Document and Entity Information (USD $) In Billions, except Share data	12 Months Ended
	Jul. 01, 2011	Aug. 03, 2011	Dec. 31, 2010
Document and Entity Information [Abstract]
Entity Registrant Name	WESTERN DIGITAL CORP
Entity Central Index Key	0000106040
Document Type	10-K
Document Period End Date	Jul. 01, 2011
Amendment Flag	false
Document Fiscal Year Focus	2011
Document Fiscal Period Focus	FY
Current Fiscal Year End Date	--07-01
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$ 7.9
Entity Common Stock, Shares Outstanding (actual number)		233,191,524