v2.4.1.9

Intangible Assets Intangible Assets Narrative (Details) (USD $) In Thousands, unless otherwise specified | 12 Months Ended |
--- | --- | ---
Dec. 31, 2014 | Dec. 31, 2013 | May 01, 2012
Finite-Lived Intangible Assets [Line Items] |  |  |
Finite-lived Intangible Assets Acquired | $ 1,453 us-gaap_FinitelivedIntangibleAssetsAcquired1 | $ (1,500)us-gaap_FinitelivedIntangibleAssetsAcquired1 |
Finite-Lived Intangible Assets, Gross | 748,148 us-gaap_FiniteLivedIntangibleAssetsGross | 804,281 us-gaap_FiniteLivedIntangibleAssetsGross |
Developed Technology Rights [Member] |  |  |
Finite-Lived Intangible Assets [Line Items] |  |  |
Finite-Lived Intangible Assets, Gross | 405,434 us-gaap_FiniteLivedIntangibleAssetsGross / us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis = us-gaap_DevelopedTechnologyRightsMember | 428,890 us-gaap_FiniteLivedIntangibleAssetsGross / us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis = us-gaap_DevelopedTechnologyRightsMember |
Customer Relationships [Member] |  |  |
Finite-Lived Intangible Assets [Line Items] |  |  |
Finite-Lived Intangible Assets, Gross | 262,930 us-gaap_FiniteLivedIntangibleAssetsGross / us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis = us-gaap_CustomerRelationshipsMember | 291,185 us-gaap_FiniteLivedIntangibleAssetsGross / us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis = us-gaap_CustomerRelationshipsMember |
Customer Relationship Associated with Error Adjustment - Balance Prior to Correction of Error [Member] |  |  |
Finite-Lived Intangible Assets [Line Items] |  |  |
Finite-Lived Intangible Assets, Gross |  |  | 1,500 us-gaap_FiniteLivedIntangibleAssetsGross / us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis = itri_CustomerRelationshipAssociatedwithErrorAdjustmentBalancePriortoCorrectionofErrorMember
Adjustment of Intangible Customer Relationship Asset Acquired [Member] | Customer Relationships [Member] |  |  |
Finite-Lived Intangible Assets [Line Items] |  |  |
Finite-lived Intangible Assets Acquired |  | $ 1,500 us-gaap_FinitelivedIntangibleAssetsAcquired1 / us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementByRestatementPeriodAndAmountAxis = itri_AdjustmentofIntangibleCustomerRelationshipAssetAcquiredMember / us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis = us-gaap_CustomerRelationshipsMember |

X
- Definition Amount of increase in assets, excluding financial assets, lacking physical substance with a definite life, resulting from a business combination. + References No definition available. + Details
Name: | us-gaap_FinitelivedIntangibleAssetsAcquired1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life. + References 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_FiniteLivedIntangibleAssetsGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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

X
- Details
Name: | us-gaap_ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementByRestatementPeriodAndAmountAxis=itri_AdjustmentofIntangibleCustomerRelationshipAssetAcquiredMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=itri_CustomerRelationshipAssociatedwithErrorAdjustmentBalancePriortoCorrectionofErrorMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=us-gaap_DevelopedTechnologyRightsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |