Shareholders’ Equity and Convertible Preferred Stock - Stock-Based Compensation Expense (Details) - USD ($) $ in Millions	12 Months Ended
Jul. 03, 2026	Jun. 27, 2025	Jun. 28, 2024
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expenses on stock-based compensation	$ 204	$ 167	$ 202
Tax benefit	(36)	(23)	(30)
Total	168	144	172
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Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expenses on stock-based compensation	33	34	36
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Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expenses on stock-based compensation	87	73	65
Income Statement Location [Axis]: us-gaap:SellingGeneralAndAdministrativeExpense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expenses on stock-based compensation	75	60	101
Income Statement Location [Axis]: wdc:BusinessRealignmentCharges
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expenses on stock-based compensation	9	0	0
RSUs and PSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expenses on stock-based compensation	188	151	182
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expenses on stock-based compensation	$ 16	$ 16	$ 20

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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