Acquisition - Purchase Price of Business Combination (Detail) (USD $) In Millions, unless otherwise specified	Mar. 08, 2012
Business Combinations [Abstract]
Acquisition of all issued and outstanding paid-up share capital of HGST	$ 4,585
Fair value of stock options, restricted stock-based awards and SARs assumed	102
Total	$ 4,687

The total cost of the acquired entity including the cash paid to shareholders of acquired entities, fair value of debt and equity securities issued to shareholders of acquired entities, the fair value of the liabilities assumed, and direct costs of the acquisition.

No definition available.

Name:	wdc_BusinessAcquisitionCostOfAcquiredEntityPurchasePriceOne
Namespace Prefix:	wdc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant