v3.25.2
Western Digital Corporation 401(k) Plan - Additional Information (Details) - USD ($)
$ in Millions
12 Months Ended
Jun. 27, 2025
Jun. 28, 2024
Jun. 30, 2023
Defined Benefit Plan Disclosure [Line Items]      
Defined contribution plan, employer matching contribution, percent of match 50.00%    
Defined contribution plan, employer matching contribution, percent of employees' gross pay 6.00%    
Defined contribution plan, employer discretionary contribution amount $ 22 $ 8 $ 13
Pre-Tax      
Defined Benefit Plan Disclosure [Line Items]      
Defined contribution plan, maximum annual contributions per employee, percent 85.00%    
Pre Tax and Post Tax      
Defined Benefit Plan Disclosure [Line Items]      
Defined contribution plan, maximum annual contributions per employee, percent 10.00%