Document and Entity Information (USD $)	12 Months Ended
	Apr. 01, 2012	May 16, 2012	Sep. 30, 2011
Document and Entity Information [Abstract]
Entity Registrant Name	QLOGIC CORP
Entity Central Index Key	0000918386
Document Type	10-K
Document Period End Date	Apr. 01, 2012
Amendment Flag	false
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	FY
Current Fiscal Year End Date	--04-01
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$ 1,284,348,000
Entity Common Stock, Shares Outstanding		97,450,000