Goodwill And Intangibles (Intangible Assets) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
Mar. 31, 2015	Dec. 31, 2013	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 26,249		$ 20,460
Accumulated Amortization	(11,336)		(11,233)
Net Carrying Amount	14,913us-gaap_FiniteLivedIntangibleAssetsNet		9,227us-gaap_FiniteLivedIntangibleAssetsNet
Patents
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	6,641		6,641
Accumulated Amortization	(4,309)		(4,221)
Net Carrying Amount	2,332		2,420
Weighted- Average Lives	6 years	6 years
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	3,357		3,660
Accumulated Amortization	(3,097)		(3,308)
Net Carrying Amount	260		352
Weighted- Average Lives	5 years	5 years
Production know-how
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	6,664		6,844
Accumulated Amortization	(2,742)		(2,630)
Net Carrying Amount	3,922		4,214
Weighted- Average Lives	8 years	8 years
Technology, trademark and tradename
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	9,587		3,315
Accumulated Amortization	(1,188)		(1,074)
Net Carrying Amount	$ 8,399		$ 2,241
Weighted- Average Lives	8 years	8 years

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetsGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_FiniteLivedIntangibleAssetsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetsNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetUsefulLife
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=ipgp_ProductionKnowHowMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=ipgp_TechnologyTrademarkAndTradenameMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=us-gaap_CustomerRelationshipsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=us-gaap_PatentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: