Commitments and Contingencies Commitments and Contingencies Narrative (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2012
Cell Relay Battery Replacements in North America [Member]
Warranty charge	$ 1.8
Certain Products in Brazil and France [Member]
Warranty charge	$ 2.3

This tag is used to for specific cases of warranty charges (adjustments) disclosed. This is a subset of the tag itri_WarrantyChangesAndAdjustments, which is defined as "Represents the aggregate Increase or Decrease in the liability during the reporting period for accruals related to preexisting product warranties (including adjustments for changes in estimates)."

No definition available.

Name:	itri_WarrantyCharge
Namespace Prefix:	itri_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration