2.4.0.8183 - Disclosure - Acquisition - Purchase Price Allocation (Detail)truefalseIn Millions, unless otherwise specifiedfalse1false USDfalsefalse$eol_PE10781---1310-K0007_STD_0_20130628_0http://www.sec.gov/CIK0000106040instant2013-06-28T00:00:000001-01-01T00:00:00iso4217_USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$2false USDfalsefalse$eol_PE10781---1310-K0007_STD_0_20120629_0http://www.sec.gov/CIK0000106040instant2012-06-29T00:00:000001-01-01T00:00:00iso4217_USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$3false USDtruefalse$eol_PE10781---1310-K0007_STD_0_20130628_0_928576x1048898http://www.sec.gov/CIK0000106040instant2013-06-28T00:00:000001-01-01T00:00:00falsefalseHitachi Global Storage Technologies [Member]us-gaap_BusinessAcquisitionAxisxbrldihttp://xbrl.org/2006/xbrldiwdc_HitachiGlobalStorageTechnologiesMemberus-gaap_BusinessAcquisitionAxisexplicitMemberiso4217_USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$4false USDtruefalse$eol_PE10781---1310-K0007_STD_0_20120308_0_928576x1048898http://www.sec.gov/CIK0000106040instant2012-03-08T00:00:000001-01-01T00:00:00falsefalseHitachi Global Storage Technologies [Member]us-gaap_BusinessAcquisitionAxisxbrldihttp://xbrl.org/2006/xbrldiwdc_HitachiGlobalStorageTechnologiesMemberus-gaap_BusinessAcquisitionAxisexplicitMemberiso4217_USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$1true 3us-gaap_BusinessAcquisitionLineItemsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Business Acquisition [Line Items]2false 4wdc_BusinessAcquisitionPurchasePriceAllocationCashAndShortTermInvestmentswdc_falsedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4truefalsefalse194000000194USD$falsetruefalsexbrli:monetaryItemTypemonetaryBusiness acquisition purchase price allocation cash and short term investments.No definition available.false2Cash and cash equivalents3false 4us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivablesus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4truefalsefalse12900000001290falsefalsefalsexbrli:monetaryItemTypemonetaryAmount due from customers or clients for goods or services, including trade receivables, that have been delivered or sold in the normal course of business, and amounts due from others, including related parties expected to be converted to cash, sold or exchanged within one year or the normal operating cycle, if longer, acquired at the acquisition date.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6910749&loc=d3e4845-128472 false2Accounts receivable4false 4us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventoryus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4truefalsefalse721000000721falsefalsefalsexbrli:monetaryItemTypemonetaryThe amount of inventory recognized as of the acquisition date.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6910749&loc=d3e4845-128472 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 55 -Paragraph 37 -URI http://asc.fasb.org/extlink&oid=25498275&loc=d3e2207-128464 false2Inventories5false 4us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOtherus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4truefalsefalse219000000219falsefalsefalsexbrli:monetaryItemTypemonetaryAmount of other assets expected to be realized or consumed before one year or the normal operating cycle, if longer, acquired at the acquisition date.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6910749&loc=d3e4845-128472 false2Other current assets6false 4us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipmentus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4truefalsefalse18130000001813falsefalsefalsexbrli:monetaryItemTypemonetaryThe amount of property, plant, and equipment recognized as of the acquisition date.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6910749&loc=d3e4845-128472 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 55 -Paragraph 37 -URI http://asc.fasb.org/extlink&oid=25498275&loc=d3e2207-128464 false2Property, plant and equipment7false 4us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssetsus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4truefalsefalse6600000066falsefalsefalsexbrli:monetaryItemTypemonetaryAmount of other assets expected to be realized or consumed after one year or the normal operating cycle, if longer, acquired at the acquisition date.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6910749&loc=d3e4845-128472 false2Other non-current assets8false 4us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayableus-gaap_truecreditinstantfalsefalsefalsefalsefalsefalsefalsetruenegatedLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4truefalsefalse-841000000-841falsefalsefalsexbrli:monetaryItemTypemonetaryAmount of liabilities incurred for goods and services received that are used in an entity's business and related party payables, assumed at the acquisition date.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6910749&loc=d3e4845-128472 false2Accounts payable9false 4us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesOtherus-gaap_truecreditinstantfalsefalsefalsefalsefalsefalsefalsetruenegatedLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4truefalsefalse-594000000-594falsefalsefalsexbrli:monetaryItemTypemonetaryAmount of other liabilities due within one year or within the normal operating cycle, if longer, assumed at the acquisition date.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6910749&loc=d3e4845-128472 false2Accrued liabilities10false 4us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesLongTermDebtus-gaap_truecreditinstantfalsefalsefalsefalsefalsefalsefalsetruenegatedLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4truefalsefalse-585000000-585falsefalsefalsexbrli:monetaryItemTypemonetaryAmount of long-term debt due after one year or the normal operating cycle, if longer, assumed at the acquisition date.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6910749&loc=d3e4845-128472 false2Debt assumed11false 4wdc_BusinessAcquisitionPurchasePriceAllocationPensionAndOtherRetirementBenefitLiabilitieswdc_falsecreditinstantfalsefalsefalsefalsefalsefalsefalsetruenegatedLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4truefalsefalse-130000000-130falsefalsefalsexbrli:monetaryItemTypemonetaryBusiness acquisition purchase price allocation pension and other retirement benefit liabilities.No definition available.false2Pension and other post-retirement benefit liabilities12false 4us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOtherus-gaap_truecreditinstantfalsefalsefalsefalsefalsefalsefalsetruenegatedLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4truefalsefalse-102000000-102falsefalsefalsexbrli:monetaryItemTypemonetaryAmount of other liabilities due after one year or the normal operating cycle, if longer, assumed at the acquisition date.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6910749&loc=d3e4845-128472 false2Other liabilities13false 4us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwillus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4truefalsefalse833000000833falsefalsefalsexbrli:monetaryItemTypemonetaryAmount of intangible assets, excluding goodwill, acquired at the acquisition date.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6910749&loc=d3e4845-128472 false2Intangible assets14false 4us-gaap_Goodwillus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse19540000001954falsefalsefalse2truefalsefalse19750000001975falsefalsefalse3truefalsefalse18000000001800falsefalsefalse4truefalsefalse18030000001803falsefalsefalsexbrli:monetaryItemTypemonetaryAmount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=14024403&loc=d3e13816-109267 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266 false2Goodwill15false 4us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNetus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalsetotalLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4truefalsefalse46870000004687USD$falsetruefalsexbrli:monetaryItemTypemonetaryAmount recognized for assets, including goodwill, in excess of (less than) the aggregate liabilities assumed.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6910749&loc=d3e4845-128472 true2TotalfalseAcquisition - Purchase Price Allocation (Detail) (USD $)MillionsUnKnownUnKnownUnKnowntruefalsefalseSheethttp://www.westerndigital.com/taxonomy/role/DisclosureAcquisitionPurchasePriceAllocation415