Organization and Basis of Presentation (Policies)	3 Months Ended
Organization and Basis of Presentation (Policies)	Oct. 03, 2025
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Western Digital Corporation (“Western Digital” or the “Company”) is a leading developer, manufacturer, and provider of data storage devices and solutions based on hard disk drives (“HDD”) technologies. The Company manufactures, markets, and sells data storage devices and solutions in the United States (“U.S.”) and in foreign countries through its sales personnel, dealers, distributors, retailers, and subsidiaries. Its broad portfolio of technology and products addresses the following key end markets: Cloud, Client, and Consumer. Cloud is comprised primarily of products for public or private cloud environments and enterprise customers. Through the Client end market, the Company provides its OEM and channel customers a broad array of high-performance HDD solutions across desktop and notebooks. The Consumer end market provides a broad range of retail and other end-user products, which capitalize on the strength of the Company’s product brand recognition and vast presence around the world. The accounting policies followed by the Company are set forth in Part II, Item 8, Note 1, Organization and Basis of Presentation, of the Notes to Consolidated Financial Statements included in the Company’s Annual Report on Form 10‑K for the year ended June 27, 2025 (the “2025 Annual Report on Form 10-K”). In the opinion of management, all adjustments necessary to fairly state the Condensed Consolidated Financial Statements have been made. Such adjustments consist of items of a normal, recurring nature. Certain information and disclosures normally included in the Consolidated Financial Statements prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”) have been condensed or omitted pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). These Condensed Consolidated Financial Statements should be read in conjunction with the Consolidated Financial Statements and the notes thereto included in the 2025 Annual Report on Form 10‑K. The results of operations for interim periods are not necessarily indicative of results to be expected for the full year. Information provided herein for the three months ended September 27, 2024 is presented on a continuing operations basis to reflect the impact of the Separation of the Company’s Flash business as discussed in further detail in Note 4, Discontinued Operations.
Fiscal Year	Fiscal Year The Company’s fiscal year ends on the Friday nearest to June 30 and typically consists of 52 weeks. Approximately every five to six years, the Company reports a 53-week fiscal year to align the fiscal year with the foregoing policy. Fiscal year 2026, which will end on July 3, 2026, will be comprised of 53 weeks, with the first quarter consisting of 14 weeks and the remaining quarters consisting of 13 weeks each. Fiscal year 2025, which ended on June 27, 2025, was comprised of 52 weeks, with all quarters presented consisting of 13 weeks. Unless otherwise indicated, references herein to specific years and quarters are to fiscal years and fiscal quarters, and references to financial information are on a consolidated continuing operations basis.
Segment Reporting	Segment Reporting The Company’s Chief Executive Officer is the Company’s Chief Operating Decision Maker (“CODM”). The CODM manages the business as a provider of data storage devices based on HDD technology. The CODM evaluates the performance of the Company and makes decisions regarding the allocation of resources based on the Company’s Net income from continuing operations and Total assets. The Company has, therefore, determined that it has one reportable segment.
Use of Estimates	Use of Estimates Company management has made estimates and assumptions relating to the reporting of certain assets and liabilities in conformity with U.S. GAAP. These estimates and assumptions have been applied using methodologies that are consistent throughout the periods presented; however, actual results could differ materially.
Recently Issued Accounting Pronouncements Not Yet Adopted	Recently Issued Accounting Pronouncements Not Yet Adopted In September 2025, the Financial Accounting Standards Board (“FASB”) issued accounting standards update (“ASU”) No. 2025-07, “Derivatives and Hedging (Topic 815) and Revenue from Contracts with Customers (Topic 606): Derivatives Scope Refinements and Scope Clarification for Share-Based Noncash Consideration from a Customer in a Revenue Contract. (“ASU 2025-07”) which (i) expands the scope exception of Topic 815 to exclude certain contracts with a variable that is based on operations or activities specific to one of the parties to the contract and (ii) clarifies the scope of share-based payments from a customer in a revenue contract. ASU 2025-07 is effective for the year beginning July 3, 2027, and interim periods within that year. Early adoption is permitted and must be applied as of the beginning of the fiscal year that includes the interim period. The Company currently does not expect this standard to have a material impact on its condensed consolidated financial statements and related disclosures. In September 2025, the FASB issued ASU No. 2025-06, “Intangibles – Goodwill and Other – Internal-Use Software (Topic 350): Targeted Improvements to the Accounting for Internal-Use Software” (“ASU 2025-06”). ASU 2025-06 amends existing references to prescriptive and sequential software development stages to better align with current software development methods, such as agile development. Under the new standard, entities will begin to capitalize eligible software costs when (i) management has authorized and committed to funding the software project, and (ii) it is probable that the project will be completed and the software will be used to perform the function intended. ASU 2025-06 is effective for the year beginning July 1, 2028, and interim periods within that year, with early adoption permitted. The Company is currently assessing the impact of this standard on its condensed consolidated financial statements and related disclosures. In November 2024, the FASB issued ASU No. 2024-03, “Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses” (“ASU 2024-03”), which is intended to improve disclosures about the expenses of public entities. The new guidance requires more detailed information about the types of expenses in commonly presented expense captions (such as cost of sales and selling, general and administrative expenses) and requires public entities to disclose, on an annual and interim basis, the amounts of expenses included in each relevant expense caption presented on the face of the income statement, within continuing operations, in a tabular format. Additionally, public entities will be required to disclose a qualitative description of the amounts remaining in relevant expense captions that are not separately disaggregated quantitatively, the total amount of selling expenses, and, in annual reporting periods, the definition of selling expenses. This standard is effective on either a prospective or retrospective basis with early adoption permitted. The Company is currently compiling the information required for these disclosures and assessing the basis of adoption and expects to adopt the guidance for annual reporting periods in its annual report for the year ending June 30, 2028. In December 2023, the FASB issued ASU No. 2023-09, “Income Taxes (Topic 740): Improvements to Income Tax Disclosures” (“ASU 2023-09”). ASU 2023-09 calls for enhanced income tax disclosure requirements surrounding the tabular rate reconciliation and income taxes paid. This standard is effective on either a prospective or retrospective basis. These incremental disclosures will be required beginning with the Company’s financial statements for the year ending July 3, 2026. The Company is currently compiling the information required for these disclosures and expects to provide any required disclosures in its annual report for the year ending July 3, 2026.
Fair Value Measurements and Investments	Financial assets and liabilities that are remeasured and reported at fair value at each reporting period are classified and disclosed in one of the following three levels: Level 1. Quoted prices in active markets for identical assets or liabilities. Level 2. Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3. Inputs that are unobservable for the asset or liability and that are significant to the fair value of the assets or liabilities.

Disclosure of accounting policy for segment reporting.

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+ Details

- Definition

Disclosure of accounting policy for the use of estimates in the preparation of financial statements in conformity with generally accepted accounting principles.

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+ Details

WESTERN DIGITAL CORP 10-Q