2.4.0.8182 - Disclosure - Acquisition - Purchase Price of Business Combination (Detail)truefalseIn Millions, unless otherwise specifiedfalse1false USDfalsefalse$eol_PE10781---1310-K0007_STD_0_20120308_0http://www.sec.gov/CIK0000106040instant2012-03-08T00:00:000001-01-01T00:00:00iso4217_USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$1true 1us-gaap_BusinessCombinationsAbstractus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Business Combinations [Abstract]2false 2wdc_IssuedAndOutstandingPaidUpShareCapitalAcquiredAsResultOfBusinessCombinationwdc_falsedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse45850000004585USD$falsetruefalsexbrli:monetaryItemTypemonetaryIssued and outstanding paid up share capital acquired as a result of business combination.No definition available.false2Acquisition of all issued and outstanding paid-up share capital of HGST3false 2wdc_FairValueOfStockOptionsRestrictedStockBasedAwardsAndStockAppreciationRightsAssumedwdc_falsedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse102000000102falsefalsefalsexbrli:monetaryItemTypemonetaryFair value of stock options restricted stock based awards and stock appreciation rights assumed.No definition available.false2Fair value of stock options, restricted stock-based awards and SARs assumed4false 2wdc_BusinessAcquisitionCostOfAcquiredEntityPurchasePriceOnewdc_falsedebitinstantfalsefalsefalsefalsefalsefalsefalsefalsetotalLabel1truefalsefalse46870000004687USD$falsetruefalsexbrli:monetaryItemTypemonetaryThe 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.true2TotalfalseAcquisition - Purchase Price of Business Combination (Detail) (USD $)MillionsUnKnownUnKnownUnKnowntruefalsefalseSheethttp://www.westerndigital.com/taxonomy/role/DisclosureAcquisitionPurchasePriceOfBusinessCombination14