Western Digital Corporation 401(k) Plan (Details) (USD $) In Millions	12 Months Ended
Jul. 01, 2011	Jul. 02, 2010	Jul. 03, 2009
Western Digital Corporation 401(k) Plan (Textuals) [Abstract]
Terms of employer contribution	The Company makes a basic matching contribution on behalf of each participating eligible employee equal to fifty percent (50%) of the eligible participant’s pre-tax contributions for the contribution cycle not to exceed 5% of the eligible participant’s compensation; provided, however, that each eligible participant shall receive a minimum annual basic matching contribution equal to fifty percent (50%) of the first $4,000 of pre-tax contributions for any calendar year
Company contributions vest period	5 years
Company contributions	$ 9	$ 9	$ 7

The increase in the fair value of plan assets from contributions made by the employer.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 132R
-Paragraph 5
-Subparagraph b
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (b)(3)
-URI http://asc.fasb.org/extlink&oid=6962843&loc=d3e1928-114920

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Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration