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.

No definition available.

+ Details

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

- Definition

Aggregate dividends declared during the period for each share of common stock outstanding.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

+ Details

Name:	us-gaap_CommonStockDividendsPerShareDeclared
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Cash outflow in the form of capital distributions and dividends to common shareholders, preferred shareholders and noncontrolling interests.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3291-108585

+ Details

Name:	us-gaap_PaymentsOfDividends
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Equity impact of dividends declared by an entity during the period. This element includes paid and unpaid dividends declared during the period.

+ References

No definition available.

+ Details

Name:	wdc_DividendsDeclared
Namespace Prefix:	wdc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

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

Shareholders' Equity - Dividends (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended						9 Months Ended
	Apr. 17, 2020	Apr. 03, 2020	Jan. 03, 2020	Oct. 04, 2019	Mar. 29, 2019	Dec. 28, 2018	Sep. 28, 2018	Apr. 03, 2020	Mar. 29, 2019
Class of Stock [Line Items]
Cash dividends declared per share (in USD per share)		$ 0.50			$ 0.50			$ 1.50	$ 1.50
Dividends declared		$ 150	$ 149	$ 149	$ 146	$ 146	$ 144	$ 448
Dividends paid								$ 445	$ 438
Subsequent Event
Class of Stock [Line Items]
Dividends paid	$ 150