Document and Entity Information Document	6 Months Ended
	Mar. 31, 2012	May 04, 2012
Entity Information [Line Items]
Entity Registrant Name	INTEGRATED SILICON SOLUTION INC
Entity Central Index Key	0000854701
Current Fiscal Year End Date	--09-30
Entity Filer Category	Accelerated Filer
Document Type	10-Q
Document Period End Date	Mar. 31, 2012
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	Q2
Amendment Flag	false
Entity Common Stock, Shares Outstanding		27,314,255