v2.4.1.9

Stock-Based Compensation Stock-Based Compensation Narrative (Details) (USD $) In Millions, except Share data, unless otherwise specified | 3 Months Ended | 9 Months Ended | 12 Months Ended
--- | --- | --- | ---
Dec. 31, 2014 | Sep. 30, 2013 | Dec. 31, 2014
Employee Stock Option [Member] |  |  |
[Line Items] |  |  |
Award vesting rights |  |  | Options generally become exercisable in three equal annual installments beginning one year from the date of grant
Unrecognized compensation expense | 2.8 us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized / us-gaap_AwardTypeAxis = us-gaap_EmployeeStockOptionMember |  | 2.8 us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized / us-gaap_AwardTypeAxis = us-gaap_EmployeeStockOptionMember
Unrecognized compensation expense, Expected weighted average period for recognition |  |  | 1 year 7 months
Stock Options Expiration Period |  |  | 10 years
Restricted Stock Units (RSUs) [Member] |  |  |
[Line Items] |  |  |
Unrecognized compensation expense | 14.5 us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized / us-gaap_AwardTypeAxis = us-gaap_RestrictedStockUnitsRSUMember |  | 14.5 us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized / us-gaap_AwardTypeAxis = us-gaap_RestrictedStockUnitsRSUMember
Unrecognized compensation expense, Expected weighted average period for recognition |  |  | 1 year 8 months
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period |  |  | 3 years
Long Term Performance Restricted Stock Award [Member] |  |  |
[Line Items] |  |  |
Restricted Awards Eligible For Vesting |  |  | 0 us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOther / us-gaap_AwardTypeAxis = itri_LongTermPerformanceRestrictedStockAwardMember
Share-based Compensation Arrangement by Share-based Payment Award, Performance Condition Vesting Range, Lower Range Limit |  |  | 0.00%itri_ShareBasedCompensationArrangementByShareBasedPaymentAwardPerformanceConditionVestingRangeLowerRangeLimit / us-gaap_AwardTypeAxis = itri_LongTermPerformanceRestrictedStockAwardMember
Share-based Compensation Arrangement by Share-based Payment Award, Performance Condition Vesting Range, Upper Range Limit |  |  | 160.00%itri_ShareBasedCompensationArrangementByShareBasedPaymentAwardPerformanceConditionVestingRangeUpperRangeLimit / us-gaap_AwardTypeAxis = itri_LongTermPerformanceRestrictedStockAwardMember
Share-based Compensation Arrangement by Share-based Payment Award, Market Condition Multiplier, Lower Range Limit |  |  | 75.00%itri_ShareBasedCompensationArrangementByShareBasedPaymentAwardMarketConditionMultiplierLowerRangeLimit / us-gaap_AwardTypeAxis = itri_LongTermPerformanceRestrictedStockAwardMember
Share-based Compensation Arrangement by Share-based Payment Award, Market Condition Multiplier, Upper Range Limit |  |  | 125.00%itri_ShareBasedCompensationArrangementByShareBasedPaymentAwardMarketConditionMultiplierUpperRangeLimit / us-gaap_AwardTypeAxis = itri_LongTermPerformanceRestrictedStockAwardMember
Share-based Compensation Arrangement by Share-based Payment Award, Possible Total Percentage of Shares Vested, Lower Range Limit |  |  | 0.00%itri_ShareBasedCompensationArrangementByShareBasedPaymentAwardPossibleTotalPercentageOfSharesVestedLowerRangeLimit / us-gaap_AwardTypeAxis = itri_LongTermPerformanceRestrictedStockAwardMember
Share-based Compensation Arrangement by Share-based Payment Award, Possible Total Percentage of Shares Vested, Upper Range Limit |  |  | 200.00%itri_ShareBasedCompensationArrangementByShareBasedPaymentAwardPossibleTotalPercentageOfSharesVestedUpperRangeLimit / us-gaap_AwardTypeAxis = itri_LongTermPerformanceRestrictedStockAwardMember
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Number of Shares |  |  | 14,433 us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares / us-gaap_AwardTypeAxis = itri_LongTermPerformanceRestrictedStockAwardMember
Employee Stock [Member] |  |  |
[Line Items] |  |  |
Number of shares available for future grant under the Stock Incentive Plan | 445,000 us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant / us-gaap_AwardTypeAxis = us-gaap_EmployeeStockMember |  | 445,000 us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant / us-gaap_AwardTypeAxis = us-gaap_EmployeeStockMember
Share-based Compensation Arrangement by Share-based Payment Award, Discount from Market Price, Purchase Date | 5.00%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPricePurchaseDate / us-gaap_AwardTypeAxis = us-gaap_EmployeeStockMember | 15.00%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPricePurchaseDate / us-gaap_AwardTypeAxis = us-gaap_EmployeeStockMember | 5.00%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPricePurchaseDate / us-gaap_AwardTypeAxis = us-gaap_EmployeeStockMember
ESPP, maximum percentage of employee salary eligible for participation | 10.00%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumEmployeeSubscriptionRate / us-gaap_AwardTypeAxis = us-gaap_EmployeeStockMember |  | 10.00%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumEmployeeSubscriptionRate / us-gaap_AwardTypeAxis = us-gaap_EmployeeStockMember
Stock Incentive Plan [Member] |  |  |
[Line Items] |  |  |
Number of shares authorized for issuance under the Stock Incentive Plan | 7,473,956 us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized / us-gaap_PlanNameAxis = itri_StockIncentivePlanMember |  | 7,473,956 us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized / us-gaap_PlanNameAxis = itri_StockIncentivePlanMember
Number of shares available for future grant under the Stock Incentive Plan | 3,680,607 us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant / us-gaap_PlanNameAxis = itri_StockIncentivePlanMember |  | 3,680,607 us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant / us-gaap_PlanNameAxis = itri_StockIncentivePlanMember
Share-based Compensation Arrangement by Share-based Payment Award, Description |  |  | The Stock Incentive Plan shares are subject to a fungible share provision such that, with respect to grants made after December 31, 2009, the authorized share reserve is reduced by (i) one share for every one share subject to a stock option or share appreciation right granted under the Plan and (ii) 1.7 shares for every one share of common stock that was subject to an award other than an option or stock appreciation right.

X
- Definition For a multiplier payout feature, which provides for the multiplication of shares earned by a percentage factor as the result of achievement against a market condition, the lower range limit of the multiplier, in percentage terms. + References No definition available. + Details
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- Definition For a multiplier payout feature, which provides for the multiplication of shares earned by a percentage factor as the result of achievement against a market condition, the upper range limit of the multiplier, in percentage terms. + References No definition available. + Details
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- Definition For awards with a performance condition that results in a variable percentage of shares being earned, relative to the number of awards originally granted, the lower range limit of the variable percentage range. + References No definition available. + Details
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- Definition For awards with a performance condition that results in a variable percentage of shares being earned, relative to the number of awards originally granted, the upper range limit of the variable percentage range. + References No definition available. + Details
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- Definition For awards whereby a variable percentage of shares will ultimately vest, relative to the number of awards originally granted, based upon the combination of multiple performance or market conditions, the lower range limit of the total variable percentage range. + References No definition available. + Details
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- Definition For awards whereby a variable percentage of shares will ultimately vest, relative to the number of awards originally granted, based upon the combination of multiple performance or market conditions, the upper range limit of the total variable percentage range. + References No definition available. + Details
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- Definition Unrecognized cost of unvested share-based compensation awards. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition Description of award terms as to how many shares or portion of an award are no longer contingent on satisfaction of either a service condition, market condition or a performance condition, thereby giving the employee the legal right to convert the award to shares, to sell the shares, and be entitled to the cash proceeds of such sale. For example, vesting may be expressed as being 25 percent of the shares under option on each anniversary of the grant date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition General descriptive information regarding an arrangement under which employees and directors receive: (a) awards of equity shares, equity share options, or other equity instruments; or (b) the entity incurs liabilities to them: (1) in amounts based, at least in part, on the price of the entity's shares or other equity instruments; or (2) that require or may require settlement by issuance of the entity's shares. Such an arrangement is usually provided to employees and directors to compensate them, provide performance incentives to them, and to attract or retain their services. May also include pertinent information particular to a plan that is not elsewhere specified in the taxonomy. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5047-113901 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition Discount rate from fair value on purchase date that participants pay for shares. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition The highest percentage of annual salary that an employee is permitted to utilize with respect to the plan. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition Other increase (decrease) in number of shares reserved for issuance under non-option equity instrument agreements that is not separately disclosed. + References No definition available. + Details
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- Definition The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(3) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition Number of options vested. + References No definition available. + Details
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