v2.4.1.9

Shareholders' Equity Share Repurchase Plan Information (Details) (USD $) In Millions, except Share data, unless otherwise specified | 2 Months Ended | 10 Months Ended | 2 Months Ended |  |  |  |
--- | --- | --- | --- | --- | --- | --- | ---
Mar. 07, 2014 | Dec. 31, 2014 | Feb. 20, 2015 | Feb. 07, 2014 | Dec. 31, 2013 | Mar. 08, 2013 | Feb. 19, 2015
Stock Repurchased and Retired During Period, Shares | 75,203 us-gaap_StockRepurchasedAndRetiredDuringPeriodShares | 910,990 us-gaap_StockRepurchasedAndRetiredDuringPeriodShares |  |  |  |  |
Stock Repurchase Program, Authorized Amount |  |  |  | $ 50.0 us-gaap_StockRepurchaseProgramAuthorizedAmount1 |  | $ 50.0 us-gaap_StockRepurchaseProgramAuthorizedAmount1 |
Stock Repurchased and Retired During Period, Value | 2.9 us-gaap_StockRepurchasedAndRetiredDuringPeriodValue | 36.7 us-gaap_StockRepurchasedAndRetiredDuringPeriodValue |  |  |  |  |
Stock Repurchase Program, Remaining Authorized Repurchase Amount |  | 13.3 us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1 |  |  |  |  |
Preferred stock, shares authorized |  | 10,000,000 us-gaap_PreferredStockSharesAuthorized |  |  | 10,000,000 us-gaap_PreferredStockSharesAuthorized |  |
Subsequent Event [Member] |  |  |  |  |  |  |
Stock Repurchased and Retired During Period, Shares |  |  | 335,251 us-gaap_StockRepurchasedAndRetiredDuringPeriodShares / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember |  |  |  |
Stock Repurchased and Retired During Period, Average Price Per Share |  |  | $ 39.62 itri_StockRepurchasedAndRetiredDuringPeriodAveragePricePerShare / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember |  |  |  |
Stock Repurchase Program, Authorized Amount |  |  |  |  |  |  | $ 50.0 us-gaap_StockRepurchaseProgramAuthorizedAmount1 / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember

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- Definition Stock Repurchased and Retired During Period, Average Price Per Share + References No definition available. + Details
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- Definition The maximum number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) permitted to be issued by an entity's charter and bylaws. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.28) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29 -Article 5 + Details
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Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

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- Definition Number of shares that have been repurchased and retired during the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29, 30 -Article 5 + Details
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Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

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- Definition Equity impact of the value of stock that has been repurchased and retired during the period. The excess of the purchase price over par value can be charged against retained earnings (once the excess is fully allocated to additional paid in capital). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29, 30, 31 -Article 5 + Details
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Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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- Definition Amount of stock repurchase plan authorized. + References No definition available. + Details
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Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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- Definition Amount remaining of a stock repurchase plan authorized. + References No definition available. + Details
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Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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- Details
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Namespace Prefix: |
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Balance Type: |
Period Type: |