187 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 March 31, 2021, the Company has another long-term note that is secured by its corporate aircraft with an outstanding principal balance of $18,912, of which, $2,641 is the current portion. 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 March 31, 2021 are as follows: 2021 (a) $ 2,864 2022 18,126 2023 16,031 Total $ 37,021 (a) For the nine-month period beginning April 1, 2021. Revolving Line of Credit Facilities:

Derivative Financial Instrument

Derivative Financial Instruments	3 Months Ended
	Mar. 31, 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: March 31, December 31, 2021 2020 Notional amounts (1) $ 18,109 $ 18,406 Fair values: Deferred income taxes and other long-term liabilities $ 514 $ 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 March 31, 2021 2020 Effective portion recognized in other comprehensive income, pretax: Interest rate swap $ 89 $ 46

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 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 March 31, 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	3 Months Ended
	Mar. 31, 2021
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXESThe effective tax rates were 23.0% and 23.5% for the three months ended March 31, 2021 and 2020, respectively. There were net discrete tax benefits of $4,288 and $2,787 for the three months ended March 31, 2021 and 2020, respectively, which were primarily related to the tax deductions for equity-based compensation that exceeded compensation expense recognized for books. The Company accounts for its uncertain tax positions in accordance with the accounting standards for income taxes. The Company continues to classify 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 three months ended March 31, 2021 and 2020: Three Months Ended March 31, 2021 2020 Balance at January 1, $ 14,706 $ 11,416 Additions for tax positions in current period 1,000 400 Foreign currency translation (182) (1,101) Balance at March 31, $ 15,524 $ 10,715

Net Income Attributable to IPG

Net Income Attributable to IPG Photonics Corporation Per Share	3 Months Ended
	Mar. 31, 2021
Earnings Per Share [Abstract]
NET INCOME ATTRIBUTABLE TO IPG PHOTONICS CORPORATION PER 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 March 31, 2021 2020 Net income attributable to IPG Photonics Corporation common stockholders $ 68,127 $ 36,403 Basic weighted average common shares 53,541 53,075 Dilutive effect of common stock equivalents 660 601 Diluted weighted average common shares 54,201 53,676 Basic net income attributable to IPG Photonics Corporation per common share $ 1.27 $ 0.69 Diluted net income attributable to IPG Photonics Corporation per common share $ 1.26 $ 0.68 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 months ended March 31, 2021 and 2020 were as follows: Three Months Ended March 31, 2021 2020 Non-qualified stock options 202,500 622,700 Restricted stock units 61,100 198,000 Performance stock units 13,800 50,300 Total weighed average anti-dilutive shares outstanding 277,400 871,000 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 requirements and other factors. The share purchase program authorization does not obligate the Company to repurchase any dollar amount or number of its shares, and repurchases may be commenced or suspended from time to time without prior notice. For the three months ended March 31, 2021, the Company repurchased 14,906 shares of common stock under the February 2019 authorization with an average price of $204.48 per share in the open market. The impact on the reduction of weighted average shares for the three months ended March 31, 2021 was 461 shares. As of March 31, 2021 the remaining

Basis of Presentation and Sig_2

Basis of Presentation and Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 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.
Adopted 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.

Basis of Presentation and Sig_3

Basis of Presentation and Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 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 March 31, 2021 2020 Balance, beginning of period $ 2,156 $ 2,547 Provision for bad debts, net of recoveries 188 (187) Foreign currency translation (37) (225) Balance, end of period $ 2,307 $ 2,135

Recent Accounting Pronounceme_2

Recent Accounting Pronouncements (Tables)	3 Months Ended
	Mar. 31, 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)	3 Months Ended
	Mar. 31, 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 March 31, 2021 2020 Sales by Application Materials processing $ 317,241 $ 218,074 Other applications 28,344 31,168 Total $ 345,585 $ 249,242 Sales by Product High Power Continuous Wave ("CW") Lasers $ 170,482 $ 119,316 Medium Power CW Lasers 15,882 11,253 Pulsed Lasers 55,395 31,839 Quasi-Continuous Wave ("QCW") Lasers 13,666 9,873 Laser and Non-Laser Systems 27,116 18,634 Other Revenue including Amplifiers, Service, Parts, Accessories and Change in Deferred Revenue 63,044 58,327 Total $ 345,585 $ 249,242 Three Months Ended March 31, 2021 2020 Sales by Geography North America $ 73,384 $ 67,339 Europe: Germany 26,260 17,411 Other including Eastern Europe/CIS 58,593 57,232 Asia and Australia: China 139,833 68,599 Japan 10,877 13,685 Other 33,110 22,823 Rest of World 3,528 2,153 Total $ 345,585 $ 249,242 Timing of Revenue Recognition Goods and services transferred at a point in time $ 332,532 $ 233,436 Goods and services transferred over time 13,053 15,806 Total $ 345,585 $ 249,242
Changes in Contract Assets and Liabilities	The following table reflects the changes in the Company's contract assets and liabilities for the three months ended March 31, 2021 and 2020: March 31, December 31, March 31, December 31, 2021 2020 Change 2020 2019 Change Contract assets Contract assets $ 7,670 $ 8,999 $ (1,329) $ 8,646 $ 9,645 $ (999) Contract liabilities Contract liabilities - current 69,526 71,246 (1,720) 62,499 59,531 2,968 Contract liabilities - long-term 2,549 2,189 360 2,377 1,820 557
Schedule of Remaining Performance Obligations	The following table represents the Company's remaining performance obligations from contracts that are recognized over time as of March 31, 2021: Remaining Performance Obligations 2021 (a) 2022 2023 2024 2025 Thereafter Total Revenue expected to be recognized for extended warranty agreements $ 3,385 $ 1,493 $ 842 $ 589 $ 263 $ 27 $ 6,599 Revenue to be earned over time from contracts to sell robotic systems 15,350 1,405 — — — — 16,755 Total $ 18,735 $ 2,898 $ 842 $ 589 $ 263 $ 27 $ 23,354 (a) For the nine-month period beginning April 1, 2021.

Restricted Cash (Tables)

Restricted Cash (Tables)	3 Months Ended
	Mar. 31, 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. March 31, December 31, 2021 2020 2020 2019 Cash and cash equivalents $ 896,741 $ 570,058 $ 876,231 $ 680,070 Restricted cash included in prepaid expenses and other current assets — 2,283 2,322 — Restricted cash included in other assets — — — 2,914 Cash, cash equivalents and restricted cash in the condensed consolidated statements of cash flows $ 896,741 $ 572,341 $ 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. March 31, December 31, 2021 2020 2020 2019 Cash and cash equivalents $ 896,741 $ 570,058 $ 876,231 $ 680,070 Restricted cash included in prepaid expenses and other current assets — 2,283 2,322 — Restricted cash included in other assets — — — 2,914 Cash, cash equivalents and restricted cash in the condensed consolidated statements of cash flows $ 896,741 $ 572,341 $ 878,553 $ 682,984

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 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 is measured at fair value: Fair Value Measurements at March 31, 2021 Total Level 1 Level 2 Level 3 Assets Cash equivalents: Money market fund deposits and term deposits $ 306,431 $ 306,431 $ — $ — Commercial paper 173,324 — 173,324 — Municipal bonds 7,998 — 7,998 — Corporate bonds 47,703 — 47,703 — Short-term investments: Corporate bonds 56,323 — 56,323 — Commercial paper 475,818 — 475,818 — Certificates of deposit 3,000 3,000 — — U.S. Treasury and agency obligations 13,000 — 13,000 — Total $ 1,083,597 $ 309,431 $ 774,166 $ — Liabilities Long-term debt $ 37,296 $ — $ 37,296 $ — Interest rate swap 514 514 Contingent purchase consideration 1,343 — — 1,343 Total $ 39,153 $ — $ 37,810 $ 1,343 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 $ — $ — U.S. Treasury and agency obligations 6,999 — 6,999 — Commercial paper 162,749 — 162,749 — Corporate bonds 29,010 — 29,010 — Short-term investments: U.S. Treasury and agency obligations 49,996 — 49,996 — Municipal bonds 7,997 — 7,997 — Corporate bonds 88,171 — 88,171 — Commercial paper 368,665 — 368,665 — 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: March 31, 2021 December 31, 2020 Book Value Fair Value Book Value Fair Value Investment maturity Less than 1 year $ 548,196 $ 548,141 $ 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 March 31, 2021 2020 Auction rate securities Balance, beginning of period $ — $ 592 Change in fair value and accretion — 2 Balance, end of period $ — $ 594 Contingent purchase consideration Balance, beginning of period $ 1,963 $ 273 Cash payments (466) (272) Foreign exchange adjustment (154) (1) Balance, end of period $ 1,343 $ —
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 March 31, 2021 2020 Auction rate securities Balance, beginning of period $ — $ 592 Change in fair value and accretion — 2 Balance, end of period $ — $ 594 Contingent purchase consideration Balance, beginning of period $ 1,963 $ 273 Cash payments (466) (272) Foreign exchange adjustment (154) (1) Balance, end of period $ 1,343 $ —

Inventories (Tables)

Inventories (Tables)	3 Months Ended
	Mar. 31, 2021
Inventory Disclosure [Abstract]
Components of Inventories	Inventories consist of the following: March 31, December 31, 2021 2020 Components and raw materials $ 190,376 $ 190,775 Work-in-process 38,066 47,251 Finished goods 139,707 126,967 Total $ 368,149 $ 364,993

Goodwill and Intangibles (Table

Goodwill and Intangibles (Tables)	3 Months Ended
	Mar. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	The following table sets forth the changes in the carrying amount of goodwill: Three Months Ended March 31, 2021 2020 Balance at January 1 $ 41,366 $ 82,092 Adjustment to goodwill during measurement period (2,205) — Foreign exchange adjustment (397) (465) Balance at March 31 $ 38,764 $ 81,627
Schedule of Intangible Assets	Intangible assets, subject to amortization, consisted of the following: March 31, 2021 December 31, 2020 Gross Accumulated Net Carrying Weighted- Average Lives Gross Carrying Accumulated Net Carrying Weighted- Customer relationships $ 59,740 $ (19,232) $ 40,508 10 years $ 58,041 $ (17,674) $ 40,367 11 years Technology, trademark and trade name 40,443 (22,206) 18,237 7 years 40,518 (20,949) 19,569 7 years Production know-how 10,413 (8,299) 2,114 7 years 9,325 (8,167) 1,158 7 years Patents 8,036 (7,127) 909 8 years 8,036 (7,016) 1,020 8 years Total $ 118,632 $ (56,864) $ 61,768 $ 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 $ 9,132 $ 11,409 10,508 $ 8,019 $ 6,505 $ 16,195 $ 61,768 (a) For the nine-month period beginning April 1, 2021.

Accrued Expenses and Other Li_2

Accrued Expenses and Other Liabilities (Tables)	3 Months Ended
	Mar. 31, 2021
Payables and Accruals [Abstract]
Components of Accrued Expenses and Other Liabilities	Accrued expenses and other liabilities consist of the following: March 31, December 31, 2021 2020 Accrued compensation $ 53,690 $ 62,785 Contract liabilities 69,526 71,246 Current portion of accrued warranty 24,056 24,345 Short-term lease liabilities 5,596 5,778 Other 9,907 12,586 Total $ 162,775 $ 176,740

Product Warranties (Tables)

Product Warranties (Tables)	3 Months Ended
	Mar. 31, 2021
Product Warranties Disclosures [Abstract]
Summary of Product Warranty Activity	Activity related to the warranty accrual was as follows:. Three Months Ended March 31, 2021 2020 Balance at January 1 $ 45,669 $ 48,866 Provision for warranty accrual 8,403 5,001 Warranty claims (7,446) (7,241) Foreign currency translation (1,382) (822) Balance at March 31 $ 45,244 $ 45,804

Financing Arrangements (Tables)

Financing Arrangements (Tables)	3 Months Ended
	Mar. 31, 2021
Debt Disclosure [Abstract]
Borrowings Under Existing Financing Arrangements	The Company's borrowings under existing financing arrangements consist of the following: March 31, December 31, 2021 2020 Total notes payable $ 37,021 $ 37,967 Less: current portion (3,828) (3,810) Total long-term debt $ 33,193 $ 34,157
Schedule of Future Principal Payments	The future principal payments for the Company’s Notes as of March 31, 2021 are as follows: 2021 (a) $ 2,864 2022 18,126 2023 16,031 Total $ 37,021 (a) For the nine-month period beginning April 1, 2021.

Derivative Financial Instrume_2

Derivative Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Fair Value of Derivatives	The fair value amounts in the condensed consolidated balance sheets were: March 31, December 31, 2021 2020 Notional amounts (1) $ 18,109 $ 18,406 Fair values: Deferred income taxes and other long-term liabilities $ 514 $ 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 March 31, 2021 2020 Effective portion recognized in other comprehensive income, pretax: Interest rate swap $ 89 $ 46

Income Taxes (Tables)

Income Taxes (Tables)	3 Months Ended
	Mar. 31, 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 three months ended March 31, 2021 and 2020: Three Months Ended March 31, 2021 2020 Balance at January 1, $ 14,706 $ 11,416 Additions for tax positions in current period 1,000 400 Foreign currency translation (182) (1,101) Balance at March 31, $ 15,524 $ 10,715

Net Income Attributable to IP_2

Net Income Attributable to IPG Photonics Corporation Per Share (Tables)	3 Months Ended
	Mar. 31, 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 March 31, 2021 2020 Net income attributable to IPG Photonics Corporation common stockholders $ 68,127 $ 36,403 Basic weighted average common shares 53,541 53,075 Dilutive effect of common stock equivalents 660 601 Diluted weighted average common shares 54,201 53,676 Basic net income attributable to IPG Photonics Corporation per common share $ 1.27 $ 0.69 Diluted net income attributable to IPG Photonics Corporation per common share $ 1.26 $ 0.68
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	The weighted average anti-dilutive shares outstanding for the three months ended March 31, 2021 and 2020 were as follows: Three Months Ended March 31, 2021 2020 Non-qualified stock options 202,500 622,700 Restricted stock units 61,100 198,000 Performance stock units 13,800 50,300 Total weighed average anti-dilutive shares outstanding 277,400 871,000

Basis of Presentation and Sig_4

Basis of Presentation and Significant Accounting Policies (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	$ 2,156	$ 2,547
Provision for bad debts, net of recoveries	188	(187)
Foreign currency translation	(37)	(225)
Balance, end of period	$ 2,307	$ 2,135

Recent Accounting Pronounceme_3

Recent Accounting Pronouncements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Mar. 31, 2021	Dec. 31, 2020
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts receivable, net	$ 238,479	$ 252,877	$ 264,321
Deferred income taxes, net	31,395	41,276	43,197
Retained earnings	$ 2,028,734	$ 2,256,318	$ 2,188,191
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201613Member
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
	Mar. 31, 2021	Mar. 31, 2020
Sales by Application
Total	$ 345,585	$ 249,242
Materials processing
Sales by Application
Total	317,241	218,074
Other applications
Sales by Application
Total	$ 28,344	$ 31,168

Revenue From Contracts With C_4

Revenue From Contracts With Customers (Disaggregation of Revenue, By Product) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Disaggregation of Revenue [Line Items]
Total	$ 345,585	$ 249,242
High Power Continuous Wave ("CW") Lasers
Disaggregation of Revenue [Line Items]
Total	170,482	119,316
Medium Power CW Lasers
Disaggregation of Revenue [Line Items]
Total	15,882	11,253
Pulsed Lasers
Disaggregation of Revenue [Line Items]
Total	55,395	31,839
Quasi-Continuous Wave ("QCW") Lasers
Disaggregation of Revenue [Line Items]
Total	13,666	9,873
Laser and Non-Laser Systems
Disaggregation of Revenue [Line Items]
Total	27,116	18,634
Other Revenue including Amplifiers, Service, Parts, Accessories and Change in Deferred Revenue
Disaggregation of Revenue [Line Items]
Total	$ 63,044	$ 58,327

Revenue From Contracts With C_5

Revenue From Contracts With Customers (Disaggregation of Revenue, By Geography) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Sales by Geography
Total	$ 345,585	$ 249,242
North America
Sales by Geography
Total	73,384	67,339
Germany
Sales by Geography
Total	26,260	17,411
Other including Eastern Europe/CIS
Sales by Geography
Total	58,593	57,232
China
Sales by Geography
Total	139,833	68,599
Japan
Sales by Geography
Total	10,877	13,685
Other
Sales by Geography
Total	33,110	22,823
Rest of World
Sales by Geography
Total	$ 3,528	$ 2,153

Revenue From Contracts With C_6

Revenue From Contracts With Customers (Disaggregation of Revenue, By Timing) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Timing of Revenue Recognition
Total	$ 345,585	$ 249,242
Goods and services transferred at a point in time
Timing of Revenue Recognition
Total	332,532	233,436
Goods and services transferred over time
Timing of Revenue Recognition
Total	$ 13,053	$ 15,806

Revenue From Contracts With C_7

Revenue From Contracts With Customers (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Concentration Risk [Line Items]
Revenue recognized that was included in the contract liability balance at the beginning of the period	$ 30,378	$ 14,995
One Customer | Customer Concentration Risk | Accounts Receivable
Concentration Risk [Line Items]
Concentration risk, percentage	22.00%		21.00%

Revenue From Contracts With C_8

Revenue From Contracts With Customers (Changes in Contract Assets and Contract Liabilities) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Contract assets
Contract assets	$ 7,670	$ 8,646	$ 8,999	$ 9,645
Contract assets, change	(1,329)	(999)
Contract liabilities
Contract liabilities - current	69,526	62,499	71,246	59,531
Contract liabilities - current, change	(1,720)	2,968
Contract liabilities - long-term	2,549	2,377	$ 2,189	$ 1,820
Contract liabilities - long-term, change	$ 360	$ 557

Revenue From Contracts With C_9

Revenue From Contracts With Customers (Schedule of Remaining Performance Obligations) (Details) $ in Thousands	Mar. 31, 2021USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations	$ 23,354
Revenue expected to be recognized for extended warranty agreements
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations	6,599
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	16,755
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations	$ 18,735
Remaining performance obligations, expected timing	9 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-04-01 | Revenue expected to be recognized for extended warranty agreements
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations	$ 3,385
Remaining performance obligations, expected timing	9 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-04-01 | 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	$ 15,350
Remaining performance obligations, expected timing	9 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	$ 2,898
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	$ 1,493
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	$ 1,405
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	$ 842
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	$ 842
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	$ 589
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	$ 589
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	$ 263
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	$ 263
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	$ 27
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	$ 27
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	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents	$ 896,741	$ 876,231	$ 570,058	$ 680,070
Restricted cash included in prepaid expenses and other current assets	0	2,322	2,283	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	$ 896,741	$ 878,553	$ 572,341	$ 682,984

Restricted Cash - Narrative (De

Restricted Cash - Narrative (Details) $ in Thousands	Mar. 15, 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	Mar. 31, 2021	Dec. 31, 2020
Assets
Total	$ 1,083,597	$ 932,571
Liabilities
Long-term debt	37,296	38,402
Interest rate swap	514	603
Contingent purchase consideration	1,343	1,963
Total	39,153	40,968
Level 1
Assets
Total	309,431	218,984
Liabilities
Long-term debt	0	0
Interest rate swap		0
Contingent purchase consideration	0	0
Total	0	0
Level 2
Assets
Total	774,166	713,587
Liabilities
Long-term debt	37,296	38,402
Interest rate swap	514	603
Contingent purchase consideration	0	0
Total	37,810	39,005
Level 3
Assets
Total	0	0
Liabilities
Long-term debt	0	0
Interest rate swap		0
Contingent purchase consideration	1,343	1,963
Total	1,343	1,963
Money market fund deposits and term deposits
Assets
Cash equivalents	306,431	218,984
Money market fund deposits and term deposits | Level 1
Assets
Cash equivalents	306,431	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	173,324	162,749
Commercial paper | Level 1
Assets
Cash equivalents	0	0
Commercial paper | Level 2
Assets
Cash equivalents	173,324	162,749
Commercial paper | Level 3
Assets
Cash equivalents	0	0
Municipal bonds
Assets
Cash equivalents	7,998
Short-term investments		7,997
Municipal bonds | Level 1
Assets
Cash equivalents	0
Short-term investments		0
Municipal bonds | Level 2
Assets
Cash equivalents	7,998
Short-term investments		7,997
Municipal bonds | Level 3
Assets
Cash equivalents	0
Short-term investments		0
Corporate bonds
Assets
Cash equivalents	47,703	29,010
Short-term investments	56,323	88,171
Corporate bonds | Level 1
Assets
Cash equivalents	0	0
Short-term investments	0	0
Corporate bonds | Level 2
Assets
Cash equivalents	47,703	29,010
Short-term investments	56,323	88,171
Corporate bonds | Level 3
Assets
Cash equivalents	0	0
Short-term investments	0	0
U.S. Treasury and agency obligations
Assets
Short-term investments	13,000
U.S. Treasury and agency obligations | Level 1
Assets
Short-term investments	0
U.S. Treasury and agency obligations | Level 2
Assets
Short-term investments	13,000
U.S. Treasury and agency obligations | Level 3
Assets
Short-term investments	0
Commercial paper
Assets
Short-term investments	475,818	368,665
Commercial paper | Level 1
Assets
Short-term investments	0	0
Commercial paper | Level 2
Assets
Short-term investments	475,818	368,665
Commercial paper | Level 3
Assets
Short-term investments	0	0
Certificates of deposit
Assets
Short-term investments	3,000
Certificates of deposit | Level 1
Assets
Short-term investments	3,000
Certificates of deposit | Level 2
Assets
Short-term investments	0
Certificates of deposit | Level 3
Assets
Short-term investments	$ 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

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 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	37,296,000		$ 38,402,000
Long-term debt, book value	37,021,000		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	Mar. 31, 2021	Dec. 31, 2020
Investment maturity
Held-to-maturity maturities, less than 1 year, book value	$ 548,196	$ 514,835
Held-to-maturity maturities, less than 1 year, fair value	$ 548,141	$ 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
	Mar. 31, 2021	Mar. 31, 2020
Auction rate securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	$ 0	$ 592
Change in fair value and accretion	0	2
Balance, end of period	0	594
Contingent purchase consideration
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	1,963	273
Cash payments		(272)
Foreign exchange adjustment	(154)	(1)
Balance, end of period	$ 1,343	$ 0

Inventories (Components Of Inve

Inventories (Components Of Inventories) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Inventory Disclosure [Abstract]
Components and raw materials	$ 190,376	$ 190,775
Work-in-process	38,066	47,251
Finished goods	139,707	126,967
Total	$ 368,149	$ 364,993

Inventories (Narrative) (Detail

Inventories (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Inventory Disclosure [Abstract]
Inventory provisions	$ 8,027	$ 8,451

Goodwill and Intangibles (Sched

Goodwill and Intangibles (Schedule of Changes) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Goodwill [Roll Forward]
Balance at January 1	$ 41,366	$ 82,092
Adjustment to goodwill during measurement period	(2,205)	0
Foreign exchange adjustment	(397)	(465)
Balance at March 31	$ 38,764	$ 81,627

Goodwill and Intangibles (Narra

Goodwill and Intangibles (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 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	38,764	$ 41,366	81,627	$ 82,092
Amortization expense	3,257		3,133
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			$ 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	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 118,632	$ 115,920
Accumulated amortization	(56,864)	(53,806)
Net carrying amount	61,768	62,114
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	59,740	58,041
Accumulated amortization	(19,232)	(17,674)
Net carrying amount	$ 40,508	$ 40,367
Weighted-average lives	10 years	11 years
Technology, trademark and trade name
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 40,443	$ 40,518
Accumulated amortization	(22,206)	(20,949)
Net carrying amount	$ 18,237	$ 19,569
Weighted-average lives	7 years	7 years
Production know-how
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 10,413	$ 9,325
Accumulated amortization	(8,299)	(8,167)
Net carrying amount	$ 2,114	$ 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	(7,127)	(7,016)
Net carrying amount	$ 909	$ 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	Mar. 31, 2021	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
2021	$ 9,132
2022	11,409
2023	10,508
2024	8,019
2025	6,505
Thereafter	16,195
Net carrying amount	$ 61,768	$ 62,114

Accrued Expenses and Other Li_3

Accrued Expenses and Other Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
Payables and Accruals [Abstract]
Accrued compensation	$ 53,690	$ 62,785
Contract liabilities	69,526	71,246	$ 62,499	$ 59,531
Current portion of accrued warranty	24,056	24,345
Short-term lease liabilities	5,596	5,778
Other	9,907	12,586
Total	$ 162,775	$ 176,740

Product Warranties (Narrative)

Product Warranties (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Product Warranty Liability [Line Items]
Accrued warranty reported in accrued expenses and other liabilities	$ 24,056	$ 24,345
Accrued warranty reported in other long-term liabilities	$ 21,188	$ 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	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Movement in Standard and Extended Product Warranty, Increase (Decrease) [Roll Forward]
Balance at January 1	$ 45,669	$ 48,866
Provision for warranty accrual	8,403	5,001
Warranty claims	(7,446)	(7,241)
Foreign currency translation	(1,382)	(822)
Balance at March 31	$ 45,244	$ 45,804

Financing Arrangements (Borrowi

Financing Arrangements (Borrowings Under Existing Financing Arrangements) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Debt Disclosure [Abstract]
Total notes payable	$ 37,021	$ 37,967
Less: current portion	(3,828)	(3,810)
Total long-term debt	$ 33,193	$ 34,157

Financing Arrangements (Narrati

Financing Arrangements (Narrative) (Details) € in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)	May 31, 2023USD ($)	Jul. 31, 2022USD ($)	Mar. 31, 2021EUR (€)	Dec. 31, 2020USD ($)
Debt Instrument [Line Items]
Total unused credit lines and overdraft facilities	$ 129,792,000
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	$ 18,912,000
Current portion of long-term note	$ 2,641,000
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	$ 18,109,000
Current portion of long-term note	1,187,000
U.S. line-of-credit
Debt Instrument [Line Items]
Line of credit	0				$ 0
Guarantees issued	3,293,000				3,300,000
Euro line-of-credit
Debt Instrument [Line Items]
Line of credit	0				0
Guarantees issued	2,895,000				3,424,000
Euro overdraft facility
Debt Instrument [Line Items]
Line of credit	0				$ 0
Letter of Credit | U.S. line-of-credit
Debt Instrument [Line Items]
Borrowing capacity	75,000,000
Letter of Credit | Euro line-of-credit
Debt Instrument [Line Items]
Borrowing capacity	58,635,000			€ 50,000
Letter of Credit | Euro overdraft facility
Debt Instrument [Line Items]
Borrowing capacity	$ 2,345,000			€ 2,000

Financing Arrangements (Future

Financing Arrangements (Future Principal Payments) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Debt Disclosure [Abstract]
2021	$ 2,864
2022	18,126
2023	16,031
Total notes payable	$ 37,021	$ 37,967

Derivative Financial Instrume_3

Derivative Financial Instruments (Fair Value) (Details) - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Derivatives, Fair Value [Line Items]
Deferred income taxes and other long-term liabilities	$ 514,000	$ 603,000
Derivative designated as a cash flow hedge | Interest rate swap
Derivatives, Fair Value [Line Items]
Derivative, notional amount	18,109,000	18,406,000
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	$ 514,000	$ 603,000

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
	Mar. 31, 2021	Mar. 31, 2020
Interest rate swap | Derivative designated as a cash flow hedge
Derivative Instruments, Gain (Loss) [Line Items]
Effective portion recognized in other comprehensive income, pretax	$ 89	$ 46

Commitments and Contingencies (

Commitments and Contingencies (Details)	Mar. 31, 2021USD ($)
Commitments and Contingencies Disclosure [Abstract]
Legal proceedings	$ 0

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Income Tax Disclosure [Abstract]
Effective tax rate	23.00%	23.50%
Discrete tax benefit	$ 4,288	$ 2,787

Income Taxes (Schedule of Unrec

Income Taxes (Schedule of Unrecognized Tax Benefits) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 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	1,000	400
Foreign currency translation	(182)	(1,101)
Balance at March 31,	$ 15,524	$ 10,715

Net Income Attributable to IP_3

Net Income Attributable to IPG Photonics Corporation Per Share (Computation of Diluted Net Income) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Earnings Per Share [Abstract]
Net income attributable to IPG Photonics Corporation common stockholders	$ 68,127	$ 36,403
Basic weighted average common shares	53,541	53,075
Dilutive effect of common stock equivalents (in shares)	660	601
Diluted weighted average common shares	54,201	53,676
Basic net income attributable to IPG Photonics Corporation per common share (in dollars per share)	$ 1.27	$ 0.69
Diluted net income attributable to IPG Photonics Corporation per common share (in dollars per share)	$ 1.26	$ 0.68

Net Income Attributable to IP_4

Net Income Attributable to IPG Photonics Corporation Per Share (Anti Dilutive Shares Excluded From EPS) (Details) - shares	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Excluded from computation of diluted weighted average common shares (in shares)	277,400	871,000
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 (in shares)	202,500	622,700
Restricted Stock Units, RSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Excluded from computation of diluted weighted average common shares (in shares)	61,100	198,000
Performance Stock Units, PSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Excluded from computation of diluted weighted average common shares (in shares)	13,800	50,300

Net Income Attributable to IP_5

Net Income Attributable to IPG Photonics Corporation Per Share (Narrative) (Details) - USD ($)	3 Months Ended
	Mar. 31, 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	461
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)	14,906
Stock repurchase average price (in dollars per share)	$ 204.48
Remaining repurchase amount	$ 243,000,000
2019 Program
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Share repurchase authorized amount			$ 125,000,000