IPG Photonics (IPGP) 10-K 2 Mar 15 2014 FY Annual report Financial data

Document_And_Entity_Informatio

Document And Entity Information (USD $)	12 Months Ended
In Billions, except Share data, unless otherwise specified	Dec. 31, 2014	Feb. 24, 2015	Jun. 30, 2014
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	FALSE
Document Period End Date	31-Dec-14
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2014
Entity Registrant Name	IPG PHOTONICS CORP
Entity Central Index Key	1111928
Current Fiscal Year End Date	-19
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		52,482,512
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Well-known Seasoned Issuer	Yes
Entity Public Float			$1.90

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
CURRENT ASSETS:
Cash and cash equivalents	$522,150	$448,776
Accounts receivable, net	143,109	103,803
Inventories	171,009	172,700
Prepaid income taxes	20,967	15,996
Prepaid expenses and other current assets	21,295	30,836
Deferred income taxes, net	15,308	14,232
Total current assets	893,838	786,343
DEFERRED INCOME TAXES, NET	5,438	4,799
GOODWILL	455	455
INTANGIBLE ASSETS, NET	9,227	9,564
PROPERTY, PLANT AND EQUIPMENT, NET	275,082	252,245
OTHER ASSETS	26,847	7,810
TOTAL	1,210,887	1,061,216
CURRENT LIABILITIES:
Revolving line-of-credit facilities	2,631	3,296
Current portion of long-term debt	13,333	1,333
Accounts payable	17,141	18,787
Accrued expenses and other liabilities	64,057	59,336
Deferred income taxes, net	3,241	2,109
Income taxes payable	21,672	15,218
Total current liabilities	122,075	100,079
DEFERRED INCOME TAXES AND OTHER LONG-TERM LIABILITIES	22,584	21,835
LONG-TERM DEBT, NET OF CURRENT PORTION	19,667	11,333
Total liabilities	164,326	133,247
COMMITMENTS AND CONTINGENCIES (NOTE 10)
IPG PHOTONICS CORPORATION STOCKHOLDERS' EQUITY:
Common stock, $0.0001 par value, 175,000,000 shares authorized; 52,369,688 shares issued and outstanding at December 31, 2014; 51,930,978 shares issued and outstanding at December 31, 2013	5	5
Additional paid-in capital	567,617	538,908
Retained earnings	591,202	390,757
Accumulated other comprehensive loss	-112,263	-1,701
Total IPG Photonics Corporation stockholders' equity	1,046,561	927,969
TOTAL	$1,210,887	$1,061,216

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Statement of Financial Position [Abstract]
Common stock, par value	$0.00	$0.00
Common stock, shares authorized	175,000,000	175,000,000
Common stock, shares issued	52,369,688	51,930,978
Common stock, shares outstanding	52,369,688	51,930,978

Consolidated_Statements_Of_Inc

Consolidated Statements Of Income (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Statement [Abstract]
NET SALES	$769,832	$648,034	$562,528
COST OF SALES	353,314	308,136	257,801
GROSS PROFIT	416,518	339,898	304,727
OPERATING EXPENSES:
Sales and marketing	30,637	26,692	23,845
Research and development	53,403	41,660	31,401
General and administrative	55,338	50,863	39,231
(Gain) loss on foreign exchange	-6,618	2,536	1,362
Total operating expenses	132,760	121,751	95,839
OPERATING INCOME	283,758	218,147	208,888
OTHER INCOME (EXPENSE), Net:
Interest (expense) income, net	-77	-1	319
Other income, net	793	155	8
Total other income (expense)	716	154	327
INCOME BEFORE PROVISION FOR INCOME TAXES	284,474	218,301	209,215
PROVISION FOR INCOME TAXES	-84,029	-62,521	-61,471
NET INCOME	200,445	155,780	147,744
LESS: NET INCOME ATTRIBUTABLE TO NONCONTROLLING INTERESTS	0	0	2,740
NET INCOME ATTRIBUTABLE TO IPG PHOTONICS CORPORATION	$200,445	$155,780	$145,004
NET INCOME ATTRIBUTABLE TO IPG PHOTONICS CORPORATION PER SHARE:
Basic (in dollars per share)	$3.85	$3.02	$2.87
Diluted (in dollars per share)	$3.79	$2.97	$2.81
WEIGHTED AVERAGE SHARES OUTSTANDING:
Basic (shares)	52,104	51,548	50,477
Diluted (shares)	52,824	52,375	51,536

Consolidated_Statements_Of_Com

Consolidated Statements Of Comprehensive Income (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Comprehensive Income [Abstract]
Net income	$200,445	$155,780	$147,744
Other comprehensive (loss) income, net of tax:
Translation adjustments	-110,734	1,125	11,225
Unrealized gain on derivatives	172	268	241
Total other comprehensive (loss) income	-110,562	1,393	11,466
Comprehensive income	89,883	157,173	159,210
Comprehensive income attributable to noncontrolling interest & redeemable noncontrolling interest	0	0	1,908
Comprehensive income attributable to IPG Photonics Corporation	$89,883	$157,173	$157,302

Consolidated_Statements_Of_Equ

Consolidated Statements Of Equity (USD $)	Total	COMMON STOCK	ADDITIONAL PAID-IN CAPITAL	RETAINED EARNINGS	ACCUMULATED OTHER COMPREHENSIVE LOSS	TOTAL IPG PHOTONICS CORPORATION STOCKHOLDERS' EQUITY	NONCONTROLLING INTERESTS
In Thousands, except Share data, unless otherwise specified
Balance at Dec. 31, 2011		$5	$332,585	$122,833	($12,100)		$287
Balance, shares at Dec. 31, 2011		47,616,115
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options, shares		456,919
Exercise of stock options and related tax benefit from exercise			8,954
Common stock issued under employee stock purchase plan, shares		36,213
Common stock issued under employee stock purchase plan			1,205
Common stock issued in a public offering, shares		3,250,000
Common stock issued in follow-on public offering			167,928
Stock-based compensation			8,565
Purchase of redeemable noncontrolling interests (NCI)			-7,794
Premium on purchase of redeemable NCI			-404
Net income attributable to IPG Photonics Corporation	145,004			145,004
Adjustments to redemption value of redeemable NCI	493			493
Dividend to shareholders	33,353			-33,353
Translation adjustments	11,225				11,225
Unrealized gain on derivatives	241				241
Purchase of redeemable NCI					-3,292
Attribution to redeemable NCI					832
Sale of redeemable NCI							-700
Other comprehensive income attributable to redeemable NCI	-1,908						9
Premium on purchase of redeemable NCI							404
Balance at Dec. 31, 2012	742,927	5	511,039	234,977	-3,094	742,927
Balance, shares at Dec. 31, 2012		51,359,247
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options, shares		540,232
Exercise of stock options and related tax benefit from exercise			14,523
Common stock issued under employee stock purchase plan, shares		31,499
Common stock issued under employee stock purchase plan			1,626
Stock-based compensation			11,720
Net income attributable to IPG Photonics Corporation	155,780			155,780
Adjustments to redemption value of redeemable NCI	0
Dividend to shareholders	0
Translation adjustments	1,125				1,125
Unrealized gain on derivatives	268				268
Other comprehensive income attributable to redeemable NCI	0
Balance at Dec. 31, 2013	927,969	5	538,908	390,757	-1,701	927,969
Balance, shares at Dec. 31, 2013		51,930,978
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options, shares	414,775	402,647
Exercise of stock options and related tax benefit from exercise			11,428
Common stock issued under employee stock purchase plan, shares		36,063
Common stock issued under employee stock purchase plan			2,109
Stock-based compensation			15,172
Net income attributable to IPG Photonics Corporation	200,445			200,445
Adjustments to redemption value of redeemable NCI	0
Dividend to shareholders	0
Translation adjustments	-110,734				-110,734
Unrealized gain on derivatives	172				172
Other comprehensive income attributable to redeemable NCI	0
Balance at Dec. 31, 2014	$1,046,561	$5	$567,617	$591,202	($112,263)	$1,046,561
Balance, shares at Dec. 31, 2014		52,369,688

Consolidated_Statements_Of_Cas

Consolidated Statements Of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$200,445	$155,780	$147,744
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	35,612	31,524	26,144
Deferred income taxes	-1,486	-6,168	5,546
Stock-based compensation	15,172	11,720	8,565
(Gains) losses on unrealized foreign currency transactions	-3,497	-235	1,250
Other	459	62	-19
Provisions for inventory, warranty & bad debt	28,036	29,975	19,967
Changes in assets and liabilities that (used) provided cash:
Accounts receivable	-48,518	-9,991	-22,706
Inventories	-42,246	-50,355	-22,975
Prepaid expenses and other current assets	-5,351	-3,980	-899
Accounts payable	3,262	974	4,375
Accrued expenses and other liabilities	-1,567	-281	-8,155
Income and other taxes payable	5,763	-30,784	21,118
Tax benefit from exercise of employee stock options	-5,979	-8,874	-4,679
Net cash provided by operating activities	180,105	119,367	175,276
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property, plant and equipment	-88,601	-70,919	-68,184
Purchase of intangible assets	-2,000	0	0
Proceeds from sales of property, plant and equipment	434	236	0
Proceeds from sale of investment	0	495	0
Proceeds from short-term investments	0	0	25,451
Acquisition of businesses	0	-5,555	-11,596
Other	87	-143	-928
Net cash used in investing activities	-90,080	-75,886	-55,257
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from line-of-credit facilities	33,282	16,843	12,760
Payments on line-of-credit facilities	-33,623	-15,990	-17,190
Purchase of noncontrolling interests	0	0	-700
Purchase of redeemable noncontrolling interests	0	0	-55,400
Principal payments on long-term borrowings	-1,667	-2,853	-2,117
Exercise of employee stock options and issuances under employee stock purchase plan	7,558	7,275	5,480
Tax benefit from exercise of employee stock options	5,979	8,874	4,679
Proceeds from follow-on public offering, net of offering expenses	0	0	167,928
Distributions to shareholders	0	0	-33,353
Net cash provided by financing activities	11,529	14,149	82,087
EFFECT OF CHANGES IN EXCHANGE RATES ON CASH AND CASH EQUIVALENTS	-28,180	7,093	1,713
NET INCREASE IN CASH AND CASH EQUIVALENTS	73,374	64,723	203,819
CASH AND CASH EQUIVALENTS b Beginning of period	448,776	384,053	180,234
CASH AND CASH EQUIVALENTS b End of period	522,150	448,776	384,053
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Cash paid for interest	253	208	864
Cash paid for income taxes	73,544	89,611	25,980
Non-cash transactions:
Demonstration units transferred from inventory to other assets	3,528	3,927	2,631
Property, plant and equipment transferred from inventory	1,551	0	0
Additions to property, plant and equipment included in accounts payable	1,084	2,132	2,071
Property purchase financed with debt	22,000	0	0
Gain on sale of property, plant and equipment offset by related notes	$0	$0	$322

Nature_Of_Business_And_Summary

Nature Of Business And Summary Of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2014
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 and diode lasers 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 — Cash and cash equivalents consist primarily of highly liquid investments, such as bank deposits, 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.
	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. Because of the Company's vertical integration, a significant or sudden decrease in sales activity could result in a significant change in the estimates of excess or obsolete inventory valuation. 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. The Company capitalized $383, $524 and $142 of interest expense in 2014, 2013 and 2012, respectively.
	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. No impairment losses have been recorded during the 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 $3,612 and $5,524 at December 31, 2014 and 2013, respectively. Amortization expense of demonstration equipment for the years ended December 31, 2014, 2013 and 2012, was $2,068, $2,725 and $2,797, 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 not amortized which is in accordance with the requirements of Financial Accounting Standards Board ("FASB") Accounting Standards Codification ("ASC") 350, Intangibles-Goodwill and Other ("FASB ASC 350"). 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. As more fully described in Note 13, the Company incurred an impairment loss of $2,803 in 2013, which is included in other income (expense) in the accompanying consolidated statements of income.
	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 FASB 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 and the selling price of installation is based on third-party evidence. Applicable revenue recognition criteria are applied separately for each separate unit of accounting. 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, which may 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 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 $25,150 and $17,679 of bank acceptance drafts at December 31, 2014 and 2013, 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:
			2014				2013				2012
	Balance at January 1		$	2,473			$	2,173			$	1,605
	Provision for bad debts, net of recoveries		579				323				642
	Uncollectable accounts written off		(617		)		(31		)		(170		)
	Foreign currency translation		(545		)		8				96
	Balance at December 31		$	1,890			$	2,473			$	2,173
	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:
			2014				2013				2012
	Balance at January 1		$	14,997			$	10,714			$	8,631
	Provision for warranty accrual		15,449				11,363				8,112
	Warranty claims		(9,165		)		(7,405		)		(6,542		)
	Foreign currency translation and other		(2,009		)		325				513
	Balance at December 31		$	19,272			$	14,997			$	10,714
	Accrued warranty reported in the accompanying consolidated financial statements as of December 31, 2014 and December 31, 2013 consists of $9,489 and $7,724 in accrued expenses and other liabilities and $9,783 and $7,273 in other long-term liabilities, respectively.
	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, auction rate securities and accounts receivable. The Company maintains substantially all of its cash and marketable securities in six 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 provide 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, accounts receivable, auction rate securities, accounts payable, drawings on revolving lines of credit, long-term debt, certain derivative instruments and contingent 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, 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, 2014
		Total				Level 1				Level 2				Level 3
	Assets
	Cash equivalents	$	266,011			$	266,011			$	—			$	—
	Auction rate securities	1,128				—				—				1,128
	Total assets	$	267,139			$	266,011			$	—			$	1,128
	Liabilities
	Contingent purchase consideration	$	98			$	—			$	—			$	98
	Interest rate swap	151				—				151				—
	Total liabilities	$	249			$	—			$	151			$	98
						Fair Value Measurements at December 31, 2013
		Total				Level 1				Level 2				Level 3
	Assets
	Cash equivalents	$	240,159			$	240,159			$	—			$	—
	Auction rate securities	1,120				—				—				1,120
	Total assets	$	241,279			$	240,159			$	—			$	1,120
	Liabilities
	Contingent purchase consideration	$	375			$	—			$	—			$	375
	Interest rate swap	423				—				423				—
Total liabilities	$	798			$	—			$	423			$	375
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 secondary markets 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, 2014 and December 31, 2013.
The interest rate swap is designated as a cash flow hedge, the fair value of which was estimated based on quoted market prices or pricing models using current market rates. Fair value at December 31, 2014 and December 31, 2013 for the interest rate swap considered prices observed in inactive secondary markets for the securities held by the Company.
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.
During the second quarter of 2013, the Company reduced the fair value of contingent consideration related to the Company's subsidiary, IPG Microsystems LLC's ("IPGM") acquisition of certain working capital and long-term assets from JP Sercel Associates Inc. ("JPSA") to $0 because management assessed that there was no possibility that milestones in the earn-out agreements would be achieved. Additionally, the Company reduced other contingent consideration for other agreements by $196. Accordingly, $2,659 is included in other income (expense) in the accompanying Consolidated Statements of Income in 2013.
The following table presents information about the Company's movement in Level 3 assets and liabilities measured at fair value:
		2014				2013
Auction Rate Securities
Balance, January 1		$	1,120			$	1,112
Change in fair value and accretion		8				8
Balance, December 31		$	1,128			$	1,120
Contingent Purchase Consideration
Balance, January 1		$	375			$	3,023
Change in fair value and currency fluctuations		(277		)		(2,648		)
Balance, December 31		$	98			$	375
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 and unrealized gains or losses on derivatives. These adjustments are accumulated within the consolidated statements of comprehensive income.
Total components of accumulated other comprehensive loss were as follows:
		December 31,
		2014				2013
Foreign currency translation adjustments		$	(112,411	)		$	(1,677	)
Unrealized loss on derivatives, net of tax of $67 and $168		(84		)		(256		)
Change in carrying value of auction rate securities		232				232
Accumulated other comprehensive loss		$	(112,263	)		$	(1,701	)
Derivative Instruments — The Company's primary market exposures are to interest rates and foreign exchange rates. The Company uses 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 interest rate swaps that are 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 cash flow hedges is an interest rate swap under which it pays fixed rates of interest.
The fair value amounts in the consolidated balance sheets were:
Notional Amounts1								Other Assets							Other Current Liabilities2				Deferred
																			Income Taxes
																			And Other
																			Long-Term
																			Liabilities2
December 31,								December 31,							December 31,				December 31,
2014				2013				2014				2013			2014		2013		2014		2013
$	11,333			$	12,666			$	—			$	—		$	151	$	—	$	—	$	423
(1) Notional amounts represent the gross contract/notional amount of the derivative outstanding.
(2) As of December 31, 2014, the remaining balance of the U.S. long-term note outstanding is considered current because the term of the note expires in June 2015. Accordingly, the interest rate swap liability has been reclassified.
The derivative gains and losses in the consolidated statements of income for the years ended December 31, 2014, 2013 and 2012, related to the Company's interest rate swap contract was as follows:
		Year Ended December 31,
		2014				2013				2012
Effective portion recognized in other comprehensive (loss) income, pretax:
Interest rate swap		$	567			$	881			$	944
Effective portion reclassified from other comprehensive (loss) income to interest expense, pretax:
Interest rate swap		$	(295	)		$	(449	)		$	(576	)
Ineffective portion recognized in income:
Interest rate swap		$	—			$	—			$	—
The Company made no adjustments to the fair value of this derivative as a result of evaluating counterparty risk.
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. Under the provisions of ASC 260, the Company is required to present basic and diluted earnings per share information separately for each class of equity instruments that participate in any income distribution with primary equity instruments. The Company calculates earnings per share in periods where a class of common stock was redeemable for other than fair value through the application of the two-class method. Until June 29, 2012, the Company had redeemable noncontrolling interests reported in the accompanying consolidated financial statements related to a 22.5% minority interest of IPG Russia. The computation of net income per share is provided in Note 9.
Recent Accounting Pronouncements — Accounting standards that have been issued or proposed by the FASB or other standards-setting bodies that do not require adoption until a future date are not expected to have a material impact on the Company's financial statements upon adoption.
Subsequent Events — The Company has considered the impact of subsequent events through the filing date of these financial statements.

StockBased_Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2014
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,
		2014				2013				2012
	Cost of sales	$	4,153			$	3,187			$	2,184
	Sales and marketing	1,567				1,195				1,052
	Research and development	3,033				1,929				1,327
	General and administrative	6,419				5,409				4,002
	Total stock-based compensation	15,172				11,720				8,565
	Tax benefit recognized	(4,865		)		(3,784		)		(2,629		)
	Net stock-based compensation	$	10,307			$	7,936			$	5,936
	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.
	The Company calculates the fair value of stock option grants using the Black-Scholes option pricing model. Determining the appropriate fair value model and calculating the fair value of stock-based payment awards require 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 weighted average assumptions used in the Black-Scholes model or the calculation of compensation were as follows for the years ended December 31.
		2014		2013		2012
	Expected term	4.7-6.1 years		4.4-6.3 years		4.0-6.6 years
	Volatility	48%-51%		51%-54%		49%-56%
	Risk-free rate of return	1.46%-1.84%		0.74%-1.32%		0.59%-1.23%
	Dividend yield	0.25%		0.25%		—%
	Forfeiture rate	3.04%-5.86%		0%-5.97%		0%-6.1%
	Incentive Plans — In April 2000, the Company's board of directors adopted the 2000 Incentive Compensation Plan (the "2000 Plan"), and in February 2006, the Company's board of directors adopted the 2006 Incentive Compensation Plan (the "2006 Plan"), which provide for the issuance of stock options and other stock and non-stock based awards to the Company's directors, employees, consultants and advisors. The Company reserved 5,833,333 shares under the 2000 Plan and 4,000,000 shares under the 2006 Plan for the issuance of awards under the plans. During 2011, the Company reserved an additional 6,084,273 shares under the 2006 Plan. In June 2006, the Company's board of directors adopted the Non-Employee Directors Stock Plan (the "Directors Plan"). Only non-employee directors are eligible to receive awards under the Directors Plan. The Company reserved 486,660 shares for issuance under the Directors Plan. Under the three plans, the Company may grant nonstatutory stock options at an exercise price at least equal to the fair value of its common stock on the date of grant, unless the board of directors or compensation committee determines otherwise on the date of grant. Incentive stock options may be granted under the 2000 Plan and the 2006 Plan at exercise prices equal to or exceeding the fair value of the common stock on the date of grant. The Company may also grant restricted stock, restricted stock units and other equity-based awards. Incentive awards generally become exercisable over periods of one to five years and expire seven to ten years from the date of the grant. The awards under the 2000 Plan and the 2006 Plan may become exercisable earlier upon the occurrence of certain change of control events at the election of the board of directors or compensation committee, and all awards under the Directors Plan automatically become exercisable upon a change of control. All shares issued under the incentive plans are registered shares newly issued by the Company. At December 31, 2014, 5,491,656 shares of the Company's stock were available for future grant under the three incentive plans.
	A summary of option activity, including the employee stock purchase plan, is presented below (see Note 11 for further information):
		Number of			Weighted-				Weighted-		Aggregate
		Options			Average				Average		Intrinsic
					Exercise				Remaining		Value
					Price				Contractual
									Life
									(In years)		(In thousands)
	Outstanding — January 1, 2014	2,674,897			$	37.63
	Granted	463,289			70.67
	Exercised	(414,775	)		16.97
	Forfeited	(31,535	)		62.94
	Outstanding — December 31, 2014	2,691,876			$	45.48			6.62		$	88,500
	Vested or expected to vest — December 31, 2014	2,554,160			$	44.58			6.53		$	85,697
	Exercisable — December 31, 2014	1,027,303			$	24.29			4.83		$	52,018
	The intrinsic value of the options exercised during the years ended December 31, 2014, 2013 and 2012, was $23,491, $30,063 and $20,792, respectively.
	The weighted-average grant fair value per share for options granted during the years ended December 31, 2014, 2013 and 2012, was $39.12, $28.28 and $26.80, respectively.
	The total compensation cost related to nonvested awards not yet recorded at December 31, 2014 was $27,310 which is expected to be recognized over a weighted average of 2.4 years.
	The aggregate fair value of awards vested during the year ended December 31, 2014 was $7,076.

Inventories

Inventories	12 Months Ended
	Dec. 31, 2014
Inventory Disclosure [Abstract]
Inventories	INVENTORIES
	Inventories consist of the following:
		December 31,
		2014		2013
	Components and raw materials	$	54,925	$	54,539
	Work-in-process	58,603		64,927
	Finished goods	57,481		53,234
	Total	$	171,009	$	172,700
	The Company recorded inventory provisions totaling $11,302, $15,128 and $8,232 for the years ended December 31, 2014, 2013 and 2012, 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, 2014
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	PROPERTY, PLANT AND EQUIPMENT
	Property, plant, and equipment consist of the following:
		December 31,
		2014			2013
	Land	$	19,248		$	15,448
	Buildings	144,629			146,730
	Machinery and equipment	202,075			165,050
	Office furniture and fixtures	25,816			23,589
	Construction-in-progress	47,285			52,911
	Total property, plant and equipment	439,053			403,728
	Accumulated depreciation	(163,971		)	(151,483		)
	Total property, plant and equipment — net	$	275,082		$	252,245
	The Company recorded depreciation expense of $31,334, $26,489 and $21,108 for the years ended December 31, 2014, 2013 and 2012, respectively.

Accrued_Expenses_And_Other_Lia

Accrued Expenses And Other Liabilities	12 Months Ended
	Dec. 31, 2014
Payables and Accruals [Abstract]
Accrued Expenses And Other Liabilities	ACCRUED EXPENSES AND OTHER LIABLILITES
	Accrued expenses and other liabilities consist of the following:
		December 31,
		2014		2013
	Accrued compensation	$	31,673	$	25,727
	Customer deposits and deferred revenue	16,605		18,489
	Current portion of accrued warranty	9,489		7,724
	Other	6,290		7,396
	Total	$	64,057	$	59,336

Financing_Arrangements

Financing Arrangements	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Financing Arrangements	FINANCING ARRANGEMENTS
	The Company's borrowings under existing financing arrangements consist of the following:
		December 31,
		2014			2013
	Revolving line of credit facilities:
	European overdraft facilities	$	828		$	1,038
	Euro line of credit	1,803			2,258
	Total	$	2,631		$	3,296
	Term debt:
	U.S. long-term note	$	11,333		$	12,666
	Collateralized long-term note	21,667			—
	Less: current portion	(13,333		)	(1,333		)
	Total long-term debt	$	19,667		$	11,333
	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 $35,000, expiring in June 2015. The line of credit bears interest at a variable rate of LIBOR plus 1.125% to 1.625% depending on the Company's financial performance. $14,100 of this credit facility is available to the Company's foreign subsidiaries including those in India, China, Japan and South Korea. At December 31, 2014, there were no drawings, however there were $87 of guarantees issued against the line which reduced the total availability. At December 31, 2014, the remaining availability under the U.S. Line of Credit totaled $34,913.
	Euro Line of Credit — The Company maintains an unsecured revolving line of credit with a principal amount of Euro 30,000 ($36,466 at December 31, 2014), expiring in July 2017. The line of credit bears interest at various rates based upon the type of loan. $19,448 is available to the Company's Russian subsidiary, $9,724 of this credit facility is available to the Company's German subsidiary, $3,647 is available to the Company's Chinese subsidiary and $3,647 is available to the Company's Italian subsidiary. Total drawings at December 31, 2014 were $1,803 with an interest rate of 1.0% and there were $4,309 of guarantees issued against the line which also reduced the total availability. At December 31, 2014, the remaining availability under this line was $30,354.
	Euro Overdraft Facilities — The Company maintains a syndicated overdraft facility with available principal of Euro 500 ($608 at December 31, 2014) 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, 2014, total drawings were $395 with an interest rate of 1.0%. The aggregate remaining availability under this line was $213.
	Other European Facilities — The Company maintains two Euro credit lines in Italy with aggregate available principal of Euro 1,500 ($1,823 as of December 31, 2014) which bear interest at 1.0% and expire in June and September 2015. Total drawings at December 31, 2014 were $433. At December 31, 2014, the aggregate remaining availability under these lines was $1,390. These facilities are collateralized by a common pool of the assets of the Company's Italian subsidiary.
	Term Debt:
	U.S. Long-Term Note — The Company has an outstanding promissory note which bears interest at LIBOR plus 0.9% to 1.3%, depending on certain financial ratios and requires monthly principal payments of $111 and interest through June 2015, at which time the remaining principal is payable. The Company entered into an interest rate swap instrument which converted the variable LIBOR rate on the original term note to a fixed rate of 5.0% per annum. For the term from August 2013 to June 2015, the Company entered into a separate interest rate swap instrument which converts the variable LIBOR rate to a fixed rate of 2.57% per annum. Changes in the fair value of the swap is included in accumulated other comprehensive loss on the consolidated balance sheets. The unrealized loss on the swap will be recognized into income over the term of the swap as a charge to interest expense.
	The Company is required to meet certain financial covenants associated with its U.S. line of credit and its original U.S. 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 it to maintain a trailing twelve month ratio of cash flow to debt service that is greater than 1.5:1. Debt service is defined as required principal and interest payments during the period. 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 two times the Company's trailing twelve months EBITDA.
	As of December 31, 2014, the remaining balance of $11,333 related to the original U.S. long-term note outstanding is considered current because the term of the note expires in June 2015.
	Collateralized Long-Term Note —In October 2014, the Company entered into a collateralized long-term note to finance the purchase of the Company's aircraft which bears a fixed interest rate of 2.81% per annum. The note requires monthly principal payments of $167 and interest through October 2019, at which time the remaining principal is payable. As of December 31, 2014, the note has a remaining balance of $21,667.

Redeemable_Noncontrolling_Inte

Redeemable Noncontrolling Interests and Stockholders' Equity	12 Months Ended
	Dec. 31, 2014
Noncontrolling Interest [Abstract]
Redeemable Noncontrolling Interests and Stockholders' Equity	REDEEMABLE NONCONTROLLING INTERESTS AND STOCKHOLDERS' EQUITY
	Redeemable Noncontrolling Interests — Redeemable noncontrolling interests reported in the accompanying consolidated financial statements related to a 22.5% minority interest of IPG Russia that was redeemed on June 29, 2012. The associated net income attributable to noncontrolling interest in 2012 was $2,740.
	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, 2014.

RelatedParty_Transactions

Related-Party Transactions	12 Months Ended
	Dec. 31, 2014
Related Party Transactions [Abstract]
Related-Party Transactions	RELATED-PARTY TRANSACTIONS
	In 2014 and 2013, the Company purchased various parts and services from a company with which one of the Company's independent directors is an executive officer. The payments made for such services for 2014 and 2013 totaled $3,687 and $130, respectively. There were no amounts due to this company at December 31, 2014, however, the Company had an amount of $1,155 in Accounts Payable due to this company at December 31, 2013.
	The Company leased from an unrelated third party approximately 12,000 square feet of office space in Marlborough, Massachusetts under an office lease expiring November 2017. A subsidiary of IP Fibre Devices (UK) Ltd. ("IPFD") purchased the building in October 2014 and acquired the lease. The Company's CEO is the managing director of IPFD, and IPFD is a stockholder of the Company. The 2014 year-end annual lease rate was $232 with annual increase of approximately 2.5% per year. The Company reimburses the landlord for its portion of certain operational costs. The Company paid IPFD $20 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 2014 year-end annual lease rate was $684 and future rent payments will be adjusted annually. The CEO also pays direct and incidental operating costs for his private use including pilot fees. The CEO paid the Company $146 in 2014 under the aircraft lease.
	In 2014, the Company sold products and services of $2,731 to OAO "RCE" Laser Processing Center ("Laser Center"), an application development and parts processing company. The Company's CEO owns approximately 39% of Laser Center, which he acquired from an unrelated third party in 2014.

Net_Income_Attributable_To_IPG

Net Income Attributable To IPG Photonics Corporation Per Share	12 Months Ended
	Dec. 31, 2014
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,
		2014		2013		2012
	Net income attributable to IPG Photonics Corporation	$	200,445	$	155,780	$	145,004
	Adjustments to redemption value of redeemable noncontrolling interests	—		—		493
	Net income attributable to common stockholders	200,445		155,780		145,497
	Weighted average shares	52,104		51,548		50,477
	Dilutive effect of common stock equivalents	720		827		1,059
	Diluted weighted average common shares	52,824		52,375		51,536
	Basic net income attributable to IPG Photonics Corporation per share	$	3.85	$	3.02	$	2.86
	Adjustments to redemption value of redeemable noncontrolling interests	—		—		0.01
	Basic net income attributable to common stockholders	$	3.85	$	3.02	$	2.87
	Diluted net income attributable to IPG Photonics Corporation per share	$	3.79	$	2.97	$	2.8
	Adjustments to redemption value of redeemable noncontrolling interests	—		—		0.01
	Diluted net income attributable to common stockholders	$	3.79	$	2.97	$	2.81
	The computation of diluted weighted average common shares excludes options to purchase 46,987 shares, 322,301 shares and 164,858 shares for the years ended December 31, 2014, 2013 and 2012, respectively, because the effect would be anti-dilutive.

Commitments_And_Contingencies

Commitments And Contingencies	12 Months Ended
	Dec. 31, 2014
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 October 2019. In addition, it leases capital equipment under operating leases. Rent expense for the years ended December 31, 2014, 2013 and 2012, totaled $5,516, $4,560 and $3,885, respectively.
	Commitments under the noncancelable lease agreements as of December 31, 2014 are as follows:
	Years Ending December 31	Facilities		Equipment		Total
	2015	$	3,439	$	951	$	4,390
	2016	2,775		573		3,348
	2017	2,491		336		2,827
	2018	1,544		145		1,689
	2019	1,224		27		1,251
	Thereafter	5		—		5
	Total	$	11,478	$	2,032	$	13,510
	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 $22,288 and $3,371 as of December 31, 2014 and 2013, respectively. Also, included is an obligation of $4,500 that the Company has as a result of entering into an agreement to purchase certain intellectual property and know-how related to laser based systems.
	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. In August 2013, the Company was sued for misappropriation of certain trade secrets, unfair trade practices, and correction of inventorship on a patent owned by the Company related to beam couplers and beam switches. The plaintiff sought damages in an unspecified amount, double damages for misappropriation of trade secrets and treble damages for unfair trade practices and correction of inventorship on one patent. The plaintiff filed in the United States District Court of the District of Massachusetts, a voluntarily dismissal of the lawsuit in August 2014. As of December 31, 2014 and through the date of the Company's subsequent review period of February 28, 2015, 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, 2014
Compensation Related Costs [Abstract]
Employee Benefit Plans	EMPLOYEE BENEFIT PLANS
	The Company maintains a 401(k) retirement savings plan covering 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, 2014, 2013 and 2012, approximated $1,445, $1,127 and $848, respectively.
	The Company has an employee stock purchase plan covering 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 $607, $498 and $452 for the years ended December 31, 2014, 2013 and 2012, respectively. As of December 31, 2014, there were 389,314 shares available for issuance under the employee stock purchase plan.

Business_Combinations

Business Combinations	12 Months Ended
	Dec. 31, 2014
Business Combinations [Abstract]
Business Combinations	BUSINESS COMBINATIONS
	On March 13, 2013, the Company acquired the working capital and long term assets of Mobius Photonics Inc. ("Mobius"), a manufacturer of high-power pulsed ultra-violet ("UV") fiber lasers for micro-machining and fine processing applications. As a result of the acquisition, the Company recorded intangible assets of $4,480 which related to production know-how with an estimated useful life of 7 years and $455 of goodwill that is deductible for federal income tax purposes. The acquisition did not have a material effect on the Company's financial results in 2013.
	On August 31, 2012, the Company's subsidiary, IPGM acquired certain working capital and long-term assets from JPSA, which is a manufacturer of laser-based systems performing fine processing of materials used in semiconductor, LED and solar applications. As a result of the acquisition, the Company recorded $2,898 of goodwill and intangible assets of $3,400, of which $2,400 related to technology and production know-how and the remainder related to customer relationships, non-compete agreements and trade names with weighted-average estimated useful lives of 10 years, 10 years, 5 years and 7 years, respectively. The acquisition did not have a material effect on the Company's financial results in 2012. In addition to cash paid, consideration included contingent consideration based on sales targets that extended for two one-year periods beginning October 1, 2012. Total possible additional payouts under these earn-outs were $18,500. As discussed in the fair value financial instruments disclosures in Note 1, the Company reduced the fair value of the contingent consideration related to IPGM to $0 during 2013. Also, as discussed in Note 13, the Company reduced the Goodwill associated with IPGM to $0 as well.

Goodwill_And_Intangibles

Goodwill And Intangibles	12 Months Ended
	Dec. 31, 2014
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, 2014 and 2013:
		31-Dec-14			31-Dec-13
	Balance at January 1	$	455		$	2,898
	Adjustment	—			(95		)
	Impairment	—			(2,803		)
	Total goodwill arising from acquisition	—			455
	Balance at December 31	$	455		$	455
	The goodwill balance at January 1, 2013 of $2,898 and the adjustment of $95, largely reflected the potential synergies and expansion of the Company's service offerings complementary to its specialized laser systems and UV and short-pulse fiber lasers resulting from the 2012 acquisition from JPSA by IPGM. During 2013, the Company carried out the two-step goodwill impairment test in accordance with the provisions of ASC 350-20-35. That analysis indicated that the fair value of the IPGM reporting unit, based on a discounted cash flow analysis, was less than the carrying value. The implied value of goodwill, as measured in step 2, was zero. Accordingly, the Company adjusted the value of goodwill associated with IPGM to $0.
	The goodwill of $455 arising from the Mobius acquisition relates to the expected synergies for the Company's expansion of product offerings with UV fiber lasers. The goodwill arising from the acquisition in 2013 is deductible over 15 years for federal tax purposes.
	Intangible assets, subject to amortization, consisted of the following:
		31-Dec-14								31-Dec-13
		Gross  Carrying		Accumulated			Net  Carrying		Weighted-	Gross  Carrying		Accumulated			Net  Carrying		Weighted-
		Amount		Amortization			Amount		Average  Lives	Amount		Amortization			Amount		Average  Lives
	Patents	$	6,641	$	(4,221	)	$	2,420	6 Years	$	4,667	$	(4,091	)	$	576	6 Years
	Customer relationships	3,660		(3,308		)	352		5 Years	4,112		(3,324		)	788		5 Years
	Production know-how	6,844		(2,630		)	4,214		8 Years	7,063		(1,747		)	5,316		8 Years
	Technology, trademark and tradename	3,315		(1,074		)	2,241		8 Years	4,271		(1,387		)	2,884		8 Years
		$	20,460	$	(11,233	)	$	9,227		$	20,113	$	(10,549	)	$	9,564
	During the third quarter of 2014, the Company purchased certain intellectual property including patent and product design rights in the amount of $2,000.
	Amortization expense for the years ended December 31, 2014, 2013 and 2012 was $2,210, $2,310 and $2,091, respectively.
	The estimated future amortization expense for intangibles as of December 31, 2014 is as follows:
	2015		2016	2017		2018		2019	Thereafter		Total
	$1,783		$1,686	$1,686		$1,621		$1,033	$1,418		$9,227
	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 reporting period, the Company assesses for factors that may be present which would cause an impairment review.
	During 2013, the Company performed an impairment analysis to assess whether there was impairment of long-lived assets of IPGM including identifiable intangibles included in the table above using the guidance in ASC 360-10-35. The Company concluded that no impairment existed as the undiscounted cash flows from IPGM are forecasted to be greater than the carrying value of identified long-lived assets.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2014
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:
		2014			2013			2012
	U.S.	$	72,800		$	59,006		$	58,964
	Foreign	211,674			159,295			150,251
	Total	$	284,474		$	218,301		$	209,215
	The Company's provision for income taxes for the years ended December 31 consisted of the following:
		2014			2013			2012
	Current:
	Federal	$	(22,549	)	$	(19,285	)	$	(16,675	)
	State	(2,823		)	(2,617		)	(309		)
	Foreign	(60,143		)	(46,787		)	(38,941		)
	Total current	$	(85,515	)	$	(68,689	)	$	(55,925	)
	Deferred:
	Federal	$	454		$	3,834		$	(2,174	)
	State	27			203			(140		)
	Foreign	1,005			2,131			(3,232		)
	Total deferred	$	1,486		$	6,168		$	(5,546	)
	Provision for income taxes	$	(84,029	)	$	(62,521	)	$	(61,471	)
	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:
		2014			2013			2012
	Tax at statutory rate	$	(99,867	)	$	(76,406	)	$	(73,225	)
	Non-U.S. rate differential — net	14,590			10,761			11,744
	State income taxes — net	(1,787		)	(1,512		)	(1,527		)
	Effect of changes in enacted tax rates on deferred tax assets and liabilities	(44		)	186			(617		)
	Nondeductible stock compensation expense	(483		)	(101		)	(1,020		)
	Other nondeductible expenses	(2,063		)	(1,666		)	(794		)
	Federal and state tax credits	5,865			7,500			4,623
	Change in reserves, including interest and penalties	(7		)	(1,273		)	(243		)
	Change in valuation allowance	—			—			(314		)
	Other — net	(233		)	(10		)	(98		)
		$	(84,029	)	$	(62,521	)	$	(61,471	)
	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:
		2014			2013			2012
	Property, plant and equipment	$	(5,310	)	$	(2,230	)	$	(3,629	)
	Inventory provisions	10,497			8,261			7,942
	Allowances and accrued liabilities	1,570			3,634			(4,829		)
	Other tax credits	726			769			1,673
	Deferred compensation	4,218			(434		)	3,538
	Net operating loss carryforwards	—			229			5
	Net deferred tax assets	$	11,701		$	10,229		$	4,700
	It is the Company's practice and intention to reinvest the earnings of non-U.S. subsidiaries in those operations. Accordingly, it has not made any provision for additional U.S. or foreign withholding taxes with respect to repatriation of earnings of non-U.S. subsidiaries. At December 31, 2014 and 2013, the cumulative unremitted earnings that are reinvested in non-U.S. subsidiaries are approximately $522,000 and $346,000, respectively.
	As of December 31, 2014, 2013 and 2012, the Company has state tax credit carry-forwards of $1,225, $2,074 and $1,419, respectively. The state tax credit carry-forwards begin expiring in 2017. In addition, the Company has UK net operating loss carry-forwards available for future periods of $2,509 related to deductions for stock-based compensation. The UK net operating loss can be carry-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 following is a tabular reconciliation of the total amounts of unrecognized tax benefits:
		2014			2013			2012
	Balance at January 1	$	6,501		$	5,392		$	4,509
	Reductions of prior period positions	(795		)	(505		)	(317		)
	Additions for tax positions in current period	788			1,614			1,200
	Balance at December 31	$	6,494		$	6,501		$	5,392
	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.
	Changes in tax laws and rates may affect recorded deferred tax assets and liabilities and the Company's effective tax rate in the future. The American Taxpayer Relief Act of 2012 (the "Act") was signed into law on January 2, 2013. Because a change in tax law is accounted for in the period of enactment, certain provisions of the Act benefiting the Company's 2012 U.S. federal taxes, including the research and experimentation credit, could not be recognized in the Company's 2012 financial results and instead is reflected in its 2013 financial results.
	Estimated penalties and interest related to the underpayment of income taxes are ($192), $374 and $352 for the years ended December 31, 2014, 2013 and 2012, respectively, and are included within the provision for income taxes. Total accrued penalties and interest related to the underpayment of income taxes are $670 and $862 at December 31, 2014 and 2013, 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	2012 — 2014
	•     Germany	2011 — 2014
	•     Russia	2010 — 2014
	The Company currently has an ongoing audit of our German subsidiary's tax filings for the years 2011-2013.
	On September 13, 2013, the United States Treasury and Internal Revenue Service issued final tangible personal property regulations that broadly apply to amounts paid to acquire, produce or improve tangible property, as well as dispositions of such property. In review of these regulations, the Company has concluded that there is no material impact on its consolidated financial position, results of operations or cash flows.

Geographic_And_Product_Informa

Geographic And Product Information	12 Months Ended
	Dec. 31, 2014
Geographic And Product Information [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,
		2014		2013		2012
	United States and other North America	$	113,233	$	116,935	$	108,316
	Europe:
	Germany	77,404		65,147		89,848
	Other including Eastern Europe/CIS	173,018		140,279		110,860
	Asia and Australia:
	Japan	72,573		67,981		69,576
	China	245,102		192,134		138,782
	Other	85,426		64,346		43,445
	Rest of World	3,076		1,212		1,701
	Total	$	769,832	$	648,034	$	562,528
	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,
		2014		2013		2012
	Materials Processing	$	731,274	$	608,702	$	492,013
	Other applications	38,558		39,332		70,515
	Total	$	769,832	$	648,034	$	562,528
	One customer comprised 11% of net sales during the years ended December 31, 2014 and 2013. No single customer comprised more than 10% of net sales during the year ended December 31, 2012. 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 23%, 21% and 16% in 2014, 2013 and 2012, respectively.
	The geographic locations of the Company's long-lived assets, net, based on physical location of the assets, as of December 31, 2014, 2013 and 2012, are as follows:
		December 31,
		2014		2013		2012
	United States	$	155,428	$	110,441	$	86,226
	Germany	51,528		52,791		47,019
	Russia	59,612		73,747		60,151
	China	6,582		5,895		6,424
	Other	12,507		13,480		15,674
		$	285,657	$	256,354	$	215,494
	Long lived assets include property, plant and equipment and demonstration equipment.

Selected_Quarterly_Financial_D

Selected Quarterly Financial Data	12 Months Ended
	Dec. 31, 2014
Selected Quarterly Financial Information [Abstract]
Selected Quarterly Financial Data (Unaudited)	SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED)
	2014	First		Second		Third		Fourth
		Quarter		Quarter		Quarter		Quarter
		(In thousands, except per share data)
	Net sales	$	170,575	$	192,204	$	199,651	$	207,402
	Gross profit	89,284		104,227		109,090		113,917
	Net income attributable to IPG Photonics Corporation	40,531		48,283		55,200		56,431
	Basic earnings per share	0.78		0.93		1.06		1.08
	Diluted earnings per share	0.77		0.92		1.05		1.07
	2013	First		Second		Third		Fourth
		Quarter		Quarter		Quarter		Quarter
		(In thousands, except per share data)
	Net sales	$	141,852	$	168,171	$	172,152	$	165,859
	Gross profit	75,641		89,922		92,813		81,522
	Net income attributable to IPG Photonics Corporation	35,127		41,720		42,338		36,595
	Basic earnings per share	0.68		0.81		0.82		0.71
	Diluted earnings per share	0.67		0.8		0.81		0.7

Nature_Of_Business_And_Summary1

Nature Of Business And Summary Of Significant Accounting Policies (Policy)	12 Months Ended
	Dec. 31, 2014
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 — Cash and cash equivalents consist primarily of highly liquid investments, such as bank deposits, 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.
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. Because of the Company's vertical integration, a significant or sudden decrease in sales activity could result in a significant change in the estimates of excess or obsolete inventory valuation. 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. No impairment losses have been recorded during the 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 not amortized which is in accordance with the requirements of Financial Accounting Standards Board ("FASB") Accounting Standards Codification ("ASC") 350, Intangibles-Goodwill and Other ("FASB ASC 350"). 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 FASB 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 and the selling price of installation is based on third-party evidence. Applicable revenue recognition criteria are applied separately for each separate unit of accounting. 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, which may 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 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 $25,150 and $17,679 of bank acceptance drafts at December 31, 2014 and 2013, 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.
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, auction rate securities and accounts receivable. The Company maintains substantially all of its cash and marketable securities in six 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 provide 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, accounts receivable, auction rate securities, accounts payable, drawings on revolving lines of credit, long-term debt, certain derivative instruments and contingent 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, 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, 2014
		Total		Level 1		Level 2		Level 3
	Assets
	Cash equivalents	$	266,011	$	266,011	$	—	$	—
	Auction rate securities	1,128		—		—		1,128
	Total assets	$	267,139	$	266,011	$	—	$	1,128
	Liabilities
	Contingent purchase consideration	$	98	$	—	$	—	$	98
	Interest rate swap	151		—		151		—
	Total liabilities	$	249	$	—	$	151	$	98
				Fair Value Measurements at December 31, 2013
		Total		Level 1		Level 2		Level 3
	Assets
	Cash equivalents	$	240,159	$	240,159	$	—	$	—
	Auction rate securities	1,120		—		—		1,120
	Total assets	$	241,279	$	240,159	$	—	$	1,120
	Liabilities
	Contingent purchase consideration	$	375	$	—	$	—	$	375
	Interest rate swap	423		—		423		—
	Total liabilities	$	798	$	—	$	423	$	375
	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 secondary markets 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, 2014 and December 31, 2013.
	The interest rate swap is designated as a cash flow hedge, the fair value of which was estimated based on quoted market prices or pricing models using current market rates. Fair value at December 31, 2014 and December 31, 2013 for the interest rate swap considered prices observed in inactive secondary markets for the securities held by the Company.
	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.
	During the second quarter of 2013, the Company reduced the fair value of contingent consideration related to the Company's subsidiary, IPG Microsystems LLC's ("IPGM") acquisition of certain working capital and long-term assets from JP Sercel Associates Inc. ("JPSA") to $0 because management assessed that there was no possibility that milestones in the earn-out agreements would be achieved. Additionally, the Company reduced other contingent consideration for other agreements by $196. Accordingly, $2,659 is included in other income (expense) in the accompanying Consolidated Statements of Income in 2013.
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 and unrealized gains or losses on derivatives. 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 uses 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 interest rate swaps that are 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	Cash Flow Hedges — The Company's cash flow hedges 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. Under the provisions of ASC 260, the Company is required to present basic and diluted earnings per share information separately for each class of equity instruments that participate in any income distribution with primary equity instruments. The Company calculates earnings per share in periods where a class of common stock was redeemable for other than fair value through the application of the two-class method. Until June 29, 2012, the Company had redeemable noncontrolling interests reported in the accompanying consolidated financial statements related to a 22.5% minority interest of IPG Russia. The computation of net income per share is provided in Note 9.
Recent Accounting Pronouncements	Recent Accounting Pronouncements — Accounting standards that have been issued or proposed by the FASB or other standards-setting bodies that do not require adoption until a future date are not expected to have a material impact on the Company's financial statements 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_Summary2

Nature Of Business And Summary Of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2014
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:
			2014				2013				2012
	Balance at January 1		$	2,473			$	2,173			$	1,605
	Provision for bad debts, net of recoveries		579				323				642
	Uncollectable accounts written off		(617		)		(31		)		(170		)
	Foreign currency translation		(545		)		8				96
	Balance at December 31		$	1,890			$	2,473			$	2,173
Summary Of Product Warranty Activity	Activity related to the warranty accrual was as follows:
			2014				2013				2012
	Balance at January 1		$	14,997			$	10,714			$	8,631
	Provision for warranty accrual		15,449				11,363				8,112
	Warranty claims		(9,165		)		(7,405		)		(6,542		)
	Foreign currency translation and other		(2,009		)		325				513
	Balance at December 31		$	19,272			$	14,997			$	10,714
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, 2014
		Total				Level 1				Level 2				Level 3
	Assets
	Cash equivalents	$	266,011			$	266,011			$	—			$	—
	Auction rate securities	1,128				—				—				1,128
	Total assets	$	267,139			$	266,011			$	—			$	1,128
	Liabilities
	Contingent purchase consideration	$	98			$	—			$	—			$	98
	Interest rate swap	151				—				151				—
	Total liabilities	$	249			$	—			$	151			$	98
						Fair Value Measurements at December 31, 2013
		Total				Level 1				Level 2				Level 3
	Assets
	Cash equivalents	$	240,159			$	240,159			$	—			$	—
	Auction rate securities	1,120				—				—				1,120
	Total assets	$	241,279			$	240,159			$	—			$	1,120
	Liabilities
	Contingent purchase consideration	$	375			$	—			$	—			$	375
	Interest rate swap	423				—				423				—
	Total liabilities	$	798			$	—			$	423			$	375
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:
			2014				2013
	Auction Rate Securities
	Balance, January 1		$	1,120			$	1,112
	Change in fair value and accretion		8				8
	Balance, December 31		$	1,128			$	1,120
	Contingent Purchase Consideration
	Balance, January 1		$	375			$	3,023
	Change in fair value and currency fluctuations		(277		)		(2,648		)
	Balance, December 31		$	98			$	375
Components Of Accumulated Other Comprehensive Income (Loss)	Total components of accumulated other comprehensive loss were as follows:
			December 31,
			2014				2013
	Foreign currency translation adjustments		$	(112,411	)		$	(1,677	)
	Unrealized loss on derivatives, net of tax of $67 and $168		(84		)		(256		)
	Change in carrying value of auction rate securities		232				232
	Accumulated other comprehensive loss		$	(112,263	)		$	(1,701	)
Fair Value Of Cash Flow Hedges	The fair value amounts in the consolidated balance sheets were:
	Notional Amounts1								Other Assets							Other Current Liabilities2				Deferred
																				Income Taxes
																				And Other
																				Long-Term
																				Liabilities2
	December 31,								December 31,							December 31,				December 31,
	2014				2013				2014				2013			2014		2013		2014		2013
	$	11,333			$	12,666			$	—			$	—		$	151	$	—	$	—	$	423
	(1) Notional amounts represent the gross contract/notional amount of the derivative outstanding.
	(2) As of December 31, 2014, the remaining balance of the U.S. long-term note outstanding is considered current because the term of the note expires in June 2015. Accordingly, the interest rate swap liability has been reclassified.
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, 2014, 2013 and 2012, related to the Company's interest rate swap contract was as follows:
			Year Ended December 31,
			2014				2013				2012
	Effective portion recognized in other comprehensive (loss) income, pretax:
	Interest rate swap		$	567			$	881			$	944
	Effective portion reclassified from other comprehensive (loss) income to interest expense, pretax:
	Interest rate swap		$	(295	)		$	(449	)		$	(576	)
	Ineffective portion recognized in income:
	Interest rate swap		$	—			$	—			$	—

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2014
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,
		2014				2013				2012
	Cost of sales	$	4,153			$	3,187			$	2,184
	Sales and marketing	1,567				1,195				1,052
	Research and development	3,033				1,929				1,327
	General and administrative	6,419				5,409				4,002
	Total stock-based compensation	15,172				11,720				8,565
	Tax benefit recognized	(4,865		)		(3,784		)		(2,629		)
	Net stock-based compensation	$	10,307			$	7,936			$	5,936
Weighted Average Assumptions	The Company calculates the fair value of stock option grants using the Black-Scholes option pricing model. Determining the appropriate fair value model and calculating the fair value of stock-based payment awards require 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 weighted average assumptions used in the Black-Scholes model or the calculation of compensation were as follows for the years ended December 31.
		2014		2013		2012
	Expected term	4.7-6.1 years		4.4-6.3 years		4.0-6.6 years
	Volatility	48%-51%		51%-54%		49%-56%
	Risk-free rate of return	1.46%-1.84%		0.74%-1.32%		0.59%-1.23%
	Dividend yield	0.25%		0.25%		—%
	Forfeiture rate	3.04%-5.86%		0%-5.97%		0%-6.1%
Summary Of Option Activity	A summary of option activity, including the employee stock purchase plan, is presented below (see Note 11 for further information):
		Number of			Weighted-				Weighted-		Aggregate
		Options			Average				Average		Intrinsic
					Exercise				Remaining		Value
					Price				Contractual
									Life
									(In years)		(In thousands)
	Outstanding — January 1, 2014	2,674,897			$	37.63
	Granted	463,289			70.67
	Exercised	(414,775	)		16.97
	Forfeited	(31,535	)		62.94
	Outstanding — December 31, 2014	2,691,876			$	45.48			6.62		$	88,500
	Vested or expected to vest — December 31, 2014	2,554,160			$	44.58			6.53		$	85,697
	Exercisable — December 31, 2014	1,027,303			$	24.29			4.83		$	52,018

Inventories_Tables

Inventories (Tables)	12 Months Ended
	Dec. 31, 2014
Inventory Disclosure [Abstract]
Components Of Inventories	Inventories consist of the following:
		December 31,
		2014		2013
	Components and raw materials	$	54,925	$	54,539
	Work-in-process	58,603		64,927
	Finished goods	57,481		53,234
	Total	$	171,009	$	172,700

Property_Plant_And_Equipment_T

Property, Plant, And Equipment (Tables)	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Components Of Property, Plant And Equipment	Property, plant, and equipment consist of the following:
		December 31,
		2014			2013
	Land	$	19,248		$	15,448
	Buildings	144,629			146,730
	Machinery and equipment	202,075			165,050
	Office furniture and fixtures	25,816			23,589
	Construction-in-progress	47,285			52,911
	Total property, plant and equipment	439,053			403,728
	Accumulated depreciation	(163,971		)	(151,483		)
	Total property, plant and equipment — net	$	275,082		$	252,245

Accrued_Expenses_And_Other_Lia1

Accrued Expenses And Other Liabilities (Tables)	12 Months Ended
	Dec. 31, 2014
Payables and Accruals [Abstract]
Components Of Accrued Expenses And Other Liabilities	Accrued expenses and other liabilities consist of the following:
		December 31,
		2014		2013
	Accrued compensation	$	31,673	$	25,727
	Customer deposits and deferred revenue	16,605		18,489
	Current portion of accrued warranty	9,489		7,724
	Other	6,290		7,396
	Total	$	64,057	$	59,336

Financing_Arrangements_Tables

Financing Arrangements (Tables)	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Borrowings Under Existing Financing Arrangements	The Company's borrowings under existing financing arrangements consist of the following:
		December 31,
		2014			2013
	Revolving line of credit facilities:
	European overdraft facilities	$	828		$	1,038
	Euro line of credit	1,803			2,258
	Total	$	2,631		$	3,296
	Term debt:
	U.S. long-term note	$	11,333		$	12,666
	Collateralized long-term note	21,667			—
	Less: current portion	(13,333		)	(1,333		)
	Total long-term debt	$	19,667		$	11,333

Net_Income_Attributable_To_IPG1

Net Income Attributable To IPG Photonics Corporation Per Share (Tables)	12 Months Ended
	Dec. 31, 2014
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,
		2014		2013		2012
	Net income attributable to IPG Photonics Corporation	$	200,445	$	155,780	$	145,004
	Adjustments to redemption value of redeemable noncontrolling interests	—		—		493
	Net income attributable to common stockholders	200,445		155,780		145,497
	Weighted average shares	52,104		51,548		50,477
	Dilutive effect of common stock equivalents	720		827		1,059
	Diluted weighted average common shares	52,824		52,375		51,536
	Basic net income attributable to IPG Photonics Corporation per share	$	3.85	$	3.02	$	2.86
	Adjustments to redemption value of redeemable noncontrolling interests	—		—		0.01
	Basic net income attributable to common stockholders	$	3.85	$	3.02	$	2.87
	Diluted net income attributable to IPG Photonics Corporation per share	$	3.79	$	2.97	$	2.8
	Adjustments to redemption value of redeemable noncontrolling interests	—		—		0.01
	Diluted net income attributable to common stockholders	$	3.79	$	2.97	$	2.81

Commitments_And_Contingencies_

Commitments And Contingencies (Tables)	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Commitments Under Noncancelable Lease Agreements	Commitments under the noncancelable lease agreements as of December 31, 2014 are as follows:
	Years Ending December 31	Facilities		Equipment		Total
	2015	$	3,439	$	951	$	4,390
	2016	2,775		573		3,348
	2017	2,491		336		2,827
	2018	1,544		145		1,689
	2019	1,224		27		1,251
	Thereafter	5		—		5
	Total	$	11,478	$	2,032	$	13,510

Goodwill_And_Intangibles_Table

Goodwill And Intangibles (Tables)	12 Months Ended
	Dec. 31, 2014
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, 2014 and 2013:
		31-Dec-14			31-Dec-13
	Balance at January 1	$	455		$	2,898
	Adjustment	—			(95		)
	Impairment	—			(2,803		)
	Total goodwill arising from acquisition	—			455
	Balance at December 31	$	455		$	455
Intangible Assets	Intangible assets, subject to amortization, consisted of the following:
		31-Dec-14								31-Dec-13
		Gross  Carrying		Accumulated			Net  Carrying		Weighted-	Gross  Carrying		Accumulated			Net  Carrying		Weighted-
		Amount		Amortization			Amount		Average  Lives	Amount		Amortization			Amount		Average  Lives
	Patents	$	6,641	$	(4,221	)	$	2,420	6 Years	$	4,667	$	(4,091	)	$	576	6 Years
	Customer relationships	3,660		(3,308		)	352		5 Years	4,112		(3,324		)	788		5 Years
	Production know-how	6,844		(2,630		)	4,214		8 Years	7,063		(1,747		)	5,316		8 Years
	Technology, trademark and tradename	3,315		(1,074		)	2,241		8 Years	4,271		(1,387		)	2,884		8 Years
		$	20,460	$	(11,233	)	$	9,227		$	20,113	$	(10,549	)	$	9,564
Estimated Future Amortization Expense For Intangibles	The estimated future amortization expense for intangibles as of December 31, 2014 is as follows:
	2015		2016	2017		2018		2019	Thereafter		Total
	$1,783		$1,686	$1,686		$1,621		$1,033	$1,418		$9,227

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Income (Loss) Before Impact Of Income Taxes	Income before the impact of income taxes for the years ended December 31 consisted of the following:
		2014			2013			2012
	U.S.	$	72,800		$	59,006		$	58,964
	Foreign	211,674			159,295			150,251
	Total	$	284,474		$	218,301		$	209,215
Provision For Income Taxes	The Company's provision for income taxes for the years ended December 31 consisted of the following:
		2014			2013			2012
	Current:
	Federal	$	(22,549	)	$	(19,285	)	$	(16,675	)
	State	(2,823		)	(2,617		)	(309		)
	Foreign	(60,143		)	(46,787		)	(38,941		)
	Total current	$	(85,515	)	$	(68,689	)	$	(55,925	)
	Deferred:
	Federal	$	454		$	3,834		$	(2,174	)
	State	27			203			(140		)
	Foreign	1,005			2,131			(3,232		)
	Total deferred	$	1,486		$	6,168		$	(5,546	)
	Provision for income taxes	$	(84,029	)	$	(62,521	)	$	(61,471	)
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:
		2014			2013			2012
	Tax at statutory rate	$	(99,867	)	$	(76,406	)	$	(73,225	)
	Non-U.S. rate differential — net	14,590			10,761			11,744
	State income taxes — net	(1,787		)	(1,512		)	(1,527		)
	Effect of changes in enacted tax rates on deferred tax assets and liabilities	(44		)	186			(617		)
	Nondeductible stock compensation expense	(483		)	(101		)	(1,020		)
	Other nondeductible expenses	(2,063		)	(1,666		)	(794		)
	Federal and state tax credits	5,865			7,500			4,623
	Change in reserves, including interest and penalties	(7		)	(1,273		)	(243		)
	Change in valuation allowance	—			—			(314		)
	Other — net	(233		)	(10		)	(98		)
		$	(84,029	)	$	(62,521	)	$	(61,471	)
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:
		2014			2013			2012
	Property, plant and equipment	$	(5,310	)	$	(2,230	)	$	(3,629	)
	Inventory provisions	10,497			8,261			7,942
	Allowances and accrued liabilities	1,570			3,634			(4,829		)
	Other tax credits	726			769			1,673
	Deferred compensation	4,218			(434		)	3,538
	Net operating loss carryforwards	—			229			5
	Net deferred tax assets	$	11,701		$	10,229		$	4,700
Reconciliation Of Unrecognized Tax Benefits	The following is a tabular reconciliation of the total amounts of unrecognized tax benefits:
		2014			2013			2012
	Balance at January 1	$	6,501		$	5,392		$	4,509
	Reductions of prior period positions	(795		)	(505		)	(317		)
	Additions for tax positions in current period	788			1,614			1,200
	Balance at December 31	$	6,494		$	6,501		$	5,392
Open Tax Years By Major Jurisdictions	Open tax years by major jurisdictions are:
	•     United States	2012 — 2014
	•     Germany	2011 — 2014
	•     Russia	2010 — 2014

Geographic_And_Product_Informa1

Geographic And Product Information (Tables)	12 Months Ended
	Dec. 31, 2014
Geographic And Product Information [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,
		2014		2013		2012
	United States and other North America	$	113,233	$	116,935	$	108,316
	Europe:
	Germany	77,404		65,147		89,848
	Other including Eastern Europe/CIS	173,018		140,279		110,860
	Asia and Australia:
	Japan	72,573		67,981		69,576
	China	245,102		192,134		138,782
	Other	85,426		64,346		43,445
	Rest of World	3,076		1,212		1,701
	Total	$	769,832	$	648,034	$	562,528
Net Sales For Product Lines	Net sales for these product lines are as follows:
		Year Ended December 31,
		2014		2013		2012
	Materials Processing	$	731,274	$	608,702	$	492,013
	Other applications	38,558		39,332		70,515
	Total	$	769,832	$	648,034	$	562,528
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, 2014, 2013 and 2012, are as follows:
		December 31,
		2014		2013		2012
	United States	$	155,428	$	110,441	$	86,226
	Germany	51,528		52,791		47,019
	Russia	59,612		73,747		60,151
	China	6,582		5,895		6,424
	Other	12,507		13,480		15,674
		$	285,657	$	256,354	$	215,494

Selected_Quarterly_Financial_D1

Selected Quarterly Financial Data (Tables)	12 Months Ended
	Dec. 31, 2014
Selected Quarterly Financial Information [Abstract]
Components Of Selected Quarterly Financial Data
	2014	First		Second		Third		Fourth
		Quarter		Quarter		Quarter		Quarter
		(In thousands, except per share data)
	Net sales	$	170,575	$	192,204	$	199,651	$	207,402
	Gross profit	89,284		104,227		109,090		113,917
	Net income attributable to IPG Photonics Corporation	40,531		48,283		55,200		56,431
	Basic earnings per share	0.78		0.93		1.06		1.08
	Diluted earnings per share	0.77		0.92		1.05		1.07
	2013	First		Second		Third		Fourth
		Quarter		Quarter		Quarter		Quarter
		(In thousands, except per share data)
	Net sales	$	141,852	$	168,171	$	172,152	$	165,859
	Gross profit	75,641		89,922		92,813		81,522
	Net income attributable to IPG Photonics Corporation	35,127		41,720		42,338		36,595
	Basic earnings per share	0.68		0.81		0.82		0.71
	Diluted earnings per share	0.67		0.8		0.81		0.7

Nature_Of_Business_And_Summary3

Nature Of Business And Summary Of Significant Accounting Policies (Narrative) (Details) (USD $)	3 Months Ended	12 Months Ended
	Jun. 30, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jun. 29, 2012
		segment
		Financial_Institution
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, interest cost capitalization		$383,000	$524,000	$142,000
Carrying value of demonstration equipment		285,657,000	256,354,000	215,494,000
Impairment		0	2,803,000
Bank acceptance drafts included in Accounts Receivable		25,150,000	17,679,000
Maturity period for bank acceptance drafts		90 days
Accrued warranty reported in accrued expenses and other liabilities		9,489,000	7,724,000
Accrued warranty reported in other long-term liabilities		9,783,000	7,273,000
Percentage of tax positions to be measured at greatest amount of tax benefit		50.00%
High-credit, quality financial institutions		6
Available-for-sale securities		1,450,000	1,450,000
Accrued contingent purchase consideration	196,000
Number of operating segments		1
Other Income (Expense)
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Accrued contingent purchase consideration	2,659,000
JPSA
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Contingent consideration aggregate fair value	0
Russian Subsidiary, NTO IRE-Polus
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Percentage of redeemable noncontrolling interests					22.50%
Not Designated as Hedging Instrument
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Outstanding derivative contracts		0
Demonstration Equipment
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Demonstration equipment, useful life (years)		3 years
Carrying value of demonstration equipment		3,612,000	5,524,000
Amortization expenses of equipment		$2,068,000	$2,725,000	$2,797,000
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
Minimum | Intangible Assets
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Economic lives of intangible assets		5 years
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
Maximum | Intangible Assets
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Economic lives of intangible assets		10 years

Nature_Of_Business_And_Summary4

Nature Of Business And Summary Of Significant Accounting Policies (Economic Useful Lives Of Property, Plant And Equipment) (Details)	12 Months Ended
	Dec. 31, 2014
Buildings
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Useful life	30 years
Minimum | Machinery and equipment
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Useful life	5 years
Minimum | Office furniture and fixtures
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Useful life	3 years
Maximum | Machinery and equipment
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Useful life	12 years
Maximum | Office furniture and fixtures
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Useful life	5 years

Nature_Of_Business_And_Summary5

Nature Of Business And Summary Of Significant Accounting Policies (Allowance For Doubtful Accounts) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance at January 1	$2,473	$2,173	$1,605
Provision for bad debts, net of recoveries	579	323	642
Uncollectable accounts written off	-617	-31	-170
Foreign currency translation	-545	8	96
Balance at December 31	$1,890	$2,473	$2,173

Nature_Of_Business_And_Summary6

Nature Of Business And Summary Of Significant Accounting Policies (Activity Related To The Warranty Accrual) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Movement in Standard Product Warranty Accrual [Roll Forward]
Balance at January 1	$14,997	$10,714	$8,631
Provision for warranty accrual	15,449	11,363	8,112
Warranty claims	-9,165	-7,405	-6,542
Foreign currency translation and other	-2,009	325	513
Balance at December 31	$19,272	$14,997	$10,714

Nature_Of_Business_And_Summary7

Nature Of Business And Summary Of Significant Accounting Policies (Assets And Liabilities Measured At Fair Value) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Total assets	$267,139	$241,279
Total liabilities	249	798
Level 1
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Total assets	266,011	240,159
Level 2
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Total liabilities	151	423
Level 3
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Total assets	1,128	1,120
Total liabilities	98	375
Cash equivalents
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Total assets	266,011	240,159
Cash equivalents | Level 1
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Total assets	266,011	240,159
Auction rate securities
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Total assets	1,128	1,120
Auction rate securities | Level 3
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Total assets	1,128	1,120
Contingent purchase consideration
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Total liabilities	98	375
Contingent purchase consideration | Level 2
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Total liabilities		0
Contingent purchase consideration | Level 3
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Total liabilities	98	375
Interest rate swap
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Total liabilities	151	423
Interest rate swap | Level 2
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Total liabilities	151	423
Interest rate swap | Level 3
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Total liabilities		$0

Nature_Of_Business_And_Summary8

Nature Of Business And Summary Of Significant Accounting Policies (Assets Measured At Fair Value On A Recurring Basis Using Significant Unobservable Inputs) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Auction rate securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, January 1	$1,120	$1,112
Change in fair value and accretion	8	8
Balance, December 31	1,128	1,120
Contingent Purchase Consideration
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, January 1	375	3,023
Change in fair value and accretion	-277	-2,648
Balance, December 31	$98	$375

Nature_Of_Business_And_Summary9

Nature Of Business And Summary Of Significant Accounting Policies (Components Of Accumulated Other Comprehensive Income (Loss)) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Foreign currency translation adjustments	($112,411)	($1,677)
Unrealized loss on derivatives, net of tax of $67 and $168	-84	-256
Change in carrying value of auction rate securities	232	232
Accumulated other comprehensive loss	-112,263	-1,701
Unrealized loss on derivatives, tax	$67	$168

Recovered_Sheet1

Nature Of Business And Summary Of Significant Accounting Policies (Fair Value Of Cash Flow Hedges) (Details) (Interest rate swap, USD $)	Dec. 31, 2014		Dec. 31, 2013
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Notional amount of derivatives	$11,333,000	[1]	$12,666,000	[1]
Other Assets
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Derivative asset fair value	0		0
Other Current Liabilities
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Derivative liability fair value	151,000	[2]	0	[2]
Deferred Income Taxes And Other Long-Term Liabilities
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Derivative liability fair value	$0	[2]	$423,000	[2]
[1]	Notional amounts represent the gross contract/notional amount of the derivative outstanding.
[2]	As of DecemberB 31, 2014, the remaining balance of the U.S. long-term note outstanding is considered current because the term of the note expires in June 2015. Accordingly, the interest rate swap liability has been reclassified.

Recovered_Sheet2

Nature Of Business And Summary Of Significant Accounting Policies (Derivative Gains And Losses In The Consolidated Statements Of Income) (Details) (Interest rate swap, USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Interest rate swap
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Effective portion recognized in other comprehensive (loss) income, pretax:	$567	$881	$944
Effective portion reclassified from other comprehensive (loss) income to interest expense, pretax:	-295	-449	-576
Ineffective portion recognized in income:	$0	$0	$0

StockBased_Compensation_Compon

Stock-Based Compensation (Components Of Stock Based Compensation) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation	$15,172	$11,720	$8,565
Tax benefit recognized	-4,865	-3,784	-2,629
Net stock-based compensation	10,307	7,936	5,936
Cost of sales
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation	4,153	3,187	2,184
Sales and marketing
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation	1,567	1,195	1,052
Research and development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation	3,033	1,929	1,327
General and administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation	$6,419	$5,409	$4,002

StockBased_Compensation_Weight

Stock-Based Compensation (Weighted Average Assumptions) (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Volatility, minimum	48.00%	51.00%	49.00%
Volatility, maximum	51.00%	54.00%	56.00%
Risk free rate of return, minimum	1.46%	0.74%	0.59%
Risk free rate of return, maximum	1.84%	1.32%	1.23%
Dividend yield	0.25%	0.25%	0.00%
Forfeiture rate, minimum	3.04%	0.00%	0.00%
Forfeiture rate, maximum	5.86%	5.97%	6.10%
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term	4 years 8 months	4 years 4 months	4 years
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term	6 years 1 month	6 years 3 months	6 years 7 months 6 days

StockBased_Compensation_Narrat

Stock-Based Compensation (Narrative) (Details) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Apr. 30, 2000	Dec. 31, 2011	Feb. 28, 2006	Jun. 30, 2006
	plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of plans	3
Shares available for future grant	5,491,656
Intrinsic value of options exercised	$23,491	$30,063	$20,792
Weighted-average grant fair value for options granted	$39.12	$28.28	$26.80
Compensation cost related to nonvested awards not yet recorded	27,310
Nonvested awards, weighted average recognition period	2 years 4 months 24 days
Fair value of awards vested	$7,076
2000 Incentive Compensation Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved under plan				5,833,333
2006 Incentive Compensation Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved under plan					6,084,273	4,000,000
Non Employee Directors Stock Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved under plan							486,660
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Period	1 year
Period until expiration	7 years
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Period	5 years
Period until expiration	10 years

StockBased_Compensation_Summar

Stock-Based Compensation (Summary Of Option Activity) (Details) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Number of Options Outstanding, Beginning Balance	2,674,897
Number of Options, Granted	463,289
Number of Options, Exercised	-414,775
Number of Options, Forfeited	-31,535
Number of Options Outstanding, Ending Balance	2,691,876
Number of Options, Vested or expected to vest	2,554,160.37
Number of Options, Exercisable	1,027,303
Weighted-Average Exercise Price, Outstanding, Beginning Balance	$37.63
Weighted-Average Exercise Price, Granted	$70.67
Weighted-Average Exercise Price, Exercised	$16.97
Weighted-Average Exercise Price, Forfeited	$62.94
Weighted-Average Exercise Price, Outstanding, Ending Balance	$45.48
Weighted-Average Exercise Price, Vested or expected to vest	$44.58
Weighted-Average Exercise Price, Exercisable	$24.29
Weighted-Average Remaining Contractual Life (In Years), Outstanding	6 years 7 months 13 days
Weighted-Average Remaining Contractual Life (In Years), Vested or expected to vest	6 years 6 months 11 days
Weighted-Average Remaining Contractual Life (In Years), Exercisable	4 years 9 months 29 days
Aggregate Intrinsic Value, Outstanding	$88,500
Aggregate Intrinsic Value, Vested or expected to vest	85,697
Aggregate Intrinsic Value, Exercisable	$52,018

Inventories_Components_Of_Inve

Inventories (Components Of Inventories) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Inventory Disclosure [Abstract]
Components and raw materials	$54,925	$54,539
Work-in-process	58,603	64,927
Finished goods	57,481	53,234
Total	171,009	172,700
Inventory provisions	$11,302	$15,128	$8,232

Property_Plant_And_Equipment_C

Property, Plant, And Equipment (Components Of Property, Plant, And Equipment) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$439,053	$403,728
Accumulated depreciation	-163,971	-151,483
Total property, plant and equipment b net	275,082	252,245
Depreciation expense	31,334	26,489	21,108
Land
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	19,248	15,448
Buildings
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	144,629	146,730
Machinery and equipment
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	202,075	165,050
Office furniture and fixtures
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	25,816	23,589
Construction-in-progress
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$47,285	$52,911

Accrued_Expenses_And_Other_Lia2

Accrued Expenses And Other Liabilities (Components Of Accrued Expenses And Other Liabilities) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Payables and Accruals [Abstract]
Accrued compensation	$31,673	$25,727
Customer deposits and deferred revenue	16,605	18,489
Current portion of accrued warranty	9,489	7,724
Other	6,290	7,396
Total	$64,057	$59,336

Financing_Arrangements_Borrowi

Financing Arrangements (Borrowings Under Existing Financing Arrangements) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Debt Instrument [Line Items]
Total drawings under credit facility	$2,631,000	$3,296,000
Less: current portion	-13,333,000	-1,333,000
Total long-term debt	19,667,000	11,333,000
European overdraft facilities
Debt Instrument [Line Items]
Total drawings under credit facility	828,000	1,038,000
Euro line of credit
Debt Instrument [Line Items]
Total drawings under credit facility	1,803,000	2,258,000
U.S. long-term note
Debt Instrument [Line Items]
Total drawings under credit facility	11,333,000	12,666,000
Collateralized long-term note
Debt Instrument [Line Items]
Total drawings under credit facility	$21,667,000	$0

Financing_Arrangements_Narrati

Financing Arrangements (Narrative) (Details)

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2014

Dec. 31, 2013

Oct. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

USD ($)

USD ($)

Interest rate swap

Interest rate swap

Long Term Note

U.S. Line Of Credit

Euro Line Of Credit

Euro Line Of Credit

Euro Line Of Credit

Euro Line Of Credit

Euro Line Of Credit

Euro Line Of Credit

Euro Overdraft Facilities

Euro Overdraft Facilities

European overdraft facilities

European overdraft facilities

U.S. long-term note

Minimum

Minimum

Maximum

Maximum

Foreign Subsidiaries

Interest rate swap

Extended Term

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

EUR (€)

Russia

Germany

China

Italy

USD ($)

EUR (€)

USD ($)

EUR (€)

USD ($)

U.S. Line Of Credit

U.S. long-term note

U.S. Line Of Credit

U.S. long-term note

U.S. Line Of Credit

U.S. long-term note

U.S. long-term note

USD ($)

USD ($)

USD ($)

USD ($)

credit_line

USD ($)

Line of Credit Facility [Line Items]

Aggregate available principal under credit facility

$35,000,000

$36,466,000

€ 30,000,000

$19,448,000

$9,724,000

$3,647,000

$3,647,000

$608,000

€ 500,000

$1,823,000

€ 1,500,000

Percentage over LIBOR

1.13%

0.90%

1.63%

1.30%

Total drawings under credit facility

2,631,000

3,296,000

395,000

433,000

14,100,000

Guarantor Obligations, Maximum Exposure, Undiscounted

87,000

4,309,000

Aggregate remaining availability

34,913,000

30,354,000

213,000

1,390,000

Interest rate on credit facility

1.00%

1.00%

1.00%

1.00%

1.00%

1.00%

Number of credit lines

2

2

Monthly principal payments

167,000

111,000

Convertible interest rate percentage

5.00%

2.57%

Debt service coverage ratio

1.5

Outstanding derivative contracts

$11,333,000

[1]

$12,666,000

[1]

Interest rate percentage

2.81%

[1]

Notional amounts represent the gross contract/notional amount of the derivative outstanding.

Redeemable_Noncontrolling_Inte1

Redeemable Noncontrolling Interests and Stockholders' Equity (Narrative) (Details) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jun. 29, 2012
Noncontrolling Interest [Line Items]
Net income (loss) attributable to NCI	$0	$0	$2,740
Common stock, shares authorized	175,000,000	175,000,000
Common stock, par value	$0.00	$0.00
Preferred stock, shares authorized	5,000,000
Preferred stock, par value	$0.00
Shares of preferred stock outstanding	0
Russian Subsidiary, NTO IRE-Polus
Noncontrolling Interest [Line Items]
Percentage of noncontrolling interest				22.50%

RelatedParty_Transactions_Deta

Related-Party Transactions (Details) (USD $)	12 Months Ended		1 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Oct. 31, 2014
	director	director
Purchased Parts and Services from Company which Outside Director is Affiliated
Related Party Transaction [Line Items]
Number of directors	1	1
Payments to suppliers	$3,687,000	$130,000
Purchased Parts and Services from Company which Outside Director is Affiliated | Director
Related Party Transaction [Line Items]
Accounts payable due to company	0	1,155,000
Leased Office Space | CEO and Chairman of the Board | Office space
Related Party Transaction [Line Items]
Area of office space	12,000
Annual lease payments	232,000
Annual increase in lease payments (percentage)	2.50%
Amount paid in transaction	20,000
Leased Aircraft | CEO and Chairman of the Board | Aircraft
Related Party Transaction [Line Items]
Annual lease payments	684,000
Amount paid in transaction			146,000
Percentage of aircraft			25.00%
Products and Services sold to Affiliated Entity | CEO and Chairman of the Board
Related Party Transaction [Line Items]
Related party revenue	$2,731,000
Ownership percentage in Laser Center	39.00%

Net_Income_Attributable_To_IPG2

Net Income Attributable To IPG Photonics Corporation Per Share (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Earnings Per Share [Abstract]
Net income attributable to IPG Photonics Corporation	$56,431	$55,200	$48,283	$40,531	$36,595	$42,338	$41,720	$35,127	$200,445	$155,780	$145,004
Adjustments to redemption value of redeemable NCI									0	0	493
Net income attributable to common stockholders									$200,445	$155,780	$145,497
Weighted average shares (shares)									52,104	51,548	50,477
Dilutive effect of common stock equivalents (shares)									720	827	1,059
Diluted weighted average common shares									52,824	52,375	51,536
Basic net income attributable to IPG Photonics Corporation per share (in dollars per share)									$3.85	$3.02	$2.86
Adjustments to redemption value of redeemable noncontrolling interests (in dollars per share)									$0	$0	$0.01
Basic net income attributable to common stockholders (in dollars per share)	$1.08	$1.06	$0.93	$0.78	$0.71	$0.82	$0.81	$0.68	$3.85	$3.02	$2.87
Diluted net income attributable to IPG Photonics Corporation per share (in dollars per share)									$3.79	$2.97	$2.80
Adjustments to redemption value of redeemable noncontrolling interests (in dollars per share)									$0	$0	$0.01
Diluted net income attributable to common stockholders (in dollars per share)	$1.07	$1.05	$0.92	$0.77	$0.70	$0.81	$0.80	$0.67	$3.79	$2.97	$2.81
Options excluded from computation of diluted weighted average common shares									46,987	322,301	164,858

Commitments_And_Contingencies_1

Commitments And Contingencies (Narrative) (Details) (USD $)	1 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Aug. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
	patent
Other Commitments [Line Items]
Operating lease, rent expense		$5,516	$4,560	$3,885
Purchase obligations		22,288	3,371
Number of patents	1
Members of senior management
Other Commitments [Line Items]
Period for terms of employment agreement		3 years
Agreement to purchase certain intellectual property and know-how related to laser based systems
Other Commitments [Line Items]
Purchase obligations		$4,500

Recovered_Sheet3

Commitments and Contingencies (Commitments Under Noncancelable Lease Agreements) (Details) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Operating Leased Assets [Line Items]
2015	$4,390
2016	3,348
2017	2,827
2018	1,689
2019	1,251
Thereafter	5
Total	13,510
Facilities
Operating Leased Assets [Line Items]
2015	3,439
2016	2,775
2017	2,491
2018	1,544
2019	1,224
Thereafter	5
Total	11,478
Equipment
Operating Leased Assets [Line Items]
2015	951
2016	573
2017	336
2018	145
2019	27
Thereafter	0
Total	$2,032

Employee_Benefit_Plans_Details

Employee Benefit Plans (Details) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Shares available for issuance	5,491,656
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%
Percentage of eligible compensation for employee contribution	6.00%
Compensation Expense	$1,445	$1,127	$848
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	$607	$498	$452
Shares available for issuance	389,314,000

Business_Combinations_Details

Business Combinations (Details) (USD $)	12 Months Ended		0 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Mar. 13, 2013	Aug. 31, 2012	Dec. 31, 2012
				Review_Period
Business Acquisition [Line Items]
Goodwill balance	$455,000	$455,000			$2,898,000
Total goodwill arising from acquisition	0	455,000
Mobius Photonics
Business Acquisition [Line Items]
Acquired finite-lived intangible asset			4,480,000
Estimated useful life	7 years
JPSA
Business Acquisition [Line Items]
Acquired finite-lived intangible asset				3,400,000
Goodwill balance		0
Total goodwill arising from acquisition				2,898,000
Contingent consideration, number of review periods				2
Contingent consideration, duration of review period				1 year
Total possible additional payouts under earn-outs				18,500,000
Contingent consideration aggregate fair value		0
Production know-how | JPSA
Business Acquisition [Line Items]
Acquired finite-lived intangible asset				$2,400,000
Estimated useful life				10 years
Customer relationships | JPSA
Business Acquisition [Line Items]
Estimated useful life				10 years
Noncompete Agreements | JPSA
Business Acquisition [Line Items]
Estimated useful life				5 years
Trade Names | JPSA
Business Acquisition [Line Items]
Estimated useful life				7 years

Goodwill_And_Intangibles_Chang

Goodwill And Intangibles (Changes In The Carrying Amount Of Goodwill) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Goodwill [Roll Forward]
Balance at January 1	$455	$2,898
Adjustment	0	-95
Impairment	0	-2,803
Total goodwill arising from acquisition	0	455
Balance at December 31	$455	$455

Goodwill_And_Intangibles_Narra

Goodwill And Intangibles (Narrative) (Details) (USD $)	12 Months Ended			3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Sep. 30, 2014
Business Acquisition [Line Items]
Goodwill balance	$455,000	$455,000	$2,898,000
Goodwill adjustment	0	95,000
Total goodwill arising from acquisition	0	455,000
Amortization expense of intangibles	2,210,000	2,310,000	2,091,000
IPG Microsystems
Business Acquisition [Line Items]
Goodwill balance		0
Patents
Business Acquisition [Line Items]
Acquired finite-lived intangible asset				$2,000,000

Goodwill_And_Intangibles_Intan

Goodwill And Intangibles (Intangible Assets) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$20,460	$20,113
Accumulated Amortization	-11,233	-10,549
Net Carrying Amount	9,227	9,564
Patents
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	6,641	4,667
Accumulated Amortization	-4,221	-4,091
Net Carrying Amount	2,420	576
Weighted- Average Lives	6 years	6 years
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	3,660	4,112
Accumulated Amortization	-3,308	-3,324
Net Carrying Amount	352	788
Weighted- Average Lives	5 years	5 years
Production know-how
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	6,844	7,063
Accumulated Amortization	-2,630	-1,747
Net Carrying Amount	4,214	5,316
Weighted- Average Lives	8 years	8 years
Technology, trademark and tradename
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	3,315	4,271
Accumulated Amortization	-1,074	-1,387
Net Carrying Amount	$2,241	$2,884
Weighted- Average Lives	8 years	8 years

Goodwill_And_Intangibles_Estim

Goodwill And Intangibles (Estimated Future Amortization Expense For Intangibles) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Goodwill and Intangible Assets Disclosure [Abstract]
2015	$1,783
2016	1,686
2017	1,686
2018	1,621
2019	1,033
Thereafter	1,418
Net Carrying Amount	$9,227	$9,564

Income_Taxes_Income_Loss_Befor

Income Taxes (Income (Loss) Before Impact Of Income Taxes) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
U.S.	$72,800	$59,006	$58,964
Foreign	211,674	159,295	150,251
INCOME BEFORE PROVISION FOR INCOME TAXES	$284,474	$218,301	$209,215

Income_Taxes_Provision_For_Inc

Income Taxes (Provision For Income Taxes) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Federal, current	($22,549)	($19,285)	($16,675)
State, current	-2,823	-2,617	-309
Foreign, current	-60,143	-46,787	-38,941
Total current	-85,515	-68,689	-55,925
Federal, deferred	454	3,834	-2,174
State, deferred	27	203	-140
Foreign, deferred	1,005	2,131	-3,232
Total deferred	1,486	6,168	-5,546
Provision for income taxes	($84,029)	($62,521)	($61,471)

Income_Taxes_Reconciliation_Of

Income Taxes (Reconciliation Of Effective Tax Rate) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Tax at statutory rate	($99,867)	($76,406)	($73,225)
Non-U.S. rate differential b net	14,590	10,761	11,744
State income taxes b net	-1,787	-1,512	-1,527
Effect of changes in enacted tax rates on deferred tax assets and liabilities	-44	186	-617
Nondeductible stock compensation expense	-483	-101	-1,020
Other nondeductible expenses	-2,063	-1,666	-794
Federal and state tax credits	5,865	7,500	4,623
Change in reserves, including interest and penalties	-7	-1,273	-243
Change in valuation allowance	0	0	-314
Other b net	-233	-10	-98
Provision for income taxes	($84,029)	($62,521)	($61,471)

Income_Taxes_Deferred_Tax_Asse

Income Taxes (Deferred Tax Assets And Liabilities) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Income Tax Disclosure [Abstract]
Property, plant and equipment	($5,310)	($2,230)	($3,629)
Inventory provisions	10,497	8,261	7,942
Allowances and accrued liabilities	1,570	3,634	-4,829
Other tax credits	726	769	1,673
Deferred compensation	4,218	-434	3,538
Net operating loss carryforwards	0	229	5
Net deferred tax assets	$11,701	$10,229	$4,700

Income_Taxes_Narrative_Details

Income Taxes (Narrative) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Tax Credit Carryforward [Line Items]
Cumulative unremitted earnings that are reinvested	$522,000	$346,000
Estimated penalties and interest related to the underpayment of income taxes	-192	374	352
Accrued penalties and interest related to the underpayment of income taxes	670	862
UK | Foreign Tax Authority
Tax Credit Carryforward [Line Items]
Net operating loss carry-forwards available for future periods	2,509
State
Tax Credit Carryforward [Line Items]
Tax credit carry forward amount	$1,225	$2,074	$1,419

Income_Taxes_Reconciliation_Of1

Income Taxes (Reconciliation Of Unrecognized Tax Benefits) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at January 1	$6,501	$5,392	$4,509
Reductions of prior period positions	-795	-505	-317
Additions for tax positions in current period	788	1,614	1,200
Balance at December 31	$6,494	$6,501	$5,392

Income_Taxes_Open_Tax_Years_By

Income Taxes (Open Tax Years By Major Jurisdictions) (Details)	12 Months Ended
	Dec. 31, 2014
Minimum | United States
Income Tax Contingency [Line Items]
Open tax years by major jurisdictions	2012
Minimum | Germany
Income Tax Contingency [Line Items]
Open tax years by major jurisdictions	2011
Minimum | Russia
Income Tax Contingency [Line Items]
Open tax years by major jurisdictions	2010
Maximum | United States
Income Tax Contingency [Line Items]
Open tax years by major jurisdictions	2014
Maximum | Germany
Income Tax Contingency [Line Items]
Open tax years by major jurisdictions	2014
Maximum | Russia
Income Tax Contingency [Line Items]
Open tax years by major jurisdictions	2014

Geographic_And_Product_Informa2

Geographic And Product Information (Geographic Sources Of Net Sales Based On Billing Addresses Of Customers) (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Geographic And Product Information [Line Items]
Net sales	$207,402	$199,651	$192,204	$170,575	$165,859	$172,152	$168,171	$141,852	$769,832	$648,034	$562,528
United States and other North America
Geographic And Product Information [Line Items]
Net sales									113,233	116,935	108,316
Germany
Geographic And Product Information [Line Items]
Net sales									77,404	65,147	89,848
Other including Eastern Europe/CIS
Geographic And Product Information [Line Items]
Net sales									173,018	140,279	110,860
Japan
Geographic And Product Information [Line Items]
Net sales									72,573	67,981	69,576
China
Geographic And Product Information [Line Items]
Net sales									245,102	192,134	138,782
Asia and Australia:
Geographic And Product Information [Line Items]
Net sales									85,426	64,346	43,445
Rest of World
Geographic And Product Information [Line Items]
Net sales									$3,076	$1,212	$1,701

Geographic_And_Product_Informa3

Geographic And Product Information (Net Sales For Product Lines) (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Product Information [Line Items]
Net sales	$207,402	$199,651	$192,204	$170,575	$165,859	$172,152	$168,171	$141,852	$769,832	$648,034	$562,528
Materials Processing
Product Information [Line Items]
Net sales									731,274	608,702	492,013
Other applications
Product Information [Line Items]
Net sales									$38,558	$39,332	$70,515

Geographic_And_Product_Informa4

Geographic And Product Information (Narrative) (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
	customer	customer
Concentration Risk [Line Items]
Number of customers	1	1,000
Number of largest customers, sales	5
Net sales by largest customers, percentage	23.00%	21.00%	16.00%
Sales
Concentration Risk [Line Items]
Concentration risk percentage	11.00%	11.00%

Geographic_And_Product_Informa5

Geographic And Product Information (Geographic Locations Of Our Long-Lived Assets, Based On Physical Location Of Assets) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Geographic And Product Information [Line Items]
Long-lived assets	$285,657	$256,354	$215,494
United States
Geographic And Product Information [Line Items]
Long-lived assets	155,428	110,441	86,226
Germany
Geographic And Product Information [Line Items]
Long-lived assets	51,528	52,791	47,019
Russia
Geographic And Product Information [Line Items]
Long-lived assets	59,612	73,747	60,151
China
Geographic And Product Information [Line Items]
Long-lived assets	6,582	5,895	6,424
Other
Geographic And Product Information [Line Items]
Long-lived assets	$12,507	$13,480	$15,674

Selected_Quarterly_Financial_D2

Selected Quarterly Financial Data (Components Of Selected Quarterly Financial Data) (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Selected Quarterly Financial Information [Abstract]
Net sales	$207,402	$199,651	$192,204	$170,575	$165,859	$172,152	$168,171	$141,852	$769,832	$648,034	$562,528
Gross profit	113,917	109,090	104,227	89,284	81,522	92,813	89,922	75,641	416,518	339,898	304,727
Net income attributable to IPG Photonics Corporation	$56,431	$55,200	$48,283	$40,531	$36,595	$42,338	$41,720	$35,127	$200,445	$155,780	$145,004
Basic earnings per share	$1.08	$1.06	$0.93	$0.78	$0.71	$0.82	$0.81	$0.68	$3.85	$3.02	$2.87
Diluted earnings per share	$1.07	$1.05	$0.92	$0.77	$0.70	$0.81	$0.80	$0.67	$3.79	$2.97	$2.81