XML 83 R65.htm IDEA: XBRL DOCUMENT v3.19.2

Pensions and Other Post-retirement Benefit Plans - Additional Information (Details) - USD ($)	12 Months Ended
	Jun. 28, 2019	Jun. 29, 2018	Jun. 30, 2017
Defined Benefit Plan Disclosure [Line Items]
Actuarial pension gains (losses)	$ 34,000,000	$ 1,000,000	$ (27,000,000)
Pension Plan | Japan Plan
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation	280,000,000
Actuarial pension gains (losses)	(35,000,000)
Prior service credits for defined benefit pension plans included in accumulated other comprehensive income at the balance sheet date	$ 0
Defined benefit pension plan, estimated expenditure (years)	5 years
Debt Securities | Pension Plan | Japan Plan
Defined Benefit Plan Disclosure [Line Items]
Target asset allocation for securities	62.00%
Equity securities | Pension Plan | Japan Plan
Defined Benefit Plan Disclosure [Line Items]
Target asset allocation for securities	35.00%
Other Assets | Pension Plan | Japan Plan
Defined Benefit Plan Disclosure [Line Items]
Target asset allocation for securities	3.00%

X

- Definition

Amount of actuarial present value of benefits attributed to employee service rendered, excluding assumptions about future compensation level.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920

+ Details

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

X

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

X

- Definition

Percentage of target investment allocation to total plan assets. Includes, but is not limited to, percentage on weighted-average basis if more than one plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 55
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=118257860&loc=d3e4179-114921

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(i)
-URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920

+ Details

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

X

- Definition

Amount, after tax and reclassification adjustment, of (increase) decrease in accumulated other comprehensive income for defined benefit plan.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=118930883&loc=d3e637-108580

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 10A
-Subparagraph (i-k)
-URI http://asc.fasb.org/extlink&oid=118930883&loc=SL7669646-108580

+ Details

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

X

- Definition

Defined benefit plan estimated annual benefits payment period.

+ References

No definition available.

+ Details

Name:	wdc_DefinedBenefitPlanEstimatedAnnualBenefitsPaymentPeriod
Namespace Prefix:	wdc_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Prior service credits for defined benefit pension plans included in accumulated other comprehensive income at the balance sheet date.

+ References

No definition available.

+ Details

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

X

- Details

Name:	us-gaap_RetirementPlanTypeAxis=us-gaap_PensionPlansDefinedBenefitMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_RetirementPlanSponsorLocationAxis=us-gaap_ForeignPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_DebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_EquitySecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_OtherAssetsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: