The net fair value of financial assets and financial liability.

No definition available.

Name:	bhp_NetFinancialAssetsAtFairValue
Namespace Prefix:	bhp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Percentage borrowings with floating rates.

+ References

No definition available.

+ Details

Name:	bhp_PercentageBorrowingsExposedToFloatingRates
Namespace Prefix:	bhp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Risk exposure associated with instruments sharing characteristic, amount of change in risk.

+ References

No definition available.

+ Details

Name:	bhp_RiskExposureAssociatedWithInstrumentsSharingCharacteristicAmountOfChangeInRisk
Namespace Prefix:	bhp_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- Definition

Risk exposure associated with instruments sharing characteristic, percentage change in risk.

+ References

No definition available.

+ Details

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

- Definition

Tonnes of exposure for provisionally priced.

+ References

No definition available.

+ Details

Name:	bhp_TonnesOfExposureForProvisionallyPriced
Namespace Prefix:	bhp_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant

- Definition

Transfer between fair value hierarchy categories.

+ References

No definition available.

+ Details

Name:	bhp_TransferBetweenFairValueHierarchyCategories
Namespace Prefix:	bhp_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of outstanding funds that the entity is obligated to repay.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2020-01-01
-Paragraph 55
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_55&doctype=Standard
-URIDate 2020-01-01

+ Details

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

- Definition

The adjustment to the basis (reference rate) used for calculation of the interest rate on borrowings. [Refer: Borrowings]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IFRS
-Number 7
-IssueDate 2020-01-01
-Paragraph 7
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2020-en-r&anchor=para_7&doctype=Standard
-URIDate 2020-01-01

+ Details

Name:	ifrs-full_BorrowingsAdjustmentToInterestRateBasis
Namespace Prefix:	ifrs-full_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The basis (reference rate) used for calculation of the interest rate on borrowings. [Refer: Borrowings]

+ References

+ Details

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

- 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

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

- Definition

The gains (losses) resulting from change in the fair value of derivatives recognised in profit or loss. [Refer: Derivatives [member]]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2020-01-01
-Paragraph 85
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_85&doctype=Standard
-URIDate 2020-01-01

+ Details

Name:	ifrs-full_GainsLossesOnChangeInFairValueOfDerivatives
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The amount of loans received.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2020-01-01
-Paragraph 112
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_112_c&doctype=Standard
-URIDate 2020-01-01

+ Details

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

- Definition

The nominal amount of the hedging instruments in hedging relationships to which the entity is applying the exceptions in the scope of the amendments for interest rate benchmark reform. [Refer: Nominal amount of hedging instrument]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2020-01-01
-Paragraph 24H
-Subparagraph e
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2020-en-r&anchor=para_24H_e&doctype=Standard
-URIDate 2020-01-01

+ Details

Name:	ifrs-full_NominalAmountOfHedgingInstrumentsInHedgingRelationshipsToWhichAmendmentsForInterestRateBenchmarkReformAreApplied
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- Definition

The amount of risk exposure associated with financial instruments with a shared characteristic that identifies a concentration of risks. [Refer: Financial instruments, class [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2020-01-01
-Paragraph B8
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2020-en-r&anchor=para_B8_c&doctype=Appendix&subtype=B
-URIDate 2020-01-01

+ Details

Name:	ifrs-full_RiskExposureAssociatedWithInstrumentsSharingCharacteristic
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	ifrs-full_TypesOfRisksAxis=ifrs-full_InterestRateRiskMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_TypesOfRisksAxis=ifrs-full_CurrencyRiskMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_TypesOfRisksAxis=ifrs-full_CommodityPriceRiskMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ClassesOfFinancialAssetsAxis=bhp_ForwardCommodityAndOtherDerivativeContractsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ClassesOfFinancialAssetsAxis=bhp_SignificantFinancialInstrumentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ClassesOfFinancialAssetsAxis=bhp_ProvisionallyPricedContractMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_TypesOfInterestRatesAxis=bhp_FixedInterestRateNotSwappedToFloatingRateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_MeasurementAxis=ifrs-full_AtFairValueMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Financial Risk Management - Additional Information (Detail) t in Thousands, $ in Millions	12 Months Ended
	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($) t	Jun. 30, 2019 USD ($)	Jun. 30, 2021 AUD ($) t	Jun. 30, 2021 GBP (£) t	Jun. 30, 2021 EUR (€) t	Jun. 30, 2021 USD ($) t	Jun. 30, 2021 CLP ($) t
Disclosure of detailed information about financial instruments [line items]
Borrowings		$ 23,605					$ 17,087
Transfer between fair value hierarchy categories	$ 0
Percentage of borrowings exposed to floating interest rate	82.00%	87.00%
Weighted average interest rate payable	USD LIBOR + 2.18 per cent	USD LIBOR + 2.95 per cent
Debt instrument variable interest rate spread		2.95%		2.18%	2.18%	2.18%	2.18%	2.18%
Fair value change on derivatives	$ 145	$ 422	$ 8
Loans received from bank							$ 2,300
Interest rate risk [member]
Disclosure of detailed information about financial instruments [line items]
Reasonable possible change in risk, percentage		1.00%		1.00%	1.00%	1.00%	1.00%	1.00%
Effect on equity and profit after taxation, due to reasonable possible change in risk		$ 47					$ 7
Notional value							16,810
Currency risk [member]
Disclosure of detailed information about financial instruments [line items]
Reasonable possible change in risk, amount				$ 0.01	£ 0.01	€ 0.01		$ 10
Effect on equity and profit after taxation, due to reasonable possible change in risk		$ 12					$ 21
Commodity price risk [member]
Disclosure of detailed information about financial instruments [line items]
Reasonable possible change in risk, percentage		10.00%		10.00%	10.00%	10.00%	10.00%	10.00%
Effect on equity and profit after taxation, due to reasonable possible change in risk		$ 8					$ 26
Commodity price risk [member] \| Forward commodity and other derivative contracts [member]
Disclosure of detailed information about financial instruments [line items]
Net asset fair value		159					138
Commodity price risk [member] \| Significant financial instruments [member]
Disclosure of detailed information about financial instruments [line items]
Net asset fair value		180					$ 121
Fair value change on derivatives	$ 59	$ 22
Commodity price risk [member] \| Provisionally priced contract [member]
Disclosure of detailed information about financial instruments [line items]
Reasonable possible change in risk, percentage		10.00%		10.00%	10.00%	10.00%	10.00%	10.00%
Tonnes of copper exposure \| t		301		254	254	254	254	254
Effect on equity and profit after taxation, due to reasonable possible change in risk		$ 134					$ 166
Fixed interest rate not swapped to floating rate [member]
Disclosure of detailed information about financial instruments [line items]
Borrowings		3,019					3,018
Fixed interest rate not swapped to floating rate [member] \| At fair value [member]
Disclosure of detailed information about financial instruments [line items]
Borrowings		$ 4,114					$ 4,052