This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 25
-Paragraph 23
-URI http://asc.fasb.org/extlink&oid=34752592&loc=d3e1043-128460

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

- Definition

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

+ References

No definition available.

+ Details

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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

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Balance Type:	credit
Period Type:	instant

- Definition

Gross amount of debt extinguished.

+ References

No definition available.

+ Details

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

- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

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

+ References

No definition available.

+ Details

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

- Definition

Debt Instrument, Voluntary Prepayment Fee, Value

+ References

No definition available.

+ Details

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

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- Details

Name:	us-gaap_ShortTermDebtTypeAxis=us-gaap_BridgeLoanMember
Namespace Prefix:
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- Details

Name:	us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
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- Details

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- Details

Name:	us-gaap_BusinessAcquisitionAxis=wdc_SanDiskMember
Namespace Prefix:
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Subsequent Event Subsequent Event - Additional Details (Details) - USD ($) $ in Millions			3 Months Ended
	Aug. 17, 2016	Jul. 21, 2016	Jul. 01, 2016	Apr. 03, 2015	Jan. 02, 2015
U.S. Term Loan B-1 [Member] [Member] \| Line of Credit [Member] \| Subsequent Event [Member]
Subsequent Event [Line Items]
Debt Instrument, Face Amount	$ 3,000
Debt Instrument, Required Quarterly Principal Payment	0.25%
U.S. Term Loan B [Member] \| Line of Credit [Member] \| Subsequent Event [Member]
Subsequent Event [Line Items]
Debt Instrument, Voluntary Prepayment Fee, Value	$ 750
Bridge Loan [Member] \| Subsequent Event [Member]
Subsequent Event [Line Items]
Extinguishment of Debt, Amount		$ 3,000
London Interbank Offered Rate (LIBOR) [Member] \| U.S. Term Loan B-1 [Member] [Member] \| Line of Credit [Member] \| Subsequent Event [Member]
Subsequent Event [Line Items]
Debt Instrument, Basis Spread on Variable Rate	3.75%
Base Rate [Member] \| U.S. Term Loan B-1 [Member] [Member] \| Line of Credit [Member] \| Subsequent Event [Member]
Subsequent Event [Line Items]
Debt Instrument, Basis Spread on Variable Rate	2.75%
SanDisk [Member]
Subsequent Event [Line Items]
Business Combination, Acquisition Related Costs			$ 116	$ 16	$ 27