Commitments and Contingencies Narrative (Details) $ in Millions	12 Months Ended
Dec. 31, 2015 USD ($)
Product Warranty Expense, Change	$ 36.7
Warranty charge	$ 29.4

This tag represents 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