CONDENSED CONSOLIDATED STATEMENTS OF INCOME (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended	9 Months Ended
Apr. 03, 2015	Mar. 28, 2014	Apr. 03, 2015	Mar. 28, 2014
Income Statement [Abstract]
Revenue, net	$ 3,550us-gaap_SalesRevenueGoodsNet	$ 3,703us-gaap_SalesRevenueGoodsNet	$ 11,381us-gaap_SalesRevenueGoodsNet	$ 11,479us-gaap_SalesRevenueGoodsNet
Cost of revenue	2,518us-gaap_CostOfGoodsSold	2,627us-gaap_CostOfGoodsSold	8,090us-gaap_CostOfGoodsSold	8,148us-gaap_CostOfGoodsSold
Gross margin	1,032us-gaap_GrossProfit	1,076us-gaap_GrossProfit	3,291us-gaap_GrossProfit	3,331us-gaap_GrossProfit
Operating expenses:
Research and development	402	418	1,265	1,235
Selling, general and administrative	199	201	583	559
Charges related to arbitration award	0wdc_ArbitrationAwardProvision	13wdc_ArbitrationAwardProvision	15wdc_ArbitrationAwardProvision	39wdc_ArbitrationAwardProvision
Employee termination, asset impairment and other charges	10	25	72	59
Total operating expenses	611us-gaap_OperatingExpenses	657us-gaap_OperatingExpenses	1,935us-gaap_OperatingExpenses	1,892us-gaap_OperatingExpenses
Operating income	421us-gaap_OperatingIncomeLoss	419us-gaap_OperatingIncomeLoss	1,356us-gaap_OperatingIncomeLoss	1,439us-gaap_OperatingIncomeLoss
Other income (expense):
Interest and other income	3us-gaap_InvestmentIncomeInterest	4us-gaap_InvestmentIncomeInterest	11us-gaap_InvestmentIncomeInterest	10us-gaap_InvestmentIncomeInterest
Interest and other expense	(12)wdc_InterestAndOtherExpense	(17)wdc_InterestAndOtherExpense	(37)wdc_InterestAndOtherExpense	(44)wdc_InterestAndOtherExpense
Total other expense, net	(9)us-gaap_NonoperatingIncomeExpense	(13)us-gaap_NonoperatingIncomeExpense	(26)us-gaap_NonoperatingIncomeExpense	(34)us-gaap_NonoperatingIncomeExpense
Income before income taxes	412	406	1,330	1,405
Income tax provision	28us-gaap_IncomeTaxExpenseBenefit	31us-gaap_IncomeTaxExpenseBenefit	85us-gaap_IncomeTaxExpenseBenefit	105us-gaap_IncomeTaxExpenseBenefit
Net income	$ 384us-gaap_NetIncomeLoss	$ 375us-gaap_NetIncomeLoss	$ 1,245us-gaap_NetIncomeLoss	$ 1,300us-gaap_NetIncomeLoss
Income per common share:
Basic	$ 1.66us-gaap_EarningsPerShareBasic	$ 1.60us-gaap_EarningsPerShareBasic	$ 5.34us-gaap_EarningsPerShareBasic	$ 5.51us-gaap_EarningsPerShareBasic
Diluted	$ 1.63us-gaap_EarningsPerShareDiluted	$ 1.55us-gaap_EarningsPerShareDiluted	$ 5.23us-gaap_EarningsPerShareDiluted	$ 5.37us-gaap_EarningsPerShareDiluted
Weighted average shares outstanding:
Basic	231	235	233	236
Diluted	236	242	238	242

Total costs related to goods produced and sold during the reporting period.

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Generally recurring costs associated with normal operations except for the portion of these expenses which can be clearly related to production and included in cost of sales or services. Includes selling, general and administrative expense.

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The costs incurred in a planned search or critical investigation aimed at discovery of new knowledge with the hope that such knowledge will be useful in developing a new product or service, a new process or technique, or in bringing about a significant improvement to an existing product or process; or to translate research findings or other knowledge into a plan or design for a new product or process or for a significant improvement to an existing product or process whether intended for sale or the entity's use, during the reporting period charged to research and development projects, excluding in-process research and development acquired in a business combination consummated during the period. Excludes software research and development, which has a separate concept.

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The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

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Amount charged against operating income for arbitration award.

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