Percentage of ownership interest held In merged entity.

No definition available.

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

- Definition

The amount of future capital expenditures that the entity is committed to make.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2020-01-01
-Paragraph 112
-Subparagraph c
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-URIDate 2020-01-01

+ Details

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Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

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

+ References

No definition available.

+ Details

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Namespace Prefix:	ifrs-full_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of tangible assets that: (a) are held for use in the production or supply of goods or services, for rental to others, or for administrative purposes; and (b) are expected to be used during more than one period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 16
-IssueDate 2020-01-01
-Paragraph 73
-Subparagraph e
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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-URIDate 2020-01-01

+ Details

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Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The amount of provision for costs related to decommissioning, restoration and rehabilitation. [Refer: Other provisions]

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Name IAS
-Number 37
-IssueDate 2020-01-01
-Section D Examples: disclosures
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Reference 2: http://www.xbrl.org/2003/role/exampleRef
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+ Details

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Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_OwnershipAxis=bhp_BhpGroupMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_NonadjustingEventsAfterReportingPeriodAxis=bhp_JansenStage1PotashProjectMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Subsequent Events - Additional Information (Detail) $ in Millions, $ in Billions	Aug. 17, 2021 USD ($)	Aug. 17, 2021 CAD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)
Disclosure of non-adjusting events after reporting period [line items]
Major growth investment commitments			$ 2,469	$ 2,585
Property, plant and equipment			$ 73,813	$ 72,362	$ 68,041
Proposed Merger of Petroleum Assets with Woodside [Member] \| Petroleum [member]
Disclosure of non-adjusting events after reporting period [line items]
Property, plant and equipment	$ 11,900
Closure and rehabilitation provisions	$ 3,900
Proposed Merger of Petroleum Assets with Woodside [Member] \| Petroleum [member] \| Woodside [Member]
Disclosure of non-adjusting events after reporting period [line items]
Percentage of ownership interest held In merged entity	52.00%	52.00%
Proposed Merger of Petroleum Assets with Woodside [Member] \| Petroleum [member] \| BHP Group [Member]
Disclosure of non-adjusting events after reporting period [line items]
Percentage of ownership interest held In merged entity	48.00%	48.00%
Jansen Stage 1 Potash Project [Member]
Disclosure of non-adjusting events after reporting period [line items]
Major growth investment commitments	$ 5,700	$ 7.5