IPG Photonics (IPGP) 10-Q 6 Aug 19 2019 Q2 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	6 Months Ended
	Jun. 30, 2019	Aug. 05, 2019
Cover page.
Amendment Flag	false
Document Fiscal Period Focus	Q2
Document Fiscal Year Focus	2019
Entity Central Index Key	0001111928
Current Fiscal Year End Date	--12-31
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2019
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
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
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Trading Symbol	IPGP
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding (in shares)		53,200,337

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 530,013	$ 544,358
Short-term investments	512,816	500,432
Accounts receivable, net	273,697	255,509
Inventories	425,996	403,579
Prepaid income taxes	49,885	43,782
Prepaid expenses and other current assets	70,675	57,764
Total current assets	1,863,082	1,805,424
Deferred income taxes, net	20,833	19,165
Goodwill	110,868	100,722
Intangible assets, net	89,906	87,139
Property, plant and equipment, net	600,977	543,068
Other assets	51,750	18,932
Total assets	2,737,416	2,574,450
Current liabilities:
Current portion of long-term debt	3,705	3,671
Accounts payable	38,016	36,302
Accrued expenses and other current liabilities	161,209	154,640
Income taxes payable	19,298	51,161
Total current liabilities	222,228	245,774
Deferred income taxes and other long-term liabilities	107,981	80,734
Long-term debt, net of current portion	39,846	41,707
Total liabilities	370,055	368,215
Commitments and contingencies (Note 12)
IPG Photonics Corporation equity:
Common stock, $0.0001 par value, 175,000,000 shares authorized; 54,629,380 and 53,182,910 shares issued and outstanding, respectively, at June 30, 2019; 54,371,701 and 52,941,607 shares issued and outstanding, respectively, at December 31, 2018	5	5
Treasury stock, at cost, 1,446,470 and 1,430,094 shares held at June 30, 2019 and December 31, 2018, respectively.	(227,282)	(224,998)
Additional paid-in capital	761,936	744,937
Retained earnings	1,975,931	1,848,500
Accumulated other comprehensive loss	(143,943)	(162,896)
Total IPG Photonics Corporation equity	2,366,647	2,205,548
Non-controlling interests	714	687
Total equity	2,367,361	2,206,235
Total liabilities and equity	$ 2,737,416	$ 2,574,450

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	175,000,000	175,000,000
Common stock, shares issued (in shares)	54,629,380	54,371,701
Common stock, shares outstanding (in shares)	53,182,910	52,941,607
Treasury stock, shares (in shares)	1,446,470	1,430,094

Condensed Consolidated Statemen

Condensed Consolidated Statements Of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Income Statement [Abstract]
Net sales	$ 363,769	$ 413,613	$ 678,816	$ 773,477
Cost of sales	183,532	178,638	349,668	335,140
Gross profit	180,237	234,975	329,148	438,337
Operating expenses:
Sales and marketing	20,663	14,536	39,938	28,052
Research and development	34,872	31,813	67,368	60,359
General and administrative	28,538	24,117	55,750	49,612
Loss (gain) on foreign exchange	5,074	2,118	6,687	(3,176)
Total operating expenses	89,147	72,584	169,743	134,847
Operating income	91,090	162,391	159,405	303,490
Other income, net:
Interest income, net	4,051	729	8,003	1,041
Other (expense) income, net	658	386	649	829
Total other income	4,709	1,115	8,652	1,870
Income before provision for income taxes	95,799	163,506	168,057	305,360
Provision for income taxes	(23,278)	(41,889)	(40,620)	(77,409)
Net income	72,521	121,617	127,437	227,951
Less: net income attributable to non-controlling interests	249	0	6	0
Net income attributable to IPG Photonics Corporation	$ 72,272	$ 121,617	$ 127,431	$ 227,951
Net income attributable to IPG Photonics Corporation per share:
Basic (in dollars per share)	$ 1.36	$ 2.27	$ 2.40	$ 4.24
Diluted (in dollars per share)	$ 1.34	$ 2.21	$ 2.36	$ 4.14
Weighted average shares outstanding:
Basic (in shares)	53,042	53,662	53,076	53,703
Diluted (in shares)	53,848	54,992	53,915	55,111

Condensed Consolidated Statem_2

Condensed Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 72,521	$ 121,617	$ 127,437	$ 227,951
Other comprehensive income, net of tax:
Translation adjustments	13,800	(78,663)	18,958	(52,025)
Unrealized (loss) gain on derivatives	8	0	(5)	2
Effect of adopted accounting standards	0	0	0	10
Total other comprehensive income	13,808	(78,663)	18,953	(52,013)
Comprehensive income	86,329	42,954	146,390	175,938
Comprehensive income attributable to non-controlling interests	267	0	27	0
Comprehensive income attributable to IPG Photonics Corporation	$ 86,062	$ 42,954	$ 146,363	$ 175,938

Condensed Consolidated Statem_3

Condensed Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Cash flows from operating activities:
Net income	$ 127,437	$ 227,951
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	47,486	38,727
Deferred income taxes	2,628	6,097
Stock-based compensation	17,031	13,724
Unrealized loss (gain) on foreign currency transactions	4,185	(1,056)
Other	170	(181)
Provisions for inventory, warranty & bad debt	22,697	20,092
Changes in assets and liabilities that (used) provided cash:
Accounts receivable	(21,056)	(9,491)
Inventories	(40,789)	(91,014)
Prepaid expenses and other assets	8,616	(1,991)
Accounts payable	(445)	9,527
Accrued expenses and other liabilities	(9,320)	(17,860)
Income and other taxes payable	(56,861)	14,026
Net cash provided by operating activities	101,779	208,551
Cash flows from investing activities:
Purchases of and deposits on property, plant and equipment	(86,492)	(96,516)
Proceeds from sales of property, plant and equipment	288	641
Purchases of short-term and long-term investments	(339,828)	(289,830)
Proceeds from short-term investments	334,680	161,618
Acquisitions of businesses, net of cash acquired	(15,115)	(4,422)
Other	209	188
Net cash used in investing activities	(106,258)	(228,321)
Cash flows from financing activities:
Proceeds from line-of-credit facilities	0	255
Payments on line-of-credit facilities	0	(255)
Principal payments on long-term borrowings	(1,827)	(1,794)
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	(32)	10,631
Purchase of treasury stock, at cost	(2,284)	(51,064)
Net cash used in financing activities	(4,143)	(42,227)
Effect of changes in exchange rates on cash, cash equivalents and restricted cash	(2,759)	(31,111)
Net decrease in cash, cash equivalents and restricted cash	(11,381)	(93,108)
Cash and cash equivalents — Beginning of period	544,358	909,900
Cash, cash equivalents and restricted cash — End of period (Note 2)	532,977	816,792
Supplemental disclosure of cash flow information:
Cash paid for interest	1,164	1,672
Cash paid for income taxes	73,855	64,495
Non-cash transactions:
Demonstration units transferred from inventory to other assets	6,572	1,720
Inventory transferred to machinery and equipment	6,444	5,000
Changes in accounts payable related to property, plant and equipment	1,959	(1,683)
Leased assets obtained in exchange for new operating lease liabilities	$ 10,698	$ 0

Condensed Consolidated Statem_4

Condensed Consolidated Statements Of Equity - USD ($) $ in Thousands	Total	Common Stock	Treasury Stock	Additional Paid In Capital	Retained Earnings	Accumulated Other Comprehensive (Loss) Income	Non- controlling Interest
Balance, beginning of year (in shares) at Dec. 31, 2017		53,629,439	378,269
Balance, beginning of period at Dec. 31, 2017	$ 2,022,322	$ 5	$ (48,933)	$ 704,727	$ 1,443,867	$ (77,344)	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options and vesting of RSU's and PSU's (in shares)		196,308
Exercise of stock options and vesting of RSU's and PSU's	3,113	$ 0		3,113
Stock-based compensation	6,415			6,415
Net income	106,334				106,334
Foreign currency translation adjustments	26,638					26,638
Unrealized (loss) gain on derivatives	2					2
Purchased common stock (in shares)		(82,898)	(82,898)
Purchased common stock	(20,071)	$ 0	$ (20,071)
Balance, end of period (in shares) at Mar. 31, 2018		53,742,849	461,167
Balance, end of period at Mar. 31, 2018	2,145,369	$ 5	$ (69,004)	714,255	1,550,807	(50,694)	0
Balance, beginning of year (in shares) at Dec. 31, 2017		53,629,439	378,269
Balance, beginning of period at Dec. 31, 2017	2,022,322	$ 5	$ (48,933)	704,727	1,443,867	(77,344)	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	227,951
Unrealized (loss) gain on derivatives	2
Balance, end of period (in shares) at Jun. 30, 2018		53,724,445	592,847
Balance, end of period at Jun. 30, 2018	2,172,157	$ 5	$ (99,997)	729,082	1,672,424	(129,357)	0
Balance, beginning of year (in shares) at Mar. 31, 2018		53,742,849	461,167
Balance, beginning of period at Mar. 31, 2018	2,145,369	$ 5	$ (69,004)	714,255	1,550,807	(50,694)	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options and vesting of RSU's and PSU's (in shares)		101,078
Exercise of stock options and vesting of RSU's and PSU's	5,230	$ 0		5,230
Stock-based compensation	7,309			7,309
Net income	121,617				121,617
Foreign currency translation adjustments	(78,663)					(78,663)
Unrealized (loss) gain on derivatives	0
Common stock issued under employee stock purchase plan (in shares)		12,198
Common stock issued under employee stock purchase plan	2,288	$ 0		2,288
Purchased common stock (in shares)		(131,680)	(131,680)
Purchased common stock	(30,993)	$ 0	$ (30,993)
Balance, end of period (in shares) at Jun. 30, 2018		53,724,445	592,847
Balance, end of period at Jun. 30, 2018	2,172,157	$ 5	$ (99,997)	729,082	1,672,424	(129,357)	0
Balance, beginning of year (in shares) at Dec. 31, 2018		52,941,607	1,430,094
Balance, beginning of period at Dec. 31, 2018	2,206,235	$ 5	$ (224,998)	744,937	1,848,500	(162,896)	687
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options and vesting of RSU's and PSU's (in shares)		166,606
Exercise of stock options and vesting of RSU's and PSU's	(6,149)	$ 0		(6,149)
Stock-based compensation	8,138			8,138
Net income	54,916				55,159		(243)
Foreign currency translation adjustments	5,161					5,158	3
Unrealized (loss) gain on derivatives	(13)					(13)
Balance, end of period (in shares) at Mar. 31, 2019		53,108,213	1,430,094
Balance, end of period at Mar. 31, 2019	2,268,288	$ 5	$ (224,998)	746,926	1,903,659	(157,751)	447
Balance, beginning of year (in shares) at Dec. 31, 2018		52,941,607	1,430,094
Balance, beginning of period at Dec. 31, 2018	2,206,235	$ 5	$ (224,998)	744,937	1,848,500	(162,896)	687
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	127,437
Unrealized (loss) gain on derivatives	(5)
Balance, end of period (in shares) at Jun. 30, 2019		53,182,910	1,446,470
Balance, end of period at Jun. 30, 2019	2,367,361	$ 5	$ (227,282)	761,936	1,975,931	(143,943)	714
Balance, beginning of year (in shares) at Mar. 31, 2019		53,108,213	1,430,094
Balance, beginning of period at Mar. 31, 2019	2,268,288	$ 5	$ (224,998)	746,926	1,903,659	(157,751)	447
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options and vesting of RSU's and PSU's (in shares)		59,590
Exercise of stock options and vesting of RSU's and PSU's	2,152			2,152
Stock-based compensation	8,893			8,893
Net income	72,521				72,272		249
Foreign currency translation adjustments	13,818					13,800	18
Unrealized (loss) gain on derivatives	8					8
Common stock issued under employee stock purchase plan (in shares)		31,483
Common stock issued under employee stock purchase plan	3,965	$ 0		3,965
Purchased common stock (in shares)		(16,376)	(16,376)
Purchased common stock	(2,284)	$ 0	$ (2,284)
Balance, end of period (in shares) at Jun. 30, 2019		53,182,910	1,446,470
Balance, end of period at Jun. 30, 2019	$ 2,367,361	$ 5	$ (227,282)	$ 761,936	$ 1,975,931	$ (143,943)	$ 714

Basis Of Presentation And Signi

Basis Of Presentation And Significant Accounting Policies	6 Months Ended
	Jun. 30, 2019
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, 2018. 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. In accordance with Accounting Standards Codification ("ASC") 842, "Leases," ("ASC 842" or the "new lease standard"), the following significant accounting policy has been adopted as of January 1, 2019. Leases — The Company determines if an arrangement is a lease at inception. Operating leases are included in other assets, other current liabilities, and other long-term liabilities on our condensed consolidated balance sheets. Right of use ("ROU") assets and lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at commencement date. As most of the Company's leases do not provide an implicit rate, IPG uses its incremental borrowing rate based on the information available at commencement date in determining the present value of future payments. The ROU assets also include any lease payments made and initial direct costs incurred and exclude lease incentives. Lease terms may include options to extend or terminate the lease when it is reasonably certain that we will exercise that option. Lease expense for minimum lease payments is recognized on a straight-line basis over the lease term. Leases with an initial term of 12 months or less are not recorded on the balance sheet; the Company recognizes lease expense for these leases on a straight-line basis over the lease term. The Company has lease agreements with lease and non-lease components, which are accounted for as a single lease component. Reclassifications — Certain prior year amounts have been reclassified to conform with current period presentation. These reclassifications had no effect on the reported results of operations.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	6 Months Ended
	Jun. 30, 2019
Accounting Policies [Abstract]
Recent Accounting Pronouncements	RECENT ACCOUNTING PRONOUNCEMENTS Adopted Pronouncements — In February 2016, the Financial Accounting Standards Board (“FASB”) issued a new standard related to leases to increase transparency and comparability among organizations by requiring the recognition of ROU assets and lease liabilities on the balance sheet. Most prominent among the changes in the standard is the recognition of ROU assets and lease liabilities by lessees for those leases classified as operating leases. The Company adopted ASC 842, as of January 1, 2019, using the modified retrospective approach as of the date of adoption. Under this approach, comparative periods have not been restated. In addition, IPG elected the package of three practical expedients permitted under the transition guidance within the new standard, which among other things, allowed for the carry forward of the historical lease classification. The cumulative effect of the changes made to the Company's condensed consolidated January 1, 2019 balance sheet for the adoption of ASC 842 related to operating leases was as follows: Balance at Balance at December 31, 2018 Adoption of ASC 842 January 1, 2019 Balance Sheet Prepaid expenses and other current assets $ 57,764 $ (324) $ 57,440 Other assets 18,932 19,463 38,395 Accrued expenses and other current liabilities 154,640 5,292 159,932 Deferred income taxes and other long-term liabilities 80,734 13,847 94,581 In the first quarter of 2018, the Company adopted FASB ASU No. 2016-18, "Statement of Cash Flows (Topic 230): Restricted Cash" ("ASU 2016-18"), which enhances and clarifies the guidance on the classification and presentation of restricted cash in the statement of cash flows and requires additional disclosure about restricted cash balances. The Company considers cash to be restricted when withdrawal or general use is legally restricted. The Company records restricted cash in other assets on the condensed consolidated balance sheets and determines classification based on the expected duration of the restriction. The reconciliation of the Company's cash and cash equivalents in the condensed consolidated balance sheets to cash, cash equivalents and restricted cash in the condensed consolidated statement of cash flows is as follows: Balance at June 30, 2019 Cash and cash equivalents $ 530,013 Restricted cash included in other assets 2,964 Cash, cash equivalents and restricted cash $ 532,977 Other Pronouncements Currently Under Evaluation — In June 2016, the FASB issued 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 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. ASU 2016-03, along with its subsequent clarifications, is effective for fiscal years beginning after December 15, 2019. The Company does not expect this standard will have a material impact to net income.

Revenue From Contracts With Cus

Revenue From Contracts With Customers	6 Months Ended
	Jun. 30, 2019
Revenue from Contract with Customer [Abstract]
Revenue From Contracts With Customers	REVENUE FROM CONTRACTS WITH CUSTOMERS The following tables represent a disaggregation of revenue from contracts with customers: Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Sales by Application Materials processing $ 345,591 $ 392,001 $ 646,676 $ 731,215 Other applications 18,178 21,612 32,140 42,262 Total $ 363,769 $ 413,613 $ 678,816 $ 773,477 Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Sales by Product High Power Continuous Wave ("CW") Lasers $ 213,411 $ 266,075 $ 392,430 $ 496,649 Medium and Low Power CW Lasers 15,415 30,972 31,013 56,372 Pulsed Lasers 40,813 41,582 72,250 79,835 Quasi-Continuous Wave ("QCW") Lasers 15,967 20,092 30,133 36,292 Laser and Non-Laser Systems 39,383 13,428 72,014 22,899 Other Revenue including Amplifiers, Service, Parts, Accessories and Change in Deferred Revenue 38,780 41,464 80,976 81,430 Total $ 363,769 $ 413,613 $ 678,816 $ 773,477 Sales by Geography North America $ 64,140 $ 47,766 $ 128,947 $ 86,943 Europe: Germany 23,664 31,989 42,283 65,225 Other including Eastern Europe/CIS 61,131 76,347 130,331 159,325 Asia and Australia: China 163,590 203,026 277,956 352,999 Japan 17,406 19,428 33,020 39,057 Other 28,929 33,314 60,667 67,521 Rest of World 4,909 1,743 5,612 2,407 Total $ 363,769 $ 413,613 $ 678,816 $ 773,477 Timing of Revenue Recognition Goods and services transferred at a point in time $ 342,037 $ 412,241 $ 634,130 $ 771,094 Goods and services transferred over time 21,732 1,372 44,686 2,383 Total $ 363,769 $ 413,613 $ 678,816 $ 773,477 One of our customers accounted for 11.6% and 13.0% of our net sales for the six months ended June 30, 2019 and 2018, respectively. The same customer accounted for 39.2% and 24.7% of our net accounts receivable as of June 30, 2019 and December 31, 2018, 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 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 is met. The Company bills customers for extended warranties upon entering into the agreement with the customer, resulting in deferred revenue. The timing of customer payments on contracts for the sale of customized robotic systems generally differs from the timing of revenue recognized, resulting in contract assets and liabilities. 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. The following table reflects the changes in the Company's contract assets and liabilities for the six months ended June 30, 2019 and 2018: June 30, January 1, June 30, January 1, 2019 2019 Change 2018 2018 Change Contract assets Contract assets $ 8,460 $ 10,102 $ (1,642) $ — $ — $ — Contract liabilities Contract liabilities - current 61,506 52,606 8,900 46,986 46,508 478 Contract liabilities - long-term 1,720 1,413 307 1,414 182 1,232 During the three months ended June 30, 2019 and June 30, 2018 the Company recognized revenue of $11,092 and $7,197, respectively, that was included in contract liabilities at the beginning of the period, respectively. During the six months ended June 30, 2019 and June 30, 2018, the Company recognized revenue of $36,252 and $35,529, respectively, that was included in contract liabilities at the beginning of the period, respectively. 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 June 30, 2019: Remaining Performance Obligations 2019 (a) 2020 2021 2022 2023 2024 and thereafter Total Revenue expected to be recognized for extended warranty agreements $ 2,638 $ 2,063 $ 636 $ 331 $ 133 $ 27 $ 5,828 Revenue to be earned over time from contracts to sell robotic systems 21,916 3,442 — — — — 25,358 Total $ 24,554 $ 5,505 $ 636 $ 331 $ 133 $ 27 $ 31,186 (a) For the six-month period beginning July 1, 2019.

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements	FAIR VALUE MEASUREMENTS The Company's financial instruments consist of cash equivalents, short-term and long-term investments, accounts receivable, auction rate securities, 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 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 Company's bond securities are reported at fair value 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. At June 30, 2019 and December 31, 2018, the Company's long-term notes consisted of a variable rate note and a fixed rate note, and the book value is considered a reasonable estimate of fair market 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, which is measured at fair value: Fair Value Measurements at June 30, 2019 Total Level 1 Level 2 Level 3 Assets Cash equivalents: Money market fund deposits and term deposits $ 187,562 $ 187,562 $ — $ — Commercial paper 39,561 — 39,561 — Short-term investments: U.S. Treasury and agency obligations 38,828 38,828 — — Corporate bonds 262,544 262,544 — — Non-U.S. government bonds 5,491 — 5,491 — Commercial paper 206,337 — 206,337 — Long-term investments and other assets: Auction rate securities 852 — — 852 Interest rate swap 28 — 28 — Total $ 741,203 $ 488,934 $ 251,417 $ 852 Liabilities Long-term debt $ 43,551 $ — $ 43,551 $ — Contingent purchase consideration 300 — — 300 Total $ 43,851 $ — $ 43,551 $ 300 Fair Value Measurements at December 31, 2018 Total Level 1 Level 2 Level 3 Assets Cash equivalents: Money market fund deposits and term deposits $ 180,965 $ 180,965 $ — $ — U.S. Treasury and agency obligations 6,495 6,495 — — Commercial paper 78,948 — 78,948 — Short-term investments: U.S. Treasury and agency obligations 116,800 116,800 — — Corporate bonds 227,009 227,009 — — Commercial paper 156,321 — 156,321 — Long-term investments and other assets: Corporate bonds 3,859 3,859 — — Auction rate securities 847 — — 847 Interest rate swaps 31 — 31 — Total $ 771,275 $ 535,128 $ 235,300 $ 847 Liabilities Long-term debt $ 45,378 $ — $ 45,378 $ — Contingent purchase consideration 898 — — 898 Total $ 46,276 $ — $ 45,378 $ 898 The fair value of the short-term investments considered held-to-maturity as of June 30, 2019 and December 31, 2018 was $513,200 and $500,130, respectively, which include an unrealized gain of $384 and unrealized loss of $302, respectively, as compared to the book value recorded on the condensed consolidated balance sheets for the same periods. There were no long-term investments considered held-to-maturity as of June 30, 2019. The fair value of the long-term investments considered held- to-maturity as of December 31, 2018 was $3,859, which represents the book value recorded within other assets on the condensed consolidated balance sheets for the same period. There were no impairments for the investments considered held-to-maturity at June 30, 2019 and December 31, 2018. The Company entered into an interest rate swap that is designated as a cash flow hedge associated with a new 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 June 30, 2019 for the interest rate swap considered pricing models whose inputs are observable for the securities held by the Company. Auction rate securities and contingent consideration are measured at fair value on a recurring basis using significant unobservable inputs (Level 3). The fair value of the auction rate securities was determined using prices observed in inactive markets with limited observable data for the securities held by the Company. The auction rate securities are considered available-for-sale securities. They had a cost basis of $852 and $847 at June 30, 2019 and December 31, 2018, respectively. There were no impairments for the investments considered available-for-sale during the quarters ended June 30, 2019 and 2018. The fair value of contingent consideration was determined using an income approach at the respective business combination date and at the reporting date. That 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 consideration. The following table presents information about the Company's movement in Level 3 assets and liabilities measured at fair value: Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Auction rate securities Balance, beginning of period $ 850 $ 1,019 $ 847 $ 1,016 Change in fair value and accretion 2 155 5 158 Balance, end of period $ 852 $ 1,174 $ 852 $ 1,174 Contingent purchase consideration Balance, beginning of period $ 294 $ 902 $ 898 $ 902 Cash payments — — (632) — Foreign exchange adjustment 6 — 34 — Balance, end of period $ 300 $ 902 $ 300 $ 902 The following table presents the effective maturity dates of held-to-maturity debt investments as of June 30, 2019 and December 31, 2018: June 30, 2019 December 31, 2018 Book Value Fair Value Book Value Fair Value Investment maturity Held-to-maturity: Less than 1 year $ 512,816 $ 513,200 $ 585,875 $ 585,573 1 through 5 years — — 3,859 3,859 Total $ 512,816 $ 513,200 $ 589,734 $ 589,432 Available-for-sale: Greater than 5 years $ 852 $ 852 $ 847 $ 847

Inventories

Inventories	6 Months Ended
	Jun. 30, 2019
Inventory Disclosure [Abstract]
Inventories	INVENTORIES Inventories consist of the following: June 30, December 31, 2019 2018 Components and raw materials $ 243,768 $ 233,594 Work-in-process 40,661 66,498 Finished components and devices 141,567 103,487 Total $ 425,996 $ 403,579 The Company recorded inventory provisions totaling $7,886 and $3,497 for the three months ended June 30, 2019 and 2018, respectively, and $12,649 and $6,854 for the six months ended June 30, 2019 and 2018, 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	6 Months Ended
	Jun. 30, 2019
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 for the six months ended June 30, 2019: Amount Balance at January 1 $ 100,722 Goodwill arising from acquisition 9,426 Adjustment to goodwill during measurement period 448 Foreign exchange adjustment 272 Balance at June 30 $ 110,868 During the fourth quarter of 2018, the Company acquired 100% of the membership units of Genesis Systems Group, LLC ("Genesis"). During the first quarter of 2019, the working capital adjustment to the purchase price was finalized resulting in an increase in the purchase price of $448. The additional purchase price was allocated entirely to goodwill. During the first quarter of 2019, the Company acquired the submarine networks division (SND) of Padtec SA, a communications equipment company based in Brazil. SND is a provider of submarine networking technology and systems. The Company paid $19,560 to acquire SND, which represents the fair value on that date. Of the purchase price, $1,956 ($1,948 at June 30, 2019) was held back for potential post-closing adjustments related to government approval of licenses. This balance is included within accrued expenses and other liabilities on the condensed consolidated balance sheets. In addition, $2,934 ($2,964 at June 30, 2019) was held back in a restricted bank account for potential post-closing adjustments related to indemnities provided by the seller. This balance related to restricted cash is included within other assets, and the liability related to the amount due to the sellers if the indemnities are satisfied is included within deferred income taxes and other long-term liabilities on the condensed consolidated balance sheets. Any excess of the acquisition consideration over the fair value of assets acquired and liabilities assumed is allocated to goodwill, which amounted to $9,426. The Company is assessing the deductibility of the goodwill for tax purposes. As a result of the acquisition, the Company recorded intangible assets of $4,825 related to production know-how with a weighted-average useful life of 6 years and $4,825 related to customer relationships with a weighted-average life of 6 years. The purchase price allocations included in the Company's condensed consolidated financial statements are not complete. They represent the preliminary fair value estimates as of June 30, 2019 and are subject to subsequent adjustment as the Company obtains additional information during the measurement period and finalizes its fair value estimates. Any subsequent adjustments to these fair value estimates occurring during the measurement period will result in changes to the amounts and allocations recorded. Intangible assets, subject to amortization, consisted of the following: June 30, 2019 December 31, 2018 Gross Carrying Accumulated Net Carrying Weighted- Average Lives Gross Carrying Accumulated Net Carrying Weighted- Patents $ 8,036 $ (6,300) $ 1,736 8 years $ 8,036 $ (6,028) $ 2,008 8 years Customer relationships 62,690 (9,468) 53,222 10 years 57,849 (6,427) 51,422 11 years Production know-how 14,006 (7,052) 6,954 7 years 9,211 (6,212) 2,999 7 years Technology, trademark and trade names 41,431 (13,437) 27,994 7 years 41,184 (10,474) 30,710 7 years Total $ 126,163 $ (36,257) $ 89,906 $ 116,280 $ (29,141) $ 87,139 Amortization expense for the three months ended June 30, 2019 and 2018 was $3,648 and $1,908, respectively. Amortization expense for the six months ended June 30, 2019 and 2018 was $6,964 and $3,839, respectively. The estimated future amortization expense for intangibles for the remainder of 2019 and subsequent years is as follows: 2019 (a) 2020 2021 2022 2023 Thereafter Total $ 7,236 $ 13,665 13,298 $ 12,404 $ 11,449 $ 31,854 $ 89,906 (a) For the six-month period beginning July 1, 2019.

Leases

Leases	6 Months Ended
	Jun. 30, 2019
Leases [Abstract]
Leases	LEASES The Company leases certain warehouses, office spaces, land, vehicles and equipment under operating lease agreements. The remaining terms of these leases range from less than 1 year to 46 years. The operating lease expense for the three and six months ended June 30, 2019 was $2,795 and $4,464, respectively. The cash paid for amounts included in the measurement of lease liabilities included in the operating cash flows from operating leases was $1,572 and $3,442 for the three and six months ended June 30, 2019, respectively. The Company does not have any finance lease arrangements. The Company's operating lease assets and lease liabilities consist of the following as of June 30, 2019: Account Classification Amount Right-of-use assets Other assets $ 27,083 Short-term lease liabilities Accrued expenses and other liabilities 5,647 Long-term lease liabilities Deferred income taxes and other long-term liabilities 21,375 Total lease liabilities $ 27,022 The table below presents the future minimum lease payments to be made under non-cancelable operating leases as of December 31, 2018: Years ending December 31, 2019 $ 6,314 2020 4,603 2021 3,358 2022 2,596 2023 2,078 Thereafter 11,340 Total $ 30,289 The table below presents the maturities of operating lease liabilities as of June 30, 2019: 2019 (a) $ 6,476 2020 5,017 2021 3,845 2022 3,189 2023 2,418 Thereafter 11,399 Total future minimum lease payments 32,344 Less: imputed interest (5,322) Present value of lease liabilities $ 27,022 (a) For the six-month period beginning July 1, 2019. Other information relevant to the Company's operating leases consist of the following as of June 30, 2019: Weighted-average remaining lease term 10 years Weighted-average discount rate 3.63 %

Accrued Expenses And Other Liab

Accrued Expenses And Other Liabilities	6 Months Ended
	Jun. 30, 2019
Payables and Accruals [Abstract]
Accrued Expenses And Other Liabilities	ACCRUED EXPENSES AND OTHER LIABILITIES Accrued expenses and other liabilities consist of the following: June 30, December 31, 2019 2018 Accrued compensation $ 55,238 $ 60,107 Contract liabilities 61,506 52,606 Current portion of accrued warranty 23,841 23,106 Short-term lease liabilities 5,647 — Other 14,977 18,821 Total $ 161,209 $ 154,640

Product Warranties

Product Warranties	6 Months Ended
	Jun. 30, 2019
Product Warranties Disclosures [Abstract]
Product Warranties	PRODUCT WARRANTIES The Company typically provides 1 to 3 years parts and service warranties on lasers and amplifiers. Most of the Company's sales offices provide support to customers in their respective geographic areas. Warranty reserves have generally been sufficient to cover product warranty repair and replacement costs. The following table summarizes product warranty accrual activity recorded during the six months ended June 30, 2019 and 2018. 2019 2018 Balance at January 1 $ 51,422 $ 47,517 Provision for warranty accrual 8,618 12,830 Warranty claims (9,430) (8,986) Foreign currency translation 1 (812) Balance at June 30 $ 50,611 $ 50,549 Accrued warranty reported in the accompanying condensed consolidated financial statements as of June 30, 2019 and December 31, 2018 consisted of $23,841 and $23,106 in accrued expenses and other liabilities, respectively, and $26,770 and $28,316 in other long-term liabilities, respectively.

Financing Arrangements

Financing Arrangements	6 Months Ended
	Jun. 30, 2019
Debt Disclosure [Abstract]
Financing Arrangements	FINANCING ARRANGEMENTS The Company's borrowings under existing financing arrangements consist of the following: June 30, December 31, 2019 2018 Long-term notes 43,551 45,378 Less: current portion (3,705) (3,671) Total long-term debt 39,846 41,707 At June 30, 2019, the Company has an unsecured long-term note with an outstanding principal balance of $20,188, of which, $1,188 is the current portion. The interest on this unsecured long-term note is variable at 1.2% above LIBOR and is fixed using an interest rate swap at 2.9% per annum. The unsecured long-term note matures in May 2023, at which time the outstanding principal balance will be $15,438. Also at June 30, 2019, the Company has another long-term note that is secured by its corporate aircraft with an outstanding principal balance of $23,363, of which, $2,517 is the current portion. The interest on this collateralized long-term note is fixed at 2.7% per annum. The collateralized long-term note matures in July 2022, at which time the outstanding principal balance will be $15,375.

Derivative Financial Instrument

Derivative Financial Instruments	6 Months Ended
	Jun. 30, 2019
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: Notional Amounts (1) Other Assets June 30, December 31, June 30, December 31, 2019 2018 2019 2018 $ 20,188 $ 20,781 $ 28 $ 31 (1) Notional amounts represent the gross contract/notional amount of the derivatives outstanding. The derivative gains and losses in the condensed consolidated financial statements for the three and six months ended June 30, 2019 and 2018, related to the Company's current and previous interest rate swap contracts were as follows: Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Effective portion recognized in other comprehensive income, pretax: Interest rate swap $ 11 $ — $ (3) $ 2

Commitments And Contingencies

Commitments And Contingencies	6 Months Ended
	Jun. 30, 2019
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 June 30, 2019 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	6 Months Ended
	Jun. 30, 2019
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES The effective tax rates for the three months ended June 30, 2019 and 2018 were 24.3% and 25.6%, respectively. For the six months ended June 30, 2019 and 2018, the effective tax rates were 24.2% and 25.4%, respectively. There were discrete tax benefits of $575 and $2,407 for the three months ended June 30, 2019 and 2018, respectively. For the six months ended June 30, 2019 and 2018, the discrete tax benefits were $2,913 and $8,907, respectively. The net discrete benefits for both years are primarily related to the excess deduction related to equity based compensation. In 2018, there was minimal guidance available regarding the Global Intangible Low-taxed Income ("GILTI") provisions of the Tax Cuts and Jobs Act. In accordance with SAB 118, which provided guidance on accounting for the tax effects of the Tax Cuts and Jobs Act, the Company was granted a measurement period of up to one year from enactment to complete the accounting related to this tax act under ASC 740, which concluded in the quarter ended December 31, 2018. For the quarter and for the six months ended June 30, 2018, the Company reflected an additional $2,390 and $4,553, respectively, related to GILTI which was then reversed in the third quarter of 2018 as a result of additional IRS guidance issued in September 2018. 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 six months ended June 30, 2019 and 2018: 2019 2018 Balance at January 1 $ 11,206 $ 10,370 Additions for tax positions in current period 49 745 Foreign currency translation 199 — Balance at June 30 $ 11,454 $ 11,115

Net Income Attributable To IPG

Net Income Attributable To IPG Photonics Corporation Per Share	6 Months Ended
	Jun. 30, 2019
Earnings Per Share [Abstract]
Net Income Attributable To IPG Photonics Corporation Per Share	NET INCOME ATTRIBUTABLE TO IPG PHOTONICS CORPORATION PER SHARE The following table sets forth the computation of diluted net income attributable to IPG Photonics Corporation per share: Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Net income attributable to IPG Photonics Corporation $ 72,272 $ 121,617 $ 127,431 $ 227,951 Net income attributable to common stockholders 72,272 121,617 127,431 227,951 Weighted average shares 53,042 53,662 53,076 53,703 Dilutive effect of common stock equivalents 806 1,330 839 1,408 Diluted weighted average common shares 53,848 54,992 53,915 55,111 Basic net income attributable to IPG Photonics Corporation per share $ 1.36 $ 2.27 $ 2.40 $ 4.24 Basic net income attributable to common stockholders $ 1.36 $ 2.27 $ 2.40 $ 4.24 Diluted net income attributable to IPG Photonics Corporation per share $ 1.34 $ 2.21 $ 2.36 $ 4.14 Diluted net income attributable to common stockholders $ 1.34 $ 2.21 $ 2.36 $ 4.14 For the three months ended June 30, 2019 and 2018, respectively, the computation of diluted weighted average common shares excludes 38,700 and 10,000 common stock equivalents because the effect of including them would be anti-dilutive. The shares excluded for the three months ended June 30, 2019 and 2018, respectively are comprised of 26,300 and 4,000 restricted stock units ("RSUs") and 7,000 and 2,000 performance stock units ("PSUs"), and 5,400 and 4,000 non-qualified stock options, respectively. For the six months ended June 30, 2019 and 2018, respectively, the computation of diluted weighted average common shares excludes 80,600 and 90,300 common stock equivalents because the effect of including them would be anti-dilutive. The shares excluded for the six months ended June 30, 2019 and 2018, respectively are comprised of 56,400 and 19,500 restricted stock units ("RSUs") and 17,500 and 6,900 performance stock units ("PSUs"), and 6,700 and 63,900 non-qualified stock options, respectively. On February 12, 2019, the Company announced that its board of directors authorized a new anti-dilutive stock repurchase program (the "2019 Program") following the completion of its $125 million repurchase program (the "2018 Program") authorized in July 2018. Under the 2019 Program, IPG is authorized to repurchase shares of common stock in an amount not to exceed the lesser of (a) 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 and (b) $125 million, exclusive of any fees, commissions or other expenses. Share repurchases will 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 2019 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 and six months ended June 30, 2019, the Company repurchased 15,380 shares of common stock under the 2019 Program with an average price of $148.52 per share in the open market. The impact on the reduction of weighted average shares for the three and six months ended June 30, 2019 was 769 and 386 shares. For the three months ended June 30, 2018, the Company repurchased 131,680 shares of its common stock under the 2018 Program with an average price of $235.37 per share in the open market. The impact on the reduction of weighted average shares for the three months ended June 30, 2018 was 82,546 shares. For the six months ended June 30, 2018, the Company repurchased 214,578 shares of its common stock with an average price of $237.98 per share in the open market. The impact on the reduction of weighted average shares for the six months ended June 30, 2018 was 97,185 shares.

Recent Accounting Pronounceme_2

Recent Accounting Pronouncements (Policies)	6 Months Ended
	Jun. 30, 2019
Accounting Policies [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, 2018.
Leases	Leases — The Company determines if an arrangement is a lease at inception. Operating leases are included in other assets, other current liabilities, and other long-term liabilities on our condensed consolidated balance sheets. Right of use ("ROU") assets and lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at commencement date. As most of the Company's leases do not provide an implicit rate, IPG uses its incremental borrowing rate based on the information available at commencement date in determining the present value of future payments. The ROU assets also include any lease payments made and initial direct costs incurred and exclude lease incentives. Lease terms may include options to extend or terminate the lease when it is reasonably certain that we will exercise that option. Lease expense for minimum lease payments is recognized on a straight-line basis over the lease term. Leases with an initial term of 12 months or less are not recorded on the balance sheet; the Company recognizes lease expense for these leases on a straight-line basis over the lease term. The Company has lease agreements with lease and non-lease components, which are accounted for as a single lease component.
Reclassifications	Reclassifications — Certain prior year amounts have been reclassified to conform with current period presentation. These reclassifications had no effect on the reported results of operations.
Recent Accounting Pronouncements	RECENT ACCOUNTING PRONOUNCEMENTS Adopted Pronouncements — In February 2016, the Financial Accounting Standards Board (“FASB”) issued a new standard related to leases to increase transparency and comparability among organizations by requiring the recognition of ROU assets and lease liabilities on the balance sheet. Most prominent among the changes in the standard is the recognition of ROU assets and lease liabilities by lessees for those leases classified as operating leases. The Company adopted ASC 842, as of January 1, 2019, using the modified retrospective approach as of the date of adoption. Under this approach, comparative periods have not been restated. In addition, IPG elected the package of three practical expedients permitted under the transition guidance within the new standard, which among other things, allowed for the carry forward of the historical lease classification. The cumulative effect of the changes made to the Company's condensed consolidated January 1, 2019 balance sheet for the adoption of ASC 842 related to operating leases was as follows: Balance at Balance at December 31, 2018 Adoption of ASC 842 January 1, 2019 Balance Sheet Prepaid expenses and other current assets $ 57,764 $ (324) $ 57,440 Other assets 18,932 19,463 38,395 Accrued expenses and other current liabilities 154,640 5,292 159,932 Deferred income taxes and other long-term liabilities 80,734 13,847 94,581 In the first quarter of 2018, the Company adopted FASB ASU No. 2016-18, "Statement of Cash Flows (Topic 230): Restricted Cash" ("ASU 2016-18"), which enhances and clarifies the guidance on the classification and presentation of restricted cash in the statement of cash flows and requires additional disclosure about restricted cash balances. The Company considers cash to be restricted when withdrawal or general use is legally restricted. The Company records restricted cash in other assets on the condensed consolidated balance sheets and determines classification based on the expected duration of the restriction. The reconciliation of the Company's cash and cash equivalents in the condensed consolidated balance sheets to cash, cash equivalents and restricted cash in the condensed consolidated statement of cash flows is as follows: Balance at June 30, 2019 Cash and cash equivalents $ 530,013 Restricted cash included in other assets 2,964 Cash, cash equivalents and restricted cash $ 532,977 Other Pronouncements Currently Under Evaluation — In June 2016, the FASB issued 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 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. ASU 2016-03, along with its subsequent clarifications, is effective for fiscal years beginning after December 15, 2019. The Company does not expect this standard will have a material impact to net income.

Recent Accounting Pronounceme_3

Recent Accounting Pronouncements (Tables)	6 Months Ended
	Jun. 30, 2019
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, 2019 balance sheet for the adoption of ASC 842 related to operating leases was as follows: Balance at Balance at December 31, 2018 Adoption of ASC 842 January 1, 2019 Balance Sheet Prepaid expenses and other current assets $ 57,764 $ (324) $ 57,440 Other assets 18,932 19,463 38,395 Accrued expenses and other current liabilities 154,640 5,292 159,932 Deferred income taxes and other long-term liabilities 80,734 13,847 94,581
Schedule of Cash and Cash Equivalents	The reconciliation of the Company's cash and cash equivalents in the condensed consolidated balance sheets to cash, cash equivalents and restricted cash in the condensed consolidated statement of cash flows is as follows: Balance at June 30, 2019 Cash and cash equivalents $ 530,013 Restricted cash included in other assets 2,964 Cash, cash equivalents and restricted cash $ 532,977
Schedule of Restricted Cash	The reconciliation of the Company's cash and cash equivalents in the condensed consolidated balance sheets to cash, cash equivalents and restricted cash in the condensed consolidated statement of cash flows is as follows: Balance at June 30, 2019 Cash and cash equivalents $ 530,013 Restricted cash included in other assets 2,964 Cash, cash equivalents and restricted cash $ 532,977

Revenue From Contracts With C_2

Revenue From Contracts With Customers (Tables)	6 Months Ended
	Jun. 30, 2019
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following tables represent a disaggregation of revenue from contracts with customers: Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Sales by Application Materials processing $ 345,591 $ 392,001 $ 646,676 $ 731,215 Other applications 18,178 21,612 32,140 42,262 Total $ 363,769 $ 413,613 $ 678,816 $ 773,477 Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Sales by Product High Power Continuous Wave ("CW") Lasers $ 213,411 $ 266,075 $ 392,430 $ 496,649 Medium and Low Power CW Lasers 15,415 30,972 31,013 56,372 Pulsed Lasers 40,813 41,582 72,250 79,835 Quasi-Continuous Wave ("QCW") Lasers 15,967 20,092 30,133 36,292 Laser and Non-Laser Systems 39,383 13,428 72,014 22,899 Other Revenue including Amplifiers, Service, Parts, Accessories and Change in Deferred Revenue 38,780 41,464 80,976 81,430 Total $ 363,769 $ 413,613 $ 678,816 $ 773,477 Sales by Geography North America $ 64,140 $ 47,766 $ 128,947 $ 86,943 Europe: Germany 23,664 31,989 42,283 65,225 Other including Eastern Europe/CIS 61,131 76,347 130,331 159,325 Asia and Australia: China 163,590 203,026 277,956 352,999 Japan 17,406 19,428 33,020 39,057 Other 28,929 33,314 60,667 67,521 Rest of World 4,909 1,743 5,612 2,407 Total $ 363,769 $ 413,613 $ 678,816 $ 773,477 Timing of Revenue Recognition Goods and services transferred at a point in time $ 342,037 $ 412,241 $ 634,130 $ 771,094 Goods and services transferred over time 21,732 1,372 44,686 2,383 Total $ 363,769 $ 413,613 $ 678,816 $ 773,477
Changes in Contract Liabilities	The following table reflects the changes in the Company's contract assets and liabilities for the six months ended June 30, 2019 and 2018: June 30, January 1, June 30, January 1, 2019 2019 Change 2018 2018 Change Contract assets Contract assets $ 8,460 $ 10,102 $ (1,642) $ — $ — $ — Contract liabilities Contract liabilities - current 61,506 52,606 8,900 46,986 46,508 478 Contract liabilities - long-term 1,720 1,413 307 1,414 182 1,232
Schedule of Remaining Performance Obligations	The following table represents the Company's remaining performance obligations from contracts that are recognized over time as of June 30, 2019: Remaining Performance Obligations 2019 (a) 2020 2021 2022 2023 2024 and thereafter Total Revenue expected to be recognized for extended warranty agreements $ 2,638 $ 2,063 $ 636 $ 331 $ 133 $ 27 $ 5,828 Revenue to be earned over time from contracts to sell robotic systems 21,916 3,442 — — — — 25,358 Total $ 24,554 $ 5,505 $ 636 $ 331 $ 133 $ 27 $ 31,186 (a) For the six-month period beginning July 1, 2019.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2019
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, which is measured at fair value: Fair Value Measurements at June 30, 2019 Total Level 1 Level 2 Level 3 Assets Cash equivalents: Money market fund deposits and term deposits $ 187,562 $ 187,562 $ — $ — Commercial paper 39,561 — 39,561 — Short-term investments: U.S. Treasury and agency obligations 38,828 38,828 — — Corporate bonds 262,544 262,544 — — Non-U.S. government bonds 5,491 — 5,491 — Commercial paper 206,337 — 206,337 — Long-term investments and other assets: Auction rate securities 852 — — 852 Interest rate swap 28 — 28 — Total $ 741,203 $ 488,934 $ 251,417 $ 852 Liabilities Long-term debt $ 43,551 $ — $ 43,551 $ — Contingent purchase consideration 300 — — 300 Total $ 43,851 $ — $ 43,551 $ 300 Fair Value Measurements at December 31, 2018 Total Level 1 Level 2 Level 3 Assets Cash equivalents: Money market fund deposits and term deposits $ 180,965 $ 180,965 $ — $ — U.S. Treasury and agency obligations 6,495 6,495 — — Commercial paper 78,948 — 78,948 — Short-term investments: U.S. Treasury and agency obligations 116,800 116,800 — — Corporate bonds 227,009 227,009 — — Commercial paper 156,321 — 156,321 — Long-term investments and other assets: Corporate bonds 3,859 3,859 — — Auction rate securities 847 — — 847 Interest rate swaps 31 — 31 — Total $ 771,275 $ 535,128 $ 235,300 $ 847 Liabilities Long-term debt $ 45,378 $ — $ 45,378 $ — Contingent purchase consideration 898 — — 898 Total $ 46,276 $ — $ 45,378 $ 898
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 June 30, Six Months Ended June 30, 2019 2018 2019 2018 Auction rate securities Balance, beginning of period $ 850 $ 1,019 $ 847 $ 1,016 Change in fair value and accretion 2 155 5 158 Balance, end of period $ 852 $ 1,174 $ 852 $ 1,174 Contingent purchase consideration Balance, beginning of period $ 294 $ 902 $ 898 $ 902 Cash payments — — (632) — Foreign exchange adjustment 6 — 34 — Balance, end of period $ 300 $ 902 $ 300 $ 902
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 June 30, Six Months Ended June 30, 2019 2018 2019 2018 Auction rate securities Balance, beginning of period $ 850 $ 1,019 $ 847 $ 1,016 Change in fair value and accretion 2 155 5 158 Balance, end of period $ 852 $ 1,174 $ 852 $ 1,174 Contingent purchase consideration Balance, beginning of period $ 294 $ 902 $ 898 $ 902 Cash payments — — (632) — Foreign exchange adjustment 6 — 34 — Balance, end of period $ 300 $ 902 $ 300 $ 902
Schedule of Effective Maturity Dates of Held To Maturity Investments	The following table presents the effective maturity dates of held-to-maturity debt investments as of June 30, 2019 and December 31, 2018: June 30, 2019 December 31, 2018 Book Value Fair Value Book Value Fair Value Investment maturity Held-to-maturity: Less than 1 year $ 512,816 $ 513,200 $ 585,875 $ 585,573 1 through 5 years — — 3,859 3,859 Total $ 512,816 $ 513,200 $ 589,734 $ 589,432 Available-for-sale: Greater than 5 years $ 852 $ 852 $ 847 $ 847

Inventories (Tables)

Inventories (Tables)	6 Months Ended
	Jun. 30, 2019
Inventory Disclosure [Abstract]
Components of Inventories	Inventories consist of the following: June 30, December 31, 2019 2018 Components and raw materials $ 243,768 $ 233,594 Work-in-process 40,661 66,498 Finished components and devices 141,567 103,487 Total $ 425,996 $ 403,579

Goodwill And Intangibles (Table

Goodwill And Intangibles (Tables)	6 Months Ended
	Jun. 30, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	The following table sets forth the changes in the carrying amount of goodwill for the six months ended June 30, 2019: Amount Balance at January 1 $ 100,722 Goodwill arising from acquisition 9,426 Adjustment to goodwill during measurement period 448 Foreign exchange adjustment 272 Balance at June 30 $ 110,868
Schedule of Intangible Assets	Intangible assets, subject to amortization, consisted of the following: June 30, 2019 December 31, 2018 Gross Carrying Accumulated Net Carrying Weighted- Average Lives Gross Carrying Accumulated Net Carrying Weighted- Patents $ 8,036 $ (6,300) $ 1,736 8 years $ 8,036 $ (6,028) $ 2,008 8 years Customer relationships 62,690 (9,468) 53,222 10 years 57,849 (6,427) 51,422 11 years Production know-how 14,006 (7,052) 6,954 7 years 9,211 (6,212) 2,999 7 years Technology, trademark and trade names 41,431 (13,437) 27,994 7 years 41,184 (10,474) 30,710 7 years Total $ 126,163 $ (36,257) $ 89,906 $ 116,280 $ (29,141) $ 87,139
Estimated Future Amortization Expense For Intangibles	The estimated future amortization expense for intangibles for the remainder of 2019 and subsequent years is as follows: 2019 (a) 2020 2021 2022 2023 Thereafter Total $ 7,236 $ 13,665 13,298 $ 12,404 $ 11,449 $ 31,854 $ 89,906 (a) For the six-month period beginning July 1, 2019.

Leases (Tables)

Leases (Tables)	6 Months Ended
	Jun. 30, 2019
Leases [Abstract]
Summary of Lease Assets and Liabilities	The Company's operating lease assets and lease liabilities consist of the following as of June 30, 2019: Account Classification Amount Right-of-use assets Other assets $ 27,083 Short-term lease liabilities Accrued expenses and other liabilities 5,647 Long-term lease liabilities Deferred income taxes and other long-term liabilities 21,375 Total lease liabilities $ 27,022
Schedule of Operating Lease Maturities	The table below presents the future minimum lease payments to be made under non-cancelable operating leases as of December 31, 2018: Years ending December 31, 2019 $ 6,314 2020 4,603 2021 3,358 2022 2,596 2023 2,078 Thereafter 11,340 Total $ 30,289 The table below presents the maturities of operating lease liabilities as of June 30, 2019: 2019 (a) $ 6,476 2020 5,017 2021 3,845 2022 3,189 2023 2,418 Thereafter 11,399 Total future minimum lease payments 32,344 Less: imputed interest (5,322) Present value of lease liabilities $ 27,022 (a) For the six-month period beginning July 1, 2019.
Schedule of Lease Information	Other information relevant to the Company's operating leases consist of the following as of June 30, 2019: Weighted-average remaining lease term 10 years Weighted-average discount rate 3.63 %

Accrued Expenses And Other Li_2

Accrued Expenses And Other Liabilities (Tables)	6 Months Ended
	Jun. 30, 2019
Payables and Accruals [Abstract]
Components of Accrued Expenses and Other Liabilities	Accrued expenses and other liabilities consist of the following: June 30, December 31, 2019 2018 Accrued compensation $ 55,238 $ 60,107 Contract liabilities 61,506 52,606 Current portion of accrued warranty 23,841 23,106 Short-term lease liabilities 5,647 — Other 14,977 18,821 Total $ 161,209 $ 154,640

Product Warranties (Tables)

Product Warranties (Tables)	6 Months Ended
	Jun. 30, 2019
Product Warranties Disclosures [Abstract]
Summary of Product Warranty Activity	The following table summarizes product warranty accrual activity recorded during the six months ended June 30, 2019 and 2018. 2019 2018 Balance at January 1 $ 51,422 $ 47,517 Provision for warranty accrual 8,618 12,830 Warranty claims (9,430) (8,986) Foreign currency translation 1 (812) Balance at June 30 $ 50,611 $ 50,549

Financing Arrangements (Tables)

Financing Arrangements (Tables)	6 Months Ended
	Jun. 30, 2019
Debt Disclosure [Abstract]
Borrowings Under Existing Financing Arrangements	The Company's borrowings under existing financing arrangements consist of the following: June 30, December 31, 2019 2018 Long-term notes 43,551 45,378 Less: current portion (3,705) (3,671) Total long-term debt 39,846 41,707

Derivative Financial Instrume_2

Derivative Financial Instruments (Tables)	6 Months Ended
	Jun. 30, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Fair Value of Derivatives	The fair value amounts in the condensed consolidated balance sheets were: Notional Amounts (1) Other Assets June 30, December 31, June 30, December 31, 2019 2018 2019 2018 $ 20,188 $ 20,781 $ 28 $ 31 (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 for the three and six months ended June 30, 2019 and 2018, related to the Company's current and previous interest rate swap contracts were as follows: Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Effective portion recognized in other comprehensive income, pretax: Interest rate swap $ 11 $ — $ (3) $ 2

Income Taxes (Tables)

Income Taxes (Tables)	6 Months Ended
	Jun. 30, 2019
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 six months ended June 30, 2019 and 2018: 2019 2018 Balance at January 1 $ 11,206 $ 10,370 Additions for tax positions in current period 49 745 Foreign currency translation 199 — Balance at June 30 $ 11,454 $ 11,115

Net Income Attributable To IP_2

Net Income Attributable To IPG Photonics Corporation Per Share (Tables)	6 Months Ended
	Jun. 30, 2019
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 share: Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Net income attributable to IPG Photonics Corporation $ 72,272 $ 121,617 $ 127,431 $ 227,951 Net income attributable to common stockholders 72,272 121,617 127,431 227,951 Weighted average shares 53,042 53,662 53,076 53,703 Dilutive effect of common stock equivalents 806 1,330 839 1,408 Diluted weighted average common shares 53,848 54,992 53,915 55,111 Basic net income attributable to IPG Photonics Corporation per share $ 1.36 $ 2.27 $ 2.40 $ 4.24 Basic net income attributable to common stockholders $ 1.36 $ 2.27 $ 2.40 $ 4.24 Diluted net income attributable to IPG Photonics Corporation per share $ 1.34 $ 2.21 $ 2.36 $ 4.14 Diluted net income attributable to common stockholders $ 1.34 $ 2.21 $ 2.36 $ 4.14

Recent Accounting Pronounceme_4

Recent Accounting Pronouncements (Cumulative Effect of Changes to Balance Sheet) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Prepaid expenses and other current assets	$ 70,675	$ 57,440	$ 57,764
Other assets	51,750	38,395	18,932
Accrued expenses and other current liabilities	161,209	159,932	154,640
Deferred income taxes and other long-term liabilities	$ 107,981	94,581	$ 80,734
Adoption of ASC 842
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Prepaid expenses and other current assets		(324)
Other assets		19,463
Accrued expenses and other current liabilities		5,292
Deferred income taxes and other long-term liabilities		$ 13,847

Recent Accounting Pronounceme_5

Recent Accounting Pronouncements (Schedule of Cash, Cash Equivalents and Restricted Cash) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2017
Accounting Policies [Abstract]
Cash and cash equivalents	$ 530,013	$ 544,358
Restricted cash included in other assets	2,964
Cash, cash equivalents and restricted cash	$ 532,977	$ 544,358	$ 816,792	$ 909,900

Revenue From Contracts With C_3

Revenue From Contracts With Customers (Disaggregation of Revenue, By Application) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Sales by Application
Total	$ 363,769	$ 413,613	$ 678,816	$ 773,477
Materials processing
Sales by Application
Total	345,591	392,001	646,676	731,215
Other applications
Sales by Application
Total	$ 18,178	$ 21,612	$ 32,140	$ 42,262

Revenue From Contracts With C_4

Revenue From Contracts With Customers (Disaggregation of Revenue, By Product) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Disaggregation of Revenue [Line Items]
Total	$ 363,769	$ 413,613	$ 678,816	$ 773,477
High Power Continuous Wave ("CW") Lasers
Disaggregation of Revenue [Line Items]
Total	213,411	266,075	392,430	496,649
Medium and Low Power CW Lasers
Disaggregation of Revenue [Line Items]
Total	15,415	30,972	31,013	56,372
Pulsed Lasers
Disaggregation of Revenue [Line Items]
Total	40,813	41,582	72,250	79,835
Quasi-Continuous Wave ("QCW") Lasers
Disaggregation of Revenue [Line Items]
Total	15,967	20,092	30,133	36,292
Laser and Non-Laser Systems
Disaggregation of Revenue [Line Items]
Total	39,383	13,428	72,014	22,899
Other Revenue including Amplifiers, Service, Parts, Accessories and Change in Deferred Revenue
Disaggregation of Revenue [Line Items]
Total	$ 38,780	$ 41,464	$ 80,976	$ 81,430

Revenue From Contracts With C_5

Revenue From Contracts With Customers (Disaggregation of Revenue, By Geography) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Sales by Geography
Total	$ 363,769	$ 413,613	$ 678,816	$ 773,477
North America
Sales by Geography
Total	64,140	47,766	128,947	86,943
Germany
Sales by Geography
Total	23,664	31,989	42,283	65,225
Other including Eastern Europe/CIS
Sales by Geography
Total	61,131	76,347	130,331	159,325
China
Sales by Geography
Total	163,590	203,026	277,956	352,999
Japan
Sales by Geography
Total	17,406	19,428	33,020	39,057
Other
Sales by Geography
Total	28,929	33,314	60,667	67,521
Rest of World
Sales by Geography
Total	$ 4,909	$ 1,743	$ 5,612	$ 2,407

Revenue From Contracts With C_6

Revenue From Contracts With Customers (Disaggregation of Revenue, By Timing) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Timing of Revenue Recognition
Total	$ 363,769	$ 413,613	$ 678,816	$ 773,477
Goods and services transferred at a point in time
Timing of Revenue Recognition
Total	342,037	412,241	634,130	771,094
Goods and services transferred over time
Timing of Revenue Recognition
Total	$ 21,732	$ 1,372	$ 44,686	$ 2,383

Revenue From Contracts With C_7

Revenue From Contracts With Customers (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Concentration Risk [Line Items]
Revenue recognized that was included in the contract liability balance at the beginning of the period	$ 11,092	$ 7,197	$ 36,252	$ 35,529
One Customer | Customer Concentration Risk | Revenue from Contract with Customer
Concentration Risk [Line Items]
Concentration risk, percentage			11.60%	13.00%
One Customer | Customer Concentration Risk | Accounts Receivable
Concentration Risk [Line Items]
Concentration risk, percentage			39.20%		24.70%

Revenue From Contracts With C_8

Revenue From Contracts With Customers (Changes in Contract Assets and Contract Liabilities) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018	Dec. 31, 2017
Contract assets
Contract assets	$ 8,460	$ 0	$ 10,102	$ 0
Contract assets, change	(1,642)	0
Contract liabilities
Contract liabilities - current	61,506	46,986	52,606	46,508
Contract liabilities - current, change	8,900	478
Contract liabilities - long-term	1,720	1,414	$ 1,413	$ 182
Contract liabilities - long-term, change	$ 307	$ 1,232

Revenue From Contracts With C_9

Revenue From Contracts With Customers (Schedule of Remaining Performance Obligations) (Details) $ in Thousands	Jun. 30, 2019USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-07-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining Performance Obligations	$ 24,554
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-07-01 | Revenue expected to be recognized for extended warranty agreements
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining Performance Obligations	$ 2,638
Remaining Performance Obligations, Expected Timing	6 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-07-01 | 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	$ 21,916
Remaining Performance Obligations, Expected Timing	6 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining Performance Obligations	$ 5,505
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01 | Revenue expected to be recognized for extended warranty agreements
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining Performance Obligations	$ 2,063
Remaining Performance Obligations, Expected Timing	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01 | 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	$ 3,442
Remaining Performance Obligations, Expected Timing	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining Performance Obligations	$ 636
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01 | Revenue expected to be recognized for extended warranty agreements
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining Performance Obligations	$ 636
Remaining Performance Obligations, Expected Timing	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01 | 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]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining Performance Obligations	$ 331
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	$ 331
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	$ 0
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	$ 133
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	$ 133
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	$ 27
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	$ 27
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]: (nil)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining Performance Obligations	$ 31,186
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil) | Revenue expected to be recognized for extended warranty agreements
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining Performance Obligations	5,828
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil) | 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	$ 25,358

Fair Value Measurements (Assets

Fair Value Measurements (Assets And Liabilities Measured At Fair Value) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Assets
Total	$ 741,203	$ 771,275
Liabilities
Long-term debt	43,551	45,378
Contingent purchase consideration	300	898
Total	43,851	46,276
Level 1
Assets
Total	488,934	535,128
Liabilities
Long-term debt	0	0
Contingent purchase consideration	0	0
Total	0	0
Level 2
Assets
Total	251,417	235,300
Liabilities
Long-term debt	43,551	45,378
Contingent purchase consideration	0	0
Total	43,551	45,378
Level 3
Assets
Total	852	847
Liabilities
Long-term debt	0	0
Contingent purchase consideration	300	898
Total	300	898
Money market fund deposits and term deposits
Assets
Cash equivalents	187,562	180,965
Money market fund deposits and term deposits | Level 1
Assets
Cash equivalents	187,562	180,965
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	39,561	78,948
Commercial paper | Level 1
Assets
Cash equivalents	0	0
Commercial paper | Level 2
Assets
Cash equivalents	39,561	78,948
Commercial paper | Level 3
Assets
Cash equivalents	0	0
U.S. Treasury and agency obligations
Assets
Cash equivalents		6,495
Short-term investments	38,828	116,800
U.S. Treasury and agency obligations | Level 1
Assets
Cash equivalents		6,495
Short-term investments	38,828	116,800
U.S. Treasury and agency obligations | Level 2
Assets
Cash equivalents		0
Short-term investments	0	0
U.S. Treasury and agency obligations | Level 3
Assets
Cash equivalents		0
Short-term investments	0	0
Corporate bonds
Assets
Short-term investments	262,544	227,009
Long-term investments and other assets		3,859
Corporate bonds | Level 1
Assets
Short-term investments	262,544	227,009
Long-term investments and other assets		3,859
Corporate bonds | Level 2
Assets
Short-term investments	0	0
Long-term investments and other assets		0
Corporate bonds | Level 3
Assets
Short-term investments	0	0
Long-term investments and other assets		0
Non-U.S. government bonds
Assets
Short-term investments	5,491
Non-U.S. government bonds | Level 1
Assets
Short-term investments	0
Non-U.S. government bonds | Level 2
Assets
Short-term investments	5,491
Non-U.S. government bonds | Level 3
Assets
Short-term investments	0
Commercial paper, not included in cash equivalents
Assets
Short-term investments	206,337	156,321
Commercial paper, not included in cash equivalents | Level 1
Assets
Short-term investments	0	0
Commercial paper, not included in cash equivalents | Level 2
Assets
Short-term investments	206,337	156,321
Commercial paper, not included in cash equivalents | Level 3
Assets
Short-term investments	0	0
Auction rate securities
Assets
Long-term investments and other assets	852	847
Auction rate securities | Level 1
Assets
Long-term investments and other assets	0	0
Auction rate securities | Level 2
Assets
Long-term investments and other assets	0	0
Auction rate securities | Level 3
Assets
Long-term investments and other assets	852	847
Interest rate swap
Assets
Long-term investments and other assets	28	31
Interest rate swap | Level 1
Assets
Long-term investments and other assets	0	0
Interest rate swap | Level 2
Assets
Long-term investments and other assets	28	31
Interest rate swap | Level 3
Assets
Long-term investments and other assets	$ 0	$ 0

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets fair value	$ 741,203	$ 771,275
Held-to-maturity Securities | Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets fair value	513,200	500,130
Unrealized gain (loss)	384	(302)
Held-to-maturity Securities | Long-Term Investment
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets fair value	0	3,859
Available-for-sale Securities | Auction rate securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, cost basis	$ 852	$ 847

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		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Auction rate securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	$ 850	$ 1,019	$ 847	$ 1,016
Change in fair value and accretion	2	155	5	158
Balance, end of period	852	1,174	852	1,174
Contingent purchase consideration
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	294	902	898	902
Cash payments	0	0	(632)	0
Foreign exchange adjustment	6	0	34	0
Balance, end of period	$ 300	$ 902	$ 300	$ 902

Fair Value Measurements (Schedu

Fair Value Measurements (Schedule of Effective Maturity Dates of Held To Maturity Investments) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Investment maturity
Held-to-maturity maturities, Less than 1 year, Book Value	$ 512,816	$ 585,875
Held-to-maturity maturities, 1 through 5 years, Book Value	0	3,859
Held-to-maturity maturities, Total Book Value	512,816	589,734
Held-to-maturity maturities, Less than 1 year, Fair Value	513,200	585,573
Held-to-maturity maturities, 1 through 5 years, Fair Value	0	3,859
Held-to-maturity maturities, Total Fair Value	513,200	589,432
Available-for-sale maturity, Greater than 5 years, Book Value	852	847
Available-for-sale maturity, Greater than 5 years, Fair Value	$ 852	$ 847

Inventories (Components Of Inve

Inventories (Components Of Inventories) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Inventory Disclosure [Abstract]
Components and raw materials	$ 243,768	$ 233,594
Work-in-process	40,661	66,498
Finished components and devices	141,567	103,487
Total	$ 425,996	$ 403,579

Inventories (Narrative) (Detail

Inventories (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Inventory Disclosure [Abstract]
Inventory provisions	$ 7,886	$ 3,497	$ 12,649	$ 6,854

Goodwill And Intangibles (Sched

Goodwill And Intangibles (Schedule of Changes) (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2019USD ($)
Goodwill [Roll Forward]
Balance at January 1	$ 100,722
Goodwill arising from acquisition	9,426
Adjustment to goodwill during measurement period	448
Foreign exchange adjustment	272
Balance at June 30	$ 110,868

Goodwill And Intangibles (Narra

Goodwill And Intangibles (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Business Acquisition [Line Items]
Restricted cash	$ 2,964			$ 2,964
Goodwill arising from acquisition				9,426
Amortization expense	3,648		$ 1,908	6,964	$ 3,839
Genesis Systems Group
Business Acquisition [Line Items]
Percentage of business acquired						100.00%
Working capital adjustment				448
Padtec SA, Submarine Networks Division
Business Acquisition [Line Items]
Purchase price		$ 19,560
Restricted cash	2,964	2,934		2,964
Goodwill arising from acquisition		9,426
Licenses | Padtec SA, Submarine Networks Division
Business Acquisition [Line Items]
Restricted cash	$ 1,948	1,956		$ 1,948
Production know-how | Padtec SA, Submarine Networks Division
Business Acquisition [Line Items]
Acquired finite-lived intangible assets		$ 4,825
Weighted average useful life of acquired intangible assets		6 years
Customer relationships | Padtec SA, Submarine Networks Division
Business Acquisition [Line Items]
Acquired finite-lived intangible assets		$ 4,825
Weighted average useful life of acquired intangible assets		6 years

Goodwill And Intangibles (Intan

Goodwill And Intangibles (Intangible Assets) (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Gross  Carrying Amount	$ 126,163	$ 116,280
Accumulated Amortization	(36,257)	(29,141)
Net  Carrying Amount	89,906	87,139
Patents
Finite-Lived Intangible Assets [Line Items]
Gross  Carrying Amount	8,036	8,036
Accumulated Amortization	(6,300)	(6,028)
Net  Carrying Amount	$ 1,736	$ 2,008
Weighted- Average  Lives	8 years	8 years
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross  Carrying Amount	$ 62,690	$ 57,849
Accumulated Amortization	(9,468)	(6,427)
Net  Carrying Amount	$ 53,222	$ 51,422
Weighted- Average  Lives	10 years	11 years
Production know-how
Finite-Lived Intangible Assets [Line Items]
Gross  Carrying Amount	$ 14,006	$ 9,211
Accumulated Amortization	(7,052)	(6,212)
Net  Carrying Amount	$ 6,954	$ 2,999
Weighted- Average  Lives	7 years	7 years
Technology, trademark and trade names
Finite-Lived Intangible Assets [Line Items]
Gross  Carrying Amount	$ 41,431	$ 41,184
Accumulated Amortization	(13,437)	(10,474)
Net  Carrying Amount	$ 27,994	$ 30,710
Weighted- Average  Lives	7 years	7 years

Goodwill And Intangibles (Estim

Goodwill And Intangibles (Estimated Future Amortization Expense For Intangibles) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
2019	$ 7,236
2020	13,665
2021	13,298
2022	12,404
2023	11,449
Thereafter	31,854
Net  Carrying Amount	$ 89,906	$ 87,139

Leases (Narrative) (Details)

Leases (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019
Lessee, Lease, Description [Line Items]
Operating lease cost	$ 2,795	$ 4,464
Operating lease payments	$ (1,572)	$ (3,442)
Minimum
Lessee, Lease, Description [Line Items]
Remaining lease term		1 year
Maximum
Lessee, Lease, Description [Line Items]
Remaining lease term		46 years

Leases (Lease Assets and Lease

Leases (Lease Assets and Lease Liabilities) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Leases [Abstract]
Right-of-use assets	$ 27,083
Short-term lease liabilities	5,647	$ 0
Long-term lease liabilities	21,375
Total lease liabilities	$ 27,022

Leases (Operating Lease Maturit

Leases (Operating Lease Maturities) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2019		$ 6,314
2020		4,603
2021		3,358
2022		2,596
2023		2,078
Thereafter		11,340
Total		$ 30,289
Operating Lease Liabilities, Payments Due [Abstract]
2019	$ 6,476
2020	5,017
2021	3,845
2022	3,189
2023	2,418
Thereafter	11,399
Total future minimum lease payments	32,344
Less: imputed interest	(5,322)
Present value of lease liabilities	$ 27,022

Leases (Lease Term and Discount

Leases (Lease Term and Discount Rate) (Details)	Jun. 30, 2019
Leases [Abstract]
Weighted-average remaining lease term	10 years
Weighted-average discount rate	3.63%

Accrued Expenses And Other Li_3

Accrued Expenses And Other Liabilities (Components Of Accrued Expenses And Other Liabilities) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Jan. 01, 2019	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2017
Payables and Accruals [Abstract]
Accrued compensation	$ 55,238		$ 60,107
Contract liabilities	61,506		52,606	$ 46,986	$ 46,508
Current portion of accrued warranty	23,841		23,106
Short-term lease liabilities	5,647		0
Other	14,977		18,821
Total	$ 161,209	$ 159,932	$ 154,640

Product Warranties (Narrative)

Product Warranties (Narrative) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Product Warranty Liability [Line Items]
Accrued warranty reported in accrued expenses and other liabilities	$ 23,841	$ 23,106
Accrued warranty reported in other long-term liabilities	$ 26,770	$ 28,316
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	3 years

Product Warranties (Summary Of

Product Warranties (Summary Of Product Warranty Activity) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Movement in Standard and Extended Product Warranty, Increase (Decrease) [Roll Forward]
Balance at January 1	$ 51,422	$ 47,517
Provision for warranty accrual	8,618	12,830
Warranty claims	(9,430)	(8,986)
Foreign currency translation	1	(812)
Balance at June 30	$ 50,611	$ 50,549

Financing Arrangements (Borrowi

Financing Arrangements (Borrowings Under Existing Financing Arrangements) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Less: current portion	$ (3,705)	$ (3,671)
Total long-term debt	39,846	41,707
Long-term notes
Debt Instrument [Line Items]
Long-term notes	$ 43,551	$ 45,378

Financing Arrangements (Narrati

Financing Arrangements (Narrative) (Details) € in Thousands	6 Months Ended
	Jun. 30, 2019USD ($)	May 31, 2023USD ($)	Jul. 31, 2022USD ($)	Jun. 30, 2019EUR (€)	Dec. 31, 2018USD ($)
Debt Instrument [Line Items]
Total unused credit lines and overdraft facilities	$ 106,680,000
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	2.90%			2.90%
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	$ 23,363,000
Current portion of long-term note	$ 2,517,000
Fixed interest rate swap	2.70%			2.70%
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	$ 20,188,000
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	1,337,000				930,000
Euro line-of-credit
Debt Instrument [Line Items]
Line of credit	0				0
Guarantees issued	1,088,000				1,166,000
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	50,000,000
Letter of Credit | Euro line-of-credit
Debt Instrument [Line Items]
Borrowing capacity	56,832,000			€ 50,000
Letter of Credit | Euro overdraft facility
Debt Instrument [Line Items]
Borrowing capacity	$ 2,273,000			€ 2,000

Derivative Financial Instrume_3

Derivative Financial Instruments (Fair Value) (Details) - Derivative designated as a cash flow hedge - Interest rate swap - USD ($)	Jun. 30, 2019	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Derivative, notional amount	$ 20,188,000	$ 20,781,000
Other Assets
Derivatives, Fair Value [Line Items]
Derivative asset, fair value	$ 28,000	$ 31,000

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		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Derivative designated as a cash flow hedge | Interest rate swap
Derivative Instruments, Gain (Loss) [Line Items]
Effective portion recognized in other comprehensive income, pretax	$ 11	$ 0	$ (3)	$ 2

Commitments And Contingencies (

Commitments And Contingencies (Narrative) (Details)	Jun. 30, 2019USD ($)
Commitments and Contingencies Disclosure [Abstract]
Legal proceedings	$ 0

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Income Tax Disclosure [Abstract]
Effective tax rate	24.30%	25.60%	24.20%	25.40%
Discrete tax benefit	$ 575	$ 2,407	$ 2,913	$ 8,907
Increase in tax expense related to Global Intangible Low Taxed Income		$ 2,390		$ 4,553

Income Taxes (Schedule of Unrec

Income Taxes (Schedule of Unrecognized Tax Benefits) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at January 1	$ 11,206	$ 10,370
Additions for tax positions in current period	49	745
Foreign currency translation	199	0
Balance at June 30	$ 11,454	$ 11,115

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		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Earnings Per Share [Abstract]
Net income attributable to IPG Photonics Corporation	$ 72,272	$ 121,617	$ 127,431	$ 227,951
Net income attributable to common stockholders	$ 72,272	$ 121,617	$ 127,431	$ 227,951
Weighted average shares (in shares)	53,042	53,662	53,076	53,703
Dilutive effect of common stock equivalents (in shares)	806	1,330	839	1,408
Diluted weighted average common shares (in shares)	53,848	54,992	53,915	55,111
Basic net income attributable to IPG Photonics Corporation per share (in dollars per share)	$ 1.36	$ 2.27	$ 2.40	$ 4.24
Basic net income attributable to common stockholders (in dollars per share)	1.36	2.27	2.40	4.24
Diluted net income attributable to IPG Photonics Corporation per share (in dollars per share)	1.34	2.21	2.36	4.14
Diluted net income attributable to common stockholders (in dollars per share)	$ 1.34	$ 2.21	$ 2.36	$ 4.14

Net Income Attributable to IP_4

Net Income Attributable to IPG Photonics Corporation Per Share (Narrative) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Feb. 12, 2019	Feb. 11, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Excluded from computation of diluted weighted average common shares (in shares)	38,700	10,000	80,600	90,300
Share repurchase amount (no more than)					$ 125,000,000	$ 125,000,000
Stock repurchased during period (in shares)	15,380	131,680	15,380	214,578
Stock repurchase average price (in dollars per share)	$ 148.52	$ 235.37	$ 148.52	$ 237.98
Decrease in weighted average shares outstanding, treasury stock (in shares)	769	82,546	386	97,185
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)	26,300	4,000	56,400	19,500
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)	7,000	2,000	17,500	6,900
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)	5,400	4,000	6,700	63,900

Uncategorized Items - ipgp-2019

Label	Element	Value
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ 616,000
AOCI Attributable to Parent [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	10,000
Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ 606,000