Document and Entity Information	3 Months Ended
	Mar. 31, 2012
Document and Entity Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2012
Entity Registrant Name	ITRON INC /WA/
Entity Central Index Key	0000780571
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding	39,958,625
Trading Symbol	ITRI