Employee Share Ownership Plans - Summary of Fair Value and Assumptions in the Calculation of Fair Value for Awards Issued (Detail) - 12 months ended Jun. 30, 2020	USD ($) yr £ / shares	USD ($) yr $ / shares
BHP Group Limited [member] \| STIP awards [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Weighted average fair value of awards granted during the year \| $	$ 25.36	$ 25.36
Estimated life of awards	3	3
Share price at grant date \| $ / shares		$ 37.24
BHP Group Limited [member] \| LTIP awards [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Weighted average fair value of awards granted during the year \| $	$ 13.67	$ 13.67
Risk-free interest rate	0.78%	0.78%
Estimated life of awards	5	5
Share price at grant date \| $ / shares		$ 37.24
Estimated volatility of share price	22.00%	22.00%
BHP Group Limited [member] \| MAP awards [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Weighted average fair value of awards granted during the year \| $	$ 21.46	$ 21.46
Dividend yield	5.30%	5.30%
BHP Group Limited [member] \| MAP awards [member] \| Bottom of range [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Estimated life of awards	1	1
Share price at grant date \| $ / shares		$ 36.53
BHP Group Limited [member] \| MAP awards [member] \| Top of range [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Estimated life of awards	5	5
Share price at grant date \| $ / shares		$ 37.24
BHP Group Limited [member] \| Shareplus [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Weighted average fair value of awards granted during the year \| $	$ 19.03	$ 19.03
Risk-free interest rate	1.49%	1.49%
Estimated life of awards	3	3
Share price at grant date \| $ / shares		$ 39.07
Dividend yield	5.08%	5.08%
BHP Group Plc [member] \| MAP awards [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Weighted average fair value of awards granted during the year \| $	$ 17.94	$ 17.94
Estimated life of awards	3	3
Share price at grant date \| £ / shares	$ 17.33
Dividend yield	6.00%	6.00%
BHP Group Plc [member] \| Shareplus [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Weighted average fair value of awards granted during the year \| $	$ 12.17	$ 12.17
Risk-free interest rate	0.66%	0.66%
Estimated life of awards	3	3
Share price at grant date \| £ / shares	$ 19.02
Dividend yield	5.60%	5.60%

The expected volatility of the share price used to calculate the fair value of the share options granted. Expected volatility is a measure of the amount by which a price is expected to fluctuate during a period. The measure of volatility used in option pricing models is the annualised standard deviation of the continuously compounded rates of return on the share over a period of time.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2019-01-01
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The option life of share options granted.

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The implied yield currently available on zero-coupon government issues of the country in whose currency the exercise price for share options granted is expressed, with a remaining term equal to the expected term of the option being valued (based on the option's remaining contractual life and taking into account the effects of expected early exercise). [Refer: Government [member]]

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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.

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- Definition

The percentage of an expected dividend used to calculate the fair value of share options granted.

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The weighted average fair value of share options granted during the period at the measurement date. [Refer: Weighted average [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-Number 2
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- Definition

The weighted average share price used as input to the option pricing model to calculate the fair value of share options granted. [Refer: Option pricing model [member]; Weighted average [member]]

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