XML 86 R68.htm IDEA: XBRL DOCUMENT
v3.19.2

Pensions and Other Post-retirement Benefit Plans - Defined Benefit Pension Plans' Major Asset Categories and Their Associated Fair Values (Details) - USD ($) $ in Millions | Jun. 28, 2019 | Jun. 29, 2018
--- | --- | ---
Defined Benefit Plan Disclosure [Line Items] |  |
Defined benefit plan, fair value of plan assets | $ 208 | $ 200
Level 1 |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Defined benefit plan, fair value of plan assets | 9 | 3
Level 2 |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Defined benefit plan, fair value of plan assets | 199 | 197
Level 3 |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Defined benefit plan, fair value of plan assets | 0 | 0
Equity Commingled/Mutual Funds |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Defined benefit plan, fair value of plan assets | 68 | 68
Equity Commingled/Mutual Funds | Level 1 |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Defined benefit plan, fair value of plan assets | 0 | 0
Equity Commingled/Mutual Funds | Level 2 |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Defined benefit plan, fair value of plan assets | 68 | 68
Equity Commingled/Mutual Funds | Level 3 |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Defined benefit plan, fair value of plan assets | 0 | 0
Fixed income commingled/mutual funds |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Defined benefit plan, fair value of plan assets | 131 | 125
Fixed income commingled/mutual funds | Level 1 |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Defined benefit plan, fair value of plan assets | 0 | 0
Fixed income commingled/mutual funds | Level 2 |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Defined benefit plan, fair value of plan assets | 131 | 125
Fixed income commingled/mutual funds | Level 3 |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Defined benefit plan, fair value of plan assets | 0 | 0
Cash equivalents and short-term investments |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Defined benefit plan, fair value of plan assets | 9 | 7
Cash equivalents and short-term investments | Level 1 |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Defined benefit plan, fair value of plan assets | 9 | 3
Cash equivalents and short-term investments | Level 2 |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Defined benefit plan, fair value of plan assets | 0 | 4
Cash equivalents and short-term investments | Level 3 |  |
Defined Benefit Plan Disclosure [Line Items] |  |
Defined benefit plan, fair value of plan assets | $ 0 | $ 0

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 Amount of asset segregated and restricted to provide benefit under defined benefit plan. Asset includes, but is not limited to, stock, bond, other investment, earning from investment, and contribution by employer and employee. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(iv)(01) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(iv)(01) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(ii) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920 Reference 4: 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 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920 Reference 6: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(ii) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=wdc_EquityCommingledMutualFundsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_AssetBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_CashAndCashEquivalentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |