IPG Photonics (IPGP) 10-K 27 Feb 17 2016 FY Annual report Financial data

Document And Entity Information

Document And Entity Information - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2016	Feb. 22, 2017	Jun. 30, 2016
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2016
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2,016
Entity Registrant Name	IPG PHOTONICS CORP
Entity Central Index Key	1,111,928
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding (in shares)		53,517,149
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Well-known Seasoned Issuer	Yes
Entity Public Float			$ 2.8

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
CURRENT ASSETS:
Cash and cash equivalents	$ 623,855	$ 582,532
Short-term investments	206,779	106,584
Accounts receivable, net	155,901	150,479
Inventories	239,010	203,738
Prepaid income taxes	34,128	33,692
Prepaid expenses and other current assets	41,289	25,564
Total current assets	1,300,962	1,102,589
DEFERRED INCOME TAXES, NET	42,442	29,732
GOODWILL	19,828	505
INTANGIBLE ASSETS, NET	28,789	11,904
PROPERTY, PLANT AND EQUIPMENT, NET	379,375	288,604
OTHER ASSETS	18,603	20,095
TOTAL	1,789,999	1,453,429
CURRENT LIABILITIES:
Current portion of long-term debt	3,188	2,000
Accounts payable	28,048	26,314
Accrued expenses and other liabilities	102,485	75,667
Income taxes payable	24,554	37,809
Total current liabilities	158,275	141,790
DEFERRED INCOME TAXES AND OTHER LONG-TERM LIABILITIES	36,365	33,307
LONG-TERM DEBT, NET OF CURRENT PORTION	37,635	17,667
Total liabilities	232,275	192,764
COMMITMENTS AND CONTINGENCIES (NOTE 10)
IPG PHOTONICS CORPORATION EQUITY:
Common stock, $0.0001 par value, 175,000,000 shares authorized; 53,354,579 and 53,251,805 shares issued and outstanding, respectively, at December 31, 2016; 52,883,902 shares issued and outstanding at December 31, 2015	5	5
Treasury stock, at cost (102,774 and 0 shares held)	(8,946)	0
Additional paid-in capital	650,974	607,649
Retained earnings	1,094,108	833,356
Accumulated other comprehensive loss	(178,583)	(181,482)
Total IPG Photonics Corporation equity	1,557,558	1,259,528
NONCONTROLLING INTERESTS	166	1,137
Total equity	1,557,724	1,260,665
TOTAL	$ 1,789,999	$ 1,453,429

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2016	Dec. 31, 2015
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)	53,354,579	52,883,902
Common stock, shares outstanding (in shares)	53,251,805	52,883,902
Treasury stock, shares (in shares)	102,774	0

Consolidated Statements Of Inco

Consolidated Statements Of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Statement [Abstract]
NET SALES	$ 1,006,173	$ 901,265	$ 769,832
COST OF SALES	453,933	409,388	353,314
GROSS PROFIT	552,240	491,877	416,518
OPERATING EXPENSES:
Sales and marketing	38,393	31,868	30,637
Research and development	78,552	63,334	53,403
General and administrative	66,486	57,192	55,338
Loss (gain) on foreign exchange	4,496	(2,560)	(6,618)
Total operating expenses	187,927	149,834	132,760
OPERATING INCOME	364,313	342,043	283,758
OTHER INCOME (EXPENSE), Net:
Interest income (expense), net	1,304	(301)	(77)
Other income (expense), net	948	(125)	793
Total other income (expense)	2,252	(426)	716
INCOME BEFORE PROVISION FOR INCOME TAXES	366,565	341,617	284,474
PROVISION FOR INCOME TAXES	(105,849)	(99,590)	(84,029)
NET INCOME	260,716	242,027	200,445
LESS: NET LOSS ATTRIBUTABLE TO NONCONTROLLING INTERESTS	(36)	(127)	0
NET INCOME ATTRIBUTABLE TO IPG PHOTONICS CORPORATION	$ 260,752	$ 242,154	$ 200,445
NET INCOME ATTRIBUTABLE TO IPG PHOTONICS CORPORATION PER SHARE:
Basic (in dollars per share)	$ 4.91	$ 4.60	$ 3.85
Diluted (in dollars per share)	$ 4.85	$ 4.53	$ 3.79
WEIGHTED AVERAGE SHARES OUTSTANDING:
Basic (in shares)	53,068	52,676	52,104
Diluted (in shares)	53,797	53,427	52,824

Consolidated Statements Of Comp

Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 260,716	$ 242,027	$ 200,445
Other comprehensive income (loss), net of tax:
Translation adjustments	3,163	(69,314)	(110,734)
Unrealized gain on derivatives	49	95	172
Unrealized loss on available-for-sale investments	(298)	0	0
Total other comprehensive income (loss)	2,914	(69,219)	(110,562)
Comprehensive income	263,630	172,808	89,883
Comprehensive (loss) income attributable to noncontrolling interest	(21)	(442)	0
Comprehensive income attributable to IPG Photonics Corporation	$ 263,651	$ 173,250	$ 89,883

Consolidated Statements Of Equi

Consolidated Statements Of Equity - USD ($) $ in Thousands	Total	COMMON STOCK	TREASURY STOCK	ADDITIONAL PAID-IN CAPITAL	RETAINED EARNINGS	ACCUMULATED OTHER COMPREHENSIVE LOSS	TOTAL IPG PHOTONICS CORPORATION EQUITY	NONCONTROLLING INTERESTS
Balance, beginning of year (in shares) at Dec. 31, 2013		(51,930,978)	0
Balance, beginning of year at Dec. 31, 2013		$ 5	$ 0	$ 538,908	$ 390,757	$ (1,701)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (in shares)		402,647
Common stock issued under employee stock purchase plan (in shares)		36,063
Purchased common stock (in shares)		0	0
Purchased common stock		$ 0	$ 0
Stock-based compensation				15,172
Exercise of stock options and related tax benefit from exercise		0		11,428
Common stock issued under employee stock purchase plan		$ 0		2,109
Net income attributable to IPG Photonics Corporation	$ 200,445				200,445
Translation adjustments	(110,734)					(110,734)
Unrealized gain on derivatives, net of tax	172					172
Unrealized loss on available-for-sale investments, net of tax	0
Purchase of NCI								$ 0
Net loss attributable to NCI	0							0
Other comprehensive income (loss) attributable to NCI	0
Balance, end of period (in shares) at Dec. 31, 2014		(52,369,688)	0
Balance, end of period at Dec. 31, 2014	1,046,561	$ 5	$ 0	567,617	591,202	(112,263)	$ 1,046,561	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (in shares)		477,785
Common stock issued under employee stock purchase plan (in shares)		36,429
Purchased common stock (in shares)		0	0
Purchased common stock		$ 0	$ 0
Stock-based compensation				18,989
Exercise of stock options and related tax benefit from exercise		0		18,582
Common stock issued under employee stock purchase plan		$ 0		2,461
Net income attributable to IPG Photonics Corporation	242,154				242,154
Translation adjustments	(69,314)					(69,314)
Unrealized gain on derivatives, net of tax	95					95
Unrealized loss on available-for-sale investments, net of tax	0
Purchase of NCI								0
Attribution to NCI								1,579
Net loss attributable to NCI	127
Other comprehensive income (loss) attributable to NCI	(442)							(315)
Balance, end of period (in shares) at Dec. 31, 2015		(52,883,902)	0
Balance, end of period at Dec. 31, 2015	$ 1,260,665	$ 5	$ 0	607,649	833,356	(181,482)	1,259,528	1,137
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (in shares)	392,887	430,930
Common stock issued under employee stock purchase plan (in shares)		39,747
Purchased common stock (in shares)		(102,774)	(102,774)
Purchased common stock		$ 0	$ (8,946)
Stock-based compensation				21,734
Exercise of stock options and related tax benefit from exercise		0		18,889
Common stock issued under employee stock purchase plan		$ 0		2,702
Net income attributable to IPG Photonics Corporation	$ 260,752				260,752
Translation adjustments	3,163					3,148
Unrealized gain on derivatives, net of tax	49					49
Unrealized loss on available-for-sale investments, net of tax	(298)					(298)
Purchase of NCI								(950)
Attribution to NCI								0
Net loss attributable to NCI	36
Other comprehensive income (loss) attributable to NCI	(21)							15
Balance, end of period (in shares) at Dec. 31, 2016		(53,251,805)	(102,774)
Balance, end of period at Dec. 31, 2016	$ 1,557,724	$ 5	$ (8,946)	$ 650,974	$ 1,094,108	$ (178,583)	$ 1,557,558	$ 166

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 260,716	$ 242,027	$ 200,445
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	51,475	42,415	35,612
Deferred income taxes	(12,908)	(7,153)	(1,486)
Stock-based compensation	21,734	18,989	15,172
Unrealized losses (gains) on foreign currency transactions	2,298	(5,491)	(3,497)
Other	2,724	510	459
Provisions for inventory, warranty and bad debt	46,469	39,985	28,036
Changes in assets and liabilities that (used) provided cash, net of acquisitions:
Accounts receivable	(11,444)	(19,036)	(48,518)
Inventories	(53,626)	(70,565)	(42,246)
Prepaid expenses and other current assets	(4,069)	1,853	(5,351)
Accounts payable	(407)	9,806	3,262
Accrued expenses and other liabilities	5,480	613	(1,567)
Income and other taxes payable	(10,746)	9,529	5,763
Tax benefit from exercise of employee stock options	(5,408)	(6,911)	(5,979)
Net cash provided by operating activities	292,288	256,571	180,105
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property, plant and equipment	(127,042)	(70,119)	(88,601)
Purchase of intangible assets	0	0	(2,000)
Proceeds from sales of property, plant and equipment	658	164	434
Proceeds from short-term investments	198,808	0	0
Purchases of short-term investments	(299,508)	(106,747)	0
Acquisition of businesses	(47,792)	(4,958)	0
Other	468	93	87
Net cash used in investing activities	(274,408)	(181,567)	(90,080)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from line-of-credit facilities	7,992	12,887	33,282
Payments on line-of-credit facilities	(7,992)	(15,227)	(33,623)
Purchase of noncontrolling interests	(950)	0	0
Proceeds on long-term borrowings	23,750	0	0
Principal payments on long-term borrowings	(2,594)	(13,333)	(1,667)
Exercise of employee stock options and issuances under employee stock purchase plan	16,183	14,132	7,558
Tax benefit from exercise of employee stock options	5,408	6,911	5,979
Purchase of Treasury Stock, at cost	(8,946)	0	0
Net cash provided by financing activities	32,851	5,370	11,529
EFFECT OF CHANGES IN EXCHANGE RATES ON CASH AND CASH EQUIVALENTS	(9,408)	(19,992)	(28,180)
NET INCREASE IN CASH AND CASH EQUIVALENTS	41,323	60,382	73,374
CASH AND CASH EQUIVALENTS — Beginning of period	582,532	522,150	448,776
CASH AND CASH EQUIVALENTS — End of period	623,855	582,532	522,150
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Cash paid for interest	942	873	253
Cash paid for income taxes	126,964	91,329	73,544
Non-cash transactions:
Demonstration units transferred from inventory to other assets	6,293	3,181	3,528
Property, plant and equipment transferred from inventory	4,529	2,951	1,551
Additions to property, plant and equipment included in accounts payable	973	350	1,084
Property purchase financed with debt	$ 0	$ 0	$ 22,000

Nature Of Business And Summary

Nature Of Business And Summary Of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature Of Business And Summary Of Significant Accounting Policies	NATURE OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Nature of Business — IPG Photonics Corporation (the "Company") is the leading developer and manufacturer of a broad line of high-performance fiber lasers, fiber amplifiers, diode lasers, laser systems and optical accessories that are used for diverse applications, primarily in materials processing. Its world headquarters are located in Oxford, Massachusetts. It also has facilities and sales offices elsewhere in the United States, Europe and Asia. Principles of Consolidation — The Company was incorporated as a Delaware corporation in December 1998. The accompanying financial statements include the accounts of the Company and its majority-owned subsidiaries. All intercompany accounts and transactions have been eliminated. Use of Estimates — The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. The Company bases its estimates on historical experience and on various other assumptions that are believed to be reasonable under the circumstances. Actual results could differ from those estimates. Foreign Currency — The financial information for entities outside the United States is measured using local currencies as the functional currency. Assets and liabilities are translated into U.S. dollars at the exchange rate in effect on the respective balance sheet dates. Income and expenses are translated into U.S. dollars based on the average rate of exchange for the corresponding period. Exchange rate differences resulting from translation adjustments are accounted for directly as a component of accumulated other comprehensive loss. Cash and Cash Equivalents and Short-Term Investments — Cash and cash equivalents consist primarily of highly liquid investments, such as bank deposits, mutual funds, marketable securities with original maturities of three months or less with insignificant interest rate risk and marketable securities with remaining maturities of three months or less at the date of acquisition. Short-term investments consist primarily of similar highly liquid investments and marketable securities with insignificant interest rate risks. Inventories — Inventories are stated at the lower of cost or market on a first-in, first-out basis. Inventories include parts and components that may be specialized in nature and subject to rapid obsolescence. The Company periodically reviews the quantities and carrying values of inventories to assess whether the inventories are recoverable. The costs associated with provisions for excess quantities, technological obsolescence, or component rejections are charged to cost of sales as incurred. Property, Plant and Equipment — Property, plant and equipment are stated at cost, less accumulated depreciation. Depreciation is determined using the straight-line method based on the estimated useful lives of the related assets. In the case of leasehold improvements, the estimated useful lives of the related assets do not exceed the remaining terms of the corresponding leases. The following table presents the assigned economic useful lives of property, plant and equipment: Category Economic Useful Life Buildings 30 years Machinery and equipment 5-12 years Office furniture and fixtures 3-5 years Expenditures for maintenance and repairs are charged to operations. Interest expense associated with significant capital projects is capitalized as a cost of the project. There was no interest expense capitalized in 2016 or 2015 . The Company capitalized $383 of interest expense in 2014 . Long-Lived Assets — Long-lived assets, which consist primarily of property, plant and equipment, are reviewed by management for impairment whenever events or changes in circumstances indicate that the carrying amount may not be recoverable. In cases in which undiscounted expected future cash flows are less than the carrying value, an impairment loss is recorded equal to the amount by which the carrying value exceeds the fair value of assets. In the fourth quarter of 2016, the Company began assessing the possible sale of its corporate aircraft included within Property, Plant and Equipment,net in its Consolidated Balance Sheets. As a result of this assessment and certain market indications of the aircraft's value if sold, the Company prepared an impairment analysis of the carrying value of the aircraft as of December 31, 2016. The impairment analysis was probability weighted considering market data available, future cash flows and whether or not the Company would sell the aircraft. Based on that analysis the Company recorded a $2,857 impairment charge included in General and administrative expense in its Consolidated Statements of Income as of December 31, 2016 . Prior to 2016 , no impairment losses had been recorded during the previous periods presented. Included in other long-term assets is certain demonstration equipment. The demonstration equipment is amortized over the respective estimated economic lives, generally 3 years . The carrying value of the demonstration equipment totaled $6,017 and $3,229 at December 31, 2016 and 2015 , respectively. Amortization expense of demonstration equipment for the years ended December 31, 2016 , 2015 and 2014 , was $2,959 , $2,345 and $2,068 , respectively. Goodwill — Goodwill is the amount by which the cost of the acquired net assets in a business acquisition exceeded the fair values of the net identifiable assets on the date of purchase. Goodwill is assessed for impairment at least annually, on a reporting unit basis, or more frequently when events and circumstances occur indicating that the recorded goodwill may be impaired. If the book value of a reporting unit exceeds its fair value, the implied fair value of goodwill is compared with the carrying amount of goodwill. If the carrying amount of goodwill exceeds the implied fair value, an impairment loss is recorded in an amount equal to that excess. Intangible Assets — Intangible assets result from the Company's various business acquisitions. Intangible assets are reported at cost, net of accumulated amortization, and are amortized on a straight-line basis either over their estimated useful lives of five to ten years or over the period the economic benefits of the intangible asset are consumed. Revenue Recognition — The Company recognizes revenue in accordance with ASC 605. Revenue from orders with multiple deliverables is divided into separate units of accounting when certain criteria are met. These separate units generally consist of equipment and installation. The consideration for the arrangement is allocated to the separate units of accounting based on their relative selling prices. The selling price of equipment is based on vendor-specific objective evidence which is the sales price of equipment sold without installation. The selling price of installation is based on third-party evidence which is the fair value of installation services offered by third parties. Revenue for laser and amplifier sources generally is recognized upon the transfer of ownership which is typically at the time of shipment. Installation revenue is recognized upon completion of the installation service which typically occurs within 30 to 90 days of delivery. For laser systems that carry customer specific processing requirements, revenue is recognized at the latter of customer acceptance date or shipment date if the customer acceptance is made prior to shipment. Returns and customer credits are insignificant and infrequent and are recorded as a reduction to revenue. Rights of return generally are not included in sales arrangements. Accounts Receivable and Allowance for Doubtful Accounts — Accounts receivable include $23,975 and $24,307 of bank acceptance drafts at December 31, 2016 and 2015 , respectively. Bank acceptance drafts are bank guarantees of payment on specified dates. The maturity of these bank acceptance drafts is less than 90 days. The Company maintains an allowance for doubtful accounts to provide for the estimated amount of accounts receivable that will not be collected. The allowance is based upon an assessment of customer creditworthiness, historical payment experience and the age of outstanding receivables. Activity related to the allowance for doubtful accounts was as follows: 2016 2015 2014 Balance at January 1 $ 1,811 $ 1,890 $ 2,473 Provision for bad debts, net of recoveries 111 427 579 Uncollectable accounts written off (76 ) (114 ) (617 ) Foreign currency translation 170 (392 ) (545 ) Balance at December 31 $ 2,016 $ 1,811 $ 1,890 Warranties — The Company typically provides one to three -year parts and service warranties on lasers and amplifiers. Most of the Company's sales offices provide support to customers in their respective geographic areas. The Company estimates the warranty accrual considering past claims experience, the number of units still covered by warranty and the average life of the remaining warranty period. The warranty accrual has generally been sufficient to cover product warranty repair and replacement costs. Activity related to the warranty accrual was as follows: 2016 2015 2014 Balance at January 1 $ 28,210 $ 19,272 $ 14,997 Provision for warranty accrual 22,483 22,808 15,449 Warranty claims (16,220 ) (12,208 ) (9,165 ) Foreign currency translation and other (495 ) (1,662 ) (2,009 ) Balance at December 31 $ 33,978 $ 28,210 $ 19,272 Accrued warranty reported in the accompanying consolidated financial statements as of December 31, 2016 and December 31, 2015 consists of $15,711 and $14,871 in accrued expenses and other liabilities and $18,267 and $13,339 in other long-term liabilities, respectively. Stock-Based Compensation — The Company accounts for stock-based compensation in accordance with ASC 718. Under the fair value recognition provision of ASC 718, the Company accounts for stock-based compensation using the fair value of the awards granted. The Company estimates the fair value of stock options granted using the Black-Scholes model, it values restricted stock units using the intrinsic value method and it uses a Monte Carlo simulation model to estimate the fair value of market-based performance stock units. The Company uses historical data to estimate pre-vesting option and restricted stock unit forfeitures and record stock-based compensation expense in its statements of income only for those options and awards that are expected to vest. The Company estimates forfeitures at the time of grant and revises these estimates, if necessary, in subsequent periods if actual forfeitures differ from the estimates. The Company amortizes the fair value of stock options and awards on a straight-line basis over the requisite service periods of the awards, which are generally the vesting periods. The description of the Company's stock-based employee compensation plans and the assumptions it uses to calculate the fair value of stock-based employee compensation is more fully described in Note 2. Advertising Expense — The cost of advertising is expensed as incurred. The Company conducts substantially all of its sales and marketing efforts through trade shows, professional and technical conferences, direct sales and our website. The Company's advertising costs were not material for the periods presented. Research and Development — Research and development costs are expensed as incurred. Income Taxes — Deferred tax assets and liabilities are recognized for the future tax consequences of temporary differences between the financial statement carrying amounts and tax basis of assets and liabilities and net operating loss carryforwards and credits using enacted rates in effect when those differences are expected to reverse. Valuation allowances are provided against deferred tax assets that are not deemed to be recoverable. The Company recognizes tax positions that are more likely than not to be sustained upon examination by relevant tax authorities. The tax positions are measured at the greatest amount of tax benefit that is more than 50 percent likely to be realized upon ultimate settlement. The Company provides reserves for potential payments of tax to various tax authorities related to uncertain tax positions and other issues. The reserves are based on a determination of whether and how much of a tax benefit taken by it in its tax filings or positions is more likely than not to be realized following resolution of uncertainties related to the tax benefit, assuming that the matter in question will be raised by the tax authorities. Concentration of Credit Risk — Financial instruments that potentially subject the Company to credit risk consist primarily of cash and cash equivalents, short-term investments, auction rate securities and accounts receivable. The Company maintains substantially all of its cash, short-term investments and marketable securities in various financial institutions, which it believes to be high-credit quality financial institutions. The Company grants credit to customers in the ordinary course of business and provides a reserve for potential credit losses. Such losses historically have been within management's expectations (see discussion related to significant customers in Note 15). Fair Value of Financial Instruments — The Company's financial instruments consist of cash equivalents, short-term investments, accounts receivable, auction rate securities, accounts payable, drawings on revolving lines of credit, long-term debt 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 cash equivalents, certain short-term investments, 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 these instruments or as a result of the competitive market interest rates, which have been negotiated. The following table presents information about the Company's assets and liabilities measured at fair value: Fair Value Measurements at December 31, 2016 Total Level 1 Level 2 Level 3 Assets Cash equivalents $ 179,699 $ 179,699 $ — $ — Short-term investments 206,616 206,616 — — Interest rate swap 77 — 77 — Auction rate securities 1,144 — — 1,144 Total assets $ 387,536 $ 386,315 $ 77 $ 1,144 Liabilities Long-term notes $ 41,351 $ — $ 41,351 $ — Total liabilities $ 41,351 $ — $ 41,351 $ — Fair Value Measurements at December 31, 2015 Total Level 1 Level 2 Level 3 Assets Cash equivalents $ 214,232 $ 214,232 $ — $ — Short-term investments 106,375 106,375 — — Auction rate securities 1,136 — — 1,136 Total assets $ 321,743 $ 320,607 $ — $ 1,136 Liabilities Long-term notes $ 19,667 $ 19,667 $ — $ — Contingent purchase consideration 20 — — 20 Total liabilities $ 19,687 $ 19,667 $ — $ 20 Short-term investments are measured and recorded at both fair value and book value with unrealized gains or losses adjusted through other comprehensive income for available-for-sale investments and with no unrealized gains or losses adjustments for those investments considered held-to-maturity. The investments in total consist of liquid investments including mutual funds, U.S. government and government agency notes, corporate notes, commercial paper and certificates of deposit with original maturities of greater than three months but less than one year. The fair value of the short-term investments considered available-for-sale as of December 31, 2016 and December 31, 2015 was $41,591 and $0 , respectively. These amounts include an unrealized loss of $432 and $0 , respectively. The fair value of the investments considered held-to-maturity as of December 31, 2016 and December 31, 2015 was $165,025 and $106,375 , respectively, which represents an unrealized loss of $163 and $209 , respectively, as compared to the book value recorded on the Consolidated Balance Sheets for the same periods. 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 long-term note in May 2023. The Company previously had a cash flow hedge which was an interest rate swap associated with a U.S. long-term note which matured in June 2015. The fair value at December 31, 2016 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 $1,450 at December 31, 2016 and December 31, 2015 . The fair value of the Company's two outstanding long-term notes was determined using pricing models whose inputs are observable for the securities held by the Company. The fair value of these two debt instruments as of December 31, 2016 and December 31, 2015 was $41,351 and $19,667 , respectively, as compared to the book values of $40,823 and $19,667 recorded on the Consolidated Balance Sheets for the same periods. The original long-term note that has a fixed rate was considered a Level 1 measurement at December 31, 2015 , as the fair value closely approximated the book value at the time. The fair value of contingent consideration was determined using an income approach at the respective business combination dates 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 business combinations that give rise to contingent consideration are more fully described in Note 12. The following table presents information about the Company's movement in Level 3 assets and liabilities measured at fair value: 2016 2015 2014 Auction Rate Securities Balance, January 1 $ 1,136 $ 1,128 $ 1,120 Period transactions 8 8 8 Balance, December 31 $ 1,144 $ 1,136 $ 1,128 Contingent Purchase Consideration Balance, January 1 $ 20 $ 98 $ 375 Period transactions (21 ) (50 ) — Change in fair value and currency fluctuations 1 (28 ) (277 ) Balance, December 31 $ — $ 20 $ 98 Comprehensive Income — Comprehensive income includes charges and credits to equity that are not the result of transactions with stockholders. Included within comprehensive income is the cumulative foreign currency translation adjustment, change in carrying value of auction rate securities, unrealized gains or losses on derivatives and unrealized gains or losses on available-for-sale investments. These adjustments are accumulated within the consolidated statements of comprehensive income. Total components of accumulated other comprehensive loss were as follows: December 31, 2016 2015 Foreign currency translation adjustments $ (178,577 ) $ (181,725 ) Change in carrying value of auction rate securities 232 232 Unrealized gain on derivatives, net of tax of $28 and $45 60 11 Unrealized loss on available-for-sale investments, net of tax of $134 and $0 (298 ) — Accumulated other comprehensive loss $ (178,583 ) $ (181,482 ) Derivative Instruments — The Company's primary market exposures are to interest rates and foreign exchange rates. The Company from time to time may use certain derivative financial instruments to help manage these exposures. The Company executes these instruments with financial institutions it judges to be credit-worthy. The Company does not hold or issue derivative financial instruments for trading or speculative purposes. The Company recognizes all derivative financial instruments as either assets or liabilities at fair value in the consolidated balance sheets. The Company has an interest rate swap that is classified as a cash flow hedge of its variable rate debt. The Company has no derivatives that are not accounted for as a hedging instrument. Cash Flow Hedges — The Company's current and previous cash flow hedge is an interest rate swap under which it pays fixed rates of interest. The fair value amounts in the consolidated balance sheets were: Notional Amounts 1 Other Assets Other Current Liabilities Deferred Income Taxes And Other Long-Term Liabilities December 31, December 31, December 31, December 31, 2016 2015 2016 2015 2016 2015 2016 2015 $ 23,156 $ — $ 77 $ — $ — $ — $ — $ — (1) Notional amounts represent the gross contract/notional amount of the derivative outstanding. The derivative gains and losses in the consolidated statements of income for the years ended December 31, 2016 , 2015 and 2014 , related to the Company's current and previous interest rate swap contracts were as follows: Year Ended December 31, 2016 2015 2014 Effective portion recognized in other comprehensive income (loss), pretax: Interest rate swap $ 85 $ 304 $ 567 Effective portion reclassified from other comprehensive income (loss) to interest expense, pretax: Interest rate swap $ (8 ) $ (153 ) $ (295 ) Ineffective portion recognized in income: Interest rate swap $ — $ — $ — Business Segment Information — The Company operates in one segment which involves the design, development, production and distribution of fiber lasers, laser systems, fiber amplifiers, and related optical components. The Company has a single, company-wide management team that administers all properties as a whole rather than as discrete operating segments. The chief decision maker, who is the Company's chief executive officer, measures financial performance as a single enterprise and not on legal entity or end market basis. Throughout the year, the chief decision maker allocates capital resources on a project-by-project basis across the Company's entire asset base to maximize profitability without regard to legal entity or end market basis. The Company operates in a number of countries throughout the world in a variety of product lines. Information regarding geographic financial information and product lines is provided in Note 15. Earnings Per Share — The Company computes net income per share in accordance with ASC 260- Earnings Per Share . Recent Accounting Pronouncements — In November 2016, the FASB issued Accounting Standards Update ("ASU") 2016-18 "Statement of Cash Flows (Topic 230): Restricted Cash" ("ASU 2016-18"), and in August 2016, the FASB issued ASU No. 2016-15, "Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments" ("ASU 2016-15"). ASU 2016-18 and ASU 2016-15 provide guidance on a total of nine specific cash flow classification issues to reduce diversity in practice. ASU 2016-18 and ASU 2016-15 are effective for fiscal years beginning after December 15, 2017, with early adoption permitted. The Company has elected to adopt these standards as of December 31, 2016 on a retrospective basis which resulted in no impact on the Company's reported cash flows for any period presented. In October 2016, the FASB issued ASU No. 2016-16, "Income Taxes (Topic 740) - Intra-Entity Transfers of Assets other than Inventory" ("ASU 2016-16"). ASU 2016-16 eliminates the current exception that prohibits the recognition of current and deferred income tax consequences for intra-entity asset transfers (other than inventory) until the asset has been sold to an outside party. The amendments will be applied on a modified retrospective basis through a cumulative effect adjustment to retained earnings. Deferred tax assets should be assessed to determine if realizable. Disclosures will be required for the (i) reason for and notice of change, (ii) effect of change on income from continuing operations and (iii) cumulative effect of change on retained earnings. Public entities will apply these changes in annual reporting periods beginning after December 15, 2017, and interim reporting periods within such period. Early adoption is permitted. The Company is currently evaluating the potential impact that the standard will have on its consolidated financial statements upon adoption. In March 2016, the FASB issued ASU No. 2016-09, "Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting" ("ASU 2016-09"). ASU 2016-09 is intended to simplify several areas of accounting for share-based compensation arrangements, including income tax impact, classification on the statement of cash flows and forfeitures. ASU 2016-09 is effective for fiscal years, and interim periods within those years, beginning after December 15, 2016, and early adoption is permitted. The impact that the standard will have on the Company's consolidated financial statements will depend upon certain criteria including the timing of the exercise and release of equity instruments, the value realized upon exercise or release of equity instruments and the fair value of the equity instruments when they were granted. The excess tax benefit from the exercise of equity instruments was $5,408 and $6,911 for the year ended December 31, 2016 and 2015 , respectively. In February 2016, the FASB issued ASU No. 2016-02, "Leases (Topic 842)" ("ASU 2016-02"). ASU 2016-02 requires a lessee to recognize assets and liabilities on the balance sheet for leases with lease terms greater than 12 months. ASU 2016-02 is effective for fiscal years, and interim periods within those years, beginning after December 15, 2018, and early adoption is permitted. The Company is currently evaluating the impact that the standard will have and does not expect it to have a material impact on its consolidated financial statements upon adoption. In January 2016, the FASB issued ASU No. 2016-01, "Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities" ("ASU 2016-01"). ASU 2016-01 addresses certain aspects of recognition, measurement, presentation, and disclosure of financial instruments. ASU 2016-01 is effective for fiscal years, and interim periods within those years, beginning after December 15, 2017, and early adoption is not permitted. The Company is currently evaluating the impact that the standard will have and does not expect it to have a material impact on its consolidated financial statements upon adoption. In November 2015, the FASB issued ASU No. 2015-17, "Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes" ("ASU 2015-17"). ASU 2015-17 removes the requirement to separate and classify deferred income tax liabilities and assets into current and noncurrent amounts and requires an entity to classify all deferred tax liabilities and assets as noncurrent. This ASU is effective for fiscal years beginning after December 15, 2016, with early adoption permitted. The Company adopted this standard during the fourth quarter ended December 31, 2016, and has retrospectively reclassified $17,156 of current net current deferred income tax assets to long-term net deferred taxes as of December 31, 2015. In May 2014, the FASB issued ASU No. 2014-09, "Revenue from Contracts with Customers" ("ASU 2014-09"). ASU 2014-09 supersedes the revenue recognition requirements in "Revenue Recognition (Topic 605)", and requires entities to recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled to in exchange for those goods or services. In August 2015, the FASB issued ASU No. 2015-14 "Revenue from Contracts with Customers" ("ASU 2015-14"), which defers the effective date of ASU 2014-09 one year to interim and annual reporting periods beginning after December 15, 2017, which would be the Company's fiscal year ending December 31, 2018. This additional guidance does not change the core principle of the revenue recognition guidance issued in May 2014, rather, it provides clarification of accounting for collections of sales taxes as well as recognition of revenue (i) associated with contract modifications, (ii) for noncash consideration, and (iii) based on the collectability of the consideration from the customer. The guidance also specifies when a contract should be considered "completed" for purposes of applying the transition guidance. The Company has completed an initial assessment of the new guidance and is currently evaluating the impact this standard may have on its financial statements and has not decided upon which one of two retrospective application methods it will be using upon adoption. Subsequent Events — The Company has considered the impact of subsequent events through the filing date of these financial statements. There were no events through the filing date of these financial statements required to be disclosed.

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	STOCK-BASED COMPENSATION Stock-based compensation is included in the following financial statement captions: Year Ended December 31, 2016 2015 2014 Cost of sales $ 6,018 $ 5,316 $ 4,153 Sales and marketing 1,820 1,998 1,567 Research and development 4,905 4,049 3,033 General and administrative 8,991 7,626 6,419 Total stock-based compensation 21,734 18,989 15,172 Tax benefit recognized (6,971 ) (6,141 ) (4,865 ) Net stock-based compensation $ 14,763 $ 12,848 $ 10,307 Incentive Plans — In February 2006, the Company's board of directors adopted the 2006 Incentive Compensation Plan (the "2006 Plan"), which provides for the issuance of stock options, restricted stock units, performance stock units, other equity-based awards and cash awards to the Company's directors, employees, consultants and advisors. In June 2006, the Company's board of directors adopted the Non-Employee Directors Stock Plan (the "Directors Plan") for non-employee directors. A total of 10,279,192 shares are reserved under the 2006 Plan, including a total of 84,273 and 194,919 shares rolled into the 2006 Plan from the Directors Plan and another plan, both of which are now inactive. The stockholders approved the 2006 Plan, the Directors Plan and subsequent amendments increasing the authorized shares. At December 31, 2016 , 4,707,611 shares of the Company's stock were available for future grant under the 2006 Plan. The Company may grant stock options only at an exercise price equal to or greater than the fair market value of its common stock on the date of grant. Equity awards generally become exercisable over periods of one to four years and generally expire ten years after the date of the grant. The vesting of awards under the the 2006 Plan accelerate following the occurrence of certain change of control events if the participant's employment is terminated within two years without cause or for good reason or if the successor entity does not agree to assume existing awards or replace with equivalent value awards. Awards granted to non-employee directors automatically become exercisable upon a change of control. All shares issued under the 2006 Plan and Directors Plan are registered shares, newly issued by the Company. Compensation cost for all stock-based payment awards is based on the estimated grant-date fair value. The Company allocates and records stock-based compensation expense on a straight-line basis over the requisite service period. Determining the appropriate fair value model and calculating the fair value of stock-based payment awards requires the use of highly subjective assumptions, including the expected life of the stock-based payment awards and stock price volatility. The assumptions used in calculating the fair value of stock-based payment awards represent management’s best estimates, but the estimates involve inherent uncertainties and the application of management judgment. As a result, if factors change and the Company uses different assumptions, its stock-based compensation expense could be materially different in the future. The Company calculates the fair value of stock option grants using the Black-Scholes option pricing model. The assumptions used in the Black-Scholes model or the calculation of compensation were as follows for the years ended December 31. 2016 2015 2014 Expected term 4.4-6.1 years 4.4-6.3 years 4.7-6.1 years Volatility 37%-45% 45%-48% 48%-51% Risk-free rate of return 1.06%-1.41% 1.38%-1.74% 1.46%-1.84% Dividend yield 0.25% 0.25% 0.25% Forfeiture rate 2.65%-5.26% 3.47%-5.88% 3.04%-5.86% A summary of option activity is presented below (see Note 11 for further information): Number of Options Weighted- Average Exercise Price Weighted- Average Remaining Contractual Life Aggregate Intrinsic Value (In years) (In thousands) Outstanding — January 1, 2016 2,224,169 $ 53.82 Granted 260,930 82.84 Exercised (392,887 ) 35.81 Forfeited (27,959 ) 72.87 Outstanding — December 31, 2016 2,064,253 $ 60.65 6.04 $ 78,556 Vested or expected to vest — December 31, 2016 1,996,705 $ 59.89 5.96 $ 77,508 Exercisable — December 31, 2016 1,067,916 $ 45.95 4.54 $ 56,345 The intrinsic value of the options exercised during the years ended December 31, 2016 , 2015 and 2014 , was $23,315 , $27,207 and $20,474 , respectively. The weighted-average grant fair value per share for options granted during the years ended December 31, 2016 , 2015 and 2014 , was $33.08 , $42.78 and $32.53 , respectively. The total compensation cost related to non-vested awards not yet recorded at December 31, 2016 was $13,756 which is expected to be recognized over a weighted-average of 2.3 years. The aggregate fair value of awards vested during the year ended December 31, 2016 was $11,909 . The following table summarizes the restricted stock units ("RSU's") activity for the year ended December 31, 2016 : Number of Shares Weighted-Average Grant-Date Fair Value Weighted- Average Remaining Contractual Life Aggregate Intrinsic Value (In years) (In thousands) Outstanding — January 1, 2016 277,719 $ 77.22 Granted 140,452 81.86 Converted (44,656 ) 70.64 Canceled (6,745 ) 81.89 Outstanding — December 31, 2016 366,770 $ 79.72 7.99 $ 36,204 Vested or expected to vest — December 31, 2016 336,240 $ 79.31 7.94 $ 33,190 The intrinsic value of the RSU's exercised during the years ended December 31, 2016 , 2015 and 2014 , was $3,931 , $3,705 and $3,017 , respectively. The weighted-average grant fair value per share for RSU's granted during the years ended December 31, 2016 , 2015 and 2014 , was $81.86 , $95.25 and $69.22 , respectively. The total compensation cost related to non-vested awards not yet recorded at December 31, 2016 was $14,434 which is expected to be recognized over a weighted-average of 2.5 years. The aggregate fair value of awards vested during the year ended December 31, 2016 was $3,186 . The Company grants performance stock units to officers. The performance stock unit agreements provide for the award of performance stock units with each unit representing the right to receive one share of the Company's common stock to be issued after the applicable award vesting period. The final number of units awarded, if any, for these performance grants will be determined as of the vesting dates, based upon the Company's total shareholder return over the performance period compared to the Russell 3000 Index and could range from no units to a maximum of twice the amount of awarded units. The weighted-average fair value of these performance units was determined using the Monte Carlo simulation model incorporating the following weighted-average assumptions: 2016 2015 Expected term 3.0 years 3.2 years Volatility 13%-32% 12%-36% Risk-free rate of return 0.88% 0.98% Dividend yield —% —% Weighted-average fair value per share 88.51 128.42 The following table summarizes the performance stock units ("PSU's") activity for the year ended December 31, 2016 : Number of Shares Weighted-Average Grant-Date Fair Value Weighted- Average Remaining Contractual Life Aggregate Intrinsic Value (In years) (In thousands) Outstanding — January 1, 2016 27,233 $ 128.54 Granted 27,272 88.51 Converted — — Canceled — — Outstanding — December 31, 2016 54,505 $ 108.51 8.64 $ 5,380 Vested or expected to vest — December 31, 2016 50,313 $ 108.59 8.64 $ 4,966 PSU's are included at 100% of target goal; under the terms of the awards, the recipient may earn between 0% and 200% of the awarded units. The total compensation cost related to nonvested awards not yet recorded at December 31, 2016 was $3,479 which is expected to be recognized over a weighted average of 2.6 years.

Inventories

Inventories	12 Months Ended
	Dec. 31, 2016
Inventory Disclosure [Abstract]
Inventories	INVENTORIES Inventories consist of the following: December 31, 2016 2015 Components and raw materials $ 93,284 $ 70,394 Work-in-process 44,723 43,259 Finished goods 101,003 90,085 Total $ 239,010 $ 203,738 The Company recorded inventory provisions totaling $22,796 , $15,364 and $11,302 for the years ended December 31, 2016 , 2015 and 2014 , 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 goods.

Property, Plant And Equipment

Property, Plant And Equipment	12 Months Ended
	Dec. 31, 2016
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	PROPERTY, PLANT AND EQUIPMENT Property, plant, and equipment consist of the following: December 31, 2016 2015 Land $ 21,811 $ 18,962 Buildings 214,830 166,784 Machinery and equipment 279,372 226,724 Office furniture and fixtures 31,210 26,981 Construction-in-progress 59,391 35,946 Total property, plant and equipment 606,614 475,397 Accumulated depreciation (227,239 ) (186,793 ) Total property, plant and equipment — net $ 379,375 $ 288,604 The Company recorded depreciation expense of $44,757 , $37,796 and $31,334 for the years ended December 31, 2016 , 2015 and 2014 , respectively.

Accrued Expenses And Other Liab

Accrued Expenses And Other Liabilities	12 Months Ended
	Dec. 31, 2016
Payables and Accruals [Abstract]
Accrued Expenses And Other Liabilities	ACCRUED EXPENSES AND OTHER LIABILITIES Accrued expenses and other liabilities consist of the following: December 31, 2016 2015 Accrued compensation $ 43,761 $ 33,617 Customer deposits and deferred revenue 34,571 21,525 Current portion of accrued warranty 15,711 14,871 Other 8,442 5,654 Total $ 102,485 $ 75,667

Financing Arrangements

Financing Arrangements	12 Months Ended
	Dec. 31, 2016
Debt Disclosure [Abstract]
Financing Arrangements	FINANCING ARRANGEMENTS The Company's borrowings under existing financing arrangements consist of the following: December 31, 2016 2015 Term debt: Long-term notes $ 40,823 $ 19,667 Less: current portion (3,188 ) (2,000 ) Total long-term debt $ 37,635 $ 17,667 The U.S. and Euro lines of credit are available to certain foreign subsidiaries and allow for borrowings in the local currencies of those subsidiaries. Revolving Line of Credit Facilities: U.S. Line of Credit — The Company maintains an unsecured revolving line of credit with available principal of up to $50,000 , expiring in April 2020. The line of credit bears interest at a variable rate of LIBOR plus 0.80% to 1.20% depending on the Company's financial performance. Part of this credit facility is available to the Company's foreign subsidiaries including those in India, China, Japan and South Korea based on management discretion. At December 31, 2016 , there were no outstanding drawings, however there were $161 of guarantees issued against the line which reduced the total availability. At December 31, 2016 , the remaining availability under this line was $49,839 . The Company is required to meet certain financial covenants associated with its U.S. line of credit and collateralized long-term note. These covenants, tested quarterly, include a debt service coverage ratio and a funded debt to earnings before interest, taxes, depreciation and amortization ("EBITDA") ratio. The debt service coverage covenant requires the Company to maintain a trailing twelve month ratio of cash flow to debt service that is greater than 1.5 :1. Debt service in the calculation is decreased by our cash held in the U.S.A. in excess of $50 million up to a maximum of $250 million . Cash flow is defined as EBITDA less unfunded capital expenditures. The funded debt to EBITDA covenant requires that the sum of all indebtedness for borrowed money on a consolidated basis be less than three times the Company's trailing twelve months EBITDA. Euro Line of Credit — The Company maintains an unsecured revolving line of credit with a principal amount of Euro 30,000 ( $31,547 at December 31, 2016 ), expiring in July 2017. The line of credit bears interest at various rates based upon the type of loan. This credit facility is available to the Company's foreign subsidiaries including those in Germany, Russia, China and Italy based on management discretion. At December 31, 2016 , there were no drawings, however there were $11,999 of guarantees issued against the line which reduced the total availability. At December 31, 2016 , the remaining availability under this line was $19,547 . Euro Overdraft Facilities — The Company maintains a syndicated overdraft facility with available principal of Euro 500 ( $526 at December 31, 2016 ) with no expiration date. This facility bears interest at market rates that vary depending upon the bank within the syndicate that advances the principal outstanding. At December 31, 2016 , there were no outstanding drawings and the aggregate remaining availability under this line was $526 . Other European Facilities — The Company maintains two Euro credit lines in Italy with aggregate available principal of Euro 1,500 ( $1,577 as of December 31, 2016 ) which bear interest at market rates and expire in June and September 2017. At December 31, 2016 , there were no outstanding drawings and the aggregate remaining availability under these lines was $1,577 . These facilities are collateralized by a common pool of the assets of the Company's Italian subsidiary. Term Debt: Long-Term Notes — At December 31, 2016 , the outstanding balance on the two long-term notes was $40,823 of which $3,188 is the current portion. During the second quarter of 2016, the Company financed the purchase of a building in Marlborough, Massachusetts with an unsecured note of $23,750 . The interest on this unsecured long-term note is variable at 1.20% above the LIBOR rate and is fixed using an interest rate swap at 2.85% per annum. The unsecured long-term note matures in May 2023, at which time the outstanding debt balance will be $15,438 . The outstanding balance on this unsecured long-term note as of December 31, 2016 was $23,156 of which $1,188 is the current portion. The Company has another note that is secured by the Company's corporate aircraft. The interest rate on this collateralized long-term note is fixed at 2.81% per annum and the collateralized long-term note matures in October 2019, at which time the outstanding debt balance will be $12,000 . The outstanding balance on this collateralized long-term note at December 31, 2016 was $17,667 of which $2,000 is the current portion.

Noncontrolling Interest and Equ

Noncontrolling Interest and Equity	12 Months Ended
	Dec. 31, 2016
Noncontrolling Interest [Abstract]
Noncontrolling Interest and Equity	NONCONTROLLING INTEREST AND EQUITY Noncontrolling Interest — Noncontrolling interest reported in the accompanying consolidated financial statements relates to an approximate 98% and 76% ownership interest in RukhTekh LLC ("RuchTech") at December 31, 2016 and December 31, 2015 , respectively. The associated net loss attributable to noncontrolling interest in 2016 and 2015 was $36 and $127 , respectively. Information regarding RuchTech's purchase is provided in Note 12. Authorized Capital — The Company has authorized capital stock consisting of 175,000,000 shares of common stock, par value $0.0001 per share, and 5,000,000 shares of preferred stock, par value $0.0001 per share. There are no shares of preferred stock outstanding as of December 31, 2016 .

Related-Party Transactions

Related-Party Transactions	12 Months Ended
	Dec. 31, 2016
Related Party Transactions [Abstract]
Related-Party Transactions	RELATED-PARTY TRANSACTIONS In 2016 , the Company purchased an office building located in Marlborough, Massachusetts from a subsidiary of IP Fibre Devices (UK) Ltd. ("IPFD") for $23,750 . The purchase price was based on the fair market value of the building determined using an independent appraisal. The appraisal was commissioned by the Nominating and Corporate Governance Committee of the Board of Directors. The Company's Chief Executive Officer ("CEO") is the managing director of IPFD. The CEO and certain founding members of the Company, which include the Senior Vice President, Chief Technology Officer and the Senior Vice President, Chief Operating Officer and Managing Director of IPG Laser GmbH, own shares in IPFD which is a stockholder of the Company. The Company leased space in the building prior to purchasing it and reimbursed the landlord for its portion of certain operational costs. The Company paid IPFD $443 and $531 for 2016 and 2015, respectively, under the office lease. The CEO leases the right to use 25% of the Company's aircraft annually under a October 2014 lease expiring November 2019. The 2016 year-end annual lease rate was $651 and future rent payments are adjusted annually. The CEO paid the Company $651 and $651 in 2016 and 2015 , respectively, under the aircraft lease. In addition, the CEO directly pays an unrelated flight management firm for the operating costs of his private use including pilot fees, fuel and other costs. In 2015 , the Company sold products and services of $497 to OAO "RCE" Laser Processing Center ("Laser Center"), an application development and parts processing company. There were no transactions in 2016 . The Company's CEO owns approximately 39% of Laser Center, which he acquired from an unrelated third party in 2014. In 2016 and 2015 , the Company purchased various equipment, parts and services from a company for which one of the Company's independent directors is an executive officer. The payments made for such equipment, parts and services for 2016 and 2015 totaled $5,392 and $683 , respectively. There were no amounts due to this company at December 31, 2016 or at December 31, 2015 . In both 2016 and 2015 , the Company sold products of $146 to a separate company with whom another of the Company's outside independent directors is affiliated.

Net Income Attributable To IPG

Net Income Attributable To IPG Photonics Corporation Per Share	12 Months Ended
	Dec. 31, 2016
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: Year Ended December 31, 2016 2015 2014 Net income attributable to IPG Photonics Corporation $ 260,752 $ 242,154 $ 200,445 Net income attributable to common stockholders 260,752 242,154 200,445 Weighted average shares 53,068 52,676 52,104 Dilutive effect of common stock equivalents 729 751 720 Diluted weighted average common shares 53,797 53,427 52,824 Basic net income attributable to IPG Photonics Corporation per share $ 4.91 $ 4.60 $ 3.85 Basic net income attributable to common stockholders $ 4.91 $ 4.60 $ 3.85 Diluted net income attributable to IPG Photonics Corporation per share $ 4.85 $ 4.53 $ 3.79 Diluted net income attributable to common stockholders $ 4.85 $ 4.53 $ 3.79 For the years ended December 31, 2016 , 2015 and 2014 , respectively, the computation of diluted weighted average common shares excludes common stock equivalents of 60,797 shares, 29,127 shares and 46,897 shares which includes RSU's of 12,711 , 18,171 and 13,300 and PSU's of 809 , 3,369 and 0 , because the effect would be anti-dilutive. In July 2016, the Company announced that its Board of Directors authorized a share repurchase program (the "Program") to mitigate the dilutive impact of shares issued upon exercise or release under the Company's various employee and director equity compensation and employee stock purchase plans. Under the Program, the Company's management is authorized to repurchase shares of common stock in an amount not to exceed the number of shares issued to employees and directors under its various employee and director equity compensation and employee stock purchase plans from January 1, 2016 through December 31, 2017. The Program limits aggregate share repurchases to no more than $100,000 over a period ending June 30, 2018. For the year ended December 31, 2016 , the Company repurchased 102,774 shares of its common stock with an average price of $87.01 per share in the open market. The impact on the reduction of weighted average shares for year ended December 31, 2016 was 20,935 shares. There were no previous Program repurchases made by the Company prior to this period.

Commitments And Contingencies

Commitments And Contingencies	12 Months Ended
	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments And Contingencies	COMMITMENTS AND CONTINGENCIES Operating Leases — The Company leases certain facilities under cancelable and noncancelable operating lease agreements which expire through December 2025. In addition, it leases capital equipment under operating leases. Rent expense for the years ended December 31, 2016 , 2015 and 2014 , totaled $7,091 , $7,365 and $5,516 , respectively. Commitments under the noncancelable lease agreements as of December 31, 2016 are as follows: Years Ending December 31 Facilities Equipment Total 2017 $ 3,245 $ 943 $ 4,188 2018 2,275 598 2,873 2019 1,613 321 1,934 2020 895 101 996 2021 545 11 556 Thereafter 681 — 681 Total $ 9,254 $ 1,974 $ 11,228 Employment Agreements — The Company has entered into employment agreements with certain members of senior management. The terms of these agreements are up to three years and include noncompetition, nonsolicitation and nondisclosure provisions, as well as provisions for defined severance for terminations of employment under certain conditions and a change of control of the Company. The Company also maintains a severance plan for certain of its senior management providing for defined severance for terminations of employment under certain conditions and a change of control of the Company. Contractual Obligations — The Company has entered into various purchase obligations that include agreements for construction of buildings, raw materials and equipment. Obligations under these agreements were $33,072 and $17,961 as of December 31, 2016 and 2015 , respectively. Legal proceedings — From 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 December 31, 2016 and through the date of the Company's subsequent review period of February 27, 2017 , the Company has no legal proceedings ongoing that management estimates could have a material effect on the Company's Consolidated Financial Statements.

Employee Benefit Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2016
Compensation Related Costs [Abstract]
Employee Benefit Plans	EMPLOYEE BENEFIT PLANS The Company maintains a 401(k) retirement savings plan offered to all of its U.S. employees. The Company makes matching contributions equal to 50% of the employee's contributions, subject to a maximum of 6% of eligible compensation. Compensation expense related to its contribution to the plan for the years ended December 31, 2016 , 2015 and 2014 , approximated $2,509 , $2,021 and $1,445 , respectively. The Company has an employee stock purchase plan offered to its U.S. and German employees. The plan allows employees who participate to purchase shares of common stock through payroll deductions at a 15% discount to the lower of the stock price on the first day or the last day of the six -month purchase period. Payroll deductions may not exceed 10% of the employee's compensation and are subject to other limitations. Compensation expense related to the employee stock purchase plan was $846 , $680 and $607 for the years ended December 31, 2016 , 2015 and 2014 , respectively. As of December 31, 2016 , there were 359,642 shares available for issuance under the employee stock purchase plan.

Business Combinations

Business Combinations	12 Months Ended
	Dec. 31, 2016
Business Combinations [Abstract]
Business Combinations	BUSINESS COMBINATIONS During the fourth quarter of 2016, the Company acquired BioPhotonic Solutions, Inc. ("BSI"). BSI develops and sells pulse shaping software technology for use in ultrafast lasers. BSI is located in East Lansing, Michigan. The total purchase price was $1,559 , subject to working capital adjustments, which represents the fair value of BSI on that date. As a result of the acquisition, the Company recorded intangible assets of $1,473 related to patents. The purchase price allocations included in the Company's financial statements are not complete. They represent the preliminary fair value estimates as of December 31, 2016 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 an adjustment to intangibles or income, as applicable. During the second quarter of 2016, the Company acquired Menara Networks, Inc. ("Menara"). Menara is located in Dallas, Texas. The Company paid $46,831 which represents the fair value of Menara on that date. As a result of the acquisition, the Company recorded intangible assets of $9,900 related to technology, tradename with a weighted-average estimated useful life of 7 years and $9,500 customer relationships with an estimated useful life of 10 years . Additionally, the Company recorded $19,325 of goodwill related to anticipated expansion of the Company's product offerings within the telecom market. The goodwill arising from this acquisition will no t be deductible for tax purposes. In 2016, the Company paid an additional $950 to increase its ownership interest in RuchTech to approximately 98% . The Company purchased a 76% ownership interest in RuchTech in 2015 for $5,000 . The fair value at the date of acquisition was $6,579 . In connection with this purchase, the Company recorded intangibles assets of $6,298 which related to purchased technology with an estimated useful life of 7 years and $64 of Goodwill that are no t deductible for federal income tax purposes.

Goodwill And Intangibles

Goodwill And Intangibles	12 Months Ended
	Dec. 31, 2016
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 years ended December 31, 2016 and 2015 : December 31, 2016 December 31, 2015 Balance at January 1 $ 505 $ 455 Foreign exchange adjustment (2 ) (14 ) Total goodwill arising from purchase 19,325 64 Balance at December 31 $ 19,828 $ 505 The goodwill arising from purchase during 2016 of $19,325 relates to anticipated expansion of the Company's product offerings within the telecom market from the acquisition of Menara. The goodwill arising from this acquisition will no t be deductible for tax purposes. The goodwill arising from purchase during 2015 of $64 , relates to anticipated expansion of the Company's high-power systems product line resulting from the 2015 purchase of a majority ownership interest in RuchTech. The goodwill arising from the purchase is no t deductible for federal tax purposes. The goodwill balance at January 1, 2015 of $455 relates to anticipated expansion of the Company's expansion of product offerings with UV fiber lasers from the acquisition of Mobius in 2013. The goodwill arising from the acquisition is deductible over 15 years for federal tax purposes. Intangible assets, subject to amortization, consisted of the following: December 31, 2016 December 31, 2015 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Weighted- Average Lives Gross Carrying Amount Accumulated Amortization Net Carrying Amount Weighted- Average Lives Patents $ 8,114 $ (4,926 ) $ 3,188 7 Years $ 6,641 $ (4,573 ) $ 2,068 6 Years Customer relationships 12,727 (3,621 ) 9,106 9 Years 3,325 (3,092 ) 233 5 Years Production know-how 6,618 (4,093 ) 2,525 8 Years 6,672 (3,339 ) 3,333 8 Years Technology, trademark and tradename 17,910 (3,940 ) 13,970 8 Years 8,247 (1,977 ) 6,270 8 Years $ 45,369 $ (16,580 ) $ 28,789 $ 24,885 $ (12,981 ) $ 11,904 Included in the table above are intangible assets from the following acquisition: • $1,473 of patents from the 2016 acquisition of BSI; • $9,900 of technology and tradename and $9,500 of customer relationships from the 2016 acquisition of Menara; and • $6,298 of technology from the 2015 acquisition of RuchTech. Amortization expense for the years ended December 31, 2016 , 2015 and 2014 was $3,759 , $2,274 and $2,210 , respectively. The estimated future amortization expense for intangibles as of December 31, 2016 is as follows: 2017 2018 2019 2020 2021 Thereafter Total $4,706 $4,641 $3,964 $3,590 $3,504 $8,384 $28,789 Impairment — In accordance with ASC 350- Intangibles-Goodwill and Other , the Company assesses the impairment of its long-lived assets including its definite-lived intangible assets and goodwill, at least annually for goodwill, and whenever changes in events or circumstances indicate that the carrying value of such assets may not be recoverable. During each annual reporting period, the Company assesses for factors that may be present which would cause an impairment review.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES Income before the impact of income taxes for the years ended December 31 consisted of the following: 2016 2015 2014 U.S. $ 103,798 $ 94,242 $ 72,800 Foreign 262,767 247,375 211,674 Total $ 366,565 $ 341,617 $ 284,474 The Company's provision for income taxes for the years ended December 31 consisted of the following: 2016 2015 2014 Current: Federal $ (41,407 ) $ (30,334 ) $ (22,549 ) State (4,750 ) (6,616 ) (2,823 ) Foreign (72,600 ) (69,793 ) (60,143 ) Total current $ (118,757 ) $ (106,743 ) $ (85,515 ) Deferred: Federal $ 8,709 $ 6,303 $ 454 State 383 312 27 Foreign 3,816 538 1,005 Total deferred $ 12,908 $ 7,153 $ 1,486 Provision for income taxes $ (105,849 ) $ (99,590 ) $ (84,029 ) A reconciliation of income tax expense at the U.S. federal statutory income tax rate to the recorded tax provision for the years ended December 31, is as follows: 2016 2015 2014 Tax at statutory rate $ (128,298 ) $ (119,566 ) $ (99,867 ) Non-U.S. rate differential — net 16,718 15,931 14,590 State income taxes — net (2,640 ) (2,094 ) (1,787 ) Effect of changes in enacted tax rates on deferred tax assets and liabilities (111 ) (153 ) (44 ) Nondeductible stock compensation expense (296 ) (338 ) (483 ) Other nondeductible expenses (2,307 ) (1,039 ) (2,063 ) Federal and state tax credits 9,840 8,837 5,865 Change in reserves, including interest and penalties 1,105 (1,522 ) (7 ) Change in valuation allowance 26 (620 ) — Other — net 114 974 (233 ) $ (105,849 ) $ (99,590 ) $ (84,029 ) The tax effects of temporary differences that give rise to significant portions of the deferred tax assets and deferred tax liabilities at December 31, are as follows: 2016 2015 2014 Property, plant and equipment $ (14,122 ) $ (8,031 ) $ (5,310 ) Inventory provisions 19,710 14,566 10,497 Allowances and accrued liabilities 5,434 2,590 1,570 Other tax credits 5,027 3,763 726 Deferred compensation 9,215 5,891 4,218 Net operating loss carryforwards 7,885 923 — Valuation allowance (662 ) (678 ) — Net deferred tax assets $ 32,487 $ 19,024 $ 11,701 The Company assesses its intention and ability to reinvest the earnings of non-U.S. subsidiaries in those operations. Based on this assessment, the Company has not made any provision for additional U.S. taxes with respect to repatriation of earnings of non-U.S. subsidiaries to the U.S. The Company has recorded a $1,636 deferred tax liability for certain withholding and dividend taxes related to possible distributions from non-U.S. subsidiaries to their non-U.S. parents. At December 31, 2016 and 2015 , the cumulative unremitted earnings that are permanently reinvested in non-U.S. subsidiaries are approximately $936,000 and $734,000 , respectively. As of December 31, 2016 , 2015 and 2014 , the Company has state tax credit carry-forwards of $5,027 , $3,740 and $1,225 , respectively. The state tax credit carry-forwards begin expiring in 2018. In addition, at December 31, 2016 , the Company has net operating loss carry-forwards available for future periods of $2,777 related to deductions for stock-based compensation for its UK subsidiary. The UK net operating loss can be carried-forward indefinitely. These amounts are not included in deferred tax assets, because when these net operating loss and state tax credit carry-forwards are utilized they will be credited to additional paid-in capital. The Company's acquisition of Menara in 2016 included net operating loss carry-forwards of $22,242 . As of December 31, 2016 , the Company has $19,826 of these net operating loss carry-forwards remaining. No valuation allowance has been provided for these carry-forwards as the Company expects to be able to fully utilize them to offset future income. The following is a tabular reconciliation of the total amounts of unrecognized tax benefits: 2016 2015 2014 Balance at January 1 $ 7,579 $ 6,494 $ 6,501 Change in prior period positions (1,876 ) 33 (795 ) Additions for tax positions in current period 700 1,052 788 Balance at December 31 $ 6,403 $ 7,579 $ 6,494 Substantially all of the liability for uncertain tax benefits related to various federal, state and foreign income tax matters, would benefit the Company's effective tax rate, if recognized. Estimated penalties and interest related to the underpayment of income taxes are ($163) , $437 and $(192) for the years ended December 31, 2016 , 2015 and 2014 , respectively, and are included within the provision for income taxes. Total accrued penalties and interest related to the underpayment of income taxes are $944 and $1,107 at December 31, 2016 and 2015 , respectively. The Company's uncertain tax positions are related to tax years that remain subject to examination by the relevant taxing authorities. If realized, all of the Company's uncertain tax positions would affect its effective tax rate. Certain of the Company's uncertain tax positions are expected to settle within one year. Open tax years by major jurisdictions are: • United States 2013 — 2016 • Germany 2013 — 2016 • Russia 2015 — 2016

Geographic And Product Informat

Geographic And Product Information	12 Months Ended
	Dec. 31, 2016
Segment Reporting [Abstract]
Geographic And Product Information	GEOGRAPHIC AND PRODUCT INFORMATION The Company markets and sells its products throughout the world through both direct sales and distribution channels. The geographic sources of the Company's net sales based on billing addresses of its customers are as follows: Year Ended December 31, 2016 2015 2014 United States and other North America $ 141,184 $ 131,525 $ 113,233 Europe: Germany 90,893 93,802 77,404 Other including Eastern Europe/CIS 224,836 189,123 173,018 Asia and Australia: China 358,476 311,946 245,102 Japan 88,592 76,033 72,573 Other 100,052 95,494 85,426 Rest of World 2,140 3,342 3,076 Total $ 1,006,173 $ 901,265 $ 769,832 Sales are derived from products for different applications: fiber lasers, diode lasers and diodes for materials processing, fiber lasers and amplifiers for advanced applications, fiber amplifiers for communications applications, and fiber lasers for medical applications. Net sales for these product lines are as follows: Year Ended December 31, 2016 2015 2014 Materials Processing $ 942,119 $ 849,335 $ 731,274 Other Applications 64,054 51,930 38,558 Total $ 1,006,173 $ 901,265 $ 769,832 No customers accounted for more than 10% of the Company's net sales during the year ended December 31, 2016 . However, one customer comprised 13% and 11% of net sales during the years ended December 31, 2015 and 2014 , respectively. The Company has historically depended on a few customers for a significant percentage of its annual net sales. The composition of this group can change from year to year. Net sales derived from the Company's five largest customers as a percentage of its annual net sales were 22% , 25% and 23% in 2016 , 2015 and 2014 , respectively. The geographic locations of the Company's long-lived assets, net, based on physical location of the assets, as of December 31, 2016 , 2015 and 2014 , are as follows: December 31, 2016 2015 2014 United States $ 230,116 $ 170,981 $ 155,428 Russia 76,966 55,150 59,612 Germany 61,792 53,678 51,528 China 8,096 6,237 6,582 Other 14,116 12,045 12,507 $ 391,086 $ 298,091 $ 285,657 Long lived assets include property, plant and equipment, related deposits on such assets and demonstration equipment.

Selected Quarterly Financial Da

Selected Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2016
Selected Quarterly Financial Information [Abstract]
Selected Quarterly Financial Data (Unaudited)	SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED) 2016 First Quarter Second Quarter Third Quarter Fourth Quarter (In thousands, except per share data) Net sales $ 207,248 $ 252,787 $ 266,017 $ 280,121 Gross profit 114,410 137,703 144,791 155,336 Net income attributable to IPG Photonics Corporation 49,326 67,058 69,235 75,133 Basic earnings per share 0.93 1.26 1.30 1.42 Diluted earnings per share 0.92 1.25 1.29 1.39 2015 First Quarter Second Quarter Third Quarter Fourth Quarter (In thousands, except per share data) Net sales $ 198,960 $ 235,138 $ 243,541 $ 223,626 Gross profit 107,827 128,703 133,304 122,043 Net income attributable to IPG Photonics Corporation 57,359 61,299 62,792 60,704 Basic earnings per share 1.09 1.16 1.19 1.15 Diluted earnings per share 1.08 1.15 1.18 1.14

Nature Of Business And Summar24

Nature Of Business And Summary Of Significant Accounting Policies (Policy)	12 Months Ended
	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Principles of Consolidation	Principles of Consolidation — The Company was incorporated as a Delaware corporation in December 1998. The accompanying financial statements include the accounts of the Company and its majority-owned subsidiaries. All intercompany accounts and transactions have been eliminated.
Use of Estimates	Use of Estimates — The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. The Company bases its estimates on historical experience and on various other assumptions that are believed to be reasonable under the circumstances. Actual results could differ from those estimates.
Foreign Currency	Foreign Currency — The financial information for entities outside the United States is measured using local currencies as the functional currency. Assets and liabilities are translated into U.S. dollars at the exchange rate in effect on the respective balance sheet dates. Income and expenses are translated into U.S. dollars based on the average rate of exchange for the corresponding period. Exchange rate differences resulting from translation adjustments are accounted for directly as a component of accumulated other comprehensive loss.
Cash and Cash Equivalents	Cash and Cash Equivalents and Short-Term Investments — Cash and cash equivalents consist primarily of highly liquid investments, such as bank deposits, mutual funds, marketable securities with original maturities of three months or less with insignificant interest rate risk and marketable securities with remaining maturities of three months or less at the date of acquisition.
Short-Term Investments	Short-term investments consist primarily of similar highly liquid investments and marketable securities with insignificant interest rate risks.
Inventories	Inventories — Inventories are stated at the lower of cost or market on a first-in, first-out basis. Inventories include parts and components that may be specialized in nature and subject to rapid obsolescence. The Company periodically reviews the quantities and carrying values of inventories to assess whether the inventories are recoverable. The costs associated with provisions for excess quantities, technological obsolescence, or component rejections are charged to cost of sales as incurred.
Property, Plant and Equipment	Property, Plant and Equipment — Property, plant and equipment are stated at cost, less accumulated depreciation. Depreciation is determined using the straight-line method based on the estimated useful lives of the related assets. In the case of leasehold improvements, the estimated useful lives of the related assets do not exceed the remaining terms of the corresponding leases. The following table presents the assigned economic useful lives of property, plant and equipment: Category Economic Useful Life Buildings 30 years Machinery and equipment 5-12 years Office furniture and fixtures 3-5 years Expenditures for maintenance and repairs are charged to operations. Interest expense associated with significant capital projects is capitalized as a cost of the project.
Long-Lived Assets	Long-Lived Assets — Long-lived assets, which consist primarily of property, plant and equipment, are reviewed by management for impairment whenever events or changes in circumstances indicate that the carrying amount may not be recoverable. In cases in which undiscounted expected future cash flows are less than the carrying value, an impairment loss is recorded equal to the amount by which the carrying value exceeds the fair value of assets. In the fourth quarter of 2016, the Company began assessing the possible sale of its corporate aircraft included within Property, Plant and Equipment,net in its Consolidated Balance Sheets. As a result of this assessment and certain market indications of the aircraft's value if sold, the Company prepared an impairment analysis of the carrying value of the aircraft as of December 31, 2016. The impairment analysis was probability weighted considering market data available, future cash flows and whether or not the Company would sell the aircraft. Based on that analysis the Company recorded a $2,857 impairment charge included in General and administrative expense in its Consolidated Statements of Income as of December 31, 2016 . Prior to 2016 , no impairment losses had been recorded during the previous periods presented. Included in other long-term assets is certain demonstration equipment. The demonstration equipment is amortized over the respective estimated economic lives, generally 3 years .
Goodwill	Goodwill — Goodwill is the amount by which the cost of the acquired net assets in a business acquisition exceeded the fair values of the net identifiable assets on the date of purchase. Goodwill is assessed for impairment at least annually, on a reporting unit basis, or more frequently when events and circumstances occur indicating that the recorded goodwill may be impaired. If the book value of a reporting unit exceeds its fair value, the implied fair value of goodwill is compared with the carrying amount of goodwill. If the carrying amount of goodwill exceeds the implied fair value, an impairment loss is recorded in an amount equal to that excess.
Intangible Assets	Intangible Assets — Intangible assets result from the Company's various business acquisitions. Intangible assets are reported at cost, net of accumulated amortization, and are amortized on a straight-line basis either over their estimated useful lives of five to ten years or over the period the economic benefits of the intangible asset are consumed.
Revenue Recognition	Revenue Recognition — The Company recognizes revenue in accordance with ASC 605. Revenue from orders with multiple deliverables is divided into separate units of accounting when certain criteria are met. These separate units generally consist of equipment and installation. The consideration for the arrangement is allocated to the separate units of accounting based on their relative selling prices. The selling price of equipment is based on vendor-specific objective evidence which is the sales price of equipment sold without installation. The selling price of installation is based on third-party evidence which is the fair value of installation services offered by third parties. Revenue for laser and amplifier sources generally is recognized upon the transfer of ownership which is typically at the time of shipment. Installation revenue is recognized upon completion of the installation service which typically occurs within 30 to 90 days of delivery. For laser systems that carry customer specific processing requirements, revenue is recognized at the latter of customer acceptance date or shipment date if the customer acceptance is made prior to shipment. Returns and customer credits are insignificant and infrequent and are recorded as a reduction to revenue. Rights of return generally are not included in sales arrangements.
Accounts Receivable and Allowance For Doubtful Accounts	Accounts Receivable and Allowance for Doubtful Accounts — Accounts receivable include $23,975 and $24,307 of bank acceptance drafts at December 31, 2016 and 2015 , respectively. Bank acceptance drafts are bank guarantees of payment on specified dates. The maturity of these bank acceptance drafts is less than 90 days. The Company maintains an allowance for doubtful accounts to provide for the estimated amount of accounts receivable that will not be collected. The allowance is based upon an assessment of customer creditworthiness, historical payment experience and the age of outstanding receivables.
Warranties	Warranties — The Company typically provides one to three -year parts and service warranties on lasers and amplifiers. Most of the Company's sales offices provide support to customers in their respective geographic areas. The Company estimates the warranty accrual considering past claims experience, the number of units still covered by warranty and the average life of the remaining warranty period. The warranty accrual has generally been sufficient to cover product warranty repair and replacement costs.
Stock-Based Compensation	Stock-Based Compensation — The Company accounts for stock-based compensation in accordance with ASC 718. Under the fair value recognition provision of ASC 718, the Company accounts for stock-based compensation using the fair value of the awards granted. The Company estimates the fair value of stock options granted using the Black-Scholes model, it values restricted stock units using the intrinsic value method and it uses a Monte Carlo simulation model to estimate the fair value of market-based performance stock units. The Company uses historical data to estimate pre-vesting option and restricted stock unit forfeitures and record stock-based compensation expense in its statements of income only for those options and awards that are expected to vest. The Company estimates forfeitures at the time of grant and revises these estimates, if necessary, in subsequent periods if actual forfeitures differ from the estimates. The Company amortizes the fair value of stock options and awards on a straight-line basis over the requisite service periods of the awards, which are generally the vesting periods. The description of the Company's stock-based employee compensation plans and the assumptions it uses to calculate the fair value of stock-based employee compensation is more fully described in Note 2.
Advertising Expense	Advertising Expense — The cost of advertising is expensed as incurred. The Company conducts substantially all of its sales and marketing efforts through trade shows, professional and technical conferences, direct sales and our website. The Company's advertising costs were not material for the periods presented.
Research and Development	Research and Development — Research and development costs are expensed as incurred.
Income Taxes	Income Taxes — Deferred tax assets and liabilities are recognized for the future tax consequences of temporary differences between the financial statement carrying amounts and tax basis of assets and liabilities and net operating loss carryforwards and credits using enacted rates in effect when those differences are expected to reverse. Valuation allowances are provided against deferred tax assets that are not deemed to be recoverable. The Company recognizes tax positions that are more likely than not to be sustained upon examination by relevant tax authorities. The tax positions are measured at the greatest amount of tax benefit that is more than 50 percent likely to be realized upon ultimate settlement. The Company provides reserves for potential payments of tax to various tax authorities related to uncertain tax positions and other issues. The reserves are based on a determination of whether and how much of a tax benefit taken by it in its tax filings or positions is more likely than not to be realized following resolution of uncertainties related to the tax benefit, assuming that the matter in question will be raised by the tax authorities.
Concentration of Credit Risk	Concentration of Credit Risk — Financial instruments that potentially subject the Company to credit risk consist primarily of cash and cash equivalents, short-term investments, auction rate securities and accounts receivable. The Company maintains substantially all of its cash, short-term investments and marketable securities in various financial institutions, which it believes to be high-credit quality financial institutions. The Company grants credit to customers in the ordinary course of business and provides a reserve for potential credit losses. Such losses historically have been within management's expectations (see discussion related to significant customers in Note 15).
Fair Value of Financial Instruments	Fair Value of Financial Instruments — The Company's financial instruments consist of cash equivalents, short-term investments, accounts receivable, auction rate securities, accounts payable, drawings on revolving lines of credit, long-term debt 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 cash equivalents, certain short-term investments, 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 these instruments or as a result of the competitive market interest rates, which have been negotiated. The following table presents information about the Company's assets and liabilities measured at fair value: Fair Value Measurements at December 31, 2016 Total Level 1 Level 2 Level 3 Assets Cash equivalents $ 179,699 $ 179,699 $ — $ — Short-term investments 206,616 206,616 — — Interest rate swap 77 — 77 — Auction rate securities 1,144 — — 1,144 Total assets $ 387,536 $ 386,315 $ 77 $ 1,144 Liabilities Long-term notes $ 41,351 $ — $ 41,351 $ — Total liabilities $ 41,351 $ — $ 41,351 $ — Fair Value Measurements at December 31, 2015 Total Level 1 Level 2 Level 3 Assets Cash equivalents $ 214,232 $ 214,232 $ — $ — Short-term investments 106,375 106,375 — — Auction rate securities 1,136 — — 1,136 Total assets $ 321,743 $ 320,607 $ — $ 1,136 Liabilities Long-term notes $ 19,667 $ 19,667 $ — $ — Contingent purchase consideration 20 — — 20 Total liabilities $ 19,687 $ 19,667 $ — $ 20 Short-term investments are measured and recorded at both fair value and book value with unrealized gains or losses adjusted through other comprehensive income for available-for-sale investments and with no unrealized gains or losses adjustments for those investments considered held-to-maturity. The investments in total consist of liquid investments including mutual funds, U.S. government and government agency notes, corporate notes, commercial paper and certificates of deposit with original maturities of greater than three months but less than one year. The fair value of the short-term investments considered available-for-sale as of December 31, 2016 and December 31, 2015 was $41,591 and $0 , respectively. These amounts include an unrealized loss of $432 and $0 , respectively. The fair value of the investments considered held-to-maturity as of December 31, 2016 and December 31, 2015 was $165,025 and $106,375 , respectively, which represents an unrealized loss of $163 and $209 , respectively, as compared to the book value recorded on the Consolidated Balance Sheets for the same periods. 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 long-term note in May 2023. The Company previously had a cash flow hedge which was an interest rate swap associated with a U.S. long-term note which matured in June 2015. The fair value at December 31, 2016 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 $1,450 at December 31, 2016 and December 31, 2015 . The fair value of the Company's two outstanding long-term notes was determined using pricing models whose inputs are observable for the securities held by the Company. The fair value of these two debt instruments as of December 31, 2016 and December 31, 2015 was $41,351 and $19,667 , respectively, as compared to the book values of $40,823 and $19,667 recorded on the Consolidated Balance Sheets for the same periods. The original long-term note that has a fixed rate was considered a Level 1 measurement at December 31, 2015 , as the fair value closely approximated the book value at the time. The fair value of contingent consideration was determined using an income approach at the respective business combination dates 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 business combinations that give rise to contingent consideration are more fully described in Note 12.
Comprehensive Income	Comprehensive Income — Comprehensive income includes charges and credits to equity that are not the result of transactions with stockholders. Included within comprehensive income is the cumulative foreign currency translation adjustment, change in carrying value of auction rate securities, unrealized gains or losses on derivatives and unrealized gains or losses on available-for-sale investments. These adjustments are accumulated within the consolidated statements of comprehensive income.
Derivative Instruments	Derivative Instruments — The Company's primary market exposures are to interest rates and foreign exchange rates. The Company from time to time may use certain derivative financial instruments to help manage these exposures. The Company executes these instruments with financial institutions it judges to be credit-worthy. The Company does not hold or issue derivative financial instruments for trading or speculative purposes. The Company recognizes all derivative financial instruments as either assets or liabilities at fair value in the consolidated balance sheets.
Cash Flow Hedges	Cash Flow Hedges — The Company's current and previous cash flow hedge is an interest rate swap under which it pays fixed rates of interest.
Business Segment Information	Business Segment Information — The Company operates in one segment which involves the design, development, production and distribution of fiber lasers, laser systems, fiber amplifiers, and related optical components. The Company has a single, company-wide management team that administers all properties as a whole rather than as discrete operating segments. The chief decision maker, who is the Company's chief executive officer, measures financial performance as a single enterprise and not on legal entity or end market basis. Throughout the year, the chief decision maker allocates capital resources on a project-by-project basis across the Company's entire asset base to maximize profitability without regard to legal entity or end market basis. The Company operates in a number of countries throughout the world in a variety of product lines. Information regarding geographic financial information and product lines is provided in Note 15.
Earnings Per Share	Earnings Per Share — The Company computes net income per share in accordance with ASC 260- Earnings Per Share .
Recent Accounting Pronouncements	Recent Accounting Pronouncements — In November 2016, the FASB issued Accounting Standards Update ("ASU") 2016-18 "Statement of Cash Flows (Topic 230): Restricted Cash" ("ASU 2016-18"), and in August 2016, the FASB issued ASU No. 2016-15, "Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments" ("ASU 2016-15"). ASU 2016-18 and ASU 2016-15 provide guidance on a total of nine specific cash flow classification issues to reduce diversity in practice. ASU 2016-18 and ASU 2016-15 are effective for fiscal years beginning after December 15, 2017, with early adoption permitted. The Company has elected to adopt these standards as of December 31, 2016 on a retrospective basis which resulted in no impact on the Company's reported cash flows for any period presented. In October 2016, the FASB issued ASU No. 2016-16, "Income Taxes (Topic 740) - Intra-Entity Transfers of Assets other than Inventory" ("ASU 2016-16"). ASU 2016-16 eliminates the current exception that prohibits the recognition of current and deferred income tax consequences for intra-entity asset transfers (other than inventory) until the asset has been sold to an outside party. The amendments will be applied on a modified retrospective basis through a cumulative effect adjustment to retained earnings. Deferred tax assets should be assessed to determine if realizable. Disclosures will be required for the (i) reason for and notice of change, (ii) effect of change on income from continuing operations and (iii) cumulative effect of change on retained earnings. Public entities will apply these changes in annual reporting periods beginning after December 15, 2017, and interim reporting periods within such period. Early adoption is permitted. The Company is currently evaluating the potential impact that the standard will have on its consolidated financial statements upon adoption. In March 2016, the FASB issued ASU No. 2016-09, "Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting" ("ASU 2016-09"). ASU 2016-09 is intended to simplify several areas of accounting for share-based compensation arrangements, including income tax impact, classification on the statement of cash flows and forfeitures. ASU 2016-09 is effective for fiscal years, and interim periods within those years, beginning after December 15, 2016, and early adoption is permitted. The impact that the standard will have on the Company's consolidated financial statements will depend upon certain criteria including the timing of the exercise and release of equity instruments, the value realized upon exercise or release of equity instruments and the fair value of the equity instruments when they were granted. The excess tax benefit from the exercise of equity instruments was $5,408 and $6,911 for the year ended December 31, 2016 and 2015 , respectively. In February 2016, the FASB issued ASU No. 2016-02, "Leases (Topic 842)" ("ASU 2016-02"). ASU 2016-02 requires a lessee to recognize assets and liabilities on the balance sheet for leases with lease terms greater than 12 months. ASU 2016-02 is effective for fiscal years, and interim periods within those years, beginning after December 15, 2018, and early adoption is permitted. The Company is currently evaluating the impact that the standard will have and does not expect it to have a material impact on its consolidated financial statements upon adoption. In January 2016, the FASB issued ASU No. 2016-01, "Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities" ("ASU 2016-01"). ASU 2016-01 addresses certain aspects of recognition, measurement, presentation, and disclosure of financial instruments. ASU 2016-01 is effective for fiscal years, and interim periods within those years, beginning after December 15, 2017, and early adoption is not permitted. The Company is currently evaluating the impact that the standard will have and does not expect it to have a material impact on its consolidated financial statements upon adoption. In November 2015, the FASB issued ASU No. 2015-17, "Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes" ("ASU 2015-17"). ASU 2015-17 removes the requirement to separate and classify deferred income tax liabilities and assets into current and noncurrent amounts and requires an entity to classify all deferred tax liabilities and assets as noncurrent. This ASU is effective for fiscal years beginning after December 15, 2016, with early adoption permitted. The Company adopted this standard during the fourth quarter ended December 31, 2016, and has retrospectively reclassified $17,156 of current net current deferred income tax assets to long-term net deferred taxes as of December 31, 2015. In May 2014, the FASB issued ASU No. 2014-09, "Revenue from Contracts with Customers" ("ASU 2014-09"). ASU 2014-09 supersedes the revenue recognition requirements in "Revenue Recognition (Topic 605)", and requires entities to recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled to in exchange for those goods or services. In August 2015, the FASB issued ASU No. 2015-14 "Revenue from Contracts with Customers" ("ASU 2015-14"), which defers the effective date of ASU 2014-09 one year to interim and annual reporting periods beginning after December 15, 2017, which would be the Company's fiscal year ending December 31, 2018. This additional guidance does not change the core principle of the revenue recognition guidance issued in May 2014, rather, it provides clarification of accounting for collections of sales taxes as well as recognition of revenue (i) associated with contract modifications, (ii) for noncash consideration, and (iii) based on the collectability of the consideration from the customer. The guidance also specifies when a contract should be considered "completed" for purposes of applying the transition guidance. The Company has completed an initial assessment of the new guidance and is currently evaluating the impact this standard may have on its financial statements and has not decided upon which one of two retrospective application methods it will be using upon adoption.
Subsequent Events	Subsequent Events — The Company has considered the impact of subsequent events through the filing date of these financial statements.

Nature Of Business And Summar25

Nature Of Business And Summary Of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Economic Useful Lives Of Property, Plant And Equipment	The following table presents the assigned economic useful lives of property, plant and equipment: Category Economic Useful Life Buildings 30 years Machinery and equipment 5-12 years Office furniture and fixtures 3-5 years
Allowance For Doubtful Accounts	Activity related to the allowance for doubtful accounts was as follows: 2016 2015 2014 Balance at January 1 $ 1,811 $ 1,890 $ 2,473 Provision for bad debts, net of recoveries 111 427 579 Uncollectable accounts written off (76 ) (114 ) (617 ) Foreign currency translation 170 (392 ) (545 ) Balance at December 31 $ 2,016 $ 1,811 $ 1,890
Summary Of Product Warranty Activity	Activity related to the warranty accrual was as follows: 2016 2015 2014 Balance at January 1 $ 28,210 $ 19,272 $ 14,997 Provision for warranty accrual 22,483 22,808 15,449 Warranty claims (16,220 ) (12,208 ) (9,165 ) Foreign currency translation and other (495 ) (1,662 ) (2,009 ) Balance at December 31 $ 33,978 $ 28,210 $ 19,272
Assets And Liabilities Measured At Fair Value	The following table presents information about the Company's assets and liabilities measured at fair value: Fair Value Measurements at December 31, 2016 Total Level 1 Level 2 Level 3 Assets Cash equivalents $ 179,699 $ 179,699 $ — $ — Short-term investments 206,616 206,616 — — Interest rate swap 77 — 77 — Auction rate securities 1,144 — — 1,144 Total assets $ 387,536 $ 386,315 $ 77 $ 1,144 Liabilities Long-term notes $ 41,351 $ — $ 41,351 $ — Total liabilities $ 41,351 $ — $ 41,351 $ — Fair Value Measurements at December 31, 2015 Total Level 1 Level 2 Level 3 Assets Cash equivalents $ 214,232 $ 214,232 $ — $ — Short-term investments 106,375 106,375 — — Auction rate securities 1,136 — — 1,136 Total assets $ 321,743 $ 320,607 $ — $ 1,136 Liabilities Long-term notes $ 19,667 $ 19,667 $ — $ — Contingent purchase consideration 20 — — 20 Total liabilities $ 19,687 $ 19,667 $ — $ 20
Assets Measured At Fair Value On A Recurring Basis Using Significant Unobservable Inputs	The following table presents information about the Company's movement in Level 3 assets and liabilities measured at fair value: 2016 2015 2014 Auction Rate Securities Balance, January 1 $ 1,136 $ 1,128 $ 1,120 Period transactions 8 8 8 Balance, December 31 $ 1,144 $ 1,136 $ 1,128 Contingent Purchase Consideration Balance, January 1 $ 20 $ 98 $ 375 Period transactions (21 ) (50 ) — Change in fair value and currency fluctuations 1 (28 ) (277 ) Balance, December 31 $ — $ 20 $ 98
Components Of Accumulated Other Comprehensive Loss	Total components of accumulated other comprehensive loss were as follows: December 31, 2016 2015 Foreign currency translation adjustments $ (178,577 ) $ (181,725 ) Change in carrying value of auction rate securities 232 232 Unrealized gain on derivatives, net of tax of $28 and $45 60 11 Unrealized loss on available-for-sale investments, net of tax of $134 and $0 (298 ) — Accumulated other comprehensive loss $ (178,583 ) $ (181,482 )
Fair Value Of Cash Flow Hedges	The fair value amounts in the consolidated balance sheets were: Notional Amounts 1 Other Assets Other Current Liabilities Deferred Income Taxes And Other Long-Term Liabilities December 31, December 31, December 31, December 31, 2016 2015 2016 2015 2016 2015 2016 2015 $ 23,156 $ — $ 77 $ — $ — $ — $ — $ — (1) Notional amounts represent the gross contract/notional amount of the derivative outstanding.
Derivative Gains (Losses) In The Consolidated Statements Of Income Related To Interest Rate Swap Contracts	The derivative gains and losses in the consolidated statements of income for the years ended December 31, 2016 , 2015 and 2014 , related to the Company's current and previous interest rate swap contracts were as follows: Year Ended December 31, 2016 2015 2014 Effective portion recognized in other comprehensive income (loss), pretax: Interest rate swap $ 85 $ 304 $ 567 Effective portion reclassified from other comprehensive income (loss) to interest expense, pretax: Interest rate swap $ (8 ) $ (153 ) $ (295 ) Ineffective portion recognized in income: Interest rate swap $ — $ — $ —

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	Stock-based compensation is included in the following financial statement captions: Year Ended December 31, 2016 2015 2014 Cost of sales $ 6,018 $ 5,316 $ 4,153 Sales and marketing 1,820 1,998 1,567 Research and development 4,905 4,049 3,033 General and administrative 8,991 7,626 6,419 Total stock-based compensation 21,734 18,989 15,172 Tax benefit recognized (6,971 ) (6,141 ) (4,865 ) Net stock-based compensation $ 14,763 $ 12,848 $ 10,307
Summary of Stock Option Valuation Assumptions	The assumptions used in the Black-Scholes model or the calculation of compensation were as follows for the years ended December 31. 2016 2015 2014 Expected term 4.4-6.1 years 4.4-6.3 years 4.7-6.1 years Volatility 37%-45% 45%-48% 48%-51% Risk-free rate of return 1.06%-1.41% 1.38%-1.74% 1.46%-1.84% Dividend yield 0.25% 0.25% 0.25% Forfeiture rate 2.65%-5.26% 3.47%-5.88% 3.04%-5.86%
Summary Of Option Activity	A summary of option activity is presented below (see Note 11 for further information): Number of Options Weighted- Average Exercise Price Weighted- Average Remaining Contractual Life Aggregate Intrinsic Value (In years) (In thousands) Outstanding — January 1, 2016 2,224,169 $ 53.82 Granted 260,930 82.84 Exercised (392,887 ) 35.81 Forfeited (27,959 ) 72.87 Outstanding — December 31, 2016 2,064,253 $ 60.65 6.04 $ 78,556 Vested or expected to vest — December 31, 2016 1,996,705 $ 59.89 5.96 $ 77,508 Exercisable — December 31, 2016 1,067,916 $ 45.95 4.54 $ 56,345
Summary of Restricted Stock Unit Activity	The following table summarizes the restricted stock units ("RSU's") activity for the year ended December 31, 2016 : Number of Shares Weighted-Average Grant-Date Fair Value Weighted- Average Remaining Contractual Life Aggregate Intrinsic Value (In years) (In thousands) Outstanding — January 1, 2016 277,719 $ 77.22 Granted 140,452 81.86 Converted (44,656 ) 70.64 Canceled (6,745 ) 81.89 Outstanding — December 31, 2016 366,770 $ 79.72 7.99 $ 36,204 Vested or expected to vest — December 31, 2016 336,240 $ 79.31 7.94 $ 33,190
Summary of Performance Units Fair Value Assessment	The weighted-average fair value of these performance units was determined using the Monte Carlo simulation model incorporating the following weighted-average assumptions: 2016 2015 Expected term 3.0 years 3.2 years Volatility 13%-32% 12%-36% Risk-free rate of return 0.88% 0.98% Dividend yield —% —% Weighted-average fair value per share 88.51 128.42
Summary of Performance Stock Unit Activity	The following table summarizes the performance stock units ("PSU's") activity for the year ended December 31, 2016 : Number of Shares Weighted-Average Grant-Date Fair Value Weighted- Average Remaining Contractual Life Aggregate Intrinsic Value (In years) (In thousands) Outstanding — January 1, 2016 27,233 $ 128.54 Granted 27,272 88.51 Converted — — Canceled — — Outstanding — December 31, 2016 54,505 $ 108.51 8.64 $ 5,380 Vested or expected to vest — December 31, 2016 50,313 $ 108.59 8.64 $ 4,966

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Dec. 31, 2016
Inventory Disclosure [Abstract]
Components Of Inventories	Inventories consist of the following: December 31, 2016 2015 Components and raw materials $ 93,284 $ 70,394 Work-in-process 44,723 43,259 Finished goods 101,003 90,085 Total $ 239,010 $ 203,738

Property, Plant And Equipment (

Property, Plant And Equipment (Tables)	12 Months Ended
	Dec. 31, 2016
Property, Plant and Equipment [Abstract]
Components Of Property, Plant And Equipment	Property, plant, and equipment consist of the following: December 31, 2016 2015 Land $ 21,811 $ 18,962 Buildings 214,830 166,784 Machinery and equipment 279,372 226,724 Office furniture and fixtures 31,210 26,981 Construction-in-progress 59,391 35,946 Total property, plant and equipment 606,614 475,397 Accumulated depreciation (227,239 ) (186,793 ) Total property, plant and equipment — net $ 379,375 $ 288,604

Accrued Expenses And Other Li29

Accrued Expenses And Other Liabilities (Tables)	12 Months Ended
	Dec. 31, 2016
Payables and Accruals [Abstract]
Components Of Accrued Expenses And Other Liabilities	Accrued expenses and other liabilities consist of the following: December 31, 2016 2015 Accrued compensation $ 43,761 $ 33,617 Customer deposits and deferred revenue 34,571 21,525 Current portion of accrued warranty 15,711 14,871 Other 8,442 5,654 Total $ 102,485 $ 75,667

Financing Arrangements (Tables)

Financing Arrangements (Tables)	12 Months Ended
	Dec. 31, 2016
Debt Disclosure [Abstract]
Borrowings Under Existing Financing Arrangements	The Company's borrowings under existing financing arrangements consist of the following: December 31, 2016 2015 Term debt: Long-term notes $ 40,823 $ 19,667 Less: current portion (3,188 ) (2,000 ) Total long-term debt $ 37,635 $ 17,667

Net Income Attributable To IP31

Net Income Attributable To IPG Photonics Corporation Per Share (Tables)	12 Months Ended
	Dec. 31, 2016
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: Year Ended December 31, 2016 2015 2014 Net income attributable to IPG Photonics Corporation $ 260,752 $ 242,154 $ 200,445 Net income attributable to common stockholders 260,752 242,154 200,445 Weighted average shares 53,068 52,676 52,104 Dilutive effect of common stock equivalents 729 751 720 Diluted weighted average common shares 53,797 53,427 52,824 Basic net income attributable to IPG Photonics Corporation per share $ 4.91 $ 4.60 $ 3.85 Basic net income attributable to common stockholders $ 4.91 $ 4.60 $ 3.85 Diluted net income attributable to IPG Photonics Corporation per share $ 4.85 $ 4.53 $ 3.79 Diluted net income attributable to common stockholders $ 4.85 $ 4.53 $ 3.79

Commitments And Contingencies (

Commitments And Contingencies (Tables)	12 Months Ended
	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments Under Noncancelable Lease Agreements	Commitments under the noncancelable lease agreements as of December 31, 2016 are as follows: Years Ending December 31 Facilities Equipment Total 2017 $ 3,245 $ 943 $ 4,188 2018 2,275 598 2,873 2019 1,613 321 1,934 2020 895 101 996 2021 545 11 556 Thereafter 681 — 681 Total $ 9,254 $ 1,974 $ 11,228

Goodwill And Intangibles (Table

Goodwill And Intangibles (Tables)	12 Months Ended
	Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Changes In The Carrying Amount Of Goodwill	The following table sets forth the changes in the carrying amount of goodwill for the years ended December 31, 2016 and 2015 : December 31, 2016 December 31, 2015 Balance at January 1 $ 505 $ 455 Foreign exchange adjustment (2 ) (14 ) Total goodwill arising from purchase 19,325 64 Balance at December 31 $ 19,828 $ 505
Intangible Assets	Intangible assets, subject to amortization, consisted of the following: December 31, 2016 December 31, 2015 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Weighted- Average Lives Gross Carrying Amount Accumulated Amortization Net Carrying Amount Weighted- Average Lives Patents $ 8,114 $ (4,926 ) $ 3,188 7 Years $ 6,641 $ (4,573 ) $ 2,068 6 Years Customer relationships 12,727 (3,621 ) 9,106 9 Years 3,325 (3,092 ) 233 5 Years Production know-how 6,618 (4,093 ) 2,525 8 Years 6,672 (3,339 ) 3,333 8 Years Technology, trademark and tradename 17,910 (3,940 ) 13,970 8 Years 8,247 (1,977 ) 6,270 8 Years $ 45,369 $ (16,580 ) $ 28,789 $ 24,885 $ (12,981 ) $ 11,904
Estimated Future Amortization Expense For Intangibles	The estimated future amortization expense for intangibles as of December 31, 2016 is as follows: 2017 2018 2019 2020 2021 Thereafter Total $4,706 $4,641 $3,964 $3,590 $3,504 $8,384 $28,789

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Income Before Impact Of Income Taxes	Income before the impact of income taxes for the years ended December 31 consisted of the following: 2016 2015 2014 U.S. $ 103,798 $ 94,242 $ 72,800 Foreign 262,767 247,375 211,674 Total $ 366,565 $ 341,617 $ 284,474
Provision For Income Taxes	The Company's provision for income taxes for the years ended December 31 consisted of the following: 2016 2015 2014 Current: Federal $ (41,407 ) $ (30,334 ) $ (22,549 ) State (4,750 ) (6,616 ) (2,823 ) Foreign (72,600 ) (69,793 ) (60,143 ) Total current $ (118,757 ) $ (106,743 ) $ (85,515 ) Deferred: Federal $ 8,709 $ 6,303 $ 454 State 383 312 27 Foreign 3,816 538 1,005 Total deferred $ 12,908 $ 7,153 $ 1,486 Provision for income taxes $ (105,849 ) $ (99,590 ) $ (84,029 )
Reconciliation Of Effective Tax Rate	A reconciliation of income tax expense at the U.S. federal statutory income tax rate to the recorded tax provision for the years ended December 31, is as follows: 2016 2015 2014 Tax at statutory rate $ (128,298 ) $ (119,566 ) $ (99,867 ) Non-U.S. rate differential — net 16,718 15,931 14,590 State income taxes — net (2,640 ) (2,094 ) (1,787 ) Effect of changes in enacted tax rates on deferred tax assets and liabilities (111 ) (153 ) (44 ) Nondeductible stock compensation expense (296 ) (338 ) (483 ) Other nondeductible expenses (2,307 ) (1,039 ) (2,063 ) Federal and state tax credits 9,840 8,837 5,865 Change in reserves, including interest and penalties 1,105 (1,522 ) (7 ) Change in valuation allowance 26 (620 ) — Other — net 114 974 (233 ) $ (105,849 ) $ (99,590 ) $ (84,029 )
Deferred Tax Assets and Liabilities	The tax effects of temporary differences that give rise to significant portions of the deferred tax assets and deferred tax liabilities at December 31, are as follows: 2016 2015 2014 Property, plant and equipment $ (14,122 ) $ (8,031 ) $ (5,310 ) Inventory provisions 19,710 14,566 10,497 Allowances and accrued liabilities 5,434 2,590 1,570 Other tax credits 5,027 3,763 726 Deferred compensation 9,215 5,891 4,218 Net operating loss carryforwards 7,885 923 — Valuation allowance (662 ) (678 ) — Net deferred tax assets $ 32,487 $ 19,024 $ 11,701
Reconciliation Of Unrecognized Tax Benefits	The following is a tabular reconciliation of the total amounts of unrecognized tax benefits: 2016 2015 2014 Balance at January 1 $ 7,579 $ 6,494 $ 6,501 Change in prior period positions (1,876 ) 33 (795 ) Additions for tax positions in current period 700 1,052 788 Balance at December 31 $ 6,403 $ 7,579 $ 6,494
Open Tax Years By Major Jurisdictions	Open tax years by major jurisdictions are: • United States 2013 — 2016 • Germany 2013 — 2016 • Russia 2015 — 2016

Geographic And Product Inform35

Geographic And Product Information (Tables)	12 Months Ended
	Dec. 31, 2016
Segment Reporting [Abstract]
Geographic Sources Of Net Sales Based On Billing Addresses Of Customers	The geographic sources of the Company's net sales based on billing addresses of its customers are as follows: Year Ended December 31, 2016 2015 2014 United States and other North America $ 141,184 $ 131,525 $ 113,233 Europe: Germany 90,893 93,802 77,404 Other including Eastern Europe/CIS 224,836 189,123 173,018 Asia and Australia: China 358,476 311,946 245,102 Japan 88,592 76,033 72,573 Other 100,052 95,494 85,426 Rest of World 2,140 3,342 3,076 Total $ 1,006,173 $ 901,265 $ 769,832
Net Sales For Product Lines	Net sales for these product lines are as follows: Year Ended December 31, 2016 2015 2014 Materials Processing $ 942,119 $ 849,335 $ 731,274 Other Applications 64,054 51,930 38,558 Total $ 1,006,173 $ 901,265 $ 769,832
Geographic Locations Of Long-Lived Assets, Based On Physical Location Of Assets	The geographic locations of the Company's long-lived assets, net, based on physical location of the assets, as of December 31, 2016 , 2015 and 2014 , are as follows: December 31, 2016 2015 2014 United States $ 230,116 $ 170,981 $ 155,428 Russia 76,966 55,150 59,612 Germany 61,792 53,678 51,528 China 8,096 6,237 6,582 Other 14,116 12,045 12,507 $ 391,086 $ 298,091 $ 285,657

Selected Quarterly Financial 36

Selected Quarterly Financial Data (Tables)	12 Months Ended
	Dec. 31, 2016
Selected Quarterly Financial Information [Abstract]
Components Of Selected Quarterly Financial Data	2016 First Quarter Second Quarter Third Quarter Fourth Quarter (In thousands, except per share data) Net sales $ 207,248 $ 252,787 $ 266,017 $ 280,121 Gross profit 114,410 137,703 144,791 155,336 Net income attributable to IPG Photonics Corporation 49,326 67,058 69,235 75,133 Basic earnings per share 0.93 1.26 1.30 1.42 Diluted earnings per share 0.92 1.25 1.29 1.39 2015 First Quarter Second Quarter Third Quarter Fourth Quarter (In thousands, except per share data) Net sales $ 198,960 $ 235,138 $ 243,541 $ 223,626 Gross profit 107,827 128,703 133,304 122,043 Net income attributable to IPG Photonics Corporation 57,359 61,299 62,792 60,704 Basic earnings per share 1.09 1.16 1.19 1.15 Diluted earnings per share 1.08 1.15 1.18 1.14

Nature Of Business And Summar37

Nature Of Business And Summary Of Significant Accounting Policies (Narrative) (Details)	12 Months Ended
	Dec. 31, 2016USD ($)segmentnote	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, interest cost capitalization	$ 0	$ 0	$ 383,000
Demonstration equipment, carrying value	391,086,000	298,091,000	285,657,000
Bank acceptance drafts	$ 23,975,000	$ 24,307,000
Maturity period for bank acceptance drafts (less than)	90 days	90 days
Accrued warranty reported in accrued expenses and other liabilities	$ 15,711,000	$ 14,871,000
Accrued warranty reported in other long-term liabilities	18,267,000	13,339,000
Available-for-sale securities, gross unrealized loss	432,000	0
Fair value	387,536,000	321,743,000
Held-to-maturity securities, unrealized loss	163,000	209,000
Available-for-sale securities, cost basis	$ 1,450,000	1,450,000
Number of outstanding long-term notes | note	2
Fair value, outstanding long-term notes	$ 41,351,000	19,687,000
Number of operating segments | segment	1
Excess tax benefit from exercise of equity instruments	$ 5,408,000	6,911,000
Accounting Standards Update 2015-17
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Deferred tax assets, net, current	17,156,000
Deferred tax liabilities, net, current	17,000
Not Designated as Hedging Instrument
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Outstanding derivative contracts	0
Long-term notes
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Book value, outstanding long-term notes	40,823,000	19,667,000
Short-term investments
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Fair value	206,616,000	106,375,000
Long-term notes
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Fair value, outstanding long-term notes	41,351,000	19,667,000
Book value, outstanding long-term notes	$ 40,823,000	19,667,000
Minimum
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Period for installation completion	30 days
Standard product warranty coverage period	1 year
Maximum
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Period for installation completion	90 days
Standard product warranty coverage period	3 years
Demonstration Equipment
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Demonstration equipment, economic useful life	3 years
Demonstration equipment, carrying value	$ 6,017,000	3,229,000
Demonstration equipment, amortization expense	$ 2,959,000	2,345,000	2,068,000
Intangible Assets | Minimum
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Economic useful lives of intangible assets	5 years
Intangible Assets | Maximum
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Economic useful lives of intangible assets	10 years
Property, Plant and Equipment
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, impairment loss	$ 2,857,000	0	$ 0
Available-for-sale Securities
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Fair value	41,591,000	$ 0
Held-to-maturity Securities | Short-term investments
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Fair value	$ 165,025,000

Nature Of Business And Summar38

Nature Of Business And Summary Of Significant Accounting Policies (Economic Useful Lives Of Property, Plant And Equipment) (Details)	12 Months Ended
	Dec. 31, 2016
Buildings
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Economic Useful Life	30 years
Minimum | Machinery and equipment
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Economic Useful Life	5 years
Minimum | Office furniture and fixtures
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Economic Useful Life	3 years
Maximum | Machinery and equipment
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Economic Useful Life	12 years
Maximum | Office furniture and fixtures
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Economic Useful Life	5 years

Nature Of Business And Summar39

Nature Of Business And Summary Of Significant Accounting Policies (Allowance For Doubtful Accounts) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance at January 1	$ 1,811	$ 1,890	$ 2,473
Provision for bad debts, net of recoveries	111	427	579
Uncollectable accounts written off	(76)	(114)	(617)
Foreign currency translation	170	(392)	(545)
Balance at December 31	$ 2,016	$ 1,811	$ 1,890

Nature Of Business And Summar40

Nature Of Business And Summary Of Significant Accounting Policies (Activity Related To The Warranty Accrual) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Movement in Standard Product Warranty Accrual [Roll Forward]
Balance at January 1	$ 28,210	$ 19,272	$ 14,997
Provision for warranty accrual	22,483	22,808	15,449
Warranty claims	(16,220)	(12,208)	(9,165)
Foreign currency translation and other	(495)	(1,662)	(2,009)
Balance at December 31	$ 33,978	$ 28,210	$ 19,272

Nature Of Business And Summar41

Nature Of Business And Summary Of Significant Accounting Policies (Assets And Liabilities Measured At Fair Value) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Assets
Total assets	$ 387,536	$ 321,743
Liabilities
Total liabilities	41,351	19,687
Level 1
Assets
Total assets	386,315	320,607
Liabilities
Total liabilities	0	19,667
Level 2
Assets
Total assets	77	0
Liabilities
Total liabilities	41,351	0
Level 3
Assets
Total assets	1,144	1,136
Liabilities
Total liabilities	0	20
Cash equivalents
Assets
Total assets	179,699	214,232
Cash equivalents | Level 1
Assets
Total assets	179,699	214,232
Cash equivalents | Level 2
Assets
Total assets	0	0
Cash equivalents | Level 3
Assets
Total assets	0	0
Short-term investments
Assets
Total assets	206,616	106,375
Short-term investments | Level 1
Assets
Total assets	206,616
Short-term investments | Level 2
Assets
Total assets	0	0
Short-term investments | Level 3
Assets
Total assets	0	0
Interest rate swap
Assets
Total assets	77
Interest rate swap | Level 1
Assets
Total assets	0
Interest rate swap | Level 2
Assets
Total assets	77
Interest rate swap | Level 3
Assets
Total assets	0
Auction rate securities
Assets
Total assets	1,144	1,136
Auction rate securities | Level 1
Assets
Total assets	0	0
Auction rate securities | Level 2
Assets
Total assets	0	0
Auction rate securities | Level 3
Assets
Total assets	1,144	1,136
Long-term notes
Liabilities
Total liabilities	41,351	19,667
Long-term notes | Level 1
Liabilities
Total liabilities	0	19,667
Long-term notes | Level 2
Liabilities
Total liabilities	41,351	0
Long-term notes | Level 3
Liabilities
Total liabilities	$ 0	0
Contingent purchase consideration
Liabilities
Total liabilities		20
Contingent purchase consideration | Level 1
Liabilities
Total liabilities		0
Contingent purchase consideration | Level 2
Liabilities
Total liabilities		0
Contingent purchase consideration | Level 3
Liabilities
Total liabilities		$ 20

Nature Of Business And Summar42

Nature Of Business And Summary Of Significant Accounting Policies (Assets Measured At Fair Value On A Recurring Basis Using Significant Unobservable Inputs) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Auction Rate Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, January 1	$ 1,136	$ 1,128	$ 1,120
Period transactions	(8)	(8)	(8)
Balance, December 31	1,144	1,136	1,128
Contingent Purchase Consideration
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, January 1	20	98	375
Period transactions	21	50	0
Change in fair value and accretion and currency fluctuations	1	(28)	(277)
Balance, December 31	$ 0	$ 20	$ 98

Nature Of Business And Summar43

Nature Of Business And Summary Of Significant Accounting Policies (Components Of Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Accumulated other comprehensive loss	$ 1,557,724	$ 1,260,665	$ 1,046,561
Unrealized gain on derivatives, tax	28	45
Unrealized loss on available-for-sale investments, tax	134	0
Foreign currency translation adjustments
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Accumulated other comprehensive loss	(178,577)	(181,725)
Accumulated Net Gain (Loss) from Cash Flow Hedges Including Portion Attributable to Noncontrolling Interest [Member]
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Accumulated other comprehensive loss	60	11
Accumulated Net Investment Gain (Loss) Including Portion Attributable to Noncontrolling Interest [Member]
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Accumulated other comprehensive loss	(298)	0
Accumulated Net Investment Gain (Loss) Including Portion Attributable to Noncontrolling Interest [Member] | Auction rate securities
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Accumulated other comprehensive loss	232	232
Accumulated other comprehensive loss
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Accumulated other comprehensive loss	$ (178,583)	$ (181,482)	$ (112,263)	$ (1,701)

Nature Of Business And Summar44

Nature Of Business And Summary Of Significant Accounting Policies (Fair Value Of Cash Flow Hedges) (Details) - Interest rate swap - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Notional amounts	$ 23,156	$ 0
Other Assets
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Derivative asset fair value	77	0
Other Current Liabilities
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Derivative liability fair value	0	0
Deferred Income Taxes And Other Long-Term Liabilities
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Derivative liability fair value	$ 0	$ 0

Nature Of Business And Summar45

Nature Of Business And Summary Of Significant Accounting Policies (Derivative Gains And Losses In The Consolidated Statements Of Income) (Details) - Interest rate swap - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Effective portion recognized in other comprehensive (loss) income, pretax	$ 85	$ 304	$ 567
Effective portion reclassified from other comprehensive (loss) income to interest expense, pretax	(8)	(153)	(295)
Ineffective portion recognized in income	$ 0	$ 0	$ 0

Stock-Based Compensation (Compo

Stock-Based Compensation (Components Of Stock Based Compensation) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation	$ 21,734	$ 18,989	$ 15,172
Tax benefit recognized	(6,971)	(6,141)	(4,865)
Net stock-based compensation	14,763	12,848	10,307
Cost of sales
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation	6,018	5,316	4,153
Sales and marketing
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation	1,820	1,998	1,567
Research and development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation	4,905	4,049	3,033
General and administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation	$ 8,991	$ 7,626	$ 6,419

Stock-Based Compensation (Narra

Stock-Based Compensation (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employment termination period	2 years
Intrinsic value of options exercised	$ 23,315	$ 27,207	$ 20,474
Weighted-average grant fair value for options granted (in dollars per share)	$ 33.08	$ 42.78	$ 32.53
Compensation cost related to nonvested awards not yet recorded	$ 13,756
Weighted-average recognition period for nonvested awards not yet recorded	2 years 3 months 18 days
Fair value of awards vested	$ 11,909
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost related to nonvested awards not yet recorded	$ 14,434
Weighted-average recognition period for nonvested awards not yet recorded	2 years 6 months
Fair value of awards vested	$ 3,186
Intrinsic value exercised	$ 3,931	$ 3,705	$ 3,017
Weighted-average grant fair value (in dollars per share)	$ 81.86	$ 95.25	$ 69.22
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost related to nonvested awards not yet recorded	$ 3,479
Weighted-average recognition period for nonvested awards not yet recorded	2 years 7 months 6 days
Weighted-average grant fair value (in dollars per share)	$ 88.51
Target goal, percentage	100.00%
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	1 year
Minimum | Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awarded units earned, percentage	0.00%
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years
Period until expiration	10 years
Maximum | Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awarded units earned, percentage	200.00%
2006 Incentive Compensation Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved under plan (in shares)	10,279,192
Shares available for future grant (in shares)	4,707,611
2006 Incentive Compensation Plan From Other Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved, previously authorized under prior plan (in shares)	84,273
2006 Incentive Compensation Plan From Directors Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved, previously authorized under prior plan (in shares)	194,919

Stock-Based Compensation (Weigh

Stock-Based Compensation (Weighted-Average Assumptions-Options) (Details)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Volatility, minimum	37.00%	45.00%	48.00%
Volatility, maximum	45.00%	48.00%	51.00%
Risk-free rate of return, minimum	1.06%	1.38%	1.46%
Risk-free rate of return, maximum	1.41%	1.74%	1.84%
Dividend yield	0.25%	0.25%	0.25%
Forfeiture rate, minimum	2.65%	3.47%	3.04%
Forfeiture rate, maximum	5.26%	5.88%	5.86%
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term	4 years 4 months 24 days	4 years 4 months 24 days	4 years 8 months 12 days
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term	6 years 1 month 6 days	6 years 3 months 18 days	6 years 1 month 6 days

Stock-Based Compensation (Summa

Stock-Based Compensation (Summary Of Option Activity) (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding, beginning balance (in shares) | shares	2,224,169
Granted (in shares) | shares	260,930
Exercised (in shares) | shares	(392,887)
Forfeited (in shares) | shares	(27,959)
Outstanding, ending balance (in shares) | shares	2,064,253
Vested or expected to vest-December 31, 2016 (in shares) | shares	1,996,705
Exercisable-December 31, 2016 (in shares) | shares	1,067,916
Weighted-Average Exercise Price, Outstanding, Beginning Balance (in dollars per share) | $ / shares	$ 53.82
Weighted-Average Exercise Price, Granted (in dollars per share) | $ / shares	82.84
Weighted-Average Exercise Price, Exercised (in dollars per share) | $ / shares	35.81
Weighted-Average Exercise Price, Forfeited (in dollars per share) | $ / shares	72.87
Weighted-Average Exercise Price, Outstanding, Ending Balance (in dollars per share) | $ / shares	60.65
Weighted-Average Exercise Price, Vested or expected to vest (in dollars per share) | $ / shares	59.89
Weighted-Average Exercise Price, Exercisable (in dollars per share) | $ / shares	$ 45.95
Weighted-Average Remaining Contractual Life, Outstanding	6 years 15 days
Weighted-Average Remaining Contractual Life, Vested or expected to vest	5 years 11 months 16 days
Weighted-Average Remaining Contractual Life, Exercisable	4 years 6 months 15 days
Aggregate Intrinsic Value, Outstanding | $	$ 78,556
Aggregate Intrinsic Value, Vested or expected to vest | $	77,508
Aggregate Intrinsic Value, Exercisable | $	$ 56,345

Stock-Based Compensation (Sum50

Stock-Based Compensation (Summary of Restricted Stock Unit Activity) (Details) - Restricted Stock Units (RSUs) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Outstanding, beginning balance (in shares)	277,719
Granted (in shares)	140,452
Converted (in shares)	(44,656)
Canceled (in shares)	(6,745)
Outstanding, ending balance (in shares)	366,770	277,719
Vested or expected to vest-December 31, 2016 (in shares)	336,240
Weighted-Average Grant-Date Fair Value, Outstanding, beginning balance (in dollars per share)	$ 77.22
Weighted-Average Grant-Date Fair Value, Granted (in dollars per share)	81.86	$ 95.25	$ 69.22
Weighted-Average Grant-Date Fair Value, Converted (in dollars per share)	70.64
Weighted-Average Grant-Date Fair Value, Canceled (in dollars per share)	81.89
Weighted-Average Grant-Date Fair Value, Outstanding, ending balance (in dollars per share)	79.72	$ 77.22
Weighted-Average Grant-Date Fair Value, Vested or expected to vest (in dollars per share)	$ 79.31
Weighted-Average Remaining Contractual Life, Outstanding	7 years 11 months 27 days
Weighted-Average Remaining Contractual Life, Vested or expected to vest	7 years 11 months 9 days
Aggregate Intrinsic Value, Outstanding	$ 36,204
Aggregate Intrinsic Value, Vested or expected to vest	$ 33,190

Stock-Based Compensation (Wei51

Stock-Based Compensation (Weighted-Average Assumptions-PSUs) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Volatility, minimum	37.00%	45.00%	48.00%
Volatility, maximum	45.00%	48.00%	51.00%
Dividend yield	0.25%	0.25%	0.25%
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term	3 years	3 years 2 months 12 days
Volatility, minimum	13.00%	12.00%
Volatility, maximum	32.00%	36.00%
Risk-free rate of return	0.88%	0.98%
Dividend yield	0.00%	0.00%
Weighted-average fair value per share (in dollars per share)	$ 88.51	$ 128.42

Stock-Based Compensation (Sum52

Stock-Based Compensation (Summary of Performance Stock Unit Activity) (Details) - Performance Shares $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Outstanding, beginning balance (in shares) | shares	27,233
Granted (in shares) | shares	27,272
Outstanding, ending balance (in shares) | shares	54,505
Vested or expected to vest-December 31, 2016 (in shares) | shares	50,313
Weighted-Average Grant-Date Fair Value, Outstanding, beginning balance (in dollars per share) | $ / shares	$ 128.54
Weighted-Average Grant-Date Fair Value, Granted (in dollars per share) | $ / shares	88.51
Weighted-Average Grant-Date Fair Value, Outstanding, ending balance (in dollars per share) | $ / shares	108.51
Weighted-Average Grant-Date Fair Value, Vested or expected to vest (in dollars per share) | $ / shares	$ 108.59
Weighted-Average Remaining Contractual Life, Outstanding	8 years 7 months 21 days
Weighted-Average Remaining Contractual Life, Vested or expected to vest	8 years 7 months 21 days
Aggregate Intrinsic Value, Outstanding | $	$ 5,380
Aggregate Intrinsic Value, Vested or expected to vest | $	$ 4,966

Inventories (Components Of Inve

Inventories (Components Of Inventories) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Inventory Disclosure [Abstract]
Components and raw materials	$ 93,284	$ 70,394
Work-in-process	44,723	43,259
Finished goods	101,003	90,085
Total	239,010	203,738
Inventory provisions	$ 22,796	$ 15,364	$ 11,302

Property, Plant And Equipment54

Property, Plant And Equipment (Components Of Property, Plant, And Equipment) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 606,614	$ 475,397
Accumulated depreciation	(227,239)	(186,793)
Total property, plant and equipment — net	379,375	288,604
Depreciation expense	44,757	37,796	$ 31,334
Land
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	21,811	18,962
Buildings
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	214,830	166,784
Machinery and equipment
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	279,372	226,724
Office furniture and fixtures
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	31,210	26,981
Construction-in-progress
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 59,391	$ 35,946

Accrued Expenses And Other Li55

Accrued Expenses And Other Liabilities (Components Of Accrued Expenses And Other Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Payables and Accruals [Abstract]
Accrued compensation	$ 43,761	$ 33,617
Customer deposits and deferred revenue	34,571	21,525
Current portion of accrued warranty	15,711	14,871
Other	8,442	5,654
Total	$ 102,485	$ 75,667

Financing Arrangements (Borrowi

Financing Arrangements (Borrowings Under Existing Financing Arrangements) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Term debt:
Less: current portion	$ (3,188)	$ (2,000)
Total long-term debt	37,635	17,667
Long-term notes
Term debt:
Long-term notes	40,823	19,667
Less: current portion	$ (3,188)	$ (2,000)

Financing Arrangements (Narrati

Financing Arrangements (Narrative) (Details)	3 Months Ended	12 Months Ended
	Jun. 30, 2016USD ($)	Dec. 31, 2016USD ($)notecredit_line	May 31, 2023USD ($)	Oct. 31, 2019USD ($)	Dec. 31, 2016EUR (€)notecredit_line	Dec. 31, 2015USD ($)
Line of Credit Facility [Line Items]
Number of outstanding long-term notes | note		2			2
Long-term notes, current portion		$ 3,188,000				$ 2,000,000
Unsecured debt, purchase of building in Massachusetts	$ 23,750,000
Long-term notes
Line of Credit Facility [Line Items]
Long-term debt		40,823,000				19,667,000
Long-term notes, current portion		3,188,000				$ 2,000,000
Unsecured Debt
Line of Credit Facility [Line Items]
Notes payable		23,156,000
Notes payable, current		1,188,000
Unsecured Debt | Scenario, Forecast
Line of Credit Facility [Line Items]
Notes payable			$ 15,438,000
Unsecured Debt | Interest rate swap
Line of Credit Facility [Line Items]
Fixed interest rate swap percentage	2.85%
Secured Debt
Line of Credit Facility [Line Items]
Notes payable		17,667,000
Notes payable, current		$ 2,000,000
Interest rate percentage		2.81%			2.81%
Secured Debt | Scenario, Forecast
Line of Credit Facility [Line Items]
Notes payable				$ 12,000,000
London Interbank Offered Rate (LIBOR) | Unsecured Debt
Line of Credit Facility [Line Items]
Percentage over LIBOR	1.20%
U.S. Line Of Credit
Line of Credit Facility [Line Items]
Aggregate available principal under credit facility		$ 50,000,000
Total drawings under credit facility		0
Guarantor obligations, maximum exposure, undiscounted		161,000
Aggregate remaining availability		$ 49,839,000
U.S. Line Of Credit | London Interbank Offered Rate (LIBOR) | Minimum
Line of Credit Facility [Line Items]
Percentage over LIBOR		0.80%
U.S. Line Of Credit | London Interbank Offered Rate (LIBOR) | Maximum
Line of Credit Facility [Line Items]
Percentage over LIBOR		1.20%
U.S. Long-Term note
Line of Credit Facility [Line Items]
Debt service coverage ratio		1.5
U.S. Long-Term note | Minimum
Line of Credit Facility [Line Items]
Debt Instrument, covenant compliance		$ 50,000,000
U.S. Long-Term note | Maximum
Line of Credit Facility [Line Items]
Debt Instrument, covenant compliance		250,000,000
Euro Line Of Credit
Line of Credit Facility [Line Items]
Aggregate available principal under credit facility		31,547,000			€ 30,000,000
Total drawings under credit facility		0
Guarantor obligations, maximum exposure, undiscounted		11,999,000
Aggregate remaining availability		19,547,000
Euro Overdraft Facilities
Line of Credit Facility [Line Items]
Aggregate available principal under credit facility		526,000			500,000
Total drawings under credit facility		0
Aggregate remaining availability		526,000
Other European Facilities
Line of Credit Facility [Line Items]
Aggregate available principal under credit facility		1,577,000			€ 1,500,000
Total drawings under credit facility		0
Aggregate remaining availability		$ 1,577,000
Number of credit lines | credit_line		2			2

Noncontrolling Interest and E58

Noncontrolling Interest and Equity (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Noncontrolling Interest [Line Items]
Net loss attributable to NCI	$ 36	$ 127	$ 0
Common stock, shares authorized (in shares)	175,000,000	175,000,000
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized (in shares)	5,000,000
Preferred stock, par value (in dollars per share)	$ 0.0001
Shares of preferred stock outstanding (in shares)	0
RuchTech
Noncontrolling Interest [Line Items]
Percentage of noncontrolling interest	98.00%	76.00%

Related-Party Transactions (Nar

Related-Party Transactions (Narrative) (Details) - USD ($)	1 Months Ended	12 Months Ended
	Oct. 31, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Related Party Transaction [Line Items]
Proceeds on long-term borrowings		$ 23,750,000	$ 0	$ 0
Members of senior management
Related Party Transaction [Line Items]
Proceeds on long-term borrowings		23,750,000
Director
Related Party Transaction [Line Items]
Related party revenue		146,000	0
Purchased Parts and Services from Company which Independent Director is Executive Officer | Director
Related Party Transaction [Line Items]
Payments to suppliers		5,392,000	683,000
Accounts payable due to company		0	0
Leased Office Space | Chief Executive Officer | Office space
Related Party Transaction [Line Items]
Related party amount of transaction		443,000	531,000
Leased Aircraft | Chief Executive Officer | Aircraft
Related Party Transaction [Line Items]
Related party amount of transaction		651,000	651,000
Percentage of aircraft leased annually	25.00%
Annual lease payments		651,000
Products and Services sold to Affiliated Entity | Chief Executive Officer
Related Party Transaction [Line Items]
Related party revenue		$ 0	$ 497,000
Ownership percentage in Laser Center		39.00%

Net Income Attributable To IP60

Net Income Attributable To IPG Photonics Corporation Per Share (Computation Diluted Net Income Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Earnings Per Share [Abstract]
Net income attributable to IPG Photonics Corporation	$ 75,133	$ 69,235	$ 67,058	$ 49,326	$ 60,704	$ 62,792	$ 61,299	$ 57,359	$ 260,752	$ 242,154	$ 200,445
Net income attributable to common stockholders									$ 260,752	$ 242,154	$ 200,445
Weighted average shares (in shares)									53,068	52,676	52,104
Dilutive effect of common stock equivalents (in shares)									729	751	720
Diluted weighted average common shares (in shares)									53,797	53,427	52,824
Basic net income attributable to IPG Photonics Corporation per share (in dollars per share)									$ 4.91	$ 4.60	$ 3.85
Basic net income attributable to common stockholders (in dollars per share)	$ 1.42	$ 1.30	$ 1.26	$ 0.93	$ 1.15	$ 1.19	$ 1.16	$ 1.09	4.91	4.60	3.85
Diluted net income attributable to IPG Photonics Corporation per share (in dollars per share)									4.85	4.53	3.79
Diluted net income attributable to common stockholders (in dollars per share)	$ 1.39	$ 1.29	$ 1.25	$ 0.92	$ 1.14	$ 1.18	$ 1.15	$ 1.08	$ 4.85	$ 4.53	$ 3.79

Net Income Attributable To IP61

Net Income Attributable To IPG Photonics Corporation Per Share (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Jul. 31, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Options excluded from computation of diluted weighted average common shares (in shares)	60,797,000	29,127,000	46,897,000
Aggregate share repurchases, amount (no more than)				$ 100,000
Stock repurchased during the period (in shares)	102,774
Stock repurchased during the period, average price per share (in dollars per share)	$ 87.01
Impact on the reduction of weighted average shares (in shares)	20,935
Restricted Stock Units (RSUs)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Options excluded from computation of diluted weighted average common shares (in shares)	12,711,000	18,171,000	13,300,000
Performance Shares (PSUs)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Options excluded from computation of diluted weighted average common shares (in shares)	809,000	3,369,000	0

Commitments And Contingencies62

Commitments And Contingencies (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Feb. 24, 2017
Other Commitments [Line Items]
Operating lease, rent expense	$ 7,091,000	$ 7,365,000	$ 5,516,000
Purchase obligations	$ 33,072,000	$ 17,961,000
Subsequent Event
Other Commitments [Line Items]
Loss contingency, loss in period				$ 0
Members of senior management
Other Commitments [Line Items]
Period for terms of employment agreement (up to)	3 years

Commitments and Contingencies63

Commitments and Contingencies (Commitments Under Noncancelable Lease Agreements) (Details) $ in Thousands	Dec. 31, 2016USD ($)
Operating Leased Assets [Line Items]
2,017	$ 4,188
2,018	2,873
2,019	1,934
2,020	996
2,021	556
Thereafter	681
Total	11,228
Facilities
Operating Leased Assets [Line Items]
2,017	3,245
2,018	2,275
2,019	1,613
2,020	895
2,021	545
Thereafter	681
Total	9,254
Equipment
Operating Leased Assets [Line Items]
2,017	943
2,018	598
2,019	321
2,020	101
2,021	11
Thereafter	0
Total	$ 1,974

Employee Benefit Plans (Narrati

Employee Benefit Plans (Narrative) (Details) - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
401 (K) Retirement Savings Plan
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Percentage of matching contribution by employee	50.00%
Compensation Expense	$ 2,509	$ 2,021	$ 1,445
401 (K) Retirement Savings Plan | Maximum
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Percentage of eligible compensation for employee contribution	6.00%
Employee Stock Purchase Plan
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Percentage of discount on stock purchase price	15.00%
Purchase period	6 months
Maximum percentage of payroll deduction of employees compensation	10.00%
Compensation expense related to employee stock purchase plan	$ 846	$ 680	$ 607
Shares available for issuance (in shares)	359,642

Business Combinations (Narrativ

Business Combinations (Narrative) (Details) - USD ($)	Mar. 15, 2015	Dec. 31, 2016	Jun. 30, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Acquired Finite-Lived Intangible Assets [Line Items]
Total goodwill arising from purchase				$ 19,325,000	$ 64,000
Additional amount paid to purchase noncontrolling interests				950,000	0	$ 0
Goodwill balance		$ 19,828,000		$ 19,828,000	$ 505,000	$ 455,000
Patents
Acquired Finite-Lived Intangible Assets [Line Items]
Economic useful lives of intangible assets				7 years	6 years
Technology, trademark and tradename
Acquired Finite-Lived Intangible Assets [Line Items]
Economic useful lives of intangible assets				8 years	8 years
Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Economic useful lives of intangible assets				9 years	5 years
BioPhotonic Solutions, Inc.
Acquired Finite-Lived Intangible Assets [Line Items]
Consideration transferred		1,559,000
BioPhotonic Solutions, Inc. | Patents
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets		1,473,000		$ 1,473,000
Menara Networks
Acquired Finite-Lived Intangible Assets [Line Items]
Consideration transferred			$ 46,831,000
Total goodwill arising from purchase			19,325,000	19,325,000
Goodwill, expected tax deductible amount		$ 0	0	$ 0
Menara Networks | Technology, trademark and tradename
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets			$ 9,900,000
Economic useful lives of intangible assets			7 years
Menara Networks | Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets			$ 9,500,000
Economic useful lives of intangible assets			10 years
RuchTech
Acquired Finite-Lived Intangible Assets [Line Items]
Consideration transferred					$ 5,000,000
Total goodwill arising from purchase					64,000
Goodwill, expected tax deductible amount					0
Additional amount paid to purchase noncontrolling interests					$ 950,000
Business combination, percentage of voting interests acquired	76.00%				98.00%
Business combination, fair value	$ 6,579,000
Estimated useful life	7 years
Goodwill balance					$ 64,000
RuchTech | Technology-Based Intangible Assets
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets	$ 6,298,000

Goodwill And Intangibles (Chang

Goodwill And Intangibles (Changes In The Carrying Amount Of Goodwill) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Goodwill [Roll Forward]
Balance at January 1	$ 505	$ 455
Foreign exchange adjustment	(2)	(14)
Total goodwill arising from purchase	19,325	64
Balance at December 31	$ 19,828	$ 505

Goodwill And Intangibles (Narra

Goodwill And Intangibles (Narrative) (Details) - USD ($)	3 Months Ended		12 Months Ended
	Jun. 30, 2016	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Total goodwill arising from purchase			$ 19,325,000	$ 64,000
Goodwill			19,828,000	505,000	$ 455,000
Amortization expense of intangibles			$ 3,759,000	2,274,000	2,210,000
Domestic Tax Authority
Business Acquisition [Line Items]
Goodwill, deductibility time period			15 years
BioPhotonic Solutions, Inc. | Patents
Business Acquisition [Line Items]
Intangible assets			$ 1,473,000
Menara Networks
Business Acquisition [Line Items]
Total goodwill arising from purchase	$ 19,325,000		19,325,000
Goodwill, expected tax deductible amount	0		$ 0
Menara Networks | Technology, trademark and tradename
Business Acquisition [Line Items]
Intangible assets	9,900,000
Menara Networks | Customer relationships
Business Acquisition [Line Items]
Intangible assets	$ 9,500,000
RuchTech
Business Acquisition [Line Items]
Total goodwill arising from purchase				64,000
Goodwill, expected tax deductible amount				0
Goodwill				$ 64,000
Acquired finite-lived intangible asset		$ 6,298,000
Mobius
Business Acquisition [Line Items]
Goodwill					$ 455,000

Goodwill And Intangibles (Intan

Goodwill And Intangibles (Intangible Assets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 45,369	$ 24,885
Accumulated Amortization	(16,580)	(12,981)
Net Carrying Amount	28,789	11,904
Patents
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	8,114	6,641
Accumulated Amortization	(4,926)	(4,573)
Net Carrying Amount	$ 3,188	$ 2,068
Weighted- Average Lives	7 years	6 years
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 12,727	$ 3,325
Accumulated Amortization	(3,621)	(3,092)
Net Carrying Amount	$ 9,106	$ 233
Weighted- Average Lives	9 years	5 years
Production know-how
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 6,618	$ 6,672
Accumulated Amortization	(4,093)	(3,339)
Net Carrying Amount	$ 2,525	$ 3,333
Weighted- Average Lives	8 years	8 years
Technology, trademark and tradename
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 17,910	$ 8,247
Accumulated Amortization	(3,940)	(1,977)
Net Carrying Amount	$ 13,970	$ 6,270
Weighted- Average Lives	8 years	8 years

Goodwill And Intangibles (Estim

Goodwill And Intangibles (Estimated Future Amortization Expense For Intangibles) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
2,017	$ 4,706
2,018	4,641
2,019	3,964
2,020	3,590
2,021	3,504
Thereafter	8,384
Net Carrying Amount	$ 28,789	$ 11,904

Income Taxes (Income Before Imp

Income Taxes (Income Before Impact Of Income Taxes) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
U.S.	$ 103,798	$ 94,242	$ 72,800
Foreign	262,767	247,375	211,674
INCOME BEFORE PROVISION FOR INCOME TAXES	$ 366,565	$ 341,617	$ 284,474

Income Taxes (Provision For Inc

Income Taxes (Provision For Income Taxes) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current:
Federal	$ (41,407)	$ (30,334)	$ (22,549)
State	(4,750)	(6,616)	(2,823)
Foreign	(72,600)	(69,793)	(60,143)
Total current	(118,757)	(106,743)	(85,515)
Deferred:
Federal	8,709	6,303	454
State	383	312	27
Foreign	3,816	538	1,005
Total deferred	12,908	7,153	1,486
Provision for income taxes	$ (105,849)	$ (99,590)	$ (84,029)

Income Taxes (Reconciliation Of

Income Taxes (Reconciliation Of Effective Tax Rate) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Tax at statutory rate	$ (128,298)	$ (119,566)	$ (99,867)
Non-U.S. rate differential — net	16,718	15,931	14,590
State income taxes — net	(2,640)	(2,094)	(1,787)
Effect of changes in enacted tax rates on deferred tax assets and liabilities	(111)	(153)	(44)
Nondeductible stock compensation expense	(296)	(338)	(483)
Other nondeductible expenses	(2,307)	(1,039)	(2,063)
Federal and state tax credits	9,840	8,837	5,865
Change in reserves, including interest and penalties	1,105	(1,522)	(7)
Change in valuation allowance	26	(620)	0
Other — net	114	974	(233)
Provision for income taxes	$ (105,849)	$ (99,590)	$ (84,029)

Income Taxes (Deferred Tax Asse

Income Taxes (Deferred Tax Assets And Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Property, plant and equipment	$ (14,122)	$ (8,031)	$ (5,310)
Inventory provisions	19,710	14,566	10,497
Allowances and accrued liabilities	5,434	2,590	1,570
Other tax credits	5,027	3,763	726
Deferred compensation	9,215	5,891	4,218
Net operating loss carryforwards	7,885	923	0
Valuation allowance	(662)	(678)	0
Net deferred tax assets	$ 32,487	$ 19,024	$ 11,701

Income Taxes (Reconciliation 74

Income Taxes (Reconciliation Of Unrecognized Tax Benefits) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at January 1	$ 7,579	$ 6,494	$ 6,501
Change in prior period positions	(1,876)	33	(795)
Additions for tax positions in current period	700	1,052	788
Balance at December 31	$ 6,403	$ 7,579	$ 6,494

Income Taxes (Open Tax Years By

Income Taxes (Open Tax Years By Major Jurisdictions) (Details)	12 Months Ended
	Dec. 31, 2016
Minimum | United States
Income Tax Contingency [Line Items]
Open tax years by major jurisdictions	2,013
Minimum | Germany
Income Tax Contingency [Line Items]
Open tax years by major jurisdictions	2,013
Minimum | Russia
Income Tax Contingency [Line Items]
Open tax years by major jurisdictions	2,015
Maximum | United States
Income Tax Contingency [Line Items]
Open tax years by major jurisdictions	2,016
Maximum | Germany
Income Tax Contingency [Line Items]
Open tax years by major jurisdictions	2,016
Maximum | Russia
Income Tax Contingency [Line Items]
Open tax years by major jurisdictions	2,016

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Jun. 30, 2016
Tax Credit Carryforward [Line Items]
Deferred tax liabilities, withholding and dividend tax, foreign	$ 1,636,000
Cumulative unremitted earnings that are reinvested	936,000,000	$ 734,000,000
Estimated penalties and interest related to the underpayment of income taxes	(163,000)	437,000	$ (192,000)
Accrued penalties and interest related to the underpayment of income taxes	944,000	1,107,000
Menara Networks
Tax Credit Carryforward [Line Items]
Net operating loss carryforwards	19,826,000			$ 22,242,000
Valuation allowance, operating loss carryforward	0
UK | Foreign Tax Authority
Tax Credit Carryforward [Line Items]
Net operating loss carryforwards	2,777,000
State
Tax Credit Carryforward [Line Items]
Tax credit carry forward amount	$ 5,027,000	$ 3,740,000	$ 1,225,000

Geographic And Product Inform77

Geographic And Product Information (Geographic Sources Of Net Sales Based On Billing Addresses Of Customers) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Geographic And Product Information [Line Items]
Net sales	$ 280,121	$ 266,017	$ 252,787	$ 207,248	$ 223,626	$ 243,541	$ 235,138	$ 198,960	$ 1,006,173	$ 901,265	$ 769,832
United States and other North America
Geographic And Product Information [Line Items]
Net sales									141,184	131,525	113,233
Germany
Geographic And Product Information [Line Items]
Net sales									90,893	93,802	77,404
Other including Eastern Europe/CIS
Geographic And Product Information [Line Items]
Net sales									224,836	189,123	173,018
China
Geographic And Product Information [Line Items]
Net sales									358,476	311,946	245,102
Japan
Geographic And Product Information [Line Items]
Net sales									88,592	76,033	72,573
Other
Geographic And Product Information [Line Items]
Net sales									100,052	95,494	85,426
Rest of World
Geographic And Product Information [Line Items]
Net sales									$ 2,140	$ 3,342	$ 3,076

Geographic And Product Inform78

Geographic And Product Information (Net Sales For Product Lines) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Product Information [Line Items]
Net sales	$ 280,121	$ 266,017	$ 252,787	$ 207,248	$ 223,626	$ 243,541	$ 235,138	$ 198,960	$ 1,006,173	$ 901,265	$ 769,832
Materials Processing
Product Information [Line Items]
Net sales									942,119	849,335	731,274
Other Applications
Product Information [Line Items]
Net sales									$ 64,054	$ 51,930	$ 38,558

Geographic And Product Inform79

Geographic And Product Information (Geographic Locations Of Our Long-Lived Assets, Based On Physical Location Of Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Geographic And Product Information [Line Items]
Long-lived assets	$ 391,086	$ 298,091	$ 285,657
United States
Geographic And Product Information [Line Items]
Long-lived assets	230,116	170,981	155,428
Russia
Geographic And Product Information [Line Items]
Long-lived assets	76,966	55,150	59,612
Germany
Geographic And Product Information [Line Items]
Long-lived assets	61,792	53,678	51,528
China
Geographic And Product Information [Line Items]
Long-lived assets	8,096	6,237	6,582
Other
Geographic And Product Information [Line Items]
Long-lived assets	$ 14,116	$ 12,045	$ 12,507

Geographic And Product Inform80

Geographic And Product Information (Narrative) (Details) - Cusotmer	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Concentration Risk [Line Items]
Number of customers	1	1	1
Number of largest customers, sales	5	5	5
Net sales by largest customers, percentage	22.00%	25.00%	23.00%
Sales
Concentration Risk [Line Items]
Concentration risk percentage		13.00%	11.00%

Selected Quarterly Financial 81

Selected Quarterly Financial Data (Components Of Selected Quarterly Financial Data) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Selected Quarterly Financial Information [Abstract]
Net sales	$ 280,121	$ 266,017	$ 252,787	$ 207,248	$ 223,626	$ 243,541	$ 235,138	$ 198,960	$ 1,006,173	$ 901,265	$ 769,832
Gross profit	155,336	144,791	137,703	114,410	122,043	133,304	128,703	107,827	552,240	491,877	416,518
Net income attributable to IPG Photonics Corporation	$ 75,133	$ 69,235	$ 67,058	$ 49,326	$ 60,704	$ 62,792	$ 61,299	$ 57,359	$ 260,752	$ 242,154	$ 200,445
Basic earnings per share (in dollars per share)	$ 1.42	$ 1.30	$ 1.26	$ 0.93	$ 1.15	$ 1.19	$ 1.16	$ 1.09	$ 4.91	$ 4.60	$ 3.85
Diluted earnings per share (in dollars per share)	$ 1.39	$ 1.29	$ 1.25	$ 0.92	$ 1.14	$ 1.18	$ 1.15	$ 1.08	$ 4.85	$ 4.53	$ 3.79