Document and Entity Information	9 Months Ended
	Sep. 30, 2011
Document and Entity Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2011
Entity Registrant Name	ITRON INC /WA/
Entity Central Index Key	0000780571
Document Fiscal Year Focus	2011
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding	40,732,045
Trading Symbol	ITRI