Percentage points added to the reference rate to compute the variable rate on the debt instrument.

No definition available.

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=34725769&loc=d3e28878-108400

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

+ Details

Name:	us-gaap_DebtInstrumentInterestRateEffectivePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of debt issuance costs (for example, but not limited to, legal, accounting, broker, and regulatory fees).

+ References

No definition available.

+ Details

Name:	us-gaap_DebtIssuanceCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6802200&loc=d3e1835-112601

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 3
-Subparagraph (SX 210.12-04.(a))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24072-122690

+ Details

Name:	us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 3
-Subparagraph (SX 210.12-04.(a))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24072-122690

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6802200&loc=d3e1835-112601

+ Details

Name:	us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

+ Details

Name:	us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

+ Details

Name:	us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The interest rate applicable to the portion of the carrying amount of long-term borrowings outstanding as of the balance sheet date, including current maturities, which accrues interest at a rate subject to change from time to time.

+ References

+ Details

Name:	us-gaap_LongTermDebtPercentageBearingVariableInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The cash inflow during the period from additional borrowings in aggregate debt. Includes proceeds from short-term and long-term debt.

+ References

No definition available.

+ Details

Name:	us-gaap_ProceedsFromIssuanceOfDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Debt Instrument, EURIBOR Applicable Margin

+ References

No definition available.

+ Details

Name:	wdc_DebtInstrumentEURIBORApplicableMargin
Namespace Prefix:	wdc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument, EURIBOR Floor

+ References

No definition available.

+ Details

Name:	wdc_DebtInstrumentEURIBORFloor
Namespace Prefix:	wdc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument, LIBOR Applicable Margin

+ References

No definition available.

+ Details

Name:	wdc_DebtInstrumentLIBORApplicableMargin
Namespace Prefix:	wdc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument, LIBOR Floor

+ References

No definition available.

+ Details

Name:	wdc_DebtInstrumentLIBORFloor
Namespace Prefix:	wdc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument, Prepayment Fee Percentage

+ References

No definition available.

+ Details

Name:	wdc_DebtInstrumentPrepaymentFeePercentage
Namespace Prefix:	wdc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The required quarterly principal payment percentage on the Term Loan B Facilities principal amount beginning in September 2016.

+ References

No definition available.

+ Details

Name:	wdc_DebtInstrumentRequiredQuarterlyPrincipalPayment
Namespace Prefix:	wdc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percent Limitation on Pledges of Capital of Foreign Subsidiaries

+ References

No definition available.

+ Details

Name:	wdc_PercentLimitationonPledgesofCapitalofForeignSubsidiaries
Namespace Prefix:	wdc_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Sublimit for Swing Line Loans Under Revolving Credit Facility.

+ References

No definition available.

+ Details

Name:	wdc_SublimitForSwingLineLoansUnderRevolvingCreditFacility
Namespace Prefix:	wdc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_LineOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=wdc_TermLoanAMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=wdc_U.S.TermLoanBMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=wdc_EuroTermLoanBMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=wdc_TermLoanBFacilitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Debt- New Credit Agreement (Details) € in Millions, $ in Millions			2 Months Ended
	May 12, 2016 USD ($)	Apr. 29, 2016 USD ($)	Jul. 01, 2016 USD ($)	Sep. 30, 2016	Apr. 29, 2016 EUR (€)	Apr. 29, 2016 USD ($)
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Year Two			$ 254
Long-term Debt, Maturities, Repayments of Principal in Year Three			357
Long-term Debt, Maturities, Repayments of Principal in Year Four			460
Long-term Debt, Maturities, Repayments of Principal in Year Five			3,306
Line of Credit [Member] \| Term Loan A [Member]
Debt Instrument [Line Items]
Debt Instrument, Term		5 years
Debt Instrument, Face Amount						$ 4,125
Proceeds from Issuance of Debt	$ 4,059
Debt Issuance Cost	$ 66
Long-term Debt, Maturities, Repayments of Principal in Year Two			206
Long-term Debt, Maturities, Repayments of Principal in Year Three			309
Long-term Debt, Maturities, Repayments of Principal in Year Four			413
Long-term Debt, Maturities, Repayments of Principal in Year Five			$ 3,197
Line of Credit [Member] \| Term Loan A [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate			2.00%
Debt Instrument, Interest Rate, Effective Percentage			2.45%
Line of Credit [Member] \| U.S. Term Loan B [Member]
Debt Instrument [Line Items]
Debt Instrument, Term		7 years
Debt Instrument, Face Amount						$ 3,750
Proceeds from Issuance of Debt		$ 3,541
Debt Issuance Cost		$ 209
Debt Instrument, LIBOR Floor					0.75%	0.75%
Debt Instrument, LIBOR Applicable Margin					5.50%	5.50%
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate			6.25%
Debt Instrument, Prepayment Fee Percentage			1.00%
Line of Credit [Member] \| U.S. Term Loan B [Member] \| Subsequent Event [Member]
Debt Instrument [Line Items]
Debt Instrument, Required Quarterly Principal Payment				0.25%
Line of Credit [Member] \| Euro Term Loan B [Member]
Debt Instrument [Line Items]
Debt Instrument, Term		7 years
Debt Instrument, Face Amount \| €					€ 885
Proceeds from Issuance of Debt		$ 980
Debt Issuance Cost		$ 28
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate			6.00%
Debt Instrument, EURIBOR Floor					0.75%	0.75%
Debt Instrument, EURIBOR Applicable Margin					5.25%	5.25%
Line of Credit [Member] \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity						$ 1,000
Sublimit for Swing Line Loans Under Revolving Credit Facility						$ 200
Line of Credit [Member] \| Term Loan B Facilities [Member]
Debt Instrument [Line Items]
Percent Limitation on Pledges of Capital of Foreign Subsidiaries			0.65