v2.4.0.6

Basis of Consolidation Policy Additional Information (Details) | 3 Months Ended
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Mar. 31, 2013
Maximum [Member] |
Ownership Interest to be Held for Consolidation [Line Items] |
Ownership Interest To Use Equity Method | 50.00%
Ownership Interest To Use Cost Method | 20.00%
Minimum [Member] |
Ownership Interest to be Held for Consolidation [Line Items] |
Ownership Interest to be Held for Consolidation | 50.00%

X
- Definition Ownership Interest to be Held for Consolidation + References No definition available. + Details
Name: | itri_OwnershipInterestToBeHeldForConsolidation
Namespace Prefix: | itri_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | itri_OwnershipInterestToBeHeldForConsolidationLineItems
Namespace Prefix: | itri_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Entities in which the company has less than 20% investment and where they do not excercise significant influence are accounted for under the cost method. + References No definition available. + Details
Name: | itri_OwnershipInterestToUseCostMethod
Namespace Prefix: | itri_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The equity method of accounting is used for entities in which the company has a 50% or less invesment and exercises significant influence. + References No definition available. + Details
Name: | itri_OwnershipInterestToUseEquityMethod
Namespace Prefix: | itri_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration