v2.4.0.6
Stock-Based Compensation Stock Option Summary (Details) (Employee Stock Option [Member], USD $)
In Thousands, except Per Share data, unless otherwise specified
 3 Months Ended
Mar. 31, 2013
Dec. 31, 2012
Mar. 31, 2012
Dec. 31, 2011
Employee Stock Option [Member]
        
[Line Items]        
Outstanding, beginning balance, Number 1,137   1,109  
Outstanding, beginning balance, Weighted Average Exercise Price Per Share $ 54.06   $ 55.97  
Outstanding, beginning balance, Aggregate Intrinsic Value $ 3,815 [1]   $ 2,323 [1]  
Granted, Number 129   54  
Granted, Weighted Average Exercise Price Per Share $ 42.76   $ 48.23  
Granted, Weighted Average Grant Date Fair Value $ 15.44   $ 18.64  
Exercised, Number (11)   (13)  
Exercised, Weighted Average Exercise Price Per Share $ 28.92   $ 21.60  
Exercised, Aggregate Intrinsic Value 171 [1]   280 [1]  
Expired, Number (3)   (1)  
Expired, Weighted Average Exercise Price Per Share $ 48.51   $ 48.51  
Outstanding, ending balance, Number 1,252 1,137 1,149 1,109
Outstanding, ending balance, Weighted Average Exercise Price Per Share $ 53.14 $ 54.06 $ 56.00 $ 55.97
Outstanding, ending balance, Weighted Average Remaining Contractual Term 5 years 1 month 21 days 4 years 9 months 21 days 4 years 5 months 4 years 6 months 3 days
Outstanding, ending balance, Aggregate Intrinsic Value 4,805 [1] 3,815 [1] 4,638 [1] 2,323 [1]
Exercisable, Number 928      
Exercisable, Weighted Average Exercise Price Per Share $ 56.63      
Exercisable, Weighted Average Remaining Contractual Term 3 years 7 months 1 day      
Exercisable, Aggregate Intrinsic Value 3,557 [1]      
Expected to Vest, Number 301      
Expected to Vest, Weighted Average Exercise Price Per Share $ 43.17      
Expected to Vest, Weighted Average Remaining Contractual Term 9 years 6 months 25 days      
Expected to Vest, Aggregate Intrinsic Value $ 1,157      
[1] The aggregate intrinsic value of outstanding stock options represents amounts that would have been received by the optionees had all in- the-money options been exercised on that date. Specifically, it is the amount by which the market value of Itron’s stock exceeded the exercise price of the outstanding in-the-money options before applicable income taxes, based on our closing stock price on the last business day of the period. The aggregate intrinsic value of stock options exercised during the period is calculated based on our stock price at the date of exercise.