Western Digital Corporation 401(k) Plan - Additional Information (Details) - USD ($) $ in Millions		12 Months Ended
	Jan. 01, 2022	Jul. 01, 2022	Jul. 02, 2021	Jul. 03, 2020
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		$ 36	$ 34	$ 33
Pre-Tax
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, maximum annual contributions per employee, percent	85.00%	75.00%
Pre Tax and Post Tax
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, maximum annual contributions per employee, percent	10.00%	10.00%
Post-Tax
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, maximum annual contributions per employee, percent		10.00%
After Amendment
Defined Benefit Plan Disclosure [Line Items]
Company contributions vest period		2 years