v3.19.2
Cover Page - USD ($)
$ in Billions
12 Months Ended
Jun. 28, 2019
Aug. 14, 2019
Dec. 28, 2018
Cover page.      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Jun. 28, 2019    
Document Transition Report false    
Entity File Number 1-8703    
Entity Registrant Name WESTERN DIGITAL CORP    
Entity Incorporation, State or Country Code DE    
Entity Tax Identification Number 33-0956711    
Entity Address, Address Line One 5601 Great Oaks Parkway    
Entity Address, City or Town San Jose,    
Entity Address, State or Province CA    
Entity Address, Postal Zip Code 95119    
City Area Code 408    
Local Phone Number 717-6000    
Title of 12(b) Security Common Stock, $.01 Par Value Per Share    
Trading Symbol WDC    
Security Exchange Name NASDAQ    
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Large Accelerated Filer    
Entity Small Business false    
Entity Emerging Growth Company false    
Entity Shell Company false    
Entity Public Float     $ 9.5
Entity Common Stock, Shares Outstanding (in shares)   296,003,875  
Entity Central Index Key 0000106040    
Current Fiscal Year End Date --06-28    
Document Fiscal Year Focus 2019    
Document Fiscal Period Focus FY    
Amendment Flag false