Shareholders’ Equity and Convertible Preferred Stock - Convertible Preferred Stock, Share Repurchase Program and Dividends (Details) $ / shares in Units, $ in Millions				12 Months Ended
	Jul. 29, 2025 $ / shares	Feb. 21, 2025 day $ / shares	Jan. 31, 2023 USD ($) day $ / shares shares	Jun. 27, 2025 USD ($) $ / shares shares	Jun. 28, 2024 USD ($) $ / shares shares	May 09, 2025 USD ($)	Jun. 30, 2023 shares	Jul. 01, 2022 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Convertible preferred stock, shares authorized (in shares)				5,000,000	5,000,000
Convertible preferred stock, par value (in dollars per share) \| $ / shares				$ 0.01	$ 0.01
Conversion of convertible preferred stock (in shares)					700,000
Convertible preferred stock, shares outstanding (in shares)				200,000	200,000		900,000	0
Preferred dividends in cash \| $				$ 8
Convertible preferred stock, liquidation preference \| $				$ 265	$ 257
Stock repurchase program, number of shares authorized to be repurchased \| $						$ 2,000
Repurchases of common stock (in shares)				2,800,000
Treasury stock, common shares at cost \| $				$ 149
Stock repurchase program, remaining authorized repurchase, amount \| $				$ 1,850
Cash dividends declared per share (in USD per share) \| $ / shares				$ 0.1
Cash dividends \| $				$ 36
Subsequent Event
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cash dividends declared per share (in USD per share) \| $ / shares	$ 0.10
Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Conversion of convertible preferred stock (in shares)				15,000,000	15,000,000
Series A Preferred Stock \| Private Placement
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Convertible preferred stock, shares authorized (in shares)			900,000
Convertible preferred stock, par value (in dollars per share) \| $ / shares			$ 0.01
Convertible Preferred Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Conversion of convertible preferred stock (in shares)				665,000
Convertible preferred stock, shares outstanding (in shares)				235,000	235,000
Initial conversion rate (in dollar per share) \| $ / shares		$ 47.75	$ 35.51
Preferred stock, convertible, conversion ratio			0.33
Consecutive trading days \| day		10
Outstanding, potentially convertible (in shares)				7,000,000	5,000,000
Accumulated stated value, percentage			110.00%	110.00%
Convertible Preferred Stock \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Consecutive trading days \| day			30
Conversion price, percentage			150.00%
Convertible Preferred Stock \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Consecutive trading days \| day			20
Convertible Preferred Stock \| Private Placement
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Convertible preferred stock, shares authorized (in shares)			5,000,000
Convertible preferred stock, par value (in dollars per share) \| $ / shares			$ 1,000
Aggregate purchase price \| $			$ 900
Issuance costs \| $			$ 24
Preferred dividend annual rate increasing per annum (as percent)			6.25%
Cumulative dividends \| $				$ 30	$ 22
Convertible Preferred Stock \| Private Placement \| January 31, 2030
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred dividend annual rate increasing per annum (as percent)			7.25%
Convertible Preferred Stock \| Private Placement \| January 31, 2033
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred dividend annual rate increasing per annum (as percent)			8.25%

WESTERN DIGITAL CORP 10-K