v2.4.1.9

Segment Information Segment results narrative (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Gross profit	$ 154,787us-gaap_GrossProfit	$ 150,762us-gaap_GrossProfit	$ 163,041us-gaap_GrossProfit	$ 154,535us-gaap_GrossProfit	$ 164,738us-gaap_GrossProfit	$ 150,084us-gaap_GrossProfit	$ 159,588us-gaap_GrossProfit	$ 140,123us-gaap_GrossProfit	$ 623,125us-gaap_GrossProfit	$ 614,533us-gaap_GrossProfit	$ 715,147us-gaap_GrossProfit
Earnings (loss) per common share - Basic	$ (1.25)us-gaap_EarningsPerShareBasic	$ 0.19us-gaap_EarningsPerShareBasic	$ 0.49us-gaap_EarningsPerShareBasic	$ (0.01)us-gaap_EarningsPerShareBasic	$ (3.93)us-gaap_EarningsPerShareBasic	$ (0.19)us-gaap_EarningsPerShareBasic	$ 0.31us-gaap_EarningsPerShareBasic	$ 0.07us-gaap_EarningsPerShareBasic	$ (0.58)us-gaap_EarningsPerShareBasic	$ (3.74)us-gaap_EarningsPerShareBasic	$ 2.73us-gaap_EarningsPerShareBasic
Earnings (loss) per common share - Diluted	$ (1.25)us-gaap_EarningsPerShareDiluted	$ 0.19us-gaap_EarningsPerShareDiluted	$ 0.49us-gaap_EarningsPerShareDiluted	$ (0.01)us-gaap_EarningsPerShareDiluted	$ (3.93)us-gaap_EarningsPerShareDiluted	$ (0.19)us-gaap_EarningsPerShareDiluted	$ 0.31us-gaap_EarningsPerShareDiluted	$ 0.06us-gaap_EarningsPerShareDiluted	$ (0.58)us-gaap_EarningsPerShareDiluted	$ (3.74)us-gaap_EarningsPerShareDiluted	$ 2.71us-gaap_EarningsPerShareDiluted
Electricity Operating Segment [Member]
Segment Reporting Information [Line Items]
Gross profit									208,476us-gaap_GrossProfit / us-gaap_StatementBusinessSegmentsAxis = itri_ElectricityOperatingSegmentMember	218,913us-gaap_GrossProfit / us-gaap_StatementBusinessSegmentsAxis = itri_ElectricityOperatingSegmentMember	295,005us-gaap_GrossProfit / us-gaap_StatementBusinessSegmentsAxis = itri_ElectricityOperatingSegmentMember
OpenWay project in North America [Member] | Electricity Operating Segment [Member] | Contracts Accounted for under Percentage of Completion [Member]
Segment Reporting Information [Line Items]
Gross profit									$ 15,900us-gaap_GrossProfit / us-gaap_ChangeInAccountingEstimateByTypeAxis = us-gaap_ContractsAccountedForUnderPercentageOfCompletionMember / us-gaap_MajorCustomersAxis = itri_OpenWayprojectinNorthAmericaMember / us-gaap_StatementBusinessSegmentsAxis = itri_ElectricityOperatingSegmentMember	$ 16,500us-gaap_GrossProfit / us-gaap_ChangeInAccountingEstimateByTypeAxis = us-gaap_ContractsAccountedForUnderPercentageOfCompletionMember / us-gaap_MajorCustomersAxis = itri_OpenWayprojectinNorthAmericaMember / us-gaap_StatementBusinessSegmentsAxis = itri_ElectricityOperatingSegmentMember
Earnings (loss) per common share - Basic									$ (0.25)us-gaap_EarningsPerShareBasic / us-gaap_ChangeInAccountingEstimateByTypeAxis = us-gaap_ContractsAccountedForUnderPercentageOfCompletionMember / us-gaap_MajorCustomersAxis = itri_OpenWayprojectinNorthAmericaMember / us-gaap_StatementBusinessSegmentsAxis = itri_ElectricityOperatingSegmentMember	$ (0.26)us-gaap_EarningsPerShareBasic / us-gaap_ChangeInAccountingEstimateByTypeAxis = us-gaap_ContractsAccountedForUnderPercentageOfCompletionMember / us-gaap_MajorCustomersAxis = itri_OpenWayprojectinNorthAmericaMember / us-gaap_StatementBusinessSegmentsAxis = itri_ElectricityOperatingSegmentMember
Earnings (loss) per common share - Diluted									$ (0.25)us-gaap_EarningsPerShareDiluted / us-gaap_ChangeInAccountingEstimateByTypeAxis = us-gaap_ContractsAccountedForUnderPercentageOfCompletionMember / us-gaap_MajorCustomersAxis = itri_OpenWayprojectinNorthAmericaMember / us-gaap_StatementBusinessSegmentsAxis = itri_ElectricityOperatingSegmentMember	$ (0.26)us-gaap_EarningsPerShareDiluted / us-gaap_ChangeInAccountingEstimateByTypeAxis = us-gaap_ContractsAccountedForUnderPercentageOfCompletionMember / us-gaap_MajorCustomersAxis = itri_OpenWayprojectinNorthAmericaMember / us-gaap_StatementBusinessSegmentsAxis = itri_ElectricityOperatingSegmentMember

X

- Definition

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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Aggregate revenue less cost of goods and services sold or operating expenses directly attributable to the revenue generation activity.

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