v3.7.0.1
Document and Entity Information - USD ($)
$ in Billions
12 Months Ended
Jun. 30, 2017
Aug. 16, 2017
Dec. 30, 2016
Document Information [Line Items]      
Entity Registrant Name WESTERN DIGITAL CORP    
Entity Central Index Key 0000106040    
Current Fiscal Year End Date --06-30    
Entity Filer Category Large Accelerated Filer    
Document Type 10-K    
Document Period End Date Jun. 30, 2017    
Document Fiscal Year Focus 2017    
Document Fiscal Period Focus FY    
Amendment Flag false    
Entity Common Stock, Shares Outstanding   294,875,015  
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Public Float     $ 15