Document and Entity Information (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Sep. 30, 2013	Dec. 07, 2013	Mar. 31, 2013
Document and Entity Information [Abstract]
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-K
Document Period End Date	Sep. 30, 2013
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		29,466,567
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 159,413