Stock-Based Compensation Stock Option Summary (Details) (Employee Stock Option [Member], USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Employee Stock Option [Member]
[Line Items]
Outstanding, beginning balance, Number	1,180		1,137		1,109
Outstanding, beginning balance, Weighted Average Exercise Price Per Share	$ 54.79		$ 54.06		$ 55.97
Outstanding, beginning balance, Weighted Average Remaining Contractual Term	4 years 4 months 15 days		4 years 7 months 22 days		4 years 9 months 23 days		4 years 6 months 2 days
Outstanding, beginning balance, Aggregate Intrinsic Value	$ 1,300	[1]	$ 3,815	[1]	$ 2,323	[1]
Granted, Number	160		129		196
Granted, Weighted Average Exercise Price Per Share	$ 35.65		$ 42.76		$ 43.27
Granted, Weighted Average Grant Date Fair Value	$ 13.65		$ 15.44		$ 16.51
Exercised, Number	(67)		(74)		(54)
Exercised, Weighted Average Exercise Price Per Share	$ 28.03		$ 23.87		$ 21.91
Exercised, Aggregate Intrinsic Value	826	[1]	1,377	[1]	1,078	[1]
Forfeited, Number	(7)
Forfeited, Weighted Average Exercise Price Per Share	$ 44.06
Expired, Number	(143)		(12)		(114)
Expired, Weighted Average Exercise Price Per Share	$ 68.97		$ 49.04		$ 69.37
Outstanding, ending balance, Number	1,123		1,180		1,137		1,109
Outstanding, ending balance, Weighted Average Exercise Price Per Share	$ 51.90		$ 54.79		$ 54.06		$ 55.97
Outstanding, ending balance, Weighted Average Remaining Contractual Term	4 years 4 months 15 days		4 years 7 months 22 days		4 years 9 months 23 days		4 years 6 months 2 days
Outstanding, ending balance, Aggregate Intrinsic Value	1,676	[1]	1,300	[1]	3,815	[1]	2,323	[1]
Exercisable, Number	819
Exercisable, Weighted Average Exercise Price Per Share	$ 56.65
Exercisable, Weighted Average Remaining Contractual Term	3 years 2 months 10 days
Exercisable, Aggregate Intrinsic Value	569	[1]
Share Based Compensation Arrangement By Share Based Payment Award Options Expected To Vest Number	296
Share Based Compensation Arrangement By Share Based Payment Award Options Expected To Vest Outstanding Weighted Average Exercise Price	$ 39.12
Share Based Compensation Arrangement By Share Based Payment Award Options Expected To Vest Weighted Average Remaining Contractual Term	7 years 8 months 15 days
Share Based Compensation Arrangement By Share Based Payment Award Options Expected To Vest Aggregate Intrinsic Value	$ 1,074	[1]

[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.